• JOSN和全局异常处理

    目录

    一、SpringMVC对JSON的支持

    1、josn的形式

    2、SpringMVC框架如何生产上述三种格式的数据

    3、导入pom依赖

    4、Springmvc.xml配置

    5、后台代码

    ClazzMapper.java

    ClazzMapper.xml

    JsonController

    6、前台代码

    7、运行

    8、优化：

     二、SpringMVC 的全局异常处理

    1、SpringMVC自带的简单异常处理器

     2、通过HandlerExceptionResovler接口实现全局异常

     3、使用@ControllerAdvice+@ExceptionHandler实现全局异常

    4、json的通统一异常处理

    一、SpringMVC对JSON的支持

    1、josn的形式

    {}->json对象
    []->json数组
    {
        msg:"",
        code:200,
        data:[]
    }->json混合对象

    2、SpringMVC框架如何生产上述三种格式的数据

    1.导入pom依赖      Jackson
    2.配置SpringMVC.xml 配置适配器
        作用是做json数据转换的
    3.使用注解@responseBody 能够将任何的数据转成json对象

    3、导入pom依赖

    2.     <dependency>
    3.       <groupId>com.fasterxml.jackson.coregroupId>
    4.       <artifactId>jackson-databindartifactId>
    5.       <version>2.9.3version>
    6.     dependency>
    7.     <dependency>
    8.       <groupId>com.fasterxml.jackson.coregroupId>
    9.       <artifactId>jackson-coreartifactId>
    10.       <version>2.9.3version>
    11.     dependency>
    12.     <dependency>
    13.       <groupId>com.fasterxml.jackson.coregroupId>
    14.       <artifactId>jackson-annotationsartifactId>
    15.       <version>2.9.3version>
    16.     dependency>

    4、Springmvc.xml配置

    2.     <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
    3.         <property name="messageConverters">
    4.             <list>
    5.                 <ref bean="mappingJackson2HttpMessageConverter"/>
    6.             list>
    7.         property>
    8.     bean>
    9.     <bean id="mappingJackson2HttpMessageConverter"
    10.           class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
    11.         
    12.         <property name="supportedMediaTypes">
    13.             <list>
    14.                 <value>text/html;charset=UTF-8value>
    15.                 <value>text/json;charset=UTF-8value>
    16.                 <value>application/json;charset=UTF-8value>
    17.             list>
    18.         property>
    19.     bean>

    5、后台代码

    ClazzBiz

    1. package com.zking.ssm.biz;
    2.  
    3. import com.zking.ssm.model.Clazz;
    4. import com.zking.ssm.util.PageBean;
    5.  
    6. import java.util.List;
    7. import java.util.Map;
    8.  
    9. public interface ClazzBiz {
    10.     int deleteByPrimaryKey(Integer cid);
    11.  
    12.     int insert(Clazz record);
    13.  
    14.     int insertSelective(Clazz record);
    15.  
    16.     Clazz selectByPrimaryKey(Integer cid);
    17.  
    18.     int updateByPrimaryKeySelective(Clazz record);
    19.  
    20.     int updateByPrimaryKey(Clazz record);
    21.  
    22.     List listPager(Clazz clazz, PageBean pageBean);
    23.  
    24.     List listMapPager(Clazz clazz, PageBean pageBean);
    25.  
    26. }

    ClazzBizImpl

    1. package com.zking.ssm.impl;
    2.  
    3. import com.zking.ssm.biz.ClazzBiz;
    4. import com.zking.ssm.mapper.ClazzMapper;
    5. import com.zking.ssm.model.Clazz;
    6. import com.zking.ssm.util.PageBean;
    7. import org.springframework.beans.factory.annotation.Autowired;
    8. import org.springframework.stereotype.Service;
    9.  
    10. import java.util.List;
    11. import java.util.Map;
    12.  
    13. /**
    14.  * @author 白未
    15.  * @site 3185579318
    16.  * @company xxx公司
    17.  * @create  2022-08-18 23:34
    18.  */
    19. @Service
    20. public class ClassBizImpl implements ClazzBiz {
    21.  
    22.     @Autowired
    23.     private ClazzMapper clazzMapper;
    24.     @Override
    25.     public int deleteByPrimaryKey(Integer cid) {
    26.         return clazzMapper.deleteByPrimaryKey(cid);
    27.     }
    28.  
    29.     @Override
    30.     public int insert(Clazz record) {
    31.         return clazzMapper.insertSelective(record);
    32.     }
    33.  
    34.     @Override
    35.     public int insertSelective(Clazz record) {
    36.         return clazzMapper.insertSelective(record);
    37.     }
    38.  
    39.     @Override
    40.     public Clazz selectByPrimaryKey(Integer cid) {
    41.         return clazzMapper.selectByPrimaryKey(cid);
    42.     }
    43.  
    44.     @Override
    45.     public int updateByPrimaryKeySelective(Clazz record) {
    46.         return clazzMapper.updateByPrimaryKeySelective(record);
    47.     }
    48.  
    49.     @Override
    50.     public int updateByPrimaryKey(Clazz record) {
    51.         return clazzMapper.updateByPrimaryKey(record);
    52.     }
    53.  
    54.     @Override
    55.     public List listPager(Clazz clazz, PageBean pageBean) {
    56.         return clazzMapper.listPager(clazz);
    57.     }
    58.  
    59.     @Override
    60.     public List listMapPager(Clazz clazz, PageBean pageBean) {
    61.         return clazzMapper.listMapPager(clazz);
    62.     }
    63. }

