example code for BAEL-3749 (#8679)

* example code for BAEL-3749

* added live test

* added live test

spring-cloud/spring-cloud-zuul/pom.xml

@@ -19,6 +19,7 @@
         <module>spring-zuul-foos-resource</module>
         <module>spring-zuul-ui</module>
         <module>spring-zuul-rate-limiting</module>
+        <module>spring-zuul-post-filter</module>
     </modules>
 
     <dependencyManagement>

spring-cloud/spring-cloud-zuul/spring-zuul-post-filter/.gitignore

@@ -0,0 +1,2 @@
+target/*
+*.iml

spring-cloud/spring-cloud-zuul/spring-zuul-post-filter/pom.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>spring-cloud-zuul</artifactId>
+        <groupId>com.baeldung.spring.cloud</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-zuul-post-filter</artifactId>
+
+    <properties>
+        <spring-cloud.version>Hoxton.SR1</spring-cloud.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
+        </dependency>
+    </dependencies>
+
+
+</project>

spring-cloud/spring-cloud-zuul/spring-zuul-post-filter/src/main/java/com/baeldung/ZuulPostFilterApplication.java

@@ -0,0 +1,14 @@
+package com.baeldung;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
+
+@SpringBootApplication
+@EnableZuulProxy
+public class ZuulPostFilterApplication {
+
+    public static void main(String... args) {
+        SpringApplication.run(ZuulPostFilterApplication.class, args);
+    }
+}

spring-cloud/spring-cloud-zuul/spring-zuul-post-filter/src/main/java/com/baeldung/controllers/GreetingController.java

@@ -0,0 +1,16 @@
+package com.baeldung.controllers;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+@Controller
+@RequestMapping("/greeting")
+public class GreetingController {
+
+    @GetMapping("/simple")
+    public ResponseEntity<String> getSimple() {
+        return ResponseEntity.ok("Hi");
+    }
+}

spring-cloud/spring-cloud-zuul/spring-zuul-post-filter/src/main/java/com/baeldung/filters/ResponseLogFilter.java

@@ -0,0 +1,58 @@
+package com.baeldung.filters;
+
+import com.google.common.io.CharStreams;
+import com.netflix.zuul.ZuulFilter;
+import com.netflix.zuul.context.RequestContext;
+import com.netflix.zuul.exception.ZuulException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.POST_TYPE;
+
+@Component
+public class ResponseLogFilter extends ZuulFilter {
+
+    private Logger logger = LoggerFactory.getLogger(ResponseLogFilter.class);
+    
+    @Override
+    public String filterType() {
+        return POST_TYPE;
+    }
+
+    @Override
+    public int filterOrder() {
+        return 0;
+    }
+
+    @Override
+    public boolean shouldFilter() {
+        return true;
+    }
+
+    @Override
+    public Object run() throws ZuulException {
+
+        RequestContext context = RequestContext.getCurrentContext();
+        try (final InputStream responseDataStream = context.getResponseDataStream()) {
+
+            if(responseDataStream == null) {
+                logger.info("BODY: {}", "");
+                return null;
+            }
+
+            String responseData = CharStreams.toString(new InputStreamReader(responseDataStream, "UTF-8"));
+            logger.info("BODY: {}", responseData);
+
+            context.setResponseBody(responseData);
+        }
+        catch (Throwable e) {
+            e.printStackTrace();
+        }
+
+        return null;
+    }
+}

spring-cloud/spring-cloud-zuul/spring-zuul-post-filter/src/main/resources/application.yml

@@ -0,0 +1,11 @@
+server:
+  port: 8080
+zuul:
+  prefix: /api
+  routes:
+    greeting-service:
+      path: /greeting/**
+      url: forward:/greeting
+    foos-service:
+      path: /foos/**
+      url: http://localhost:8081/spring-zuul-foos-resource/foos

spring-cloud/spring-cloud-zuul/spring-zuul-post-filter/src/test/java/com/baeldung/ZuulPostFilterLiveTest.java

@@ -0,0 +1,30 @@
+package com.baeldung;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment= SpringBootTest.WebEnvironment.DEFINED_PORT)
+public class ZuulPostFilterLiveTest {
+
+    @LocalServerPort
+    private int port;
+    private static final String SIMPLE_GREETING = "/api/greeting/simple";
+    private TestRestTemplate restTemplate = new TestRestTemplate();
+
+    @Test
+    public void whenClientCallApi_thenLogAndReturnResponseBody() {
+        String url = "http://localhost:" + port + SIMPLE_GREETING;
+        ResponseEntity<String> response = restTemplate.getForEntity(url, String.class);
+        assertTrue(response.getStatusCode().is2xxSuccessful());
+        assertEquals(response.getBody(), "Hi");
+    }
+}