SSM-项目整合简单思路

1.首先我们先写好dao与mapper

2.然后我们实现service层，要明白service与dao层的区别，它是根据具体业务实现：

3.Controller层：调用后台的业务逻辑，并且返回数据给到前端jsp页面上，可以理解为最终的实现层，也是与数据交接的地方；（一般来说，Controller层获取的数是由前端jquery实现ajax获取前台数据给到对应controller的）

4.这里的验证方式是通过ajax来实现的

5.工具类：MD5Utils

1.盐值；2.DigestUtils.md5DigestAsHex(xxx.getBytes());

6.拦截器的实现：只有登录的用户才有资格访问

拦截器实现思路：1.实现HandlerInterceptor 2.利用preHandle()方法进行拦截

7.配置文件

1.首先是web.xml

2.application.xml配置

3.spring-mvc.xml配置

1.首先我们先写好dao与mapper

UserDao：

package com.yanzhen.dao;import java.util.List;
import java.util.Map;import com.yanzhen.entity.User;public interface UserDao {public int create(User pi);public int delete(Map<String, Object> paramMap);public int update(Map<String, Object> paramMap);public List<User> query(Map<String, Object> paramMap);public User detail(Map<String, Object> paramMap);public int count(Map<String, Object> paramMap);
}

UserMaper

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.yanzhen.dao.UserDao"><resultMap type="com.yanzhen.entity.User" id="User"><id column="id" property="id"/><result column="id" property="id"/><result column="name" property="name"/><result column="remark" property="remark"/><result column="user_name" property="userName"/><result column="user_pwd" property="userPwd"/></resultMap><insert id="create" keyProperty="id" useGeneratedKeys="true" parameterType="com.yanzhen.entity.User">insert into tb_user(name,remark,user_name,user_pwd)values(#{name},#{remark},#{userName},#{userPwd})</insert><select id="query" resultMap="User">select * from tb_user<include refid="UserFindCriteria"/><if test="offset!=null and rows!=null">limit ${offset} , ${rows}</if></select><select id="count" resultType="int">select count(1) from tb_user<include refid="UserFindCriteria"/></select><select id="detail" resultMap="User">select * from tb_user<include refid="UserFindCriteria"/>limit 1</select><delete id="delete">delete from tb_user<include refid="UserFindCriteria"/></delete><update id="update">update tb_user<include refid="UserUpdateCriteria"/><include refid="UserFindCriteria"/></update><sql id="UserFindCriteria"><where><if test="id != null">and id = #{id}</if><if test="name != null and name != ''">and name like concat('%',#{name},'%')</if><if test="remark != null and remark != ''">and remark = #{remark}</if><if test="userName != null and userName != ''">and user_name like concat('%',#{userName},'%')</if><if test="userPwd != null and userPwd != ''">and user_pwd = #{userPwd}</if></where></sql><sql id="UserUpdateCriteria"><set><if test="updateId != null">id = #{updateId},</if><if test="updateName != null and updateName != ''">name = #{updateName},</if><if test="updateRemark != null and updateRemark != ''">remark = #{updateRemark},</if><if test="updateUserName != null and updateUserName != ''">user_name = #{updateUserName},</if><if test="updateUserPwd != null and updateUserPwd != ''">user_pwd = #{updateUserPwd},</if></set></sql>
</mapper>

2.然后我们实现service层，要明白service与dao层的区别，它是根据具体业务实现：

比如说登录，我们service层首先将userName与userPwd放入map容器中并返回map容器

然后dao层调用查询单个用户的方法(参数都为map),所以userName与userPwd需要放入map中

package com.yanzhen.service;import com.yanzhen.dao.UserDao;
import com.yanzhen.entity.User;
import com.yanzhen.entity.User;
import com.yanzhen.utils.BeanMapUtils;
import com.yanzhen.utils.MD5Utils;
import com.yanzhen.utils.MapParameter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;import java.util.List;
import java.util.Map;@Service
public class UserService {@Autowiredprivate UserDao userDao;public int create(User pi) {pi.setUserPwd(MD5Utils.getMD5(pi.getUserPwd()));return userDao.create(pi);}public int delete(Integer id) {return userDao.delete(MapParameter.getInstance().addId(id).getMap());}public int delete(String ids) {int flag = 0;for (String str : ids.split(",")) {flag = userDao.delete(MapParameter.getInstance().addId(Integer.parseInt(str)).getMap());}return flag;}public int update(User user) {Map<String, Object> map = MapParameter.getInstance().add(BeanMapUtils.beanToMapForUpdate(user)).addId(user.getId()).getMap();return userDao.update(map);}public List<User> query(User user) {return userDao.query(BeanMapUtils.beanToMap(user));}public User detail(Integer id) {return userDao.detail(MapParameter.getInstance().addId(id).getMap());}public int count(User user) {return userDao.count(BeanMapUtils.beanToMap(user));}public User login(String userName,String password){Map<String, Object> map = MapParameter.getInstance().add("userName", userName).add("userPwd", password).getMap();//将用户信息放入map容器中return userDao.detail(map);//根据map信息在mapper中的sql语句中进行查询,返回用户}}