    ClazzMapper.java

    1. package com.zking.ssm.mapper;
    2.  
    3. import com.zking.ssm.model.Clazz;
    4. import org.springframework.stereotype.Repository;
    5.  
    6. import java.util.List;
    7. import java.util.Map;
    8.  
    9. @Repository
    10. public interface ClazzMapper {
    11.     int deleteByPrimaryKey(Integer cid);
    12.  
    13.     int insert(Clazz record);
    14.  
    15.     int insertSelective(Clazz record);
    16.  
    17.     Clazz selectByPrimaryKey(Integer cid);
    18.  
    19.     List listPager(Clazz clazz);
    20.  
    21.     List listMapPager(Clazz clazz);
    22.  
    23.     int updateByPrimaryKeySelective(Clazz record);
    24.  
    25.     int updateByPrimaryKey(Clazz record);
    26. }

    ClazzMapper.xml

    1. "1.0" encoding="UTF-8" ?>
    2. mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
    3. <mapper namespace="com.zking.ssm.mapper.ClazzMapper" >
    4.   <resultMap id="BaseResultMap" type="com.zking.ssm.model.Clazz" >
    5.     <constructor >
    6.       <idArg column="cid" jdbcType="INTEGER" javaType="java.lang.Integer" />
    7.       <arg column="cname" jdbcType="VARCHAR" javaType="java.lang.String" />
    8.       <arg column="cteacher" jdbcType="VARCHAR" javaType="java.lang.String" />
    9.       <arg column="pic" jdbcType="VARCHAR" javaType="java.lang.String" />
    10.     constructor>
    11.   resultMap>
    12.   <sql id="Base_Column_List" >
    13.     cid, cname, cteacher, pic
    14.   sql>
    15.   <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    16.     select 
    17.     <include refid="Base_Column_List" />
    18.     from t_struts_class
    19.     where cid = #{cid,jdbcType=INTEGER}
    20.   select>
    21.  
    22.   <select id="listPager" resultType="com.zking.ssm.model.Clazz" parameterType="com.zking.ssm.model.Clazz" >
    23.     select
    24.     <include refid="Base_Column_List" />
    25.     from t_struts_class
    26.     <where>
    27.       <if test="cname !=null and cname !='' ">
    28.          and cname like CONCAT('%','#{cname}','%')
    29.       if>
    30.       <if test="cid !=null and cid !='' ">
    31.          and cname = #{cid}
    32.       if>
    33.     where>
    34.   select>
    35.  
    36.   <select id="listMapPager" resultType="java.util.Map" parameterType="com.zking.ssm.model.Clazz" >
    37.     select
    38.     <include refid="Base_Column_List" />
    39.     from t_struts_class
    40.     <where>
    41.       <if test="cname != null and cname != ''">
    42.         and cname like concat('%',#{cname},'%')
    43.       if>
    44.       <if test="cid != null and cid != ''">
    45.         and cid = #{cid}
    46.       if>
    47.     where>
    48.   select>
    49.  
    50.   <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    51.     delete from t_struts_class
    52.     where cid = #{cid,jdbcType=INTEGER}
    53.   delete>
    54.   <insert id="insert" parameterType="com.zking.ssm.model.Clazz" >
    55.     insert into t_struts_class (cid, cname, cteacher, 
    56.       pic)
    57.     values (#{cid,jdbcType=INTEGER}, #{cname,jdbcType=VARCHAR}, #{cteacher,jdbcType=VARCHAR}, 
    58.       #{pic,jdbcType=VARCHAR})
    59.   insert>
    60.   <insert id="insertSelective" parameterType="com.zking.ssm.model.Clazz" >
    61.     insert into t_struts_class
    62.     <trim prefix="(" suffix=")" suffixOverrides="," >
    63.       <if test="cid != null" >
    64.         cid,
    65.       if>
    66.       <if test="cname != null" >
    67.         cname,
    68.       if>
    69.       <if test="cteacher != null" >
    70.         cteacher,
    71.       if>
    72.       <if test="pic != null" >
    73.         pic,
    74.       if>
    75.     trim>
    76.     <trim prefix="values (" suffix=")" suffixOverrides="," >
    77.       <if test="cid != null" >
    78.         #{cid,jdbcType=INTEGER},
    79.       if>
    80.       <if test="cname != null" >
    81.         #{cname,jdbcType=VARCHAR},
    82.       if>
    83.       <if test="cteacher != null" >
    84.         #{cteacher,jdbcType=VARCHAR},
    85.       if>
    86.       <if test="pic != null" >
    87.         #{pic,jdbcType=VARCHAR},
    88.       if>
    89.     trim>
    90.   insert>
    91.   <update id="updateByPrimaryKeySelective" parameterType="com.zking.ssm.model.Clazz" >
    92.     update t_struts_class
    93.     <set >
    94.       <if test="cname != null" >
    95.         cname = #{cname,jdbcType=VARCHAR},
    96.       if>
    97.       <if test="cteacher != null" >
    98.         cteacher = #{cteacher,jdbcType=VARCHAR},
    99.       if>
    100.       <if test="pic != null" >
    101.         pic = #{pic,jdbcType=VARCHAR},
    102.       if>
    103.     set>
    104.     where cid = #{cid,jdbcType=INTEGER}
    105.   update>
    106.   <update id="updateByPrimaryKey" parameterType="com.zking.ssm.model.Clazz" >
    107.     update t_struts_class
    108.     set cname = #{cname,jdbcType=VARCHAR},
    109.       cteacher = #{cteacher,jdbcType=VARCHAR},
    110.       pic = #{pic,jdbcType=VARCHAR}
    111.     where cid = #{cid,jdbcType=INTEGER}
    112.   update>
    113. mapper>

