Spring Cloud Gateway全局异常处理的方法详解

package com.cxytiandi.gateway.exception;

import java.util.hashmap;

import java.util.map;

import org.springframework.boot.autoconfigure.web.errorproperties;

import org.springframework.boot.autoconfigure.web.resourceproperties;

import org.springframework.boot.autoconfigure.web.reactive.error.defaulterrorwebexceptionhandler;

import org.springframework.boot.web.reactive.error.errorattributes;

import org.springframework.context.applicationcontext;

import org.springframework.http.httpstatus;

import org.springframework.web.reactive.function.server.requestpredicates;

import org.springframework.web.reactive.function.server.routerfunction;

import org.springframework.web.reactive.function.server.routerfunctions;

import org.springframework.web.reactive.function.server.serverrequest;

import org.springframework.web.reactive.function.server.serverresponse;

/**

  * 自定义异常处理

  *

  * <p>异常时用json代替html异常信息<p>

  *

  * @author yinjihuan

  *

  */

public class jsonexceptionhandler extends defaulterrorwebexceptionhandler {

  public jsonexceptionhandler(errorattributes errorattributes, resourceproperties resourceproperties,

  errorproperties errorproperties, applicationcontext applicationcontext) {

  super (errorattributes, resourceproperties, errorproperties, applicationcontext);

  }

  /**

  * 获取异常属性

  */

  @override

  protected map<string, object> geterrorattributes(serverrequest request, boolean includestacktrace) {

  int code = 500 ;

  throwable error = super .geterror(request);

  if (error instanceof org.springframework.cloud.gateway.support.notfoundexception) {

  code = 404 ;

  }

  return response(code, this .buildmessage(request, error));

  }

  /**

  * 指定响应处理方法为json处理的方法

  * @param errorattributes

  */

  @override

  protected routerfunction<serverresponse> getroutingfunction(errorattributes errorattributes) {

  return routerfunctions.route(requestpredicates.all(), this ::rendererrorresponse);

  }

  /**

  * 根据code获取对应的httpstatus

  * @param errorattributes

  */

  @override

  protected httpstatus gethttpstatus(map<string, object> errorattributes) {

  int statuscode = ( int ) errorattributes.get( "code" );

  return httpstatus.valueof(statuscode);

  }

  /**

  * 构建异常信息

  * @param request

  * @param ex

  * @return

  */

  private string buildmessage(serverrequest request, throwable ex) {

  stringbuilder message = new stringbuilder( "failed to handle request [" );

  message.append(request.methodname());

  message.append( " " );

  message.append(request.uri());

  message.append( "]" );

  if (ex != null ) {

  message.append( ": " );

  message.append(ex.getmessage());

  }

  return message.tostring();

  }

  /**

  * 构建返回的json数据格式

  * @param status 状态码

  * @param errormessage 异常信息

  * @return

  */

  public static map<string, object> response( int status, string errormessage) {

  map<string, object> map = new hashmap<>();

  map.put( "code" , status);

  map.put( "message" , errormessage);

  map.put( "data" , null );

  return map;

  }

}

package com.cxytiandi.gateway.exception;

import java.util.collections;

import java.util.list;

import org.springframework.beans.factory.objectprovider;

import org.springframework.boot.autoconfigure.web.resourceproperties;

import org.springframework.boot.autoconfigure.web.serverproperties;

import org.springframework.boot.context.properties.enableconfigurationproperties;

import org.springframework.boot.web.reactive.error.errorattributes;

import org.springframework.boot.web.reactive.error.errorwebexceptionhandler;

import org.springframework.context.applicationcontext;

import org.springframework.context.annotation.bean;

import org.springframework.context.annotation.configuration;

import org.springframework.core.ordered;

import org.springframework.core.annotation.order;

import org.springframework.http.codec.servercodecconfigurer;

import org.springframework.web.reactive.result.view.viewresolver;

/**

  * 覆盖默认的异常处理

  *

  * @author yinjihuan

  *

  */

@configuration

@enableconfigurationproperties ({serverproperties. class , resourceproperties. class })

public class errorhandlerconfiguration {

  private final serverproperties serverproperties;

  private final applicationcontext applicationcontext;

  private final resourceproperties resourceproperties;

  private final list<viewresolver> viewresolvers;

  private final servercodecconfigurer servercodecconfigurer;

  public errorhandlerconfiguration(serverproperties serverproperties,

           resourceproperties resourceproperties,

           objectprovider<list<viewresolver>> viewresolversprovider,

           servercodecconfigurer servercodecconfigurer,

           applicationcontext applicationcontext) {

   this .serverproperties = serverproperties;

   this .applicationcontext = applicationcontext;

   this .resourceproperties = resourceproperties;

   this .viewresolvers = viewresolversprovider.getifavailable(collections::emptylist);

   this .servercodecconfigurer = servercodecconfigurer;

  }

  @bean

  @order (ordered.highest_precedence)

  public errorwebexceptionhandler errorwebexceptionhandler(errorattributes errorattributes) {

   jsonexceptionhandler exceptionhandler = new jsonexceptionhandler(

     errorattributes,

     this .resourceproperties,

     this .serverproperties.geterror(),

     this .applicationcontext);

   exceptionhandler.setviewresolvers( this .viewresolvers);

   exceptionhandler.setmessagewriters( this .servercodecconfigurer.getwriters());

   exceptionhandler.setmessagereaders( this .servercodecconfigurer.getreaders());

   return exceptionhandler;

  }

}

@override

protected routerfunction<serverresponse> getroutingfunction(

  errorattributes errorattributes) {

   return routerfunctions.route(acceptstexthtml(), this ::rendererrorview)

  .androute(requestpredicates.all(), this ::rendererrorresponse);

}

protected routerfunction<serverresponse> getroutingfunction(errorattributes errorattributes) {

  return routerfunctions.route(requestpredicates.all(), this ::rendererrorresponse);

}

protected httpstatus gethttpstatus(map<string, object> errorattributes) {

  int statuscode = ( int ) errorattributes.get( "status" );

  return httpstatus.valueof(statuscode);

}

@override

protected httpstatus gethttpstatus(map<string, object> errorattributes) {

  int statuscode = ( int ) errorattributes.get( "code" );

  return httpstatus.valueof(statuscode);

}