因为我们这个项目是有三种登录方式，所以学生以及老师也要各自实现自己login方法，反正都是根据用户名以及密码查询用户，就不具体演示了

3.Controller层：调用后台的业务逻辑，并且返回数据给到前端jsp页面上，可以理解为最终的实现层，也是与数据交接的地方；（一般来说，Controller层获取的数是由前端jquery实现ajax获取前台数据给到对应controller的）

思路：1.参数为用户名及密码，登录类型，验证码，session；2.进行错误验证（比如说用户名密码为空的情况）；3.根据type具体类型为多少来实现不同的登录方式；4.登录方式的实现(验证session)

package com.yanzhen.controller;import com.yanzhen.entity.Student;
import com.yanzhen.entity.Teacher;
import com.yanzhen.entity.User;
import com.yanzhen.service.StudentService;
import com.yanzhen.service.TeacherService;
import com.yanzhen.service.UserService;
import com.yanzhen.utils.Code;
import com.yanzhen.utils.MD5Utils;
import com.yanzhen.utils.MapControll;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.ResponseBody;import javax.servlet.http.HttpSession;
import java.util.Map;@Controller
public class LoginController {@Autowiredprivate UserService userService;@Autowiredprivate StudentService studentService;@Autowiredprivate TeacherService teacherService;@GetMapping("/login")public String login(){return "login";}@PostMapping("/login")@ResponseBodypublic Map<String,Object> login(String userName, String password, String type,String captcha, HttpSession session){if(StringUtils.isEmpty(userName) || StringUtils.isEmpty(password) || StringUtils.isEmpty(type)){return MapControll.getInstance().error("用户名或密码不能为空").getMap();}String _captcha = (String)session.getAttribute("captcha");if(StringUtils.isEmpty(captcha)){return MapControll.getInstance().error("验证码不能为空").getMap();}if(!captcha.equals(_captcha)){return MapControll.getInstance().error("验证码错误").getMap();}//管理员登录if("1".equals(type)){User user = userService.login(userName, MD5Utils.getMD5(password));if(user != null){//此时user的业务层返回了用户，然后我们将这些用户放入session中session.setAttribute("user",user);session.setAttribute("type",1);return MapControll.getInstance().success().add("data",user).getMap();}else{return MapControll.getInstance().error("用户名或密码错误").getMap();}}//老师登录if("2".equals(type)){Teacher teacher = teacherService.login(userName, MD5Utils.getMD5(password));if(teacher != null){
//                将用户信息放入session中，并且放入用户类型session.setAttribute("user",teacher);session.setAttribute("type",2);//用户信息存在,将用户信息放入map容器中，并且放入成功提示信息，返回map容器，后给前端页面ajax中的datareturn MapControll.getInstance().success().add("data",teacher).getMap();}else{return MapControll.getInstance().error("用户名或密码错误").getMap();}}//学生登录if("3".equals(type)){Student student = studentService.login(userName, MD5Utils.getMD5(password));if(student != null){session.setAttribute("user",student);session.setAttribute("type",3);return MapControll.getInstance().success().add("data",student).getMap();}else{return MapControll.getInstance().error("用户名或密码错误").getMap();}}return MapControll.getInstance().error("用户名或密码错误").getMap();}}

