springMVC之JSON和全局异常处理

      com.fasterxml.jackson.core

      jackson-databind

      2.9.3





      com.fasterxml.jackson.core

      jackson-core

      2.9.3





      com.fasterxml.jackson.core

      jackson-annotations

      2.9.3

pom.xml


"1.0" encoding="UTF-8"?>
 
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>ideamavenartifactId>
        <groupId>org.examplegroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>
 
    <artifactId>ssm2artifactId>
    <packaging>warpackaging>
 
    <name>ssm2 Maven Webappname>
    
    <url>http://www.example.comurl>
 
    <properties>
        <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
        <maven.compiler.source>1.8maven.compiler.source>
        <maven.compiler.target>1.8maven.compiler.target>
        <maven.compiler.plugin.version>3.7.0maven.compiler.plugin.version>
 
        
        
        <spring.version>5.0.2.RELEASEspring.version>
        
        <mybatis.version>3.4.5mybatis.version>
        
        <mysql.version>5.1.44mysql.version>
        
        <pagehelper.version>5.1.2pagehelper.version>
        
        <mybatis.spring.version>1.3.1mybatis.spring.version>
        
        <commons.dbcp2.version>2.1.1commons.dbcp2.version>
        <commons.pool2.version>2.4.3commons.pool2.version>
        
        <log4j2.version>2.9.1log4j2.version>
        
        <junit.version>4.12junit.version>
        <servlet.version>4.0.0servlet.version>
        <lombok.version>1.18.2lombok.version>
    properties>
 
    <dependencies>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-contextartifactId>
            <version>${spring.version}version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-ormartifactId>
            <version>${spring.version}version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-txartifactId>
            <version>${spring.version}version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-aspectsartifactId>
            <version>${spring.version}version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-webartifactId>
            <version>${spring.version}version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-testartifactId>
            <version>${spring.version}version>
        dependency>
 
        
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatisartifactId>
            <version>${mybatis.version}version>
        dependency>
        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>${mysql.version}version>
        dependency>
        
        <dependency>
            <groupId>com.github.pagehelpergroupId>
            <artifactId>pagehelperartifactId>
            <version>${pagehelper.version}version>
        dependency>
        
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatis-springartifactId>
            <version>${mybatis.spring.version}version>
        dependency>
 
        
        <dependency>
            <groupId>org.apache.commonsgroupId>
            <artifactId>commons-dbcp2artifactId>
            <version>${commons.dbcp2.version}version>
        dependency>
        <dependency>
            <groupId>org.apache.commonsgroupId>
            <artifactId>commons-pool2artifactId>
            <version>${commons.pool2.version}version>
        dependency>
 
        
        
        <dependency>
            <groupId>org.apache.logging.log4jgroupId>
            <artifactId>log4j-coreartifactId>
            <version>${log4j2.version}version>
        dependency>
        <dependency>
            <groupId>org.apache.logging.log4jgroupId>
            <artifactId>log4j-apiartifactId>
            <version>${log4j2.version}version>
        dependency>
        
        <dependency>
            <groupId>org.apache.logging.log4jgroupId>
            <artifactId>log4j-webartifactId>
            <version>${log4j2.version}version>
        dependency>
 
        
        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <version>${junit.version}version>
            <scope>testscope>
        dependency>
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>javax.servlet-apiartifactId>
            <version>${servlet.version}version>
            <scope>providedscope>
        dependency>
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <version>${lombok.version}version>
            <scope>providedscope>
        dependency>
 
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-webmvcartifactId>
            <version>${spring.version}version>
        dependency>
 
        
        <dependency>
            <groupId>javax.servlet.jspgroupId>
            <artifactId>javax.servlet.jsp-apiartifactId>
            <version>2.3.3version>
        dependency>
        <dependency>
            <groupId>jstlgroupId>
            <artifactId>jstlartifactId>
            <version>1.2version>
        dependency>
        <dependency>
            <groupId>taglibsgroupId>
            <artifactId>standardartifactId>
            <version>1.1.2version>
        dependency>
 
        <dependency>
            <groupId>commons-fileuploadgroupId>
            <artifactId>commons-fileuploadartifactId>
            <version>1.3.3version>
        dependency>
 
        
        <dependency>
            <groupId>org.hibernategroupId>
            <artifactId>hibernate-validatorartifactId>
            <version>6.0.7.Finalversion>
        dependency>
 
