哈喽，大家好！我是话里人，欢迎大家来到本期Blog，本期将对EasyExcel和POI作为前置知识快速入门，为项目的继续运行做好铺垫~

在线教育

1. EasyExcel 入门

1.1 EasyExcel概述

​ EasyExcel是一个基于Java的简单、省内存的读写Excel的开源项目。在尽可能节约内存的情况下支持读写百M的Excel工具。

​ 官网: https://easyexcel.opensource.alibaba.com/docs/current/

​ Github地址：https://github.com/alibaba/easyexcel

1.2 EasyExcel 特点

• Java解析、生成Excel比较有名的框架有Apache poi、jxl，但他们都存在一个严重的问题就是非常的耗内存。

• EasyExcel 重写了poi，使一个3M的excel只需要几M内存，并且再大的excel不会出现内存溢出。

  • 64M内存1分钟内读取75M(46W行25列)的Excel。

1.3 环境搭建

1.3.1 测试父项目

• 项目名：zx-test-parent

  

• 修改pom文件

      <dependencies><!-- 测试 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId></dependency></dependencies>
  

1.3.2 测试excel项目

• 项目名：zx-test-excel

  

  

• 修改pom，添加依赖

      <dependencies><dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>3.1.1</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies>
  

1.4 基本操作

1.4.1 测试JavaBean

package com.czxy.zx.demo01;import com.alibaba.excel.annotation.ExcelProperty;
import lombok.Data;import java.util.Date;/*** Created by tanxintong.*/
@Data
public class Student {@ExcelProperty("编号")private String id;@ExcelProperty("姓名")private String name;@ExcelProperty("年龄")private Integer age;@ExcelProperty("电话")private String telephone;@ExcelProperty("邮箱")private String email;@ExcelProperty("生日")private Date brithday;
}

1.4.2 测试文件路径

package com.czxy.zx.demo01;import org.junit.jupiter.api.Test;/*** @author txt* @email tanxintong9968@163.com*/
public class TestExcel {/*** 获得根路径* @return*/public String getPath() {return this.getClass().getResource("/").getPath();}@Testpublic void testPath() {// 测试文件路径String path = getPath() + "student_demo.xls";System.out.println(path);}}

1.4.3 写操作

• excel 属于 office组件一个软件

• 存在若干版本，大体上划分2种情况，2007前的，2007年后的

  • 2003版：扩展名 xls，内容比较少，最大单元格 IV65536 ，256列(IV)
  • 2007版：扩展名 xlsx，内容较多，最大单元格 XFD1048576，16384列(XFD)

   /*** 准备数据* @return*/private List<Student> getData(){List<Student> list = new ArrayList<Student>();for(int i = 0 ; i < 10 ; i ++){Student student = new Student();student.setId("stu" + i);student.setName("wang" + i);student.setAge( 18 + i );student.setTelephone("1361234" + i);student.setEmail("wang" + i + "@czxy.com");student.setBrithday(new Date());list.add(student);}return list;}@Testpublic void testWrite(){String file = getPath() + "student_demo.xls";//EasyExcel.write(位置,对象).sheet("表名").doWrite(数据);EasyExcel.write(file,Student.class).sheet("班级").doWrite(getData());}

1.4.3 读操作

• 处理类：

  • 处理类需要实现 AnalysisEventListener 接口

  package com.czxy.zx.demo01;import com.alibaba.excel.context.AnalysisContext;
  import com.alibaba.excel.event.AnalysisEventListener;
  import com.czxy.zx.domain.Student;/*** @author txt* @email tanxintong9968@163.com*/
  public class StudentListener extends AnalysisEventListener<Student> {@Overridepublic void invoke(Student student, AnalysisContext analysisContext) {System.out.println(student);}@Overridepublic void doAfterAllAnalysed(AnalysisContext analysisContext) {System.out.println("解析完成");}
  }

• 测试

      @Testpublic void testRead(){String file = getPath() + "student_demo.xls";//EasyExcel.read(文件, 封装对象, 处理类).sheet("表").doRead();EasyExcel.read(file, Student.class, new StudentListener()).sheet("班级").doRead();}
  

1.5 复杂操作

1.5.1 复合表头

package com.czxy.zx.demo02;import com.alibaba.excel.annotation.ExcelProperty;import com.alibaba.excel.annotation.format.DateTimeFormat;import com.alibaba.excel.annotation.write.style.ColumnWidth;import com.alibaba.excel.annotation.write.style.ContentRowHeight;import com.alibaba.excel.annotation.write.style.HeadRowHeight;import lombok.Data;import java.util.Date;/*** @author txt* @email tanxintong9968@163.com*/
@Data
@ContentRowHeight(20)
@HeadRowHeight(20)  //行高
@ColumnWidth(25)    //列宽
public class Student2 {@ExcelProperty("编号")private String id;@ExcelProperty({"基本信息","姓名"})   //复制表头private String name;@ExcelProperty({"基本信息","年龄"})private Integer age;@ExcelProperty("电话")private String telephone;@ExcelProperty("邮箱")private String email;@ExcelProperty("生日")@DateTimeFormat("yyyy年MM月dd日")private Date brithday;
}

1.5.2 写操作：多表

package com.czxy.zx.demo02;import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.write.metadata.WriteSheet;
import com.czxy.zx.demo01.Student;
import org.junit.Test;import java.util.ArrayList;
import java.util.Date;
import java.util.List;/*** @author txt* @email tanxintong9968@163.com*/
public class TestExcel2 {/*** 获得根路径* @return*/public String getPath() {return this.getClass().getResource("/").getPath();}/*** 准备数据* @return*/private List<Student2> getData(Integer flag){List<Student2> list = new ArrayList<Student2>();for(int m = 0 ; m < 10 ; m ++){String i = "" + flag + m ;Student2 student = new Student2();student.setId("stu" + i);student.setName("wang" + i);student.setAge( 18 );student.setTelephone("1361234" + i);student.setEmail("wang" + i + "@czxy.com");student.setBrithday(new Date());list.add(student);}return list;}@Testpublic void testMoreSheetWrite(){String file = getPath() + "student_demo2.xls";ExcelWriter excelWriter = EasyExcel.write(file).build();for (int i = 0; i < 5; i++) {WriteSheet writeSheet = EasyExcel.writerSheet(i, "模板" + i).head(Student2.class).build();// 分页去数据库查询数据 这里可以去数据库查询每一页的数据List<Student2> data = getData(i);excelWriter.write(data, writeSheet);}excelWriter.finish();}}

