Springboot实现自定义错误页面的方法(错误处理机制)

	@Override
	public Map getErrorAttributes(WebRequest webRequest, ErrorAttributeOptions options) {
		Map errorAttributes = getErrorAttributes(webRequest, options.isIncluded(Include.STACK_TRACE));
		if (Boolean.TRUE.equals(this.includeException)) {
			options = options.including(Include.EXCEPTION);
		}
		if (!options.isIncluded(Include.EXCEPTION)) {
			errorAttributes.remove("exception");
		}
		if (!options.isIncluded(Include.STACK_TRACE)) {
			errorAttributes.remove("trace");
		}
		if (!options.isIncluded(Include.MESSAGE) && errorAttributes.get("message") != null) {
			errorAttributes.put("message", "");
		}
		if (!options.isIncluded(Include.BINDING_ERRORS)) {
			errorAttributes.remove("errors");
		}
		return errorAttributes;
	}

	@Override
	@Deprecated
	public Map getErrorAttributes(WebRequest webRequest, boolean includeStackTrace) {
		Map errorAttributes = new LinkedHashMap<>();
		errorAttributes.put("timestamp", new Date());
		addStatus(errorAttributes, webRequest);
		addErrorDetails(errorAttributes, webRequest, includeStackTrace);
		addPath(errorAttributes, webRequest);
		return errorAttributes;
	}

@RequestMapping(produces = MediaType.TEXT_HTML_VALUE)
	public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
		HttpStatus status = getStatus(request);
		Map model = Collections
				.unmodifiableMap(getErrorAttributes(request, getErrorAttributeOptions(request, MediaType.TEXT_HTML)));
		response.setStatus(status.value());
		ModelAndView modelAndView = resolveErrorView(request, response, status, model);
		return (modelAndView != null) ? modelAndView : new ModelAndView("error", model);
	}

	@RequestMapping
	public ResponseEntity> error(HttpServletRequest request) {
		HttpStatus status = getStatus(request);
		if (status == HttpStatus.NO_CONTENT) {
			return new ResponseEntity<>(status);
		}
		Map body = getErrorAttributes(request, getErrorAttributeOptions(request, MediaType.ALL));
		return new ResponseEntity<>(body, status);
	}

	@Override
	public ModelAndView resolveErrorView(HttpServletRequest request, HttpStatus status,
			Map model) {
			
		//获取错误状态码，这里可以看出他将状态码传入了resolve方法
		ModelAndView modelAndView = resolve(String.valueOf(status), model);
		if (modelAndView == null && SERIES_VIEWS.containsKey(status.series())) {
			modelAndView = resolve(SERIES_VIEWS.get(status.series()), model);
		}
		return modelAndView;
	}

	private ModelAndView resolve(String viewName, Map model) {
		//从这里可以得知，当我们报404错误的时候，他会去error文件夹找404的页面，如果500就找500的页面。
		String errorViewName = "error/" + viewName;
		//模板引擎可以解析这个页面地址就用模板引擎解析
		TemplateAvailabilityProvider provider = this.templateAvailabilityProviders
				.getProvider(errorViewName, this.applicationContext);
		//模板引擎可用的情况下返回到errorViewName指定的视图地址
		if (provider != null) {
			return new ModelAndView(errorViewName, model);
		}
		//模板引擎不可用，就在静态资源文件夹下找errorViewName对应的页面 error/404.html
		return resolveResource(errorViewName, model);
	}

	
		org.springframework.boot
		spring-boot-starter-thymeleaf
	
	
		org.springframework.boot
		spring-boot-starter-web
	

	
		org.springframework.boot
		spring-boot-starter-tomcat
		provided
	

package com.gzl.cn;

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(HttpStatus.NOT_FOUND)
public class NotFoundException extends RuntimeException {

  public NotFoundException() {
  }

  public NotFoundException(String message) {
    super(message);
  }

  public NotFoundException(String message, Throwable cause) {
    super(message, cause);
  }
}

package com.gzl.cn.handler;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;

@ControllerAdvice
public class ControllerExceptionHandler {

  private final Logger logger = LoggerFactory.getLogger(this.getClass());


  @ExceptionHandler(Exception.class)
  public ModelAndView exceptionHander(HttpServletRequest request, Exception e) throws Exception {
    logger.error("Requst URL : {}，Exception : {}", request.getRequestURL(),e);
		
		//假如是自定义的异常，就让他进入404，其他的一概都进入error页面
    if (AnnotationUtils.findAnnotation(e.getClass(), ResponseStatus.class) != null) {
      throw e;
    }

    ModelAndView mv = new ModelAndView();
    mv.addObject("url",request.getRequestURL());
    mv.addObject("exception", e);
    mv.setViewName("error/error");
    return mv;
  }
}

package com.gzl.cn.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;

import com.gzl.cn.NotFoundException;

@Controller
public class HelloController {

  //这个请求我们抛出我们定义的错误，然后被拦截到直接跳到404，这个一般当有一些数据查不到的时候手动抛出
  @GetMapping("/test")
  public String test(Model model){
    String a = null;
    if(a == null) {
    	throw new NotFoundException();
    }
    System.out.println(a.toString());
    return "success";
  }
  
  //这个请求由于a为null直接进500页面
  @GetMapping("/test2")
  public String test2(Model model){
    String a = null;
    System.out.println(a.toString());
    return "success";
  }
}

	
404
  
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错误
  
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