    JsonController

    1. package com.zking.ssm.controller;
    2.  
    3. import com.zking.ssm.biz.ClazzBiz;
    4. import com.zking.ssm.model.Clazz;
    5. import com.zking.ssm.util.PageBean;
    6. import org.springframework.beans.factory.annotation.Autowired;
    7. import org.springframework.stereotype.Controller;
    8. import org.springframework.web.bind.annotation.RequestMapping;
    9. import org.springframework.web.bind.annotation.ResponseBody;
    10.  
    11. import javax.servlet.http.HttpServletRequest;
    12. import java.util.HashMap;
    13. import java.util.List;
    14. import java.util.Map;
    15.  
    16. /**
    17.  * @author 白未
    18.  * @site 3185579318
    19.  * @company xxx公司
    20.  * @create  2022-08-22 16:56
    21.  */
    22. @Controller
    23. @RequestMapping("/clz/json")
    24. public class JsonController {
    25.  
    26.     @Autowired
    27.     private ClazzBiz clazzBiz;
    28.  
    29.     @ResponseBody
    30.     @RequestMapping("/clzEdit")
    31.     public String clzEdit(){
    32.         System.out.println("JsonController.clzEdit");
    33.         return "clzEdit";
    34.     }
    35.  
    36.     //List
    37.     @ResponseBody
    38.     @RequestMapping("/list")
    39.     public List list(HttpServletRequest request,Clazz clazz){
    40.         PageBean pageBean = new PageBean();
    41.         pageBean.setRequest(request);
    42. //      [{},{}]
    43.         return this.clazzBiz.listPager(clazz,pageBean);
    44.     }
    45. //  List
    46.     @ResponseBody
    47.     @RequestMapping("/listMap")
    48.     public List listMap(HttpServletRequest request, Clazz clazz){
    49.         PageBean pageBean = new PageBean();
    50.         pageBean.setRequest(request);
    51. //      [{},{}]
    52.         return this.clazzBiz.listMapPager(clazz,pageBean);
    53.     }
    54.  
    55. //    Map
    56.     @ResponseBody
    57.     @RequestMapping("/map")
    58.     public Map map(HttpServletRequest request, Clazz clazz){
    59.         PageBean pageBean = new PageBean();
    60.         pageBean.setRequest(request);
    61.     //      {}
    62.     return this.clazzBiz.listMapPager(clazz,pageBean).get(0);
    63.     }
    64. //  T
    65.     @ResponseBody
    66.     @RequestMapping("/load")
    67.     public Map load(HttpServletRequest request, Clazz clazz){
    68. //        http//localhost:8080/clz/json/load?cid=2
    69.         PageBean pageBean = new PageBean();
    70.         pageBean.setRequest(request);
    71.         //      {}
    72.         return this.clazzBiz.listMapPager(clazz,pageBean).get(0);
    73.     }
    74.  
    75. //  {
    76. //	    msg:"",
    77. //	    code:200,
    78. //	    data:[]
    79. //    pageBean:{}
    80. //  }
    81.     @ResponseBody
    82.     @RequestMapping("/hunhe")
    83.     public Map hunhe(HttpServletRequest request, Clazz clazz){
    84. //        http//localhost:8080/clz/json/load?cid=2
    85.         PageBean pageBean = new PageBean();
    86.         pageBean.setRequest(request);
    87.         List lst = this.clazzBiz.listPager(clazz,pageBean);
    88.         Map map = new HashMap();
    89.         map.put("data",lst);
    90.         map.put("pagebean",pageBean);
    91.         return map;
    92.     }
    93.  
    94. }