1.5.3 读操作：多表

• 具有缓存处理类

  package com.czxy.zx.demo02;import com.alibaba.excel.context.AnalysisContext;
  import com.alibaba.excel.event.AnalysisEventListener;import java.util.ArrayList;
  import java.util.List;/*** Created by tanxintong.*/
  public class Student2Listener extends AnalysisEventListener<Student2> {// 批量操作数private static final int BATCH_COUNT = 10;// 用于缓存信息private List<Student2> cache = new ArrayList<Student2>();public void invoke(Student2 student, AnalysisContext analysisContext) {//保存学生信息cache.add(student);if(cache.size() >= BATCH_COUNT){// 保存数据saveData();}}public void doAfterAllAnalysed(AnalysisContext analysisContext) {//最后的不够 BATCH_COUNT 倍数saveData();}private void saveData() {// 集合不为空if(! cache.isEmpty()) {// 处理缓存数据System.out.println(cache);// 清空缓存cache.clear();}}
  }

• 读操作

  @Testpublic void testMoreRead(){String file = getPath() + "student_demo2.xls";//EasyExcel.read(文件, 封装对象, 处理类).sheet("表").doRead();ExcelReader excelReader = EasyExcel.read(file, Student2.class, new Student2Listener()).build();// 确定需要解析的sheetfor (int i = 0; i < 5; i++) {ReadSheet readSheet = EasyExcel.readSheet("模板" + i).build();excelReader.read(readSheet);}excelReader.finish();}
  

1.6.4 写操作：多对象

• Student

  @Data
  @NoArgsConstructor
  @AllArgsConstructor
  public class Student {@ExcelProperty("姓名")private String name;@ExcelProperty("年龄")private Integer age;
  }

• Book

  @Data
  @NoArgsConstructor
  @AllArgsConstructor
  @HeadRowHeight(50)
  @HeadFontStyle(fontName = "黑体",italic =  BooleanEnum.TRUE, color = Font.COLOR_RED, underline = 2)
  public class Book {@ExcelProperty("编号")private String id;@ExcelProperty({"作者信息","姓名"})private String authorName;@ExcelProperty({"作者信息","年龄"})private Integer authorAge;@ExcelProperty({"书籍基本信息","标题"})private String title;@ContentFontStyle(fontName = "楷书",italic =  BooleanEnum.TRUE, color = Font.COLOR_RED, underline = -1)@ExcelProperty({"书籍基本信息","价格"})private Double price;@ExcelProperty({"书籍基本信息","出版日期"})@DateTimeFormat("yyyy年MM月dd日")private Date publishDate;
  }
  

• 实现

  package com.czxy.zx.demo03;import com.alibaba.excel.EasyExcel;
  import com.alibaba.excel.ExcelWriter;
  import com.alibaba.excel.write.metadata.WriteSheet;
  import com.czxy.zx.demo01.Student;
  import com.czxy.zx.demo02.Book;
  import org.junit.Test;import java.util.*;/*** @author txt* @email tanxintong9968@163.com*/
  public class TestManyObject {// 获得当前项目的运行时的根目录public String getPath() {return this.getClass().getResource("/").getPath();}// 模拟数据public List<Student> getStudentData() {List<Student> list = new ArrayList<>();for (int i = 0; i < 20; i++) {list.add(new Student("张三" + i, 18 + i));}return list;}public List<Book> getBookData() {List<Book> list = new ArrayList<>();for (int i = 0; i < 20; i++) {list.add(new Book(i+"" , "张三" + i , 18 +i, "坏蛋是怎么"+i, 998d+i, new Date()));}return list;}// 遍历map即可private Map<Class<?>, List<?>> getData() {Map<Class<?>, List<?>> map = new HashMap<>();map.put(Student.class, getStudentData());map.put(Book.class, getBookData());return map;}@Testpublic void testManyObject() {String file = getPath() + "many_object.xlsx";//1 开始写ExcelWriter excelWriter = EasyExcel.write(file).build();//2 依次写每一个对象for(Map.Entry<Class<?>, List<?>> entry : getData().entrySet()) {Class<?> clazz = entry.getKey();            //类型List<?> data = entry.getValue();            //数据WriteSheet writeSheet = EasyExcel.writerSheet(clazz.getSimpleName()).head(clazz).build();excelWriter.write(data, writeSheet);}//3 写完成excelWriter.finish();}
  }

1.6 扩展：excel备份数据库

• 步骤
  • 步骤1：添加坐标
  • 步骤2：编写封装类
  • 步骤3：编写核心类

• 步骤1：添加坐标

      <dependencies><dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>3.0.5</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><dependency><groupId>commons-dbutils</groupId><artifactId>commons-dbutils</artifactId><version>1.7</version></dependency></dependencies>
  

• 步骤2：编写封装类

  package com.czxy.zx.demo03;import com.alibaba.excel.annotation.ExcelProperty;
  import com.alibaba.excel.annotation.write.style.ColumnWidth;
  import com.alibaba.excel.annotation.write.style.ContentRowHeight;
  import com.alibaba.excel.annotation.write.style.HeadRowHeight;
  import lombok.Data;import java.util.Date;
  import java.util.List;/*** 课程**/
  @Data
  @ContentRowHeight(20)
  @HeadRowHeight(20)  //行高
  @ColumnWidth(25)    //列宽
  public class Chapter {@ExcelProperty("章节ID")private String id;@ExcelProperty("课程ID")private String courseId;@ExcelProperty("章节名称")private String title;@ExcelProperty("显示排序")private Integer sort;@ExcelProperty("创建时间")private Date gmtCreate;@ExcelProperty("更新时间")private Date gmtModified;}

  package com.czxy.zx.demo03;import com.alibaba.excel.annotation.ExcelProperty;
  import com.alibaba.excel.annotation.format.DateTimeFormat;
  import com.alibaba.excel.annotation.write.style.ColumnWidth;
  import com.alibaba.excel.annotation.write.style.ContentRowHeight;
  import com.alibaba.excel.annotation.write.style.HeadRowHeight;
  import lombok.Data;import java.util.Date;/*** 课程**/
  @Data
  @ContentRowHeight(20)
  @HeadRowHeight(20)  //行高
  @ColumnWidth(25)    //列宽
  public class Course {@ExcelProperty("课程ID")private String id;@ExcelProperty("课程讲师ID")private String teacherId;@ExcelProperty("课程专业ID二级分类ID")private String subjectId;@ExcelProperty("一级分类ID")private String subjectParentId;@ExcelProperty("课程标题")private String title;@ExcelProperty("课程销售价格，设置为0则可免费观看")private Double price;@ExcelProperty("总课时")private Integer lessonNum;@ExcelProperty("课程封面图片路径")private String cover;@ExcelProperty("销售数量")private Long buyCount;@ExcelProperty("浏览数量")private Long viewCount;@ExcelProperty("乐观锁")private Long version;@ExcelProperty("视频状态 Draft未发布  Normal已发布")private String status;@ExcelProperty("创建时间")@DateTimeFormat("yyyy年MM月dd日")private Date gmtCreate;@ExcelProperty("更新时间")@DateTimeFormat("yyyy年MM月dd日")private Date gmtModified;}

