Spring Boot异常处理！！！

SpringBoot默认的处理异常的机制：SpringBoot 默认的已经提供了一套处理异常的机制。一旦程序中出现了异常 SpringBoot 会向/error 的 url 发送请求。在 springBoot 中提供了一个叫 BasicErrorController 来处理/error 请求，然后跳转到默认显示异常的页面来展示异常信息

如果我们需要将所有的异常同一跳转到自定义的错误页面，需要再src/main/resources/

templates 目录下创建 error.html 页面。注意：名称必须叫 error

1.controller:

/** Copyright (c) 2020, 2024,  All rights reserved.**/
package com.by.controller;import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;/*** <p>Project: springboot - DomeContorller</p>* <p>Powered by scl On 2024-01-15 10:02:34</p>* <p>描述：<p>** @author 孙臣龙 [1846080280@qq.com]* @version 1.0* @since 17*/
@Controller
public class DomeController {@RequestMapping("show1")public String show1() {System.out.println(6 / 0);return "error";}@RequestMapping("show2")public String show2() {String str=null;str.length();return "error";}
}

2.定义错误页面

error.html:

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body>
<h1>error1</h1>
出错啦！！！！汗流浃背了！！！
<span th:text="${msg}"></span>
</body>
</html>

error.html:

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body>
<h1>error2</h1>
出错啦！！！！汗流浃背了！！！
<span th:text="${msg}"></span>
</body>
</html>

3.定义全局异常处理类：

GlobalException：（普通的处理请求）

/** Copyright (c) 2020, 2024,  All rights reserved.**/
package com.by.exception;import org.springframework.context.annotation.ComponentScan;
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;/*** <p>Project: springboot - GlobalException</p>* <p>Powered by scl On 2024-01-15 10:11:29</p>* <p>描述：<p>** @author 孙臣龙 [1846080280@qq.com]* @version 1.0* @since 17*/
@Component
public class GlobalException implements HandlerExceptionResolver {@Overridepublic ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {ModelAndView modelAndView = new ModelAndView();if (e instanceof NullPointerException){modelAndView.setViewName("error1");} else if (e instanceof ArithmeticException) {modelAndView.setViewName("error2");}modelAndView.addObject("msg",e.toString());return modelAndView;}
}

AjaxGlobalException：（ajax的请求方式，返回的使json数据）

/** Copyright (c) 2020, 2024,  All rights reserved.**/
package com.by.exception;import javafx.beans.property.adapter.ReadOnlyJavaBeanBooleanProperty;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;import java.util.HashMap;
import java.util.Map;/*** <p>Project: springboot - AjaxGlobalException</p>* <p>Powered by scl On 2024-01-15 10:48:17</p>* <p>描述：<p>** @author 孙臣龙 [1846080280@qq.com]* @version 1.0* @since 17*/
//@ControllerAdvice
public class AjaxGlobalException {@ResponseBody@ExceptionHandlerpublic Map errorHandler(Exception e){Map<String , Object> m = new HashMap<>();m.put("status",500);m.put("msg",e.toString());return m;}
}