springMVC之JSON和全局异常处理

分类：菜鸟笔记作者：weixin_62735525

目录

一、json解析

1.1 导入pom依赖

1.2 添加适配器

1.3 使用注解 完成后台代码

①返回JSON字符串

 JsonController 

index.jsp

​编辑

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

  2.1 使用springMVC提供的简单异常处理器

2.2 使用接口

 2.3 使用注解

 三、json统一处理

一、json解析

springMVC框架如何产生JSON格式的数据：

        ①、导入pom依赖 Jackson

        ②、配置springMVC.xml 作用：是做JSON数据转换的

        ③、使用注解@responseBody能够将任何数据转成JSON对象

1.1 导入pom依赖

<dependency>

      <groupId>com.fasterxml.jackson.core</groupId>

      <artifactId>jackson-databind</artifactId>

      <version>2.9.3</version>

    </dependency>

    <dependency>

      <groupId>com.fasterxml.jackson.core</groupId>

      <artifactId>jackson-core</artifactId>

      <version>2.9.3</version>

    </dependency>

    <dependency>

      <groupId>com.fasterxml.jackson.core</groupId>

      <artifactId>jackson-annotations</artifactId>

      <version>2.9.3</version>

    </dependency>

 pom.xml

<?xml version="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>ideamaven</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>ssm2</artifactId>
    <packaging>war</packaging>

    <name>ssm2 Maven Webapp</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <maven.compiler.plugin.version>3.7.0</maven.compiler.plugin.version>

        <!--添加jar包依赖-->
        <!--1.spring 5.0.2.RELEASE相关-->
        <spring.version>5.0.2.RELEASE</spring.version>
        <!--2.mybatis相关-->
        <mybatis.version>3.4.5</mybatis.version>
        <!--mysql-->
        <mysql.version>5.1.44</mysql.version>
        <!--pagehelper分页jar依赖-->
        <pagehelper.version>5.1.2</pagehelper.version>
        <!--mybatis与spring集成jar依赖-->
        <mybatis.spring.version>1.3.1</mybatis.spring.version>
        <!--3.dbcp2连接池相关 druid-->
        <commons.dbcp2.version>2.1.1</commons.dbcp2.version>
        <commons.pool2.version>2.4.3</commons.pool2.version>
        <!--4.log日志相关-->
        <log4j2.version>2.9.1</log4j2.version>
        <!--5.其他-->
        <junit.version>4.12</junit.version>
        <servlet.version>4.0.0</servlet.version>
        <lombok.version>1.18.2</lombok.version>
    </properties>

    <dependencies>
        <!--1.spring相关-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!--2.mybatis相关-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.version}</version>
        </dependency>
        <!--pagehelper分页插件jar包依赖-->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>${pagehelper.version}</version>
        </dependency>
        <!--mybatis与spring集成jar包依赖-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>${mybatis.spring.version}</version>
        </dependency>

        <!--3.dbcp2连接池相关-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>${commons.dbcp2.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
            <version>${commons.pool2.version}</version>
        </dependency>

        <!--4.log日志相关依赖-->
        <!--核心log4j2jar包-->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>${log4j2.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>${log4j2.version}</version>
        </dependency>
        <!--web工程需要包含log4j-web，非web工程不需要-->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-web</artifactId>
            <version>${log4j2.version}</version>
        </dependency>

        <!--5.其他-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>${servlet.version}</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- jsp依赖-->
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>javax.servlet.jsp-api</artifactId>
            <version>2.3.3</version>
        </dependency>
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>

        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.3</version>
        </dependency>

        <!--做服务端参数校验 ISR303-->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>6.0.7.Final</version>
        </dependency>

        <!--用来springMVC支持JSON转换的-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.3</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.3</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.3</version>
        </dependency>



    </dependencies>


    <build>
        <finalName>ssm2</finalName>

        <resources>
            <!--解决mybatis-generator-maven-plugin运行时没有将XxxMapper.xml文件放入target文件夹的问题-->
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
            <!--解决mybatis-generator-maven-plugin运行时没有将jdbc.properites文件放入target文件夹的问题-->
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>jdbc.properties</include>
                    <include>*.xml</include>
                </includes>
            </resource>
        </resources>



        <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
            <plugins>

                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <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.generator</groupId>
                    <artifactId>mybatis-generator-maven-plugin</artifactId>
                    <version>1.3.2</version>
                    <dependencies>
                        <!--使用Mybatis-generator插件不能使用太高版本的mysql驱动 -->
                        <dependency>
                            <groupId>mysql</groupId>
                            <artifactId>mysql-connector-java</artifactId>
                            <version>${mysql.version}</version>
                        </dependency>
                    </dependencies>
                    <configuration>
                        <overwrite>true</overwrite>
                    </configuration>
                </plugin>



