使用Volley上传文件

使用浏览器上传文件，然后通过Wireshark抓包分析，发现发送的数据大概是这个样子。

MIME Multipart Media Encapsulation, Type: multipart/form-data, Boundary: "----WebKitFormBoundary1UBMMKIkN58civN4"
    [Type: multipart/form-data]
    First boundary: ------WebKitFormBoundary1UBMMKIkN58civN4

    Encapsulated multipart part: 
        Content-Disposition: form-data; name="name"


        Data (16 bytes)
    Boundary: 
------WebKitFormBoundary1UBMMKIkN58civN4

    Encapsulated multipart part:  (image/png)
        Content-Disposition: form-data; name="photo[]"; filename="Screenshot (2).png"

        Content-Type: image/png


        Portable Network Graphics
    Boundary: 
------WebKitFormBoundary1UBMMKIkN58civN4

    Encapsulated multipart part:  (image/png)
    Boundary: 
------WebKitFormBoundary1UBMMKIkN58civN4

    Encapsulated multipart part:  (image/png)
    Boundary: 
------WebKitFormBoundary1UBMMKIkN58civN4

    Encapsulated multipart part:  (image/png)
    Boundary: 
------WebKitFormBoundary1UBMMKIkN58civN4

    Encapsulated multipart part:  (image/png)
    Last boundary: 
------WebKitFormBoundary1UBMMKIkN58civN4--

　首先来自定义一个HttpEntity，

package cc.dewdrop.volleydemo.utils;

import com.android.volley.VolleyLog;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.message.BasicHeader;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.activation.MimetypesFileTypeMap;

/**
 * Created by Tingkuo on 12/1/2015.
 */
public class FileUploadEntity implements HttpEntity {

    private static final String TAG = FileUploadEntity.class.getSimpleName();

    private static final String BOUNDARY = "__FILE_UPLOAD_ENTITY__";

    private ByteArrayOutputStream mOutputStream;

    public FileUploadEntity() {
        mOutputStream = new ByteArrayOutputStream();

        try {
            writeFirstBoundary();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void writeFirstBoundary() throws IOException {
        VolleyLog.e("writeFirstBoundary");
        mOutputStream.write(("--" + BOUNDARY + "
").getBytes());
        mOutputStream.write(("Content-Disposition: form-data; name="" + "name" + ""

").getBytes());
        mOutputStream.write("Content-Transfer-Encoding: binary

".getBytes());
        mOutputStream.flush();
    }


    private void writeLastBoundary() throws IOException {
        VolleyLog.e("writeLastBoundary");
        mOