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SpringCloud gateway如何修改返回數(shù)據(jù)

更新時間：2021年06月30日 17:14:47 作者：buddie

這篇文章主要介紹了SpringCloud gateway如何修改返回數(shù)據(jù)的操作，具有很好的參考價值，希望對大家有所幫助。如有錯誤或未考慮完全的地方，望不吝賜教

版本說明

開源軟件	版本
springboot	2.1.6.RELEASE
jdk	11.0.3

gradle

主要引入了springboot 2.1,lombok

plugins {
    id 'org.springframework.boot' version '2.1.6.RELEASE'
    id 'java'
    id "io.freefair.lombok" version "3.6.6"
}apply plugin: 'io.spring.dependency-management'group = 'cn.buddie.demo'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '11'repositories {
    mavenCentral()
}ext {
    set('springCloudVersion', "Greenwich.SR2")
}dependencies {
    implementation 'org.springframework.cloud:spring-cloud-starter-gateway'
    compile 'org.projectlombok:lombok:1.18.8'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}dependencyManagement {
    imports {
        mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
    }
}

yaml

定義路由及過濾器 test-route路由，當(dāng)Path為/users時，轉(zhuǎn)到uri中配置的鏈接http://127.0.0.1:8123/users中。使用UnionResult來過濾

spring:
  cloud:
    gateway:
      enabled: true
      routes:
      - id: test-route
        uri: http://127.0.0.1:8123/users
        predicates:
        - Path=/users
        filters:
        - UnionResult

filter

yaml中配置的filter名字，加“GatewayFilterFactory”,就是對應(yīng)的過濾器Java類

package cn.buddie.demo.springcloudgateway.filter;import cn.buddie.demo.springcloudgateway.model.UnionResult;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.rewrite.ModifyResponseBodyGatewayFilterFactory;
import org.springframework.cloud.gateway.filter.factory.rewrite.RewriteFunction;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Mono;/**
 * description
 *
 * @author buddie.wei
 * @date 2019/7/20
 */
@Component
public class UnionResultGatewayFilterFactory extends ModifyResponseBodyGatewayFilterFactory {
    @Override
    public GatewayFilter apply(Config config) {
        return new ModifyResponseGatewayFilter(this.getConfig());
    }
    private Config getConfig() {
        Config cf = new Config();
        // Config.setRewriteFunction(Class<T> inClass, Class<R> outClass, RewriteFunction<T, R> rewriteFunction)
        // inClass 原數(shù)據(jù)類型，可以指定為具體數(shù)據(jù)類型，我這里指定為Object,是為了處理多種數(shù)據(jù)類型。
        //                      當(dāng)然支持多接口返回多數(shù)據(jù)類型的統(tǒng)一修改，yaml中的配置，path,uri需要做相關(guān)調(diào)整
        // outClass 目標(biāo)數(shù)據(jù)類型
        // rewriteFunction 內(nèi)容重寫方法
        cf.setRewriteFunction(Object.class, UnionResult.class, getRewriteFunction());
        return cf;
    }    private RewriteFunction<Object, UnionResult> getRewriteFunction() {
        return (exchange, resp) -> Mono.just(UnionResult.builder().requestId(exchange.getRequest().getHeaders().getFirst("cn-buddie.demo.requestId")).result(resp).build());
    }
}

model

package cn.buddie.demo.springcloudgateway.model;import lombok.Builder;
import lombok.Getter;
import lombok.Setter;/**
 * description
 *
 * @author buddie.wei
 * @date 2019/7/20
 */
@Getter
@Setter
@Builder
public class UnionResult {
    private String requestId;
    private Object result;
}

SpringCloud gateway修改返回的響應(yīng)體

問題描述：

在gateway中修改返回的響應(yīng)體，在全局Filter中添加如下代碼：

import org.springframework.core.Ordered;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;@Component
public class RequestGlobalFilter implements GlobalFilter, Ordered {
 //...
 
 @Override
 public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
  //...
  ResponseDecorator decorator = new ResponseDecorator(exchange.getResponse());
  return chain.filter(exchange.mutate().response(decorator).build());
 } @Override
 public int getOrder() {
  return -1000;
 }
}

通過.response(decorator)設(shè)置一個響應(yīng)裝飾器（自定義），以下是裝飾器具體實現(xiàn)：

import cn.hutool.json.JSONObject;
import org.reactivestreams.Publisher;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.core.io.buffer.DefaultDataBufferFactory;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.http.server.reactive.ServerHttpResponseDecorator;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import java.nio.charset.Charset;/**
 * @author visy.wang
 * @desc 響應(yīng)裝飾器（重構(gòu)響應(yīng)體）
 */
public class ResponseDecorator extends ServerHttpResponseDecorator{
 public ResponseDecorator(ServerHttpResponse delegate){
  super(delegate);
 } @Override
 @SuppressWarnings(value = "unchecked")
 public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {  if(body instanceof Flux) {
   Flux<DataBuffer> fluxBody = (Flux<DataBuffer>) body;   return super.writeWith(fluxBody.buffer().map(dataBuffers -> {
    DataBufferFactory dataBufferFactory = new DefaultDataBufferFactory();
    DataBuffer join = dataBufferFactory.join(dataBuffers);    byte[] content = new byte[join.readableByteCount()];
    join.read(content);
    DataBufferUtils.release(join);// 釋放掉內(nèi)存
    
    String bodyStr = new String(content, Charset.forName("UTF-8"));                //修改響應(yīng)體
    bodyStr = modifyBody(bodyStr);    getDelegate().getHeaders().setContentLength(bodyStr.getBytes().length);
    return bufferFactory().wrap(bodyStr.getBytes());
   }));
  }
  return super.writeWith(body);
 }    //重寫這個函數(shù)即可
 private String modifyBody(String jsonStr){
  JSONObject json = new JSONObject(jsonStr);
        //TODO...修改響應(yīng)體
  return json.toString();
 }
}

以上為個人經(jīng)驗，希望能給大家一個參考，也希望大家多多支持腳本之家。

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