        
        <dependency>
            <groupId>com.fasterxml.jackson.coregroupId>
            <artifactId>jackson-databindartifactId>
            <version>2.9.3version>
        dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.coregroupId>
            <artifactId>jackson-coreartifactId>
            <version>2.9.3version>
        dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.coregroupId>
            <artifactId>jackson-annotationsartifactId>
            <version>2.9.3version>
        dependency>
 
 
 
    dependencies>
 
 
    <build>
        <finalName>ssm2finalName>
 
        <resources>
            
            <resource>
                <directory>src/main/javadirectory>
                <includes>
                    <include>**/*.xmlinclude>
                includes>
            resource>
            
            <resource>
                <directory>src/main/resourcesdirectory>
                <includes>
                    <include>jdbc.propertiesinclude>
                    <include>*.xmlinclude>
                includes>
            resource>
        resources>
 
 
 
        <pluginManagement>
            <plugins>
 
                <plugin>
                    <groupId>org.apache.maven.pluginsgroupId>
                    <artifactId>maven-compiler-pluginartifactId>
                    <version>${maven.compiler.plugin.version}version>
                    <configuration>
                        <source>${maven.compiler.source}source>
                        <target>${maven.compiler.target}target>
                        <encoding>${project.build.sourceEncoding}encoding>
                    configuration>
                plugin>
                <plugin>
                    <groupId>org.mybatis.generatorgroupId>
                    <artifactId>mybatis-generator-maven-pluginartifactId>
                    <version>1.3.2version>
                    <dependencies>
                        
                        <dependency>
                            <groupId>mysqlgroupId>
                            <artifactId>mysql-connector-javaartifactId>
                            <version>${mysql.version}version>
                        dependency>
                    dependencies>
                    <configuration>
                        <overwrite>trueoverwrite>
                    configuration>
                plugin>
 
 
 
                <plugin>
                    <artifactId>maven-clean-pluginartifactId>
                    <version>3.1.0version>
                plugin>
                
                <plugin>
                    <artifactId>maven-resources-pluginartifactId>
                    <version>3.0.2version>
                plugin>
                <plugin>
                    <artifactId>maven-compiler-pluginartifactId>
                    <version>3.8.0version>
                plugin>
                <plugin>
                    <artifactId>maven-surefire-pluginartifactId>
                    <version>2.22.1version>
                plugin>
                <plugin>
                    <artifactId>maven-war-pluginartifactId>
                    <version>3.2.2version>
                plugin>
                <plugin>
                    <artifactId>maven-install-pluginartifactId>
                    <version>2.5.2version>
                plugin>
                <plugin>
                    <artifactId>maven-deploy-pluginartifactId>
                    <version>2.8.2version>
                plugin>
            plugins>
        pluginManagement>
    build>
project>

1.2 添加适配器

支持json数据返回的适配器


<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="mappingJackson2HttpMessageConverter"/>
            list>
        property>
    bean>
    <bean id="mappingJackson2HttpMessageConverter"
          class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
        
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8value>
                <value>text/json;charset=UTF-8value>
                <value>application/json;charset=UTF-8value>
            list>
        property>
    bean>

springmvc-servlet.xml


"1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    
    
    <aop:aspectj-autoproxy/>
    <context:component-scan base-package="com.cdl"/>
 
    
    
    
    <mvc:annotation-driven>mvc:annotation-driven>
 
    
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        
        <property name="viewClass"
                  value="org.springframework.web.servlet.view.JstlView">property>
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp"/>
    bean>
 
    
    
    
    
    <mvc:resources location="/static/" mapping="/static/**"/>
 
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        
        <property name="defaultEncoding" value="UTF-8">property>
        
        <property name="maxUploadSize" value="52428800">property>
        
        <property name="resolveLazily" value="true"/>
    bean>
 
    
        
 
    
    
 
    
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="mappingJackson2HttpMessageConverter"/>
            list>
        property>
    bean>
    <bean id="mappingJackson2HttpMessageConverter"
          class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
        
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8value>
                <value>text/json;charset=UTF-8value>
                <value>application/json;charset=UTF-8value>
            list>
        property>
    bean>
 
 
beans>

1.3 使用注解完成后台代码

①返回JSON字符串


package com.cdl.ssm.controller;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-22 16:42
 */
@Controller
@RequestMapping("/clz/json")
public class JsonController {
 