• 步骤3：编写核心类

  package com.czxy.zx.demo03;import com.alibaba.excel.EasyExcel;
  import com.alibaba.excel.ExcelWriter;
  import com.alibaba.excel.write.metadata.WriteSheet;
  import com.czxy.zx.demo02.Student2;
  import org.apache.commons.dbutils.BasicRowProcessor;
  import org.apache.commons.dbutils.DbUtils;
  import org.apache.commons.dbutils.GenerousBeanProcessor;
  import org.apache.commons.dbutils.QueryRunner;
  import org.apache.commons.dbutils.handlers.BeanListHandler;
  import org.junit.Test;import java.sql.*;
  import java.util.*;/*** @author txt* @email tanxintong9968@163.com*/
  public class TestBackdb {public Class getClassByTableName(String tableName) {Map<String,Class> map = new HashMap<>();map.put("edu_chapter", Chapter.class);map.put("edu_course", Course.class);return map.get(tableName);}public String getPath() {return this.getClass().getResource("/").getPath();}public Connection getConnection() {try {Class.forName("com.mysql.jdbc.Driver");String url = "jdbc:mysql://127.0.0.1:3306/zx_edu_course?useUnicode=true&characterEncoding=utf8";String username = "root";String password = "1234";Properties props =new Properties();props.setProperty("user", username);props.setProperty("password", password);props.setProperty("remarks", "true");               //设置可以获取remarks信息props.setProperty("useInformationSchema", "true");  //设置可以获取tables remarks信息return DriverManager.getConnection(url, props);} catch (Exception e) {throw new RuntimeException(e);}}@Testpublic void testDB() throws Exception {String file = getPath() + "db.xls";QueryRunner queryRunner = new QueryRunner();ExcelWriter excelWriter = EasyExcel.write(file).build();String dbName = "zx_edu_course";//获得连接Connection conn = getConnection();//语句执行者Statement st = conn.createStatement();//数据库的元数据DatabaseMetaData databaseMetaData = conn.getMetaData();//获得所有的数据库ResultSet catalogResultSet = databaseMetaData.getCatalogs();//遍历所有的数据库while(catalogResultSet.next()) {//获得数据库的名称String databaseName = catalogResultSet.getString(1);if(dbName.equals(databaseName)) {//使用数据库st.execute("use " + databaseName);ResultSet tableResultSet = databaseMetaData.getTables(databaseName, null, null, null);//遍历所有的表名while(tableResultSet.next()) {//表名String tableName = tableResultSet.getString(3);             //TABLE_NAMEString tableRemarks = tableResultSet.getString("REMARKS"); //获得表的备注// 通过表名获得excel处理类Class excelBeanClass = getClassByTableName(tableName);if(excelBeanClass != null) {//获得当前表的所有数据String sql = "select * from " + tableName;//List data = (List) queryRunner.query(conn, sql, new BeanListHandler<>(excelBeanClass, new BasicRowProcessor(new GenerousBeanProcessor()) ));// 创建sheetWriteSheet writeSheet = EasyExcel.writerSheet(tableRemarks != null ? tableRemarks : tableName).head(excelBeanClass).build();excelWriter.write(data, writeSheet);}}}}//写入完成excelWriter.finish();}}

2. 课程科目操作

2.0 分析

2.1 环境搭建

2.1.1 数据库

CREATE DATABASE zx_edu_course;
USE zx_edu_course;CREATE TABLE `edu_subject`  (`id` VARCHAR(32) NOT NULL PRIMARY KEY COMMENT '课程科目ID',`title` VARCHAR(10) NOT NULL COMMENT '科目名称',`parent_id` VARCHAR(32) NOT NULL DEFAULT '0' COMMENT '父ID',`sort` INT(10)  NOT NULL DEFAULT 0 COMMENT '排序字段',`gmt_create` DATETIME NOT NULL COMMENT '创建时间',`gmt_modified` DATETIME NOT NULL COMMENT '更新时间'
) COMMENT = '课程科目';INSERT INTO `edu_subject` VALUES ('1', '云计算', '0', 0, '2020-06-26 09:41:21', '2020-02-20 23:25:58');
INSERT INTO `edu_subject` VALUES ('2', '系统/运维', '0', 0, '2020-02-20 23:29:59', '2020-02-20 23:29:59');
INSERT INTO `edu_subject` VALUES ('3', '数据库', '0', 0, '2020-02-20 23:30:13', '2020-02-20 23:30:13');
INSERT INTO `edu_subject` VALUES ('4', '服务器', '0', 0, '2020-02-20 23:30:19', '2020-02-20 23:30:19');INSERT INTO `edu_subject` VALUES ('5', 'MySQL', '3', 1, '2020-02-20 23:30:13', '2020-02-20 23:30:13');
INSERT INTO `edu_subject` VALUES ('6', 'Oracle', '3', 2, '2020-02-20 23:30:13', '2020-02-20 23:30:13');
INSERT INTO `edu_subject` VALUES ('7', 'Tomcat', '4', 1, '2020-02-20 23:30:13', '2020-02-20 23:30:13');
INSERT INTO `edu_subject` VALUES ('8', 'Nginx ', '4', 2, '2020-02-20 23:30:13', '2020-02-20 23:30:13');INSERT INTO `edu_subject` VALUES ('9', 'MySQL优化', '5', 1, '2020-02-20 23:30:13', '2020-02-20 23:30:13');

