Spring：文件上传 RESTFUL Web 服务

Question

我正在使用 Spring 4.0 为 RESTFUL Web 服务创建 POC。 如果我们只传递字符串或任何其他基本数据类型，它工作正常。

@RequestMapping(value="/upload/file", method=RequestMapping.post)
public String uploadFile(@RequestParam("fileName", required=false) String fileName){
    logger.info("initialization of object");
    //----------------------------------------

     System.out.Println("name of File : " + fileName);  

    //----------------------------------------
}

这很好用。 但是如果我想将字节流或文件对象传递给函数，我该如何编写具有这些参数的函数？以及如何编写具有传递字节流的客户端？

@RequestMapping(value="/upload/file", method=RequestMapping.post)
public String uploadFile(@RequestParam("file", required=false) byte [] fileName){
     //---------------------
     // 
}

我尝试了这段代码，但得到 415 错误。

@RequestMapping(value = "/upload/file", method = RequestMethod.POST, consumes="multipart/form-data")
public @ResponseBody String uploadFileContentFromBytes(@RequestBody MultipartFormDataInput input,  Model model) {
    logger.info("Get Content. "); 
  //------------
   }  

客户端代码 - 使用 apache HttpClient

private static void executeClient() {
    HttpClient client = new DefaultHttpClient();
    HttpPost postReqeust = new HttpPost(SERVER_URI + "/file");

    try{
        // Set Various Attributes
        MultipartEntity multipartEntity = new MultipartEntity();
        multipartEntity.addPart("fileType" , new StringBody("DOCX"));

        FileBody fileBody = new FileBody(new File("D:\\demo.docx"), "application/octect-stream");
        // prepare payload
        multipartEntity.addPart("attachment", fileBody);

        //Set to request body
        postReqeust.setEntity(multipartEntity);

        HttpResponse response = client.execute(postReqeust) ;

        //Verify response if any
        if (response != null)
        {
            System.out.println(response.getStatusLine().getStatusCode());
        }

    }
    catch(Exception ex){
        ex.printStackTrace();
    }

Answer 1

你可以像下面这样创建你的休息服务。

@RequestMapping(value="/upload", method=RequestMethod.POST)
    public @ResponseBody String handleFileUpload( 
            @RequestParam("file") MultipartFile file){
            String name = "test11";
        if (!file.isEmpty()) {
            try {
                byte[] bytes = file.getBytes();
                BufferedOutputStream stream = 
                        new BufferedOutputStream(new FileOutputStream(new File(name + "-uploaded")));
                stream.write(bytes);
                stream.close();
                return "You successfully uploaded " + name + " into " + name + "-uploaded !";
            } catch (Exception e) {
                return "You failed to upload " + name + " => " + e.getMessage();
            }
        } else {
            return "You failed to upload " + name + " because the file was empty.";
        }
    }

对于客户端，请执行以下操作。

import java.io.File;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.ContentBody;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.util.EntityUtils;


public class Test {
  public static void main(String[] args) throws Exception {
    HttpClient httpclient = new DefaultHttpClient();
    httpclient.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);

    HttpPost httppost = new HttpPost("http://localhost:8080/upload");
    File file = new File("C:\\Users\\Kamal\\Desktop\\PDFServlet1.pdf");

    MultipartEntity mpEntity = new MultipartEntity();
    ContentBody cbFile = new FileBody(file, "multipart/form-data");
    mpEntity.addPart("file", cbFile);


    httppost.setEntity(mpEntity);
    System.out.println("executing request " + httppost.getRequestLine());
    HttpResponse response = httpclient.execute(httppost);
    HttpEntity resEntity = response.getEntity();

    System.out.println(response.getStatusLine());
    if (resEntity != null) {
      System.out.println(EntityUtils.toString(resEntity));
    }
    if (resEntity != null) {
      resEntity.consumeContent();
    }

    httpclient.getConnectionManager().shutdown();
  }
}

Answer 2

<bean id="multipartResolver"
	class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
</bean>

需要此代码