    @ResponseBody
    @RequestMapping("/clzEdit")
    public String clzEdit(){
        System.out.println("JsonController.clzEdit");
        return "clzEdit";
    }
 
}

结果：

返回一个字符串而不是跳一个页面了

添加一个listMapPager的方法

在clazzMapper.xml中配置该方法


 <select id="listMapPager"  parameterType="com.cdl.ssm.model.Clazz" resultType="java.util.Map">
    select
    <include refid="Base_Column_List" />
    from t_struts_class
    <where>
      <if test="cname != null and cname!= ''">
        and cname like CONCAT('%',#{cname},'%')
      if>
      <if test="cid != null and cid!= ''">
        and cid = #{cid}
      if>
    where>
  select>

ClazzMapper


package com.cdl.ssm.mapper;
 
import com.cdl.ssm.model.Clazz;
import org.springframework.stereotype.Repository;
 
import java.util.List;
import java.util.Map;
 
@Repository
public interface ClazzMapper {
    int deleteByPrimaryKey(Integer cid);
 
    int insert(Clazz record);
 
    int insertSelective(Clazz record);
 
    Clazz selectByPrimaryKey(Integer cid);
 
    List listPager(Clazz clazz);
 
    List listMapPager(Clazz clazz);
 
    int updateByPrimaryKeySelective(Clazz record);
 
    int updateByPrimaryKey(Clazz record);
}

ClazzBiz


package com.cdl.ssm.biz;
 
import com.cdl.ssm.model.Clazz;
import com.cdl.ssm.util.PageBean;
 
import java.util.List;
import java.util.Map;
 
public interface ClazzBiz {
    int deleteByPrimaryKey(Integer cid);
 
    int insert(Clazz record);
 
    int insertSelective(Clazz record);
 
    Clazz selectByPrimaryKey(Integer cid);
 
    List listPager(Clazz clazz, PageBean pageBean);
 
    int updateByPrimaryKeySelective(Clazz record);
 
    int updateByPrimaryKey(Clazz record);
 
 
    List listMapPager(Clazz clazz, PageBean pageBean);
 
 
}

ClazzBizImpl


package com.cdl.ssm.biz.impl;
 
import com.cdl.ssm.biz.ClazzBiz;
import com.cdl.ssm.mapper.ClazzMapper;
import com.cdl.ssm.model.Clazz;
import com.cdl.ssm.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
import java.util.List;
import java.util.Map;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-17 20:22
 */
@Service
public class ClazzBizImpl implements ClazzBiz {
    @Autowired
    private ClazzMapper clazzMapper;
 
    @Override
    public int deleteByPrimaryKey(Integer cid) {
        return clazzMapper.deleteByPrimaryKey(cid);
    }
 
    @Override
    public int insert(Clazz record) {
        return clazzMapper.insert(record);
    }
 
    @Override
    public int insertSelective(Clazz record) {
        return clazzMapper.insertSelective(record);
    }
 
    @Override
    public Clazz selectByPrimaryKey(Integer cid) {
        return clazzMapper.selectByPrimaryKey(cid);
    }
 
    @Override
    public List listPager(Clazz clazz, PageBean pageBean) {
        List clazzes = clazzMapper.listPager(clazz);
       // System.out.println(clazzes);
        return clazzes;
    }
 
    @Override
    public int updateByPrimaryKeySelective(Clazz record) {
        return clazzMapper.updateByPrimaryKeySelective(record);
    }
 
    @Override
    public int updateByPrimaryKey(Clazz record) {
        return clazzMapper.updateByPrimaryKey(record);
    }
 
    @Override
    public List listMapPager(Clazz clazz, PageBean pageBean) {
        return clazzMapper.listMapPager(clazz);
    }
}

JsonController


package com.cdl.ssm.controller;
 
import com.cdl.ssm.biz.ClazzBiz;
import com.cdl.ssm.model.Clazz;
import com.cdl.ssm.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
 
import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-22 16:42
 */
@Controller
@RequestMapping("/clz/json")
public class JsonController {
 
    @Autowired
    private ClazzBiz clazzBiz;
 