2.1.2 后端：环境

• 项目名：zx-service-course

• pom文件

  <dependencies><!--web起步依赖--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!-- nacos 客户端 --><dependency><groupId>com.alibaba.nacos</groupId><artifactId>nacos-client</artifactId></dependency><!-- nacos 服务发现 --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--swagger2--><dependency><groupId>io.springfox</groupId><artifactId>springfox-swagger2</artifactId></dependency><dependency><groupId>io.springfox</groupId><artifactId>springfox-swagger-ui</artifactId></dependency><!-- feign 远程调用 --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!--测试--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId></dependency><!-- mybatis plus--><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>${mybatis.plus.version}</version></dependency><!-- mysql驱动 --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><!--自定义项目--><dependency><groupId>com.czxy.zx</groupId><artifactId>zx-common31</artifactId></dependency><dependency><groupId>com.czxy.zx</groupId><artifactId>zx-domain31</artifactId></dependency><!-- redis 启动器 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><!-- JavaMail 启动器 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-mail</artifactId></dependency><!-- MQ 启动器 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-amqp</artifactId></dependency><!-- fastjson --><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId></dependency><!--开发者工具--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><optional>true</optional></dependency><dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>3.0.5</version></dependency></dependencies>
  

• yml文件

  # 服务端口号
  server:port: 9020
  # 服务名
  spring:application:name: course-servicedatasource:driverClassName: com.mysql.jdbc.Driverurl: jdbc:mysql://127.0.0.1:3306/zx_edu_course?useUnicode=true&characterEncoding=utf8username: rootpassword: 1234druid:    #druid 连接池配置initial-size: 1       #初始化连接池大小min-idle: 1           #最小连接数max-active: 20        #最大连接数test-on-borrow: true  #获取连接时候验证，会影响性能cloud:nacos:discovery:server-addr: 127.0.0.1:8848   #nacos服务地址redis:database: 0       #数据库索引，取值0-15，表示16个库可选择host: 127.0.0.1   #服务器地址port: 6379        #服务器连接端口号mail:host: smtp.126.com          #发送邮件服务器username: itcast_lt@126.com #账号password: 1qaz2wsx          #密码default-encoding: UTF-8     #默认编码时rabbitmq:host: 127.0.0.1port: 5672username: guestpassowrd: guestvirtualHost: /devtools:restart:enabled: true  #设置开启热部署additional-paths: src/main/java #重启目录exclude: WEB-INF/**freemarker:cache: false    #页面不加载缓存，修改即时生效#开启log4j打印SQL语句
  logging:level:com:czxy:mapper: debug# mp日志打印
  mybatis-plus:configuration:log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

• 启动类

  package com.czxy.zx;import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
  import org.springframework.cloud.openfeign.EnableFeignClients;/*** @author txt* @email tanxintong9968@163.com*/
  @SpringBootApplication
  @EnableDiscoveryClient
  @EnableFeignClients
  public class CourseServiceApplication {public static void main(String[] args) {SpringApplication.run(CourseServiceApplication.class,args);}
  }

• 拷贝配置

  

• 配置类 – MyBatisPlusConfig

package com.czxy.zx.course.config;import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;@Component
public class MyBatisPlusConfig {@Beanpublic MybatisPlusInterceptor mybatisPlusInterceptor(){MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();mybatisPlusInterceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));return mybatisPlusInterceptor;}
}

• 配置类 – Swagger2ConfigurationV3

package com.czxy.zx.course.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.*;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spi.service.contexts.SecurityContext;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;import java.util.ArrayList;
import java.util.List;/*** Swagger2 配置类，* 访问路径：swagger-ui.html* 自动注册：*     位置：resources/META-INF/spring.factories*     内容：*        org.springframework.boot.autoconfigure.EnableAutoConfiguration=\*          com.czxy.changgou4.config.Swagger2Configuration*/
@Configuration
@EnableSwagger2
public class Swagger2ConfigurationV3 {@Beanpublic Docket createRestApi() {// 1 确定文档Swagger版本Docket docket = new Docket(DocumentationType.SWAGGER_2);// 2 设置 api基本信息docket.apiInfo(apiInfo());// 3 设置自定义加载路径docket = docket.select().apis(RequestHandlerSelectors.basePackage("com.czxy")).paths(PathSelectors.any()).build();//4 设置权限docket.securitySchemes(securitySchemes());docket.securityContexts(securityContexts());return docket;}private ApiInfo apiInfo() {return new ApiInfoBuilder().title("API").description("基于swagger接口文档").contact(new Contact("梁桐","http://www.javaliang.com","liangtong@itcast.cn")).version("1.0").build();}private List<ApiKey> securitySchemes() {List<ApiKey> list = new ArrayList<>();// name 为参数名  keyname是页面传值显示的 keyname， name在swagger鉴权中使用list.add(new ApiKey("Authorization", "X-Token", "header"));return list;}private List<SecurityContext> securityContexts() {List<SecurityContext> list = new ArrayList<>();list.add(SecurityContext.builder().securityReferences(defaultAuth()).forPaths(PathSelectors.regex("^(?!auth).*$")).build());return list;}private List<SecurityReference> defaultAuth() {AuthorizationScope authorizationScope = new AuthorizationScope("global", "accessEverything");AuthorizationScope[] authorizationScopes = new AuthorizationScope[1];authorizationScopes[0] = authorizationScope;List<SecurityReference> list = new ArrayList();list.add(new SecurityReference("Authorization", authorizationScopes));return list;}}

2.1.3 后端：基本模块

• 创建JavaBean

  package com.czxy.zx.domain;import com.baomidou.mybatisplus.annotation.IdType;
  import com.baomidou.mybatisplus.annotation.TableField;
  import com.baomidou.mybatisplus.annotation.TableId;
  import com.baomidou.mybatisplus.annotation.TableName;
  import com.fasterxml.jackson.annotation.JsonFormat;
  import lombok.Data;
  import org.springframework.format.annotation.DateTimeFormat;import java.util.ArrayList;
  import java.util.Date;
  import java.util.List;/*** 课程科目(EduSubject)表实体类** @author txt*/
  @Data
  @TableName("edu_subject")
  public class EduSubject{@TableId(type = IdType.ASSIGN_UUID)//课程科目IDprivate String id;//科目名称private String title;//父IDprivate String parentId;//排序字段private Integer sort;//创建时间@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss",timezone = "GMT+8")private Date gmtCreate;//更新时间@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss",timezone = "GMT+8")private Date gmtModified;@TableField(exist = false)@JsonInclude(JsonInclude.Include.NON_EMPTY)     //生成json数据，不包含空元素private List<EduSubject> children = new ArrayList<>();}
  

