Spring Boot全局异常捕捉！

项目中避免不了有异常！

为了用户体验，常常把异常捕获起来，展现一个友好的页面，提醒用户！

在pom.xml中：

<?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">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.accord</groupId>
	<artifactId>SpringBootHelloWorld</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>war</packaging>

	<name>SpringBootHelloWorld</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.10.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-tomcat</artifactId>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>fastjson</artifactId>
			<version>1.2.15</version>
		</dependency>
		
		<!-- 添加MySQL数据库驱动依赖包. -->
		<dependency>
				<groupId>mysql</groupId>
				<artifactId>mysql-connector-java</artifactId>
		</dependency>
		
		<!-- 添加Spring-data-jpa依赖. -->
		<dependency>
		    <groupId>org.springframework.boot</groupId>
		    <artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>
		
	</dependencies>

	<build>
		<plugins>
			
			<!-- 添加springloader plugin -->
			<plugin>
	          		<groupId>org.springframework.boot</groupId>
	          		<artifactId>spring-boot-maven-plugin </artifactId>
	          		<dependencies>  
			           <!--springloaded  hot deploy -->  
			           <dependency>  
			               <groupId>org.springframework</groupId>  
			               <artifactId>springloaded</artifactId>  
			               <version>1.2.4.RELEASE</version>
			           </dependency>  
			        </dependencies>  
			        <executions>  
			           <execution>  
			               <goals>  
			                   <goal>repackage</goal>  
			               </goals>  
			               <configuration>  
			                   <classifier>exec</classifier>  
			               </configuration>  
			           </execution>  
		       		</executions>
			</plugin>
			
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

新建一个类GlobalDefaultExceptionHandler，
在class注解上@ControllerAdvice,
在方法上注解上@ExceptionHandler(value = Exception.class)，具体代码

import javax.servlet.http.HttpServletRequest;

import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;


/**
 * 1、新建一个Class,这里取名为GlobalDefaultExceptionHandler
 * 2、在class上添加注解，@ControllerAdvice;
 * 3、在class中添加一个方法
 * 4、在方法上添加@ExcetionHandler拦截相应的异常信息；
 * 5、如果返回的是View -- 方法的返回值是ModelAndView;
 * 6、如果返回的是String或者是Json数据，那么需要在方法上添加@ResponseBody注解.
 */
@ControllerAdvice
public class GlobalDefaultExceptionHandler {
	
	
	
	@ExceptionHandler(Exception.class)
	@ResponseBody
	public String defaultExceptionHandler(HttpServletRequest req,Exception e){
		//是返回的String.
		
		//ModelAndView -- 介绍 模板引擎...? 
		//ModelAndView mv = new ModelAndView();
		//mv.setViewName(viewName);
		
		return "对不起，服务器繁忙，请稍后再试！";
	}
	
}

不捕获异常的页面如下：

捕获异常的页面如下：

对不起，服务器繁忙，请稍后再试！