    6、前台代码

    1. <%--
    2.   Created by IntelliJ IDEA.
    3.   User: Administrator
    4.   Date: 2022/8/23
    5.   Time: 19:45
    6.   To change this template use File | Settings | File Templates.
    7. --%>
    8. <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    9. <html>
    10. <head>
    11.     <title>测试json数据返回title>
    12. head>
    13. <body>
    14. <a href="${pageContext.request.contextPath}/clz/json/list">返回list<T>对象a><hr>
    15. <a href="${pageContext.request.contextPath}/clz/json/listMap">返回list<Map>对象a><hr>
    16. <a href="${pageContext.request.contextPath}/clz/json/load?cid=1">返回T对象a><hr>
    17. <a href="${pageContext.request.contextPath}/clz/json/map?cid=1">返回Map对象a><hr>
    18. <a href="${pageContext.request.contextPath}/clz/json/hunhe">返回混合对象a><hr>
    19.  
    20. body>
    21. html>

    7、运行

     list

     list

     T

     Map

     混合

    8、优化：

    @ResponseBody+@Controller=@restController

     二、SpringMVC 的全局异常处理

    1、SpringMVC自带的简单异常处理器

    SpringMVC的配置

    2.     <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
    3.         
    4.         <property name="defaultErrorView" value="error"/>
    5.         
    6.         <property name="exceptionAttribute" value="ex"/>
    7.         
    8.         <property name="exceptionMappings">
    9.             <props>
    10.                 <prop key="java.lang.RuntimeException">errorprop>
    11.             props>
    12.             
    13.         property>
    14.     bean>
    15.

    error.jsp

    1. <%--
    2.   Created by IntelliJ IDEA.
    3.   User: Administrator
    4.   Date: 2022/8/23
    5.   Time: 21:22
    6.   To change this template use File | Settings | File Templates.
    7. --%>
    8. <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    9. <html>
    10. <head>
    11.     <title>错误信息页面title>
    12. head>
    13. <body>
    14. ${ex}
    15. body>
    16. html>

    list

    list

     2、通过HandlerExceptionResovler接口实现全局异常

    先将上面SpringMVC中关于异常处理的配置取消掉

    GlobalException.java
    1. package com.zking.ssm.exception;
    2.  
    3. /**
    4.  * @author 白未
    5.  * @site 3185579318
    6.  * @company xxx公司
    7.  * @create  2022-08-23 21:45
    8.  */
    9. public class GlobalException extends RuntimeException{
    10.  
    11.     public GlobalException() {
    12.     }
    13.  
    14.     public GlobalException(String message) {
    15.         super(message);
    16.     }
    17.  
    18.     public GlobalException(String message, Throwable cause) {
    19.         super(message, cause);
    20.     }
    21.  
    22.     public GlobalException(Throwable cause) {
    23.         super(cause);
    24.     }
    25.  
    26.     public GlobalException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
    27.         super(message, cause, enableSuppression, writableStackTrace);
    28.     }
    29. }