• 创建mapper

package com.czxy.zx.course.mapper;import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.czxy.zx.domain.EduSubject;
import org.apache.ibatis.annotations.Mapper;/*** @author txt* @email tanxintong9968@163.com*/
@Mapper
public interface EduSubjectMapper extends BaseMapper<EduSubject> {}

• 创建service

  

  • 接口

    package com.czxy.zx.course.service;import com.baomidou.mybatisplus.extension.service.IService;
    import com.czxy.zx.domain.EduSubject;/*** @author txt* @email tanxintong9968@163.com*/
    public interface EduSubjectService extends IService<EduSubject> {}

  • 实现类

    package com.czxy.zx.course.service.impl;import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
    import com.czxy.zx.course.mapper.EduSubjectMapper;
    import com.czxy.zx.course.service.EduSubjectService;
    import com.czxy.zx.domain.EduSubject;
    import org.springframework.stereotype.Service;
    import org.springframework.transaction.annotation.Transactional;/*** @author txt* @email tanxintong9968@163.com*/
    @Service
    @Transactional
    public class EduSubjectServiceImpl extends ServiceImpl<EduSubjectMapper, EduSubject> implements EduSubjectService {}

• 创建controller

  

  package com.czxy.zx.course.controller;import com.czxy.zx.course.service.EduSubjectService;
  import org.springframework.web.bind.annotation.RequestMapping;
  import org.springframework.web.bind.annotation.RestController;import javax.annotation.Resource;/*** @author txt* @email tanxintong9968@163.com*/
  @RestController
  @RequestMapping("/subject")
  public class EduSubjectController {@Resourceprivate EduSubjectService eduSubjectService;}

• 配置类

  

• 配置类 – MyBatisPlusConfig

package com.czxy.zx.course.config;import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;@Component
public class MyBatisPlusConfig {@Beanpublic MybatisPlusInterceptor mybatisPlusInterceptor(){MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();mybatisPlusInterceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));return mybatisPlusInterceptor;}
}

• 配置类 – Swagger2ConfigurationV3

package com.czxy.zx.course.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.*;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spi.service.contexts.SecurityContext;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;import java.util.ArrayList;
import java.util.List;/*** Swagger2 配置类，* 访问路径：swagger-ui.html* 自动注册：*     位置：resources/META-INF/spring.factories*     内容：*        org.springframework.boot.autoconfigure.EnableAutoConfiguration=\*          com.czxy.changgou4.config.Swagger2Configuration*/
@Configuration
@EnableSwagger2
public class Swagger2ConfigurationV3 {@Beanpublic Docket createRestApi() {// 1 确定文档Swagger版本Docket docket = new Docket(DocumentationType.SWAGGER_2);// 2 设置 api基本信息docket.apiInfo(apiInfo());// 3 设置自定义加载路径docket = docket.select().apis(RequestHandlerSelectors.basePackage("com.czxy")).paths(PathSelectors.any()).build();//4 设置权限docket.securitySchemes(securitySchemes());docket.securityContexts(securityContexts());return docket;}private ApiInfo apiInfo() {return new ApiInfoBuilder().title("API").description("基于swagger接口文档").contact(new Contact("梁桐","http://www.javaliang.com","liangtong@itcast.cn")).version("1.0").build();}private List<ApiKey> securitySchemes() {List<ApiKey> list = new ArrayList<>();// name 为参数名  keyname是页面传值显示的 keyname， name在swagger鉴权中使用list.add(new ApiKey("Authorization", "X-Token", "header"));return list;}private List<SecurityContext> securityContexts() {List<SecurityContext> list = new ArrayList<>();list.add(SecurityContext.builder().securityReferences(defaultAuth()).forPaths(PathSelectors.regex("^(?!auth).*$")).build());return list;}private List<SecurityReference> defaultAuth() {AuthorizationScope authorizationScope = new AuthorizationScope("global", "accessEverything");AuthorizationScope[] authorizationScopes = new AuthorizationScope[1];authorizationScopes[0] = authorizationScope;List<SecurityReference> list = new ArrayList();list.add(new SecurityReference("Authorization", authorizationScopes));return list;}}

2.1.4 前端

• 创建路由模块

  

  /** When your routing table is too long, you can split it into small modules **/import Layout from '@/layout'const courseRouter = {path: '/course',           // 当前模块前缀路径，必须以/开头component: Layout,          // 采用布局组件显示当前模块【默认】redirect: '/course/subjectList',  // “教师管理”默认显示路由name: '课程管理',            // 路由名称meta: {title: '课程管理',         // 一级菜单名称，children.length==0 隐藏icon: 'table'             // 一级菜单图标，children.length==0 隐藏},children: [{path: 'subjectList',component: () => import('@/views/edu/course/subjectList.vue'),name: '科目列表',meta: { title: '科目列表', icon: 'list' }   //二级菜单名称}]
  }
  export default courseRouter

• 创建 subjectList.vue 页面

  

• 配置路由

  

2.2 查询所有

• 以树形table展示数据

2.2.1 后端实现

• 修改 EduSubjectController

package com.czxy.zx.course.controller;import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.czxy.zx.course.service.EduSubjectService;
import com.czxy.zx.domain.EduSubject;
import com.czxy.zx.vo.BaseResult;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;/*** @author txt* @email tanxintong9968@163.com*/
@RestController
@RequestMapping("/subject")
public class EduSubjectController {@Resourceprivate EduSubjectService eduSubjectService;@GetMappingpublic BaseResult findAll() {//1 查询所有QueryWrapper queryWrapper = new QueryWrapper();queryWrapper.orderByAsc("parent_id");List<EduSubject> list = eduSubjectService.list(queryWrapper);//2 处理父子关系List<EduSubject> resultList = new ArrayList<>();Map<String,EduSubject> cache = new HashMap<>();list.forEach(eduSubject -> {// 获得父EduSubject parentEduSubject = cache.get(eduSubject.getParentId());// 如果没有父表示第一层，如果有父追加if(parentEduSubject != null) {// 如果有孩子，判断父对象的集合List<EduSubject> temp = parentEduSubject.getChildren();if(temp == null) {parentEduSubject.setChildren(new ArrayList<>());}// 将孩子添加到父对象的集合中parentEduSubject.getChildren().add(eduSubject);} else {resultList.add(eduSubject);}// 缓存当前cache.put(eduSubject.getId(),eduSubject);});return BaseResult.ok("查询成功", resultList);}}