    @ResponseBody
    @RequestMapping("/clzEdit")
    public String clzEdit(){
        System.out.println("JsonController.clzEdit");
        return "clzEdit";
    }
 
    //返回list
    @ResponseBody
    @RequestMapping("/list")
    public List list(HttpServletRequest request,Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        return this.clazzBiz.listPager(clazz,pageBean);
    }
 
    //返回list
    @ResponseBody
    @RequestMapping("/listMap")
    public List listMap(HttpServletRequest request, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        return this.clazzBiz.listMapPager(clazz,pageBean);
    }
 
    //返回单个Map集合
    @ResponseBody
    @RequestMapping("/map")
    public Map map(HttpServletRequest req, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        return this.clazzBiz.listMapPager(clazz,pageBean).get(0);
    }
 
    //T
    @ResponseBody
    @RequestMapping("/load")
    public Clazz load(HttpServletRequest req, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        return this.clazzBiz.listPager(clazz,pageBean).get(0);
    }
 
    //混合
    @ResponseBody
    @RequestMapping("/hunhe")
    public Map hunhe(HttpServletRequest req, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        List lst = this.clazzBiz.listPager(clazz, pageBean);
        Map map = new HashMap();
        map.put("data",lst);
        map.put("pagebean",pageBean);
         return map;
    }
 
}

index.jsp


<%--
  Created by IntelliJ IDEA.
  User: Lenovo
  Date: 2022/8/19
  Time: 20:33
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>测试json数据返回title>
head>
<body>
<a href="${pageContext.request.contextPath}/clz/json/list">返回list<T>对象a><hr>
<a href="${pageContext.request.contextPath}/clz/json/listMap">返回list<Map>对象a><hr>
<a href="${pageContext.request.contextPath}/clz/json/load?cid=1">返回T对象a><hr>
<a href="${pageContext.request.contextPath}/clz/json/map?cid=1">返回map对象a><hr>
<a href="${pageContext.request.contextPath}/clz/json/hunhe">返回混合对象a><hr>
 
 
body>
html>

②、返回List

③、返回List

④、返回T

⑤、返回Map

⑥、返回混合

二、全局异常处理的三种形式

@ResponseBody+@Controller=@RestController
为什么要用全局异常处理：

在springmvc中，能将所有类型的异常处理从各处理过程解耦出来，既保证了相关处理过程的功能较单一，也实现了异常信息的统一处理和维护

JsonController


package com.cdl.ssm.controller;
 
import com.cdl.ssm.biz.ClazzBiz;
import com.cdl.ssm.model.Clazz;
import com.cdl.ssm.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-22 16:42
 */
@RestController
@RequestMapping("/clz/json")
public class JsonController {
 
    @Autowired
    private ClazzBiz clazzBiz;
 
    @RequestMapping("/clzEdit")
    public String clzEdit(){
        System.out.println("JsonController.clzEdit");
        return "clzEdit";
    }
 
    //返回list
    @RequestMapping("/list")
    public List list(HttpServletRequest request,Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        if (true)
            throw new RuntimeException("查询异常，错误出现在 JsonController.list...");
        return this.clazzBiz.listPager(clazz,pageBean);
    }
 
    //返回list
    @RequestMapping("/listMap")
    public List listMap(HttpServletRequest request, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        return this.clazzBiz.listMapPager(clazz,pageBean);
    }
 
    //返回单个Map集合
    @RequestMapping("/map")
    public Map map(HttpServletRequest req, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        return this.clazzBiz.listMapPager(clazz,pageBean).get(0);
    }
 
    //T
    @RequestMapping("/load")
    public Clazz load(HttpServletRequest req, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        return this.clazzBiz.listPager(clazz,pageBean).get(0);
    }
 
    //混合
    @RequestMapping("/hunhe")
    public Map hunhe(HttpServletRequest req, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        List lst = this.clazzBiz.listPager(clazz, pageBean);
        Map map = new HashMap();
        map.put("data",lst);
        map.put("pagebean",pageBean);
         return map;
    }
 
}

ClazzBizImpl


package com.cdl.ssm.biz.impl;
 
import com.cdl.ssm.biz.ClazzBiz;
import com.cdl.ssm.mapper.ClazzMapper;
import com.cdl.ssm.model.Clazz;
import com.cdl.ssm.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
import java.util.List;
import java.util.Map;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-17 20:22
 */
@Service
public class ClazzBizImpl implements ClazzBiz {
    @Autowired
    private ClazzMapper clazzMapper;
 
