patelmayurm@gmail.com. Added Example for FileUpload using Spring RestTemplate

spring-rest/src/main/java/com/baeldung/web/upload/app/Application.java

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+package com.baeldung.web.upload.app;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+import org.springframework.context.annotation.ComponentScan;
+
+@EnableAutoConfiguration
+@ComponentScan("com.baeldung.web.upload")
+@SpringBootApplication
+public class Application extends SpringBootServletInitializer {
+
+    public static void main(final String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+}

spring-rest/src/main/java/com/baeldung/web/upload/client/MultipartFileUploadClient.java

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+package com.baeldung.web.upload.client;
+
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.core.io.Resource;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class MultipartFileUploadClient {
+
+    public static void main(String[] args) throws IOException {
+        uploadSingleFile();
+        uploadMultipleFile();
+    }
+
+    private static void uploadSingleFile() throws IOException {
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.MULTIPART_FORM_DATA);
+
+        MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
+        body.add("file", getTestFile());
+
+
+        HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(body, headers);
+        String serverUrl = "http://localhost:8082/spring-rest/fileserver/singlefileupload/";
+        RestTemplate restTemplate = new RestTemplate();
+        ResponseEntity<String> response = restTemplate.postForEntity(serverUrl, requestEntity, String.class);
+        System.out.println("Response code: " + response.getStatusCode());
+    }
+
+    private static void uploadMultipleFile() throws IOException {
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.MULTIPART_FORM_DATA);
+
+        MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
+        body.add("files", getTestFile());
+        body.add("files", getTestFile());
+        body.add("files", getTestFile());
+
+        HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(body, headers);
+        String serverUrl = "http://localhost:8082/spring-rest/fileserver/multiplefileupload/";
+        RestTemplate restTemplate = new RestTemplate();
+        ResponseEntity<String> response = restTemplate.postForEntity(serverUrl, requestEntity, String.class);
+        System.out.println("Response code: " + response.getStatusCode());
+    }
+
+    public static Resource getTestFile() throws IOException {
+        Path testFile = Files.createTempFile("test-file", ".txt");
+        System.out.println("Creating and Uploading Test File: " + testFile);
+        Files.write(testFile, "Hello World !!, This is a test file.".getBytes());
+        return new FileSystemResource(testFile.toFile());
+    }
+}

spring-rest/src/main/java/com/baeldung/web/upload/controller/FileServerResource.java

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+package com.baeldung.web.upload.controller;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+
+import java.io.IOException;
+import java.util.List;
+
+@RestController
+@RequestMapping("/fileserver")
+public class FileServerResource {
+
+    @RequestMapping(path = "/singlefileupload/", method = RequestMethod.POST)
+    public ResponseEntity<String> processFile(@RequestParam("file") MultipartFile file) throws IOException {
+
+        byte[] bytes = file.getBytes();
+
+        System.out.println("File Name: " + file.getOriginalFilename());
+        System.out.println("File Content Type: " + file.getContentType());
+        System.out.println("File Content:\n" + new String(bytes));
+
+        return (new ResponseEntity<>("Successful", null, HttpStatus.OK));
+    }
+
+    @RequestMapping(path = "/multiplefileupload/", method = RequestMethod.POST)
+    public ResponseEntity<String> processFile(@RequestParam("files") List<MultipartFile> files) throws IOException {
+
+        for (MultipartFile file : files) {
+            byte[] bytes = file.getBytes();
+
+            System.out.println("File Name: " + file.getOriginalFilename());
+            System.out.println("File Content Type: " + file.getContentType());
+            System.out.println("File Content:\n" + new String(bytes));
+        }
+
+        return (new ResponseEntity<>("Successful", null, HttpStatus.OK));
+    }
+}