2.2.2 前端接口

import axios from '@/utils/request'// 查询所有课程科目
export function findAllSub() {return axios.get('/course-service/subject');
}

2.2.3 前端实现

• 修改 @/views/edu/course/subjectList.vue

  

<template><div><el-tablev-loading="listLoading":data="subjectList"borderfithighlight-current-rowstyle="width: 100%;"row-key="title":tree-props="{children: 'children'}"><el-table-column label="科目名称" prop="title" align="center" width="200"></el-table-column><el-table-column label="排序" prop="sort" width="80px" min-width="50px"></el-table-column><el-table-column label="添加时间" width="200px" align="center"><template slot-scope="{row}"><span>{{ row.gmtCreate | parseTime('{y}-{m}-{d} {h}:{i}') }}</span></template></el-table-column><el-table-column label="更新时间" width="200px" align="center"><template slot-scope="{row}"><span>{{ row.gmtModified | parseTime('{y}-{m}-{d} {h}:{i}') }}</span></template></el-table-column><el-table-column label="操作" align="center" class-name="small-padding fixed-width"><template slot-scope="{row,$index}"><el-button type="primary" size="mini">修改</el-button><el-button v-if="row.status!='deleted'" size="mini" type="danger" >删除</el-button></template></el-table-column></el-table></div>
</template><script>
import { findAllSub } from '@/api/edu/course'export default {data() {return {subjectList: [] ,listLoading: false,}},methods: {async findAllSubject() {  // 查询所有this.listLoading = truelet { data } = await findAllSub()this.subjectList = datathis.listLoading = false}},mounted() {this.findAllSubject()},
}
</script><style></style>

2.3 导入科目

2.3.1 需求

2.3.2 前端

• 使用 upload组件

      <!-- 文件上传 --><el-uploadclass="upload-demo":action="updateUrl":limit="1":on-exceed="handleExceed":before-upload="beforeUpload":on-remove="handleRemove":on-success="handleSuccess":file-list="fileList"><el-button size="small" type="primary">点击上传</el-button><div slot="tip" class="el-upload__tip">只能上传xls或xlsx文件，且不超过500kb</div></el-upload>
  

• 声明变量

    data() {return {fileList: [],     //上传文件列表updateUrl: process.env.VUE_APP_BASE_API + '/course-service/subject/upload',   //上传路径}},
  

• 编写处理函数

  handleExceed(files, fileList) {   // 超出个数限制this.$message.warning(`当前选择1个文件`);},beforeUpload(file) {      // 上传文件之前// 是否是 xlsx 文件（2003）const isXlsx = file.type === 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'// 是否是 xls 文件（2010）const isXls = file.type === 'application/vnd.ms-excel'const isLt2M = file.size / 1024 / 1024 < 2;if (!isXlsx && !isXls) {this.$message.error('上传文件不是excel文件!');}if (!isLt2M) {this.$message.error('上传文件大小不能超过 2MB!');}return (isXlsx || isXls) && isLt2M;},handleRemove(file, fileList) {  // 文件列表移除文件console.log(file, fileList);},handleSuccess(response, file, fileList) { // 文件上传成功// 成功提示this.$message.success(response.message)// 刷新this.findAllSubject()}
  

2.3.2 前端：完整版

<template><div><el-tablev-loading="listLoading":data="subjectList"borderfithighlight-current-rowstyle="width: 100%;"row-key="title":tree-props="{children: 'children'}"><el-table-column label="科目名称" prop="title" align="left" width="200"></el-table-column><el-table-column label="排序" prop="sort" width="80px" min-width="50px"></el-table-column><el-table-column label="添加时间" width="200px" align="center"><template slot-scope="{row}"><span>{{ row.gmtCreate | parseTime('{y}-{m}-{d} {h}:{i}') }}</span></template></el-table-column><el-table-column label="更新时间" width="200px" align="center"><template slot-scope="{row}"><span>{{ row.gmtModified | parseTime('{y}-{m}-{d} {h}:{i}') }}</span></template></el-table-column><el-table-column label="操作" align="center" class-name="small-padding fixed-width"><template slot-scope="{row}"><el-button type="primary" size="mini">修改</el-button><el-button v-if="row.status!='deleted'" size="mini" type="danger" >删除</el-button></template></el-table-column></el-table><!-- 文件上传 --><el-uploadclass="upload-demo":action="updateUrl":limit="1":on-exceed="handleExceed":before-upload="beforeUpload":on-remove="handleRemove":on-success="handleSuccess":file-list="fileList"><el-button size="small" type="primary">点击上传</el-button><div slot="tip" class="el-upload__tip">只能上传xls或xlsx文件，且不超过500kb</div></el-upload></div>
</template><script>
import { findAllSub } from '@/api/edu/course'export default {data() {return {subjectList: [] ,listLoading: false,fileList: [],     //上传文件列表updateUrl: process.env.VUE_APP_BASE_API + '/course-service/subject/upload',   //上传路径}},methods: {async findAllSubject() {  // 查询所有this.listLoading = truelet { data } = await findAllSub()this.subjectList = datathis.listLoading = false},handleExceed(files, fileList) {   // 超出个数限制this.$message.warning(`当前选择1个文件`);},beforeUpload(file) {      // 上传文件之前// 是否是 xlsx 文件（2003）const isXlsx = file.type === 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'// 是否是 xls 文件（2010）const isXls = file.type === 'application/vnd.ms-excel'const isLt2M = file.size / 1024 / 1024 < 2;if (!isXlsx && !isXls) {this.$message.error('上传文件不是excel文件!');}if (!isLt2M) {this.$message.error('上传文件大小不能超过 2MB!');}return (isXlsx || isXls) && isLt2M;},handleRemove(file, fileList) {  // 文件列表移除文件console.log(file, fileList);},handleSuccess(response, file, fileList) { // 文件上传成功// 成功提示this.$message.success(response.message)// 刷新this.findAllSubject()}},mounted() {this.findAllSubject()},
}
</script><style></style>