    @Override
    public int deleteByPrimaryKey(Integer cid) {
        return clazzMapper.deleteByPrimaryKey(cid);
    }
 
    @Override
    public int insert(Clazz record) {
        return clazzMapper.insert(record);
    }
 
    @Override
    public int insertSelective(Clazz record) {
        return clazzMapper.insertSelective(record);
    }
 
    @Override
    public Clazz selectByPrimaryKey(Integer cid) {
        return clazzMapper.selectByPrimaryKey(cid);
    }
 
    @Override
    public List listPager(Clazz clazz, PageBean pageBean) {
        List clazzes = clazzMapper.listPager(clazz);
       // System.out.println(clazzes);
        return clazzes;
    }
 
    @Override
    public int updateByPrimaryKeySelective(Clazz record) {
        return clazzMapper.updateByPrimaryKeySelective(record);
    }
 
    @Override
    public int updateByPrimaryKey(Clazz record) {
        return clazzMapper.updateByPrimaryKey(record);
    }
 
    @Override
    public List listMapPager(Clazz clazz, PageBean pageBean) {
        if (true)
            throw new RuntimeException("查询异常，错误出现在 ClazzBizImpl.list...");
        return clazzMapper.listMapPager(clazz);
    }
}

这样标记异常很不方便，所以我们要采用springMVC的三种异常处理方式

1、配置springmvc.xml使用SpringMVC提供的简单异常处理器SimpleMappingExceptionResolver；

2、实现Spring的异常处理接口HandlerExceptionResolver自定义自己的异常处理器；

3、使用@ControllerAdvice + @ExceptionHandler

2.1 使用springMVC提供的简单异常处理器

                error

springmvc-servlet.xml


"1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    
    
    <aop:aspectj-autoproxy/>
    <context:component-scan base-package="com.cdl"/>
 
    
    
    
    <mvc:annotation-driven>mvc:annotation-driven>
 
    
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        
        <property name="viewClass"
                  value="org.springframework.web.servlet.view.JstlView">property>
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp"/>
    bean>
 
    
    
    
    
    <mvc:resources location="/static/" mapping="/static/**"/>
 
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        
        <property name="defaultEncoding" value="UTF-8">property>
        
        <property name="maxUploadSize" value="52428800">property>
        
        <property name="resolveLazily" value="true"/>
    bean>
 
    
        
 
    
    
 
    
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="mappingJackson2HttpMessageConverter"/>
            list>
        property>
    bean>
    <bean id="mappingJackson2HttpMessageConverter"
          class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
        
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8value>
                <value>text/json;charset=UTF-8value>
                <value>application/json;charset=UTF-8value>
            list>
        property>
    bean>
 
    
    
    <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
        
        <property name="defaultErrorView" value="error"/>
        
        <property name="exceptionAttribute" value="ex"/>
        
        <property name="exceptionMappings">
            <props>
                <prop key="java.lang.RuntimeException">errorprop>
            props>
            
        property>
    bean>
 
 
beans>

error.jsp


 
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>错误信息页面title>
head>
<body>
${ex}
body>
html>

因为不太灵活，采取第二中方式

2.2 使用接口

把统一异常处理注了，以免产生冲突

GlobalException


package com.cdl.ssm.exception;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-22 20:05
 */
public class GlobalException extends  RuntimeException{
 
    public GlobalException() {
    }
 
    public GlobalException(String message) {
        super(message);
    }
 
    public GlobalException(String message, Throwable cause) {
        super(message, cause);
    }
 
    public GlobalException(Throwable cause) {
        super(cause);
    }
 
    public GlobalException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
    }
}

GlobalHandlerExceptionResovler


package com.cdl.ssm.exception;
 
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-22 20:15
 *
 * 处理全局异常的解析器
 */
@Component
public class GlobalHandlerExceptionResovler implements HandlerExceptionResolver {
 
    /**
     *
     * @param httpServletRequest
     * @param httpServletResponse
     * @param o 目标对象
     * @param e 目标对象执行出现的异常对象
     * @return
     */
    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
 
