moved spring-rest-compress module to spring-resttemplate-2 module

spring-resttemplate-2/README.md

@@ -8,3 +8,4 @@ This module contains articles about Spring RestTemplate
 - [Proxies With RestTemplate](https://www.baeldung.com/java-resttemplate-proxy)
 - [A Custom Media Type for a Spring REST API](https://www.baeldung.com/spring-rest-custom-media-type)
 - [RestTemplate Post Request with JSON](https://www.baeldung.com/spring-resttemplate-post-json)
+- [How to compress requests using the Spring RestTemplate](https://www.baeldung.com/spring-resttemplate-compressing-requests)

spring-resttemplate-2/pom.xml

@@ -20,7 +20,30 @@
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.springframework.boot</groupId>
+                    <artifactId>spring-boot-starter-tomcat</artifactId>
+                </exclusion>
+            </exclusions>
         </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-jetty</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+            <version>${commons-io.version}</version>
+        </dependency>
+
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>

spring-resttemplate-2/src/main/java/com/baeldung/compress/CompressingClientHttpRequestInterceptor.java

@@ -0,0 +1,38 @@
+package com.baeldung.compress;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpRequest;
+import org.springframework.http.client.ClientHttpRequestExecution;
+import org.springframework.http.client.ClientHttpRequestInterceptor;
+import org.springframework.http.client.ClientHttpResponse;
+
+import java.io.IOException;
+
+public class CompressingClientHttpRequestInterceptor implements ClientHttpRequestInterceptor {
+
+    private static final Logger LOG = LoggerFactory.getLogger(CompressingClientHttpRequestInterceptor.class);
+
+    private static final String GZIP_ENCODING = "gzip";
+
+    /**
+     * Compress a request body using Gzip and add Http headers.
+     *
+     * @param req
+     * @param body
+     * @param exec
+     * @return
+     * @throws IOException
+     */
+    @Override
+    public ClientHttpResponse intercept(HttpRequest req, byte[] body, ClientHttpRequestExecution exec)
+            throws IOException {
+        LOG.info("Compressing request...");
+        HttpHeaders httpHeaders = req.getHeaders();
+        httpHeaders.add(HttpHeaders.CONTENT_ENCODING, GZIP_ENCODING);
+        httpHeaders.add(HttpHeaders.ACCEPT_ENCODING, GZIP_ENCODING);
+        return exec.execute(req, GzipUtils.compress(body));
+    }
+
+}

spring-resttemplate-2/src/main/java/com/baeldung/compress/GzipUtils.java

@@ -0,0 +1,52 @@
+package com.baeldung.compress;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.GZIPOutputStream;
+
+import org.apache.commons.io.IOUtils;
+
+public class GzipUtils {
+
+    /**
+     * Gzip a string.
+     *
+     * @param text
+     * @return
+     * @throws Exception
+     */
+    public static byte[] compress(String text) throws Exception {
+        return GzipUtils.compress(text.getBytes(StandardCharsets.UTF_8));
+    }
+
+    /**
+     * Gzip a byte array.
+     *
+     * @param body
+     * @return
+     * @throws IOException
+     */
+    public static byte[] compress(byte[] body) throws IOException {
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        try (GZIPOutputStream gzipOutputStream = new GZIPOutputStream(baos)) {
+            gzipOutputStream.write(body);
+        }
+        return baos.toByteArray();
+    }
+
+    /**
+     * Decompress a Gzipped byte array to a String.
+     *
+     * @param body
+     * @return
+     * @throws IOException
+     */
+    public static String decompress(byte[] body) throws IOException {
+        try (GZIPInputStream gzipInputStream = new GZIPInputStream(new ByteArrayInputStream(body))) {
+            return IOUtils.toString(gzipInputStream, StandardCharsets.UTF_8);
+        }
+    }
+}

spring-resttemplate-2/src/main/java/com/baeldung/compress/JettyWebServerConfiguration.java

@@ -0,0 +1,38 @@
+package com.baeldung.compress;
+
+import org.eclipse.jetty.server.handler.HandlerCollection;
+import org.eclipse.jetty.server.handler.gzip.GzipHandler;
+import org.springframework.boot.web.embedded.jetty.JettyServletWebServerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * Configure Jetty web server so it handles compressed requests.
+ */
+@Configuration
+public class JettyWebServerConfiguration {
+
+    private static final int MIN_BYTES = 1;
+
+    /**
+     * Customise the Jetty web server to automatically decompress requests.
+     */
+    @Bean
+    public JettyServletWebServerFactory jettyServletWebServerFactory() {
+
+        JettyServletWebServerFactory factory = new JettyServletWebServerFactory();
+        factory.addServerCustomizers(server -> {
+
+            GzipHandler gzipHandler = new GzipHandler();
+            // Enable request decompression
+            gzipHandler.setInflateBufferSize(MIN_BYTES);
+            gzipHandler.setHandler(server.getHandler());
+
+            HandlerCollection handlerCollection = new HandlerCollection(gzipHandler);
+            server.setHandler(handlerCollection);
+        });
+
+        return factory;
+    }
+
+}