    GlobalExceptionHandler.java

    1. package com.zking.ssm.exception;
    2.  
    3. import org.springframework.stereotype.Component;
    4. import org.springframework.web.servlet.HandlerExceptionResolver;
    5. import org.springframework.web.servlet.ModelAndView;
    6.  
    7. import javax.servlet.http.HttpServletRequest;
    8. import javax.servlet.http.HttpServletResponse;
    9.  
    10. /**
    11.  * @author 白未
    12.  * @site 3185579318
    13.  * @company xxx公司
    14.  * @create  2022-08-23 21:48
    15.  *
    16.  * 处理全局异常的解析器
    17.  */
    18.  
    19. @Component
    20. public class GlobalHandlerExceptionResovler implements HandlerExceptionResolver {
    21.     /**
    22.      *
    23.      * @param httpServletRequest
    24.      * @param httpServletResponse
    25.      * @param o 目标对象
    26.      * @param e 目标对象执行，出现的异常对象
    27.      * @return
    28.      */
    29.     @Override
    30.     public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
    31.         ModelAndView mv = new ModelAndView();
    32.         mv.setViewName("error");
    33.         if(e instanceof GlobalException){
    34.             GlobalException exception =(GlobalException)e;
    35.             mv.addObject("ex",null);
    36.             mv.addObject("msg","全局异常，错误码520");
    37.         }else if(e instanceof GlobalException) {
    38.             GlobalException exception = (GlobalException) e;
    39.             mv.addObject("ex", null);
    40.             mv.addObject("msg", "运行时异常，错误码666");
    41.         }
    42.         return mv;
    43.     }
    44. }

    controller层

    1. @RequestMapping("/load")
    2.     public Map load(HttpServletRequest request, Clazz clazz){
    3. //        http//localhost:8080/clz/json/load?cid=2
    4.         PageBean pageBean = new PageBean();
    5.         pageBean.setRequest(request);
    6.         if(true)
    7.             throw  new GlobalException("系统繁忙，请参考曾超sb");
    8.         //      {}
    9.         return this.clazzBiz.listMapPager(clazz,pageBean).get(0);
    10.     }

    运行

     3、使用@ControllerAdvice+@ExceptionHandler实现全局异常

    GlobalExceptionResolver
    1. package com.zking.ssm.exception;
    2.  
    3. import org.springframework.web.bind.annotation.ControllerAdvice;
    4. import org.springframework.web.bind.annotation.ExceptionHandler;
    5. import org.springframework.web.servlet.ModelAndView;
    6.  
    7. /**
    8.  * @author 白未
    9.  * @site 3185579318
    10.  * @company xxx公司
    11.  * @create  2022-08-23 22:56
    12.  */
    13. @ControllerAdvice
    14. public class GlobalExceptionResolver {
    15.     @ExceptionHandler
    16.     public ModelAndView handler(Exception e){
    17.         ModelAndView mv = new ModelAndView();
    18.         mv.setViewName("error");
    19.         if(e instanceof GlobalException){
    20.             GlobalException exception =(GlobalException)e;
    21.             mv.addObject("ex","系统繁忙");
    22.             mv.addObject("msg","全局异常 GlobalExceptionResolver，错误码520");
    23.         }else if(e instanceof GlobalException) {
    24.             GlobalException exception = (GlobalException) e;
    25.             mv.addObject("ex", null);
    26.             mv.addObject("msg", "运行时异常 GlobalExceptionResolver，错误码666");
    27.         }
    28.         return mv;
    29.     }
    30. }

    4、json的通统一异常处理

    GlobalExceptionResolver2
    1. package com.zking.ssm.exception;
    2.  
    3. import org.springframework.web.bind.annotation.ControllerAdvice;
    4. import org.springframework.web.bind.annotation.ExceptionHandler;
    5. import org.springframework.web.bind.annotation.RequestAttribute;
    6. import org.springframework.web.bind.annotation.RestControllerAdvice;
    7. import org.springframework.web.servlet.ModelAndView;
    8.  
    9. import java.util.HashMap;
    10. import java.util.Map;
    11.  
    12. /**
    13.  * @author 白未
    14.  * @site 3185579318
    15.  * @company xxx公司
    16.  * @create  2022-08-23 22:56
    17.  *
    18.  * 当出现异常统一向前端响应错误信息的json数据
    19.  */
    20. @RestControllerAdvice
    21. public class GlobalExceptionResolver2 {
    22.     @ExceptionHandler
    23.     public Map handler(Exception e){
    24.         Map map = new HashMap();
    25.         if(e instanceof GlobalException){
    26.             GlobalException exception =(GlobalException)e;
    27.             map.put("ex",exception.getMessage());
    28.             map.put("msg","全局异常 GlobalExceptionResolver，错误码520");
    29.         }else if(e instanceof RuntimeException) {
    30.             RuntimeException exception = (RuntimeException) e;
    31.             map.put("ex", exception.getMessage());
    32.             map.put("msg", "运行时异常 GlobalExceptionResolver，错误码666");
    33.         }
    34.         return map;
    35.     }
    36. }

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  • 原文地址：https://blog.csdn.net/yzq102873/article/details/126469151