1、手机上传压缩后的图片到服务器

2、后台接收到图片进行图片重命名、保存

后台代码

package service;

import java.io.File;

import java.io.IOException;

import java.util.List;

import javax.servlet.Servlet;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;

import org.apache.commons.fileupload.FileUploadException;

import org.apache.commons.fileupload.disk.DiskFileItemFactory;

import org.apache.commons.fileupload.servlet.ServletFileUpload;

import bean.UpdateHeadBean;

import net.sf.json.JSONObject;

import utils.DbUtil;

@WebServlet("/UpdateHead")

public class UpdateHead extends HttpServlet implements Servlet{

private static final long serialVersionUID = 1L;

public UpdateHead() {

super();

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws

ServletException, IOException {

this.doPost(request, response);

response.getWriter().append("Served at: ").append(request.getContextPath());

}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,

IOException {

response.setCharacterEncoding("UTF-8");

DiskFileItemFactory factory = new DiskFileItemFactory();

ServletFileUpload upload = new ServletFileUpload(factory);

List items;

UpdateHeadBean updateHeadBean = new UpdateHeadBean();

try {

int uId = 0;

String pic =null;

String headName = null;

items = upload.parseRequest(request);//参数是HttpServletRequest对象

for (FileItem item : items){//遍历所有客户端提交的参数(包括文件域)

if(item.isFormField()){

if("uPic".equals(item.getFieldName())){//获取手机端传的参数(用户id)

uId=Integer.valueOf(item.getString());

pic = DbUtil.queryPic(uId);

System.out.println("value："+item.getString());

}

}else{

String key = item.getFieldName();//取出文件域的键

String value = item.getName();//取出文件域的值

long fileLen = item.getSize();//取出上传文件的尺寸

String mimeType = item.getContentType();//取出上传文件的类型

File f=new File("D:\\test\\");//文件地址(上传后服务器硬盘地址)

f.mkdirs();

headName = System.currentTimeMillis()+value.substring(value.indexOf("."),value.length());

//保存图片到服务器

item.write(new File(f+"\\"+headName));//保存上传的文件到服务器本地

System.out.println("value："+headName);

}

updateHeadBean.setStatus(0);

updateHeadBean.setMsg("上传成功");

}

//根据用户id保存图片名称到数据库

DbUtil.saveHead(headName, uId);

//删除原来的图片文件

if(pic!=null&&pic!="1520848305600.jpg"){

File file = new File("d:\\test\\"+pic);

try {

if (file.exists()) {// 上面文件创建,已存在就删除

boolean d = file.delete();

}

} catch (Exception e) {

e.printStackTrace();

}

}

} catch (Exception e) {

updateHeadBean.setStatus(1);

updateHeadBean.setMsg("上传失败");

e.printStackTrace();

}

//实体类转为json字符串返回给客户端

JSONObject msg = JSONObject.fromObject(updateHeadBean);

response.getWriter().write(msg.toString());

}

}

数据库操作类

package utils;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import bean.Student;

public class DbUtil {

/*

* 保存数据

*/

public static Object saveData(String name,int age,String pss){

Connection connection = null;

PreparedStatement preparedStatement = null;

ResultSet rs = null;

Object retId = null;

try{

// 获取连接

connection = JdbcUtils.getConnection();

// 准备sql语句

String sql = "INSERT INTO students(name,age,pss) VALUES(?,?,?)";

// 获取PrepareStatement对象

preparedStatement = connection.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);

// 填充占位符

preparedStatement.setString(1, name);

preparedStatement.setInt(2, age);

preparedStatement.setString(3, pss);

// 执行sql

preparedStatement.executeUpdate();

rs = preparedStatement.getGeneratedKeys();

if (rs.next()){

retId = rs.getObject(1);}

return retId;

}catch(SQLException  e){

e.printStackTrace();

return null;

}finally{

JdbcUtils.releaseDB(connection, preparedStatement, null);

}

}

/*

* 查询数据

*/

public static String queryData(String name){

Connection connection = null;

ResultSet rs = null;

try{

// 获取连接

connection = JdbcUtils.getConnection();

Statement statement = connection.createStatement();

rs=statement.executeQuery("select * from students where name='"+name+"'");

if(rs.next()){

String userName = rs.getString("name");

return "注册成功！";

}

}catch(SQLException  e){

e.printStackTrace();

return "错误！";

}

finally{

try {

connection.close();

rs.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

return "错误！";

}

/*

* 查询数据

*/

public static String queryPic(int id){

Connection connection = null;

ResultSet rs = null;

try{

// 获取连接

connection = JdbcUtils.getConnection();

Statement statement = connection.createStatement();

rs=statement.executeQuery("select * from students where id='"+id+"'");

if(rs.next()){

String pic = rs.getString("pic");

return pic;

}

}catch(SQLException  e){

e.printStackTrace();

return null;

}

finally{

try {

connection.close();

rs.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

return null;

}

public static Object queryData(String name,String pss,boolean flag){

Connection connection = null;

ResultSet rs = null;

try{

// 获取连接

connection = JdbcUtils.getConnection();

Statement statement = connection.createStatement();

rs=statement.executeQuery("select * from students where name='"+name+"'and pss ='"+pss+"'");

if(rs.next()){

Object msg;

if(flag){

msg = rs.getInt("id");

}else{

msg = rs.getString("pic");

}

return msg;

}

}catch(SQLException  e){

e.printStackTrace();

return null;

}

finally{

try {

connection.close();

rs.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

return null;

}

/**

* 保存上传的头像

*/

public static boolean saveHead(String picName,int id){

Connection connection = null;

PreparedStatement preparedStatement = null;

try{

// 获取连接

connection = JdbcUtils.getConnection();

// 准备sql语句  UPDATE Person SET FirstName = 'Fred' WHERE LastName = 'Wilson'

String sql = "update students set pic=? where id='"+id+"'";

// 获取PrepareStatement对象

preparedStatement = connection.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);

// 填充占位符

preparedStatement.setString(1, picName);

// 执行sql

preparedStatement.execute();

return true;

}catch(SQLException  e){

e.printStackTrace();

return false;

}finally{

JdbcUtils.releaseDB(connection, preparedStatement, null);

}

}

}

3、使用tomcat映射图片地址

打开Tomcat安装文件夹——>conf——>Catalina——>localhost

创建xml文件 pic.xml (文件名必须与Context path的值一致)，docBase与workDir的值为图片所在文件夹，配置好后可在浏览器通过192.168.0.101:8080/pic/文件名 访问图片(192.168.0.101:8080为本机ip与tomcat端口号)

docBase="D:/test"

workDir="D:/test"

debug="0"

reloadable="true"

crossContext="true" />