Spring boot集中異常處理方法實例
集中異常處理
以下代碼可在github獲?。?a target="_blank" rel="external nofollow" >https://github.com/Syske/learning-dome-code/tree/master/springboot-learning
方式一:ExceptionHandle
定義自己的異常類型,根據不同類型做不同處理,比如我定義的MyException:
public class MyException extends RuntimeException {
public MyException(String msg) {
super(msg);
}
}
然后通過MyExceptionHandle處理該異常,需要注意的是異常不能在filter中拋出,拋出也沒法捕獲
@RestControllerAdvice
public class MyExceptionHandle {
@ExceptionHandler(MyException.class)
public Result exceptionHandle(MyException e) {
return Result.getFailed( "system error:MyException" + e.getMessage());
}
}
在controller、service以及攔截器的預處理方法中都可以完美捕獲,這里特殊說下攔截器:
public class MyInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
//throw new MyException("攔截器錯誤:MyInterceptor");
// 這里的異常會完美捕獲,并返回
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
throw new MyException("攔截器錯誤:MyInterceptor");
/** 能捕獲異常信息并返回給客戶端,但并不會覆蓋已經請求成功的返回結果,但會包含在返回結果中,比如我的返回結果:
{"code":1,"success":true,"msg":"請求成功","result":true}{"code":0,"success":false,"msg":"system error:MyException攔截器錯誤:MyInterceptor","result":null}
*/
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
throw new MyException("攔截器錯誤:MyInterceptor");
// 這里拋出的異常并不能被捕獲,會直接在后臺拋出,相當于回掉函數,請求結果已經返回
}
}
上面的解釋已經夠清楚了,就不做過多說明了。剛剛我們說了,上面的這種方式,對于filter是不起作用的,下面我們說的這種方式,主要就是針對filter來說的
方式二:ExceptionFilter
定義一個controller,請求路徑可以自己指定,比如/error/exthrow:
@Controller
public class ExceptionController {
@RequestMapping("/error/exthrow")
public void rethrow(HttpServletRequest request) throws Exception {
throw ((Exception) request.getAttribute("filter.error"));
}
}
再定義一個異常攔截器,在需要拋出異常的攔截器中直接拋出異常,然后在異常攔截器中try-catch,發(fā)生異常時直接轉發(fā)至前面定義的異常controller,這里需要注意的是,如果你的filter是實現Filter或者繼承OncePerRequestFilter,那你不需要任何處理,直接request.setAttribute("filter.error", e)就可以了。
由于我把自己的filter交給shiro管理,而且是繼承BasicHttpAuthenticationFilter的,不知到什么原因,直接catch到的異常類型是ServletException,為了拿到真正的異常信息,我需要通過getCause()方法獲取filter中拋出的異常。因為controller拋出的異常最后還是會交給我們定義的MyExceptionHandle去處理,如果獲取到的異常不是我們自定義的異?;蛘咚淖宇惖脑?,就會返回500錯誤(在這個示例前,我以為所有的filter都是這樣的,后來實踐后發(fā)現并不是這樣😂)。
@Component
public class ExceptionFilter implements Filter {
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
try {
chain.doFilter(request, response);
} catch (Exception e) {
request.setAttribute("filter.error", e);
//將異常分發(fā)到/error/exthrow控制器
request.getRequestDispatcher("/error/exthrow").forward(request, response);
}
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void destroy() {
}
}
我的filter:
實現Filter接口:
public class MyFilter implements Filter {
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
throw new MyException("MyFilter過濾器拋出異常");
//filterChain.doFilter(servletRequest, servletResponse);
}
}
filter2繼承OncePerRequestFilter:
public class MyFilter2 extends OncePerRequestFilter {
@Override
protected void doFilterInternal(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, FilterChain filterChain) throws ServletException, IOException {
throw new MyException("MyFilter2異常");
}
}
filter配置類:
@Bean
public FilterRegistrationBean myFilterRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new MyFilter());
registration.setName("myFilter");
registration.addUrlPatterns("/*");
//此處盡量小,要比其他Filter靠前
registration.setOrder(1);
return registration;
}
@Bean
public FilterRegistrationBean myFilter2Registration() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new MyFilter2());
registration.setName("myFilter2");
registration.addUrlPatterns("/*");
//此處盡量小,要比其他Filter靠前
registration.setOrder(2);
return registration;
}
/**
* 配置攔截器
* @return
*/
@Bean
public FilterRegistrationBean exceptionFilterRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new ExceptionFilter());
registration.setName("exceptionFilter");
//此處盡量小,要比其他Filter靠前
registration.setOrder(-1);
return registration;
}
方式三:BasicErrorController
其實spring boot原生提供了異常集中處理,我們經常會看到:

但是這種方式不夠友好,而且大部分情況不滿足我們的需求,我們可以通過繼承這個controller,然后重寫error方法或者errorHtml方法,或者兩個都重寫,區(qū)別是errorHtml是處理請求頭為text/html的請求發(fā)生的異常,而error是除了這個之外的其他異常。
下面是我定義的baseController,error部分返回的結果是空,還需要進一步的研究:
@RestController
@RequestMapping(value = "error")
public class MyBaseErrorController extends BasicErrorController {
public MyBaseErrorController(ErrorAttributes errorAttributes) {
super(errorAttributes, new ErrorProperties());
}
@Override
@RequestMapping(produces = {MediaType.ALL_VALUE})
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
return new ResponseEntity<Map<String, Object>>(Result.failedResultMap(000, "未知錯誤"), HttpStatus.OK);
}
@RequestMapping(
produces = {"text/html"}
)
public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
HttpStatus status = this.getStatus(request);
response.setStatus(status.value());
return null;
}
}
最后,對于以上問題我最后的解決方法是繼承ErrorController,然后定義errorHtml和error,更重要的是@RequestMapping注解,然后在方法中response寫入返回值,這種方式不夠優(yōu)雅:
@RestController
@RequestMapping(value = "error")
public class MyBaseErrorController implements ErrorController {
private static final String path_default = "/error";
@Autowired
private ErrorAttributes errorAttributes;
@RequestMapping(produces = {MediaType.ALL_VALUE})
public void error(HttpServletRequest request, HttpServletResponse response) {
setJsonError(response);
}
@RequestMapping(
produces = {"text/html"}
)
public void errorHtml(HttpServletRequest request, HttpServletResponse response) {
setJsonError(response);
}
@Override
public String getErrorPath() {
return path_default;
}
private void setJsonError(HttpServletResponse response) {
PrintWriter writer = null;
try {
response.setStatus(200);
response.setHeader("Content-type", "text/html;charset=UTF-8");
response.setCharacterEncoding("UTF-8");
writer = response.getWriter();
writer.write(JSON.toJSONString(Result.getFailed("未知錯誤", null)));
} catch (IOException e) {
e.printStackTrace();
} finally {
if (writer != null) {
writer.close();
}
}
}
}
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持腳本之家。