spring-resttemplate-2/src/main/java/com/baeldung/compress/Message.java

@@ -0,0 +1,29 @@
+package com.baeldung.compress;
+
+public class Message {
+
+    private String text;
+
+    public Message() {
+    }
+
+    public Message(String text) {
+        this.text = text;
+    }
+
+    public String getText() {
+        return text;
+    }
+
+    public void setText(String text) {
+        this.text = text;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder sb = new StringBuilder("Message {");
+        sb.append("text='").append(text).append('\'');
+        sb.append('}');
+        return sb.toString();
+    }
+}

spring-resttemplate-2/src/main/java/com/baeldung/compress/MessageController.java

@@ -0,0 +1,38 @@
+package com.baeldung.compress;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Map;
+
+@RestController
+public class MessageController {
+
+    protected static final String PROCESSED = "Processed ";
+
+    protected static final String REQUEST_MAPPING = "process";
+
+    private static final Logger LOG = LoggerFactory.getLogger(MessageController.class);
+
+    /**
+     * A simple endpoint that responds with "Processed " + supplied Message content.
+     *
+     * @param headers
+     * @param message
+     * @return
+     */
+    @PostMapping(value = REQUEST_MAPPING)
+    public ResponseEntity<String> processMessage(@RequestHeader Map<String, String> headers,
+            @RequestBody Message message) {
+
+        // Print headers
+        headers.forEach((k, v) -> LOG.info(k + "=" + v));
+
+        return ResponseEntity.ok(PROCESSED + message.getText());
+    }
+}

spring-resttemplate-2/src/main/java/com/baeldung/compress/RestTemplateConfiguration.java

@@ -0,0 +1,21 @@
+package com.baeldung.compress;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.client.RestTemplate;
+
+@Configuration
+public class RestTemplateConfiguration {
+
+    /**
+     * A RestTemplate that compresses requests.
+     *
+     * @return RestTemplate
+     */
+    @Bean
+    public RestTemplate getRestTemplate() {
+        RestTemplate restTemplate = new RestTemplate();
+        restTemplate.getInterceptors().add(new CompressingClientHttpRequestInterceptor());
+        return restTemplate;
+    }
+}

spring-resttemplate-2/src/main/java/com/baeldung/compress/SpringCompressRequestApplication.java

@@ -0,0 +1,15 @@
+package com.baeldung.compress;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+@EnableAutoConfiguration
+public class SpringCompressRequestApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringCompressRequestApplication.class, args);
+    }
+
+}

spring-resttemplate-2/src/test/java/com/baeldung/compress/GzipUtilsUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.compress;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class GzipUtilsUnitTest {
+
+    @Test
+    public void givenCompressedText_whenDecompressed_thenSuccessful() throws Exception {
+        final String expectedText = "Hello Baeldung!";
+        byte[] compressedText = GzipUtils.compress(expectedText);
+        String decompressedText = GzipUtils.decompress(compressedText);
+        assertNotNull(compressedText);
+        assertEquals(expectedText, decompressedText);
+    }
+
+}

spring-resttemplate-2/src/test/java/com/baeldung/compress/MessageControllerUnitTest.java

@@ -0,0 +1,56 @@
+package com.baeldung.compress;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.web.client.RestTemplate;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+public class MessageControllerUnitTest {
+
+	private static final Logger LOG = LoggerFactory.getLogger(MessageControllerUnitTest.class);
+
+	@Autowired
+	private RestTemplate restTemplate;
+
+	@LocalServerPort
+	private int randomServerPort;
+
+	/**
+	 * As a further test you can intercept the request body, using a tool like
+	 * Wireshark, to see the request body is actually gzipped.
+	 *
+	 * @throws Exception
+	 */
+	@Test
+	public void givenRestTemplate_whenPostCompressedRequest_thenRespondsSuccessfully() throws Exception {
+
+		final String text = "Hello Baeldung!";
+		Message message = new Message(text);
+
+		HttpEntity<Message> request = new HttpEntity<>(message);
+		String uri = String.format("http://localhost:%s/%s", randomServerPort, MessageController.REQUEST_MAPPING);
+
+		ResponseEntity<String> responseEntity = restTemplate.postForEntity(uri, request, String.class);
+
+		String response = responseEntity.getBody();
+		LOG.info("Got response [{}]", response);
+
+		assertEquals(HttpStatus.OK, responseEntity.getStatusCode());
+		assertNotNull(response);
+		assertEquals(MessageController.PROCESSED + text, response);
+	}
+
+}