                <plugin>
                    <artifactId>maven-clean-plugin</artifactId>
                    <version>3.1.0</version>
                </plugin>
                <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
                <plugin>
                    <artifactId>maven-resources-plugin</artifactId>
                    <version>3.0.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.0</version>
                </plugin>
                <plugin>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <version>2.22.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-war-plugin</artifactId>
                    <version>3.2.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-install-plugin</artifactId>
                    <version>2.5.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-deploy-plugin</artifactId>
                    <version>2.8.2</version>
                </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">
        <!--处理中文乱码以及避免IE执行AJAX时，返回JSON出现下载文件-->
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8</value>
                <value>text/json;charset=UTF-8</value>
                <value>application/json;charset=UTF-8</value>
            </list>
        </property>
    </bean>

springmvc-servlet.xml

<?xml version="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">
    <!-- 通过context:component-scan元素扫描指定包下的控制器-->
    <!--1) 扫描com.cdl.zf及子子孙孙包下的控制器(扫描范围过大，耗时)-->
    <aop:aspectj-autoproxy/>
    <context:component-scan base-package="com.cdl"/>

    <!--2) 此标签默认注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter -->
    <!--两个bean，这两个bean是spring MVC为@Controllers分发请求所必须的。并提供了数据绑定支持，-->
    <!--@NumberFormatannotation支持，@DateTimeFormat支持，@Valid支持，读写XML的支持（JAXB），读写JSON的支持（Jackson）-->
    <mvc:annotation-driven></mvc:annotation-driven>

    <!--3) ViewResolver -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- viewClass需要在pom中引入两个包：standard.jar and jstl.jar -->
        <property name="viewClass"
                  value="org.springframework.web.servlet.view.JstlView"></property>
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--4) 单独处理图片、样式、js等资源 -->
    <!--<mvc:resources location="/css/" mapping="/css/**"/>-->
    <!--<mvc:resources location="/images/" mapping="/images/**"/>-->
    <!--<mvc:resources location="/js/" mapping="/js/**"/>-->
    <mvc:resources location="/static/" mapping="/static/**"/>

    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- 必须和用户JSP 的pageEncoding属性一致，以便正确解析表单的内容 -->
        <property name="defaultEncoding" value="UTF-8"></property>
        <!-- 文件最大大小(字节) 1024*1024*50=50M-->
        <property name="maxUploadSize" value="52428800"></property>
        <!--resolveLazily属性启用是为了推迟文件解析，以便捕获文件大小异常-->
        <property name="resolveLazily" value="true"/>
    </bean>

    <!--配置拦截器-->
        <!--<mvc:interceptors>
            &lt;!&ndash;针对所有的请求进行拦截&ndash;&gt;
            <bean class="com.cdl.ssm.intercept.OneHandlerInterceptor"></bean>
        </mvc:interceptors>-->

    <!--配置拦截器链-->
    <!--<mvc:interceptors>
       <mvc:interceptor>
           <mvc:mapping path="/**"/>
           <bean class="com.cdl.ssm.intercept.OneHandlerInterceptor"></bean>
       </mvc:interceptor>
      &lt;!&ndash;  <mvc:interceptor>
            <mvc:mapping path="/clz/**"/>
            <bean class="com.cdl.ssm.intercept.TwoHandlerInterceptor"></bean>
        </mvc:interceptor>&ndash;&gt;
    </mvc:interceptors>-->

    <!--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">
        <!--处理中文乱码以及避免IE执行AJAX时，返回JSON出现下载文件-->
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8</value>
                <value>text/json;charset=UTF-8</value>
                <value>application/json;charset=UTF-8</value>
            </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<Clazz> listPager(Clazz clazz);

    List<Map> 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<Clazz> listPager(Clazz clazz, PageBean pageBean);

    int updateByPrimaryKeySelective(Clazz record);

    int updateByPrimaryKey(Clazz record);


    List<Map> 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<Clazz> listPager(Clazz clazz, PageBean pageBean) {
        List<Clazz> 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<Map> 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<T>
    @ResponseBody
    @RequestMapping("/list")
    public List<Clazz> list(HttpServletRequest request,Clazz clazz){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        return this.clazzBiz.listPager(clazz,pageBean);
    }

