如何使用 Apache HttpClient 4 获取文件上传的进度条? [英] How to get a progress bar for a file upload with Apache HttpClient 4?

问题描述

我有以下代码用于使用 Apache 的 HTTP 客户端 (org.apache.http.client) 上传文件:

I've got the following code for a file upload with Apache's HTTP-Client (org.apache.http.client):

  public static void main(String[] args) throws Exception
  {
    String fileName = "test.avi";
    File file = new File(fileName);

    String serverResponse = null;
    HttpParams params = new BasicHttpParams();
    params.setParameter(HttpProtocolParams.USE_EXPECT_CONTINUE, true);
    HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
    HttpClient client = new DefaultHttpClient(params);
    HttpPut put = new HttpPut("http://localhost:8080/" + fileName);

    FileEntity fileEntity = new FileEntity(file, "binary/octet-stream");
    put.setEntity(fileEntity);   

    HttpResponse response = client.execute(put);
    HttpEntity entity = response.getEntity();
    if (entity != null)
    {
      serverResponse = EntityUtils.toString(entity);
      System.out.println(serverResponse);
    }
  }

它工作得很好，但现在我想要一个显示文件上传进度的进度条.这怎么可能?我在 File Upload with Java (with progress bar) 但它是为 Apache HTTP Client 3 (org.apache.commons.httpclient) 设计的，并且 RequestEntity 类在 Apache HTTP Client 4 中不存在.;(

It work's quite well but now I want to have a progress bar which shows the progress of the file upload. How can this be made? I found a code snippet at File Upload with Java (with progress bar) but it is designed for Apache HTTP Client 3 (org.apache.commons.httpclient) and the RequestEntity class does not exist in Apache HTTP Client 4. ;(

也许你们中有人有办法?

Maybe someone of you has an approach?

多多问候

本尼

推荐答案

大家好！

我自己解决了这个问题，并做了一个简单的例子.
如果有任何问题，请随时提问.

I solved the problem myself and made ​​a simple example to it.
If there are any questions, feel free to ask.

我们开始！

ApplicationView.java

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
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.HttpPut;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.util.EntityUtils;

public class ApplicationView implements ActionListener
{

  File file = new File("C:/Temp/my-upload.avi");
  JProgressBar progressBar = null;

  public ApplicationView()
  {
    super();
  }

  public void createView()
  {
    JFrame frame = new JFrame("File Upload with progress bar - Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setBounds(0, 0, 300, 200);
    frame.setVisible(true);

    progressBar = new JProgressBar(0, 100);
    progressBar.setBounds(20, 20, 200, 30);
    progressBar.setStringPainted(true);
    progressBar.setVisible(true);

    JButton button = new JButton("upload");
    button.setBounds(progressBar.getX(),
            progressBar.getY() + progressBar.getHeight() + 20,
            100,
            40);
    button.addActionListener(this);

    JPanel panel = (JPanel) frame.getContentPane();
    panel.setLayout(null);
    panel.add(progressBar);
    panel.add(button);
    panel.setVisible(true);
  }

  public void actionPerformed(ActionEvent e)
  {
    try
    {
      sendFile(this.file, this.progressBar);
    }
    catch (Exception ex)
    {
      System.out.println(ex.getLocalizedMessage());
    }
  }

  private void sendFile(File file, JProgressBar progressBar) throws Exception
  {
    String serverResponse = null;
    HttpParams params = new BasicHttpParams();
    params.setParameter(HttpProtocolParams.USE_EXPECT_CONTINUE, true);
    HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
    HttpClient client = new DefaultHttpClient(params);
    HttpPut put = new HttpPut("http://localhost:8080/" + file.getName());

    ProgressBarListener listener = new ProgressBarListener(progressBar);
    FileEntityWithProgressBar fileEntity = new FileEntityWithProgressBar(file, "binary/octet-stream", listener);
    put.setEntity(fileEntity);

    HttpResponse response = client.execute(put);
    HttpEntity entity = response.getEntity();
    if (entity != null)
    {
      serverResponse = EntityUtils.toString(entity);
      System.out.println(serverResponse);
    }
  }
}

FileEntityWithProgressBar.java

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.apache.http.entity.AbstractHttpEntity;

/**
 * File entity which supports a progress bar.<br/>
 * Based on "org.apache.http.entity.FileEntity".
 * @author Benny Neugebauer (www.bennyn.de)
 */
public class FileEntityWithProgressBar extends AbstractHttpEntity implements Cloneable
{

  protected final File file;
  private final ProgressBarListener listener;
  private long transferredBytes;

  public FileEntityWithProgressBar(final File file, final String contentType, ProgressBarListener listener)
  {
    super();
    if (file == null)
    {
      throw new IllegalArgumentException("File may not be null");
    }
    this.file = file;
    this.listener = listener;
    this.transferredBytes = 0;
    setContentType(contentType);
  }

  public boolean isRepeatable()
  {
    return true;
  }

  public long getContentLength()
  {
    return this.file.length();
  }

  public InputStream getContent() throws IOException
  {
    return new FileInputStream(this.file);
  }

  public void writeTo(final OutputStream outstream) throws IOException
  {
    if (outstream == null)
    {
      throw new IllegalArgumentException("Output stream may not be null");
    }
    InputStream instream = new FileInputStream(this.file);
    try
    {
      byte[] tmp = new byte[4096];
      int l;
      while ((l = instream.read(tmp)) != -1)
      {
        outstream.write(tmp, 0, l);
        this.transferredBytes += l;
        this.listener.updateTransferred(this.transferredBytes);
      }
      outstream.flush();
    }
    finally
    {
      instream.close();
    }
  }

  public boolean isStreaming()
  {
    return false;
  }

  @Override
  public Object clone() throws CloneNotSupportedException
  {
    return super.clone();
  }
}

ProgressBarListener.java

import javax.swing.JProgressBar;

public class ProgressBarListener
{

  private int transferedMegaBytes = 0;
  private JProgressBar progressBar = null;

  public ProgressBarListener()
  {
    super();
  }

  public ProgressBarListener(JProgressBar progressBar)
  {
    this();
    this.progressBar = progressBar;
  }

  public void updateTransferred(long transferedBytes)
  {
    transferedMegaBytes = (int) (transferedBytes / 1048576);
    this.progressBar.setValue(transferedMegaBytes);
    this.progressBar.paint(progressBar.getGraphics());
    System.out.println("Transferred: " + transferedMegaBytes + " Megabytes.");
  }
}

快乐编码！

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