使用进度条上传大文件，Android中没有OutOfMemory错误

Question

我在上传大型视频文件时遇到问题（最多150MB）

1.当我使用此代码Link1。我能够使用进度条上传小文件，但由于我的文件很大，所以android给了我 OutOfMemory错误。

2.如果我使用此代码Link2。我能够上传大文件（这确实是一个很好的解决方案），但不知道如何显示progess（如20％完成或80％完成等）.so请指导我。

Answer 1

最后我得到了我想要分享的问题的解决方案......

1.第一个解决方案 Link1 此解决方案适用于图片上传等15MB的小文件。但是，如果文件非常大，我无法摆脱OutOfMemory错误。

2.第二个解决方案（ Link2 ）确实是一个很好的解决方案，为了显示进度条，我使用了自定义的MultipartEntity类。代码在这里：

    import java.io.FilterOutputStream;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.nio.charset.Charset;

    import org.apache.http.entity.mime.HttpMultipartMode;
    import org.apache.http.entity.mime.MultipartEntity;

    public class CustomMultiPartEntity extends MultipartEntity

{

    private final ProgressListener listener;

    public CustomMultiPartEntity(final ProgressListener listener)
    {
        super();
        this.listener = listener;
    }

    public CustomMultiPartEntity(final HttpMultipartMode mode, final ProgressListener listener)
    {
        super(mode);
        this.listener = listener;
    }

    public CustomMultiPartEntity(HttpMultipartMode mode, final String boundary, final Charset charset, final ProgressListener listener)
    {
        super(mode, boundary, charset);
        this.listener = listener;
    }

    @Override
    public void writeTo(final OutputStream outstream) throws IOException
    {
        super.writeTo(new CountingOutputStream(outstream, this.listener));
    }

    public static interface ProgressListener
    {
        void transferred(long num);
    }

    public static class CountingOutputStream extends FilterOutputStream
    {

        private final ProgressListener listener;
        private long transferred;

        public CountingOutputStream(final OutputStream out, final ProgressListener listener)
        {
            super(out);
            this.listener = listener;
            this.transferred = 0;
        }

        public void write(byte[] b, int off, int len) throws IOException
        {
            out.write(b, off, len);
            this.transferred += len;
            this.listener.transferred(this.transferred);
        }

        public void write(int b) throws IOException
        {
            out.write(b);
            this.transferred++;
            this.listener.transferred(this.transferred);
        }
    }
}

我的活动代码是

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

import com.example.fileupload.CustomMultiPartEntity.ProgressListener;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener {
    private ProgressBar pb;
    private final String filename = "/mnt/sdcard/vid.mp4";
    // private final String filename = "/mnt/sdcard/a.3gp";
    private String urlString = "http://10.0.2.2:8080/FileUploadServlet1/UploadServlet";
    private TextView tv;
    long totalSize = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.textView1);
        findViewById(R.id.button1).setOnClickListener(this);
        tv.setText("init");
        pb = (ProgressBar) findViewById(R.id.progressBar1);

    }

    private class Uploadtask extends AsyncTask<Void, Integer, String> {
        @Override
        protected void onPreExecute() {
            pb.setProgress(0);
            tv.setText("shuru");
            super.onPreExecute();
        }

        @Override
        protected void onProgressUpdate(Integer... progress) {
            pb.setProgress(progress[0]);
        }

        @Override
        protected String doInBackground(Void... params) {
            return upload();
        }

        private String upload() {
            String responseString = "no";

            File sourceFile = new File(filename);
            if (!sourceFile.isFile()) {
                return "not a file";
            }
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost(urlString);


            try {
                CustomMultiPartEntity entity=new CustomMultiPartEntity(new ProgressListener() {

                    @Override
                    public void transferred(long num) {
                        publishProgress((int) ((num / (float) totalSize) * 100));                       
                    }
                });

                entity.addPart("type", new StringBody("video"));
                entity.addPart("uploadedfile", new FileBody(sourceFile));
                totalSize = entity.getContentLength();
                httppost.setEntity(entity);
                HttpResponse response = httpclient.execute(httppost);
                HttpEntity r_entity = response.getEntity();
                responseString = EntityUtils.toString(r_entity);

            } catch (ClientProtocolException e) {
                responseString = e.toString();
            } catch (IOException e) {
                responseString = e.toString();
            }

            return responseString;

        }


        @Override
        protected void onPostExecute(String result) {
            tv.setText(result);
            super.onPostExecute(result);
        }

    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        new Uploadtask().execute();
    }

}