使用SpringMVC统一处理异常_如何使用spring mvc做到统一异常处理?-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_60619970/article/details/133245487

使用SpringMVC统一处理异常

文章目录

使用SpringMVC统一处理异常

创建maven工程导入依赖准备工作

导入依赖

 <dependencies>
        <!-- spring-webmvc依赖 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.16.RELEASE</version>
        </dependency>
		 <!-- 使用servlet组件 -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
        </dependency>
        <!-- 返回json格式数据 -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.15.0</version>
        </dependency>
    </dependencies>

创建spring的核心配置文件

<?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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
	  <!--    扫描注解-->
    <context:component-scan base-package="com.liu.controller,com.liu.exception"/>
    <!--    添加处理器映射器-->
    <mvc:annotation-driven/>
    <!--    添加视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
    <!--    静态资源放行-->
    <mvc:default-servlet-handler/>
</beans>

在web.xml中配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <!--    配置前端控制器  就是配置servlet-->
    <servlet>
        <servlet-name>dispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!--        配置servlet的初始化参数-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
<!--    DispatcherServlet 可以配置 / 和  /* 可以拦截所有资源
    1.配置/，不会拦截jsp
    2.配置/*，会拦截所有资源
    如果没有使用jsp使用哪个都可以
-->
    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

在webapp下的WEB-INF创建error文件夹error.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
error....
</body>
</html>

实现统一处理的三种方式：

方式一：使用servlet的知识

在web.xml配置

<error-page>
    <location>/WEB-INF/error/error.jsp</location>
</error-page>

创建ErrorController类

@Controller
@RequestMapping
public class ErrorController {
    @GetMapping("error")
    public String error(){
        int i=1/0;//制造异常
        return "success";
    }
}

在url发起请求localhost:8080/error,则会跳转到error.jsp

方式二：实现HandlerExceptionResolver接口

创建HandlerExceptionResolver的实现类

@Component
public class MyException implements HandlerExceptionResolver {
    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("msg",e.getMessage());
        modelAndView.setViewName("error/error");
        return modelAndView;
    }
}

创建ErrorController类

@Controller
@RequestMapping
public class ErrorController {
    @GetMapping("error")
    public String error(){
        int i=1/0;//制造异常
        return "success";
    }
}

在url发起请求localhost:8080/error,则会跳转到error.jsp

方式三：使用@ExceptionHandler注解实现异常处理

创建枚举类

/*
1.定义一个枚举类，
2.定义一个自定义异常类
3.异常类实体
4.配置全局唯一的异常类
 */
public enum StatusEnum {
    ERROR(3001,"用户不存在");
    private Integer status;
    private String msg;

    StatusEnum(Integer status, String msg) {
        this.status = status;
        this.msg = msg;
    }

    public Integer getStatus() {
        return status;
    }

    public String getMsg() {
        return msg;
    }
}

创建自定义异常类

package com.liu.exception;

import com.liu.enums.StatusEnum;

/**
 * @author: LYJ
 * @className: MyException1
 * @description:
 * @date :2023/9/24 16:37
 * @version: 0.1
 * @since: jdk11
 */
public class MyException1 extends RuntimeException{
    private StatusEnum statusEnum;

    public MyException1(StatusEnum statusEnum) {
        this.statusEnum = statusEnum;
    }

    public StatusEnum getStatusEnum() {
        return statusEnum;
    }
}

创建异常实体类

package com.liu.pojo;

/**
 * @author: LYJ
 * @className: ExceptionResult
 * @description:
 * @date :2023/9/24 16:38
 * @version: 0.1
 * @since: jdk11
 */
public class ExceptionResult {
    private Integer status;
    private String msg;

    public ExceptionResult(Integer status, String msg) {
        this.status = status;
        this.msg = msg;
    }

    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }
}

创建异常处理类统一处理异常

@ControllerAdvice//添加该注解表示：该类是异常处理类
@ResponseBody //返回json数据
public class MyExceptionHandler {
    @ExceptionHandler(MyException1.class)
    public ExceptionResult handler(MyException1 myException1){
        StatusEnum statusEnum = myException1.getStatusEnum();
        ExceptionResult exceptionResult = new ExceptionResult(statusEnum.getStatus(), statusEnum.getMsg());
        return exceptionResult;
    }
}

创建一个controller类抛出异常

@Controller
@RequestMapping
public class ErrorController {
    @GetMapping("getError")
    public String error1(){
        throw new MyException1(StatusEnum.ERROR);
    }
}