2.3.4 后端

1） 完善JavaBean

package com.czxy.zx.domain;import com.baomidou.mybatisplus.annotation.*;
import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.Data;
import org.springframework.format.annotation.DateTimeFormat;import java.util.ArrayList;
import java.util.Date;
import java.util.List;/*** 课程科目(EduSubject)表实体类** @author txt*/
@Data
@TableName("edu_subject")
public class EduSubject{@TableId(type = IdType.ASSIGN_UUID)//课程科目IDprivate String id;//科目名称private String title;//父IDprivate String parentId;//排序字段private Integer sort;//创建时间@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss",timezone = "GMT+8")@TableField(fill = FieldFill.INSERT)private Date gmtCreate;//更新时间@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss",timezone = "GMT+8")@TableField(fill = FieldFill.INSERT)private Date gmtModified;@TableField(exist = false)private List<EduSubject> children = new ArrayList<>();}

2）填充数据处理类

package com.czxy.zx.course.handler;import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;import java.util.Date;/*** @author txt* @email tanxintong9968@163.com*/
@Component
public class SubjectMetaObjectHandler implements MetaObjectHandler {@Overridepublic void insertFill(MetaObject metaObject) {// 创建时间this.setFieldValByName("gmtCreate",new Date(), metaObject);// 修改时间this.setFieldValByName("gmtModified",new Date() , metaObject);}@Overridepublic void updateFill(MetaObject metaObject) {// 修改时，填充的内容this.setFieldValByName("gmtModified",new Date() , metaObject);}
}

3）service：通过title查询

• 接口

  package com.czxy.zx.course.service;import com.baomidou.mybatisplus.extension.service.IService;
  import com.czxy.zx.domain.EduSubject;/*** @author txt* @email tanxintong9968@163.com*/
  public interface EduSubjectService extends IService<EduSubject> {/*** 通过title查询* @param title* @return*/EduSubject findByTitle(String title);
  }

• 实现类

  package com.czxy.zx.course.service.impl;import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
  import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
  import com.czxy.zx.course.mapper.EduSubjectMapper;
  import com.czxy.zx.course.service.EduSubjectService;
  import com.czxy.zx.domain.EduSubject;
  import org.springframework.stereotype.Service;
  import org.springframework.transaction.annotation.Transactional;/*** @author txt* @email tanxintong9968@163.com*/
  @Service
  @Transactional
  public class EduSubjectServiceImpl extends ServiceImpl<EduSubjectMapper, EduSubject> implements EduSubjectService {@Overridepublic EduSubject findByTitle(String title) {QueryWrapper queryWrapper = new QueryWrapper();queryWrapper.eq("title", title);EduSubject eduSubject = baseMapper.selectOne(queryWrapper);return eduSubject;}
  }

4）controller：上传

 /*** 文件上传* @param file* @return*/@PostMapping("/upload")public BaseResult upload(MultipartFile file) {try {// 解析excelEasyExcel.read(file.getInputStream(), UploadSubjectVo.class, eduSubjectListener).sheet(0).doRead();return BaseResult.ok("上传成功");} catch (IOException e) {return BaseResult.error("上传失败");}}

5）excel内容封装类

package com.czxy.zx.course.upload;import com.alibaba.excel.annotation.ExcelProperty;
import lombok.Data;/*** @author txt* @email tanxintong9968@163.com*/
@Data
public class UploadSubjectVo {@ExcelProperty("一级分类")private String oneLevel;@ExcelProperty("二级分类")private String twoLevel;}

6）上传内容处理类

package com.czxy.zx.course.upload;import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.czxy.zx.course.service.EduSubjectService;
import com.czxy.zx.domain.EduSubject;
import org.springframework.stereotype.Component;import javax.annotation.Resource;/*** @author txt* @email tanxintong9968@163.com*/
@Component
public class EduSubjectListener extends AnalysisEventListener<UploadSubjectVo> {@Resourceprivate EduSubjectService eduSubjectService;@Overridepublic void invoke(UploadSubjectVo uploadSubjectVo, AnalysisContext analysisContext) {// 1. 处理一级// 1.1 查询一级EduSubject oneSubject = eduSubjectService.findByTitle(uploadSubjectVo.getOneLevel());// 1.2 保存一级if(oneSubject == null) {oneSubject = new EduSubject();oneSubject.setTitle(uploadSubjectVo.getOneLevel());oneSubject.setSort(0);oneSubject.setParentId("0");        // 一级默认0eduSubjectService.save(oneSubject);}// 2. 处理二级// 2.1 查询二级EduSubject twoSubject = eduSubjectService.findByTitle(uploadSubjectVo.getTwoLevel());// 2.2 保存二级if(twoSubject == null) {twoSubject = new EduSubject();twoSubject.setTitle(uploadSubjectVo.getTwoLevel());twoSubject.setSort(0);twoSubject.setParentId(oneSubject.getId()); //二级的父ID为一级的IDeduSubjectService.save(twoSubject);}}@Overridepublic void doAfterAllAnalysed(AnalysisContext analysisContext) {}
}

3.POI入门

3.1 POI 概述

3.1.1 简介

​ Apache POI是Apache软件基金会的开放源码函式库，POI提供API给Java程序对Microsoft Office格式档案读和写的功能。

功能	描述
HSSFWorkBook	提供读写Microsoft Excel格式档案的功能，xls文档
XSSFWorkBook	提供读写Microsoft Excel OOXML格式档案的功能，xlsx文件
HWPF	提供读写Microsoft Word格式档案的功能
HSLF	提供读写Microsoft PowerPoint格式档案的功能
HDGF	提供读写Microsoft Visio格式档案的功能

3.1.2 官网

http://poi.apache.org/

3.2 入门案例

3.2.1 环境搭建

• 创建项目：

• 修改pom

  <dependencies><!--xls--><dependency><groupId>org.apache.poi</groupId><artifactId>poi</artifactId><version>3.9</version></dependency><!--xlsx--><dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml</artifactId><version>3.9</version></dependency><!--日期格式化工具--><dependency><groupId>joda-time</groupId><artifactId>joda-time</artifactId><version>2.10.1</version></dependency><!--test--><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency></dependencies>
  

