Spring boot異常統一處理方法：@ControllerAdvice註解的使用、全域性異常捕獲、自定義異常捕獲
摘要：
一、全域性異常
1、首先建立異常處理包和類
2、使用@ControllerAdvice註解，全域性捕獲異常類，只要作用在@RequestMapping上，所有的異常都會被捕獲
package com.example.demo.exception;
import or...
一、全域性異常
1、首先建立異常處理包和類
2、使用@ControllerAdvice註解，全域性捕獲異常類，只要作用在@RequestMapping上，所有的異常都會被捕獲
package com.example.demo.exception;
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;
/**
* 全域性捕獲異常類，只要作用在@RequestMapping上，所有的異常都會被捕獲
*/
@ResponseBody
@ControllerAdvice
public class MyControllerAdvice {
@ExceptionHandler(value = Exception.class)
public Map<String,Object> errorHandle(Exception e){
Map<String,Object> map = new HashMap<String,Object>();
map.put("code",-1);
map.put("msg",e.getMessage());
return map;
}
}
這上面有個需要注意的是要加上 @ResponseBody 註解，如果不加會怎麼樣呢，我們試下，報錯：
javax.servlet.ServletException: Circular view path [hello]: would dispatch back to the current handler URL [/hello] again. Check your ViewResolver setup! (Hint: This may be the result of an unspecified view, due to default view name generation.) at org.springframework.web.servlet.view.InternalResourceView.prepareForRendering(InternalResourceView.java:209) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:147) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:314) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1325) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1069) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1008) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.31.jar:8.5.31] at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.6.RELEASE.jar:5.0.6.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.31.jar:8.5.31] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
因為是個json的格式，所以必須要有@ResponseBody
3、測試：在hello裡面造個異常
package com.example.demo;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController {
@Value("${gwf.name}")
private String msg;
@RequestMapping("/hello")
public String hello() {
int num = 1/0;
return this.msg;
}
}
結果： 
二、自定義異常
1、首先建立自定義異常類：注意需要繼承 extends RuntimeException
package com.example.demo.exception;
public class BusinessException extends RuntimeException{
private String code;
private String msg;
public BusinessException(String code, String msg) {
super();
this.code = code;
this.msg = msg;
}
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
}
這裡介紹下idea自動生成get/set和建構函式的快捷鍵：alt + insert，然後選擇getter和setter，constructor，自動生成get、set方法和建構函式
2、然後就是自定義異常捕獲
package com.example.demo.exception;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import java.util.HashMap;
import java.util.Map;
/**
* 全域性捕獲異常類，只要作用在@RequestMapping上，所有的異常都會被捕獲
*/
@ResponseBody
@ControllerAdvice
public class MyControllerAdvice {
@ExceptionHandler(value = Exception.class)
public Map<String,Object> errorHandle(Exception e){
Map<String,Object> map = new HashMap<String,Object>();
map.put("code",-1);
map.put("msg",e.getMessage());
return map;
}
@ExceptionHandler(value = BusinessException.class)
public Map<String,Object> errorHandle(BusinessException e){
Map<String,Object> map = new HashMap<String,Object>();
map.put("code",e.getCode());
map.put("msg",e.getMsg());
return map;
}
}
3、最後我們測試下：丟擲自定義異常
package com.example.demo;
import com.example.demo.exception.BusinessException;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController {
@Value("${gwf.name}")
private String msg;
@RequestMapping("/hello")
public String hello() {
//int num = 1/0;
throw new BusinessException("100","密碼錯誤");
//return this.msg;
}
}
結果： 