    //返回list<Map>
    @ResponseBody
    @RequestMapping("/listMap")
    public List<Map> 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<Clazz> 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="${pageContext.request.contextPath}/clz/json/list">返回list&lt;T&gt;对象</a><hr>
<a href="${pageContext.request.contextPath}/clz/json/listMap">返回list&lt;Map&gt;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<T>

③、返回List<Map>

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<T>
    @RequestMapping("/list")
    public List<Clazz> 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<Map>
    @RequestMapping("/listMap")
    public List<Map> 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<Clazz> 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<Clazz> listPager(Clazz clazz, PageBean pageBean) {
        List<Clazz> 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<Map> 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

<!-- springmvc提供的简单异常处理器 -->

    <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">

        <!-- 定义默认的异常处理页面 -->

        <property name="defaultErrorView" value="error"/>

        <!-- 定义异常处理页面用来获取异常信息的变量名，也可不定义，默认名为exception -->

        <property name="exceptionAttribute" value="ex"/>

        <!-- 定义需要特殊处理的异常，这是重要点 -->

        <property name="exceptionMappings">

            <props>

                <prop key="java.lang.RuntimeException">error</prop>

            </props>

            <!-- 还可以定义其他的自定义异常 -->

        </property>

    </bean>

springmvc-servlet.xml

<?xml version="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">
    <!-- 通过context:component-scan元素扫描指定包下的控制器-->
    <!--1) 扫描com.cdl.zf及子子孙孙包下的控制器(扫描范围过大，耗时)-->
    <aop:aspectj-autoproxy/>
    <context:component-scan base-package="com.cdl"/>

    <!--2) 此标签默认注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter -->
    <!--两个bean，这两个bean是spring MVC为@Controllers分发请求所必须的。并提供了数据绑定支持，-->
    <!--@NumberFormatannotation支持，@DateTimeFormat支持，@Valid支持，读写XML的支持（JAXB），读写JSON的支持（Jackson）-->
    <mvc:annotation-driven></mvc:annotation-driven>

    <!--3) ViewResolver -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- viewClass需要在pom中引入两个包：standard.jar and jstl.jar -->
        <property name="viewClass"
                  value="org.springframework.web.servlet.view.JstlView"></property>
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--4) 单独处理图片、样式、js等资源 -->
    <!--<mvc:resources location="/css/" mapping="/css/**"/>-->
    <!--<mvc:resources location="/images/" mapping="/images/**"/>-->
    <!--<mvc:resources location="/js/" mapping="/js/**"/>-->
    <mvc:resources location="/static/" mapping="/static/**"/>

    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- 必须和用户JSP 的pageEncoding属性一致，以便正确解析表单的内容 -->
        <property name="defaultEncoding" value="UTF-8"></property>
        <!-- 文件最大大小(字节) 1024*1024*50=50M-->
        <property name="maxUploadSize" value="52428800"></property>
        <!--resolveLazily属性启用是为了推迟文件解析，以便捕获文件大小异常-->
        <property name="resolveLazily" value="true"/>
    </bean>

    <!--配置拦截器-->
        <!--<mvc:interceptors>
            &lt;!&ndash;针对所有的请求进行拦截&ndash;&gt;
            <bean class="com.cdl.ssm.intercept.OneHandlerInterceptor"></bean>
        </mvc:interceptors>-->

    <!--配置拦截器链-->
    <!--<mvc:interceptors>
       <mvc:interceptor>
           <mvc:mapping path="/**"/>
           <bean class="com.cdl.ssm.intercept.OneHandlerInterceptor"></bean>
       </mvc:interceptor>
      &lt;!&ndash;  <mvc:interceptor>
            <mvc:mapping path="/clz/**"/>
            <bean class="com.cdl.ssm.intercept.TwoHandlerInterceptor"></bean>
        </mvc:interceptor>&ndash;&gt;
    </mvc:interceptors>-->

    <!--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">
        <!--处理中文乱码以及避免IE执行AJAX时，返回JSON出现下载文件-->
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8</value>
                <value>text/json;charset=UTF-8</value>
                <value>application/json;charset=UTF-8</value>
            </list>
        </property>
    </bean>

    <!--统一异常处理-->
    <!-- springmvc提供的简单异常处理器 -->
    <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
        <!-- 定义默认的异常处理页面 -->
        <property name="defaultErrorView" value="error"/>
        <!-- 定义异常处理页面用来获取异常信息的变量名，也可不定义，默认名为exception -->
        <property name="exceptionAttribute" value="ex"/>
        <!-- 定义需要特殊处理的异常，这是重要点 -->
        <property name="exceptionMappings">
            <props>
                <prop key="java.lang.RuntimeException">error</prop>
            </props>
            <!-- 还可以定义其他的自定义异常 -->
        </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<T>
    @RequestMapping("/list")
    public List<Clazz> 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<Map>
    @RequestMapping("/listMap")
    public List<Map> 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<Clazz> 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