        ModelAndView mv = new ModelAndView();
        mv.setViewName("error");
        if(e instanceof  GlobalException){
            GlobalException exception =(GlobalException) e;
            mv.addObject("ex",exception.getMessage());
            mv.addObject("msg","全局异常，错误码203");
        } else if(e instanceof  RuntimeException){
            RuntimeException exception =(RuntimeException) e;
            mv.addObject("ex",exception.getMessage());
            mv.addObject("msg","运行异常，错误码503");
        }
        return mv;
    }
}

JsonController


package com.cdl.ssm.controller;
 
import com.cdl.ssm.biz.ClazzBiz;
import com.cdl.ssm.exception.GlobalException;
import com.cdl.ssm.model.Clazz;
import com.cdl.ssm.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-22 16:42
 */
@RestController
@RequestMapping("/clz/json")
public class JsonController {
 
    @Autowired
    private ClazzBiz clazzBiz;
 
    @RequestMapping("/clzEdit")
    public String clzEdit(){
        System.out.println("JsonController.clzEdit");
        return "clzEdit";
    }
 
    //返回list
    @RequestMapping("/list")
    public List list(HttpServletRequest request,Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        if (true)
            throw new RuntimeException("查询异常，错误出现在 JsonController.list...");
        return this.clazzBiz.listPager(clazz,pageBean);
    }
 
    //返回list
    @RequestMapping("/listMap")
    public List listMap(HttpServletRequest request, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        return this.clazzBiz.listMapPager(clazz,pageBean);
    }
 
    //返回单个Map集合
    @RequestMapping("/map")
    public Map map(HttpServletRequest req, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        return this.clazzBiz.listMapPager(clazz,pageBean).get(0);
    }
 
    //T
    @RequestMapping("/load")
    public Clazz load(HttpServletRequest req, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        if(true)
            throw new GlobalException("系统繁忙,请参考E007；");
        return this.clazzBiz.listPager(clazz,pageBean).get(0);
    }
 
    //混合
    @RequestMapping("/hunhe")
    public Map hunhe(HttpServletRequest req, Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        List lst = this.clazzBiz.listPager(clazz, pageBean);
        Map map = new HashMap();
        map.put("data",lst);
        map.put("pagebean",pageBean);
         return map;
    }
 
}

error.jsp


 
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>错误信息页面title>
head>
<body>
${msg}
<hr>
${ex}
body>
html>

点击出现以下两种结果

2.3 使用注解

为了不受使用接口的影响

如图注释

GlobalExceptionResolver


package com.cdl.ssm.exception;
 
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-24 8:55
 */
@ControllerAdvice
public class GlobalExceptionResolver {
 
    @ExceptionHandler
    public ModelAndView handler(Exception e){
        ModelAndView mv = new ModelAndView();
        mv.setViewName("error");
        if(e instanceof  GlobalException){
            GlobalException exception =(GlobalException) e;
            mv.addObject("ex",exception.getMessage());
            mv.addObject("msg","GlobalExceptionResolver全局异常，错误码203");
        } else if(e instanceof  RuntimeException){
            RuntimeException exception =(RuntimeException) e;
            mv.addObject("ex",exception.getMessage());
            mv.addObject("msg","GlobalExceptionResolver运行异常，错误码503");
        }
        return mv;
    }
 
 
 
}

点击出现两种结果

三、json统一处理

GlobalExceptionResolver2


package com.cdl.ssm.exception;
 
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
 
import java.util.HashMap;
import java.util.Map;
 
/**
 * @author cdl
 * @site www.cdl.com
 * @create 2022-08-24 8:55
 *
 * 当出现异常，统一向前端响应错误信息的JSON对象数据
 */
@RestControllerAdvice
public class GlobalExceptionResolver2 {
 
    @ExceptionHandler
    public Map handler(Exception e){
       Map map = new HashMap();
        if(e instanceof  GlobalException){
            GlobalException exception =(GlobalException) e;
            map.put("ex",exception.getMessage());
            map.put("msg","GlobalExceptionResolver2全局异常，错误码203");
        } else if(e instanceof  RuntimeException){
            RuntimeException exception =(RuntimeException) e;
            map.put("ex",exception.getMessage());
            map.put("msg","GlobalExceptionResolver2运行异常，错误码503");
        }
        return map;
    }
 
 
 
}

出现以下两种结果

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原文地址：https://blog.csdn.net/weixin_62735525/article/details/126468559