3.2.2 xls文件写操作

• excel2003 文件扩展名为 xls
• 名词：
  • 工作簿：一个excel文件，就是一个工作簿
  • 工作表：一个工作簿中，可以所有多个工作表Sheet
  • 行：每一个工作表，包含多行row
  • 单元格：每行有多个单元格Cell组成。

package com.zx.poi;import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.joda.time.DateTime;
import org.junit.Test;import java.io.FileOutputStream;
import java.io.IOException;public class Excel03Test {@Testpublic void testWrite03() throws IOException {// 创建新的Excel 工作簿Workbook workbook = new HSSFWorkbook();// 在Excel工作簿中建一工作表，其名为缺省值 Sheet0//Sheet sheet = workbook.createSheet();// 如要新建一名为"信息统计"的工作表，其语句为：Sheet sheet = workbook.createSheet("信息统计");// 创建行（row 1）Row row1 = sheet.createRow(0);// 创建单元格（col 1-1）Cell cell11 = row1.createCell(0);cell11.setCellValue("今日人数");// 创建单元格（col 1-2）Cell cell12 = row1.createCell(1);cell12.setCellValue(666);// 创建行（row 2）Row row2 = sheet.createRow(1);// 创建单元格（col 2-1）Cell cell21 = row2.createCell(0);cell21.setCellValue("统计时间");//创建单元格（第三列）Cell cell22 = row2.createCell(1);String dateTime = new DateTime().toString("yyyy-MM-dd HH:mm:ss");cell22.setCellValue(dateTime);// 新建一输出文件流（注意：要先创建文件夹）FileOutputStream out = new FileOutputStream("d://zx/a.xls");// 把相应的Excel 工作簿存盘workbook.write(out);// 操作结束，关闭文件out.close();System.out.println("文件生成成功");}
}

3.2.3 xlsx 文件写操作

excel2007+ 文件扩展名为 xlsx

package com.zx.poi;import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.joda.time.DateTime;
import org.junit.Test;import java.io.FileOutputStream;
import java.io.IOException;public class Excel07Test {@Testpublic void testWrite07() throws IOException {// 创建新的Excel 工作簿Workbook workbook = new XSSFWorkbook();// 在Excel工作簿中建一工作表，其名为缺省值 Sheet0//Sheet sheet = workbook.createSheet();// 如要新建一名为"信息统计"的工作表，其语句为：Sheet sheet = workbook.createSheet("信息统计");// 创建行（row 1）Row row1 = sheet.createRow(0);// 创建单元格（col 1-1）Cell cell11 = row1.createCell(0);cell11.setCellValue("今日人数");// 创建单元格（col 1-2）Cell cell12 = row1.createCell(1);cell12.setCellValue(666);// 创建行（row 2）Row row2 = sheet.createRow(1);// 创建单元格（col 2-1）Cell cell21 = row2.createCell(0);cell21.setCellValue("统计时间");//创建单元格（第三列）Cell cell22 = row2.createCell(1);String dateTime = new DateTime().toString("yyyy-MM-dd HH:mm:ss");cell22.setCellValue(dateTime);// 新建一输出文件流（注意：要先创建文件夹）FileOutputStream out = new FileOutputStream("d://zx/b.xlsx");// 把相应的Excel 工作簿存盘workbook.write(out);// 操作结束，关闭文件out.close();System.out.println("文件生成成功");}
}

3.2.4 xls 文件读操作

// xls 2003 文件读操作@Testpublic void testXlsRead() throws Exception {//1 确定文件流FileInputStream is = new FileInputStream("D:\\xml\\user.xls");//2 开始读// 2.1 工作簿HSSFWorkbook workbook = new HSSFWorkbook(is);// 2.2 工作表HSSFSheet sheet = workbook.getSheet("用户表");int rowStart = sheet.getFirstRowNum();      //第一行索引号（从0开始）int rowEnd = sheet.getLastRowNum();         //最后一行的索引号（从0开始）// 2.3 行for(int i = rowStart ; i <= rowEnd ; i ++) {HSSFRow row = sheet.getRow(i);int cellStart = row.getFirstCellNum();      //第一列的索引号（从0开始）int cellEnd = row.getLastCellNum() ;        //最后一列的编号（从1开始）// 2.4 列for(int c = cellStart; c < cellEnd ; c++) {HSSFCell cell = row.getCell(c);
//                System.out.println(cell.getCellType());if(cell.getCellType() == Cell.CELL_TYPE_STRING) {// 字符串System.out.print(row.getCell(c).getStringCellValue() + ", ");}if(cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {// 字符串System.out.print(row.getCell(c).getNumericCellValue() + ", ");}}System.out.println();}// 3 释放资源is.close();}

3.2.5 xlsx 文件读操作

 // xlsx 2007 文件读操作@Testpublic void testXlsxRead() throws Exception {//1 确定文件流FileInputStream is = new FileInputStream("D:\\xml\\user.xlsx");//2 开始读// 2.1 工作簿Workbook workbook = new XSSFWorkbook(is);// 2.2 工作表Sheet sheet = workbook.getSheet("用户表");int rowStart = sheet.getFirstRowNum();      //第一行索引号（从0开始）int rowEnd = sheet.getLastRowNum();         //最后一行的索引号（从0开始）// 2.3 行for(int i = rowStart ; i <= rowEnd ; i ++) {Row row = sheet.getRow(i);int cellStart = row.getFirstCellNum();      //第一列的索引号（从0开始）int cellEnd = row.getLastCellNum() ;        //最后一列的编号（从1开始）// 2.4 列for(int c = cellStart; c < cellEnd ; c++) {Cell cell = row.getCell(c);
//                System.out.println(cell.getCellType());if(cell.getCellType() == Cell.CELL_TYPE_STRING) {// 字符串System.out.print(row.getCell(c).getStringCellValue() + ", ");}if(cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {// 字符串System.out.print(row.getCell(c).getNumericCellValue() + ", ");}}System.out.println();}// 3 释放资源is.close();}

3.2.6 读取不同类型的数据

@Test
public void testRead07() throws Exception{InputStream is = new FileInputStream("d:/0704.xlsx");Workbook workbook = new XSSFWorkbook(is);Sheet sheet = workbook.getSheetAt(0);// 读取第一行第一列Row row = sheet.getRow(0);Cell cell1 = row.getCell(0);Cell cell2 = row.getCell(1);// 输出单元内容System.out.println(cell1.getStringCellValue());System.out.println(cell2.getNumericCellValue());// 操作结束，关闭文件is.close();
}

end

好啦，以上就是本期全部内容，能看到这里的人呀，都是能人。

十年修得同船渡，大家一起点关注。

我是话里人，感谢各位【能人】的：点赞、收藏和评论，我们下期见！

各位能人们的支持就是话里人前进的巨大动力~

注：如果本篇Blog有任何错误和建议，欢迎能人们留言！

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