这里用StringUtils来验证userName、password、type、captcha是否为空，如果为空就返回错误，将错误信息放入map容器中(这里用了自定义工具类)

package com.yanzhen.utils;import java.util.HashMap;
import java.util.List;
import java.util.Map;public class MapControll {//目标对象private Map<String,Object> paramMap = new HashMap<>();//私有构造private MapControll(){}public static MapControll getInstance(){return new MapControll();}public MapControll add(String key, Object value){paramMap.put(key,value);return this;//this这里指的就是对象new MapController();}public MapControll success(){paramMap.put("code",Code.SUCCESS.getCode());paramMap.put("msg",Code.SUCCESS.getMsg());//msg为返回给前端的信息，作为验证，若为1000说明成功，则跳转到首页return this;}public MapControll error(){paramMap.put("code",Code.ERROR.getCode());paramMap.put("msg",Code.ERROR.getMsg());return this;}public MapControll error(String msg){paramMap.put("code",Code.ERROR.getCode());paramMap.put("msg",msg);return this;}public MapControll notEmpty(){paramMap.put("code",Code.NOT_EMPTY.getCode());paramMap.put("msg",Code.NOT_EMPTY.getMsg());return this;}public MapControll nodata(){paramMap.put("code",Code.NODATA.getCode());paramMap.put("msg",Code.NODATA.getMsg());return this;}public MapControll page(List<?> list,Integer count){paramMap.put("data",list);paramMap.put("count",count);return this;}public MapControll put(String key, Object value){this.add(key,value);return this;}public MapControll addId(Object value){paramMap.put("id",value);return this;}public MapControll add(Map<String,Object> map){for (Map.Entry<String, Object> entry : map.entrySet()) {paramMap.put(entry.getKey(),entry.getValue());}return this;}public MapControll put(Map<String,Object> map){return this.add(map);}public Map<String,Object> getMap(){return paramMap;}}

至于具体管理员学生老师登录：1.根据类型判断；2.调用业务层方法获取用户；3.如果用户不为空放入session中，type也要放入，然后将用户信息放入map容器中，且调用success得到正确码给，并且返回map容器，将返回数据给到前端验证

4.这里的验证方式是通过ajax来实现的
  // 进行登录操作form.on('submit(login)', function (data) {$.ajax({url:"${basePath}login",type:"POST",dataType:'json',data:data.field,success:function(data){if(data.code == "1000"){location.href = "index";}else{//登录失败显示出后端返回给前端的数据layer.msg(data.msg,{time:2000});}}});return false;});
最重要的三个点：1.url：对应着controller ；2.data：给对应controller传去的数据 ; 3.success:来自后台controller回显的数据，这里起了一个验证效果;

5.工具类：MD5Utils

1.盐值；2.DigestUtils.md5DigestAsHex(xxx.getBytes());

package com.yanzhen.utils;import org.springframework.util.DigestUtils;public class MD5Utils {//盐private static final String salt = "StudentSystemManager###$$@@";public static String getMD5(String string){String val = string+salt;return DigestUtils.md5DigestAsHex(val.getBytes());}public static void main(String[] args) {System.out.println(getMD5("123456"));}}

6.拦截器的实现：只有登录的用户才有资格访问

拦截器实现思路：1.实现HandlerInterceptor 2.利用preHandle()方法进行拦截

3.req.getSession(),如果session中为空则抛出异常(自定义异常)，否则通过

package com.yanzhen.utils;import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;public class PermissionInterceptor implements HandlerInterceptor {//可以根据session中是否有信息进行拦截@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {HttpSession session = request.getSession();
//        如果session中user信息不为空，则放行，否则抛出异常并且传入message提示if(session.getAttribute("user") != null){return true;}else{throw new PermissionException("没有权限访问");}}}

自定义异常：继承运行异常，当异常出现，可以自定义异常所报出的信息

package com.yanzhen.utils;public class PermissionException extends  RuntimeException {//自定义异常public PermissionException(String message) {super(message);}
}

但是我们还需要处理异常，因为你如果没有权限而去访问就会报出405，所以我们要有一个全局异常处理，这样我们就可以返回一个error页面或者返回json，相对来说比较友好

package com.yanzhen.utils;import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;import javax.jws.HandlerChain;
import java.util.Map;@ControllerAdvice
public class GlobalControllerAdvice {
//全局异常处理private final String ERROR = "error";
//设定全局处理的异常@ExceptionHandler(value=PermissionException.class)public ModelAndView noPermission(PermissionException e){//new一个返回页面为errorModelAndView modelAndView = new ModelAndView(ERROR);//绑定：将异常中的message信息与error页面绑定，也就是说当抛出PermissionException异常时,就返回error页面modelAndView.addObject(ERROR,e.getMessage());return modelAndView;}@ExceptionHandler(value=RuntimeException.class)@ResponseBodypublic Map<String,Object> runtimeException(RuntimeException e){e.printStackTrace();return MapControll.getInstance().error().getMap();}}