 

 

版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 dio@foxmail.com 举报，一经查实，本站将立刻删除。

javajavajson前端前端

相关推荐

如何学习编程？新手菜鸟如何学编程？
学习编程是顺着互联网的发展潮流，是一件好事。新手如何学习编程？其实不难，不过在学习编程之前你得先了解你的目的是什么？这个很重要，因为目的决定你的发展方向、决定你的发展速度。
it行业都是什么工作？it行业主要做什么？
IT行业是什么工作做什么？IT行业的工作有：产品策划类、页面设计类、前端与移动、开发与测试、营销推广类、数据运营类、运营维护类、游戏相关类等，根据不同的分类下面有细分了不同的岗位。
女生学Java好就业吗？女生适合学Java编程吗？
女生学Java好就业吗？女生适合学Java编程吗？目前有不少女生学习Java开发，但要结合自身的情况，先了解自己适不适合去学习Java，不要盲目的选择不适合自己的Java培训班进行学习。只要肯下功夫钻研，多看、多想、多练
mysql-connect-confused
Can’t connect to local MySQL server through socket \'/var/lib/mysql/mysql.sock问题 1.进入mysql路径
oracle基本命令
oracle基本命令 一、登录操作 1.管理员登录 # 管理员登录 sqlplus / as sysdba 2.普通用户登录
shell判断服务是否启动
一、背景 因为项目中需要通北京网络，所以需要连vpn，但是服务器有时候会断掉，所以写个shell脚本每五分钟去判断是否连接，于是就有下面的shell脚本。
SQL BETWEEN 操作符
BETWEEN 操作符选取介于两个值之间的数据范围内的值。这些值可以是数值、文本或者日期。
​​windows上传ipa到开发者中心app store的方法
假如你已经使用过苹果开发者中心上架app，你肯定知道在苹果开发者中心的web界面，无法直接提交ipa文件，而是需要使用第三方工具，将ipa文件上传到构建版本，开...
SQL 入门篇之什么是别名？
下面的 SQL 语句指定了两个别名，一个是 name 列的别名，一个是 country 列的别名。**提示：**如果列名称包含空格，要求使用双引号或方括号：
windows上传ipa文件到app store的方法​
在使用H5混合开发的app打包后，需要将ipa文件上传到appstore进行发布，就需要去苹果开发者中心进行发布。​
SQL AND & OR 运算符
+----+--------------+---------------------------+-------+---------+
C++ 数组
数组的声明并不是声明一个个单独的变量，比如 number0、number1、...、number99，而是声明一个数组变量，比如 numbers，然后使用 nu...
最全iOS 应用上架流程提交到AppStore
第一步：到appuploader官网下载辅助工具和iCloud驱动，使用前面创建的AppID登录。
SQL ALTER TABLE 语句
如需删除表中的列，请使用下面的语法（请注意，某些数据库系统不允许这种在数据库表中删除列的方式）：
dism操作巨慢
前不久在制作win11pe，制作了一版，1.26GB，太大了，不满意，想再裁剪下，发现这次dism mount正常，commit或discard巨慢，以前都很快...
三种方法卸载Symantec Endpoint Protection 赛门铁克
赛门铁克各个版本概览：https://knowledge.broadcom.com/external/article?legacyId=tech163829
python3.6、python3.10用什么版本的pip
实测Python 3.6.6用pip 21.3.1，再高就报错了，Python 3.10.7用pip 22.3.1是可以的
博通和诺顿
Broadcom Corporation （博通公司，股票代号AVGO）是全球领先的有线和无线通信半导体公司。其产品实现向家庭、 办公室和移动环境以及在这些环境...
高版本c4d在低版本windows系统上打开后不显示窗格
发现个问题，server2016上安装了c4d这些版本，低版本的正常显示窗格，但红色圈出的高版本c4d打开后不显示窗格，
基础网络windows不要使用TAT、如何卸载TAT
TAT：https://cloud.tencent.com/document/product/1340
pythonJavaScriptjavaHTMLPHPreactjsC#AndroidCSSNode.jssqlrpython-3.xMysqLjQueryc++pandasFlutterangularIOSdjangolinuxswifttypescript路由器JSON路由器设置无线路由器h3c华三华三路由器设置华三路由器电脑软件教程arraysdocker软件图文教程Cvue.jslaravelspring-boot