7.配置文件

1.首先是web.xml

三步骤：1.前端控制器DispatcherServlet(注意里面初始化加载的spring-mvc.xml);

2.配置web.xml配置文件的节点<context-param>：当你启动项目时,容器就会读取它，并将Context-param中的给到servletContext上下文，并且会读取listener对上下文进行监听

3.配置过滤器filter
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"version="4.0"><servlet><servlet-name>student_system</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:spring-mvc.xml</param-value></init-param><load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name>student_system</servlet-name><url-pattern>/</url-pattern></servlet-mapping><context-param><param-name>contextConfigLocation</param-name><param-value>classpath:applicationContext.xml</param-value></context-param><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener><filter><filter-name>encodingFilter</filter-name><filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class><init-param><param-name>encoding</param-name><param-value>utf-8</param-value></init-param></filter><filter-mapping><filter-name>encodingFilter</filter-name><url-pattern>/*</url-pattern></filter-mapping>


</web-app>
2.application.xml配置

我们这里就不多配置一个spring-service.xml了（这种配置方式狂神视频中有），我们直接全部放在application.xml中；

1.首先是扫描service,扫描其注解（类似这种文件形式的都是<context:xxx>）
 <context:component-scan base-package="com.yanzhen.service" />
2.配置数据库配置文件位置与数据源驱动参数
<context:property-placeholder location="classpath:db.properties" /><bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource"><property name="driverClassName" value="${jdbc.driver}"></property><property name="url" value="${jdbc.url}"></property><property name="username" value="${jdbc.username}"></property><property name="password" value="${jdbc.password}"></property></bean>
3.配置sqlSessionFactory（因为是由sqlSessionFactoryBuilder读取mybatis配置文件而得到的关键对象，可以理解为sqlSessionFactory是mybatis的核心，是它配置文件的实例，里面所有的sql操作）：里面要注入数据源驱动参数，mybatis配置文件，并且扫描所有的mapper
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><property name="dataSource" ref="dataSource"/><property name="configLocation" value="classpath:mybatis-config.xml"></property><property name="mapperLocations"><list><value>classpath:com/yanzhen/dao/*.xml</value></list></property><property name="plugins"><array><bean class="com.github.pagehelper.PageInterceptor"><property name="properties"><value>helperDialect=mysql</value></property></bean></array></property></bean>
像在xml中对bean中属性进行赋值一般有两种方式：1.ref：将其他bean作为属性值引入；2.value：除了能将其他bean作为属性值引入之外，还能引入路径

4.MapperScannerConfigurer的配置，作用类似于sqlSessionTemplate的配置
 <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><property name="basePackage" value="com.yanzhen.dao"></property><property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property></bean>
3.spring-mvc.xml配置

1.mvc一般是和controller接轨的，因为controller和前端页面有关系，所以要扫描controller以及utils下的文件
 <context:component-scan base-package="com.yanzhen.controller,com.yanzhen.utils" />
2.因为web.xml中配置了前端控制器Dispatcher，所以这里要配置一个<mvc:annotation-driven>，作用：注解驱动，能够自动注册@RequestMappingHandlerMapping映射器以及@RequestMappingHandlerAdapter适配器；

映射器作用：controller中每个方法都对应着一个@RequestMapping，它的作用就是识别注解下的方法，根据注解定义的url与方法进行匹配，然后交给前端控制器；

适配器：方法与@RequestMapping进行适配；
<mvc:annotation-driven><mvc:message-converters><bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"><property name="objectMapper"><bean class="com.fasterxml.jackson.databind.ObjectMapper"><property name="dateFormat"><bean class="java.text.SimpleDateFormat"><constructor-arg type="java.lang.String" value="yyyy-MM-dd"/></bean></property></bean></property></bean></mvc:message-converters></mvc:annotation-driven>
3.视图解析器配置：
 <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"><property name="prefix" value="/WEB-INF/page/"></property><property name="suffix" value=".jsp"></property></bean>
4.拦截器配置：
<mvc:interceptors><mvc:interceptor><mvc:mapping path="/**/*"/><bean class="com.yanzhen.utils.PathInterceptor" /></mvc:interceptor><mvc:interceptor><mvc:mapping path="/**/*"/><mvc:exclude-mapping path="/login"/><mvc:exclude-mapping path="/logout"/>
<mvc:exclude-mapping path="/captcha/*"/>
<mvc:exclude-mapping path="/static/**"/><bean class="com.yanzhen.utils.PermissionInterceptor"/></mvc:interceptor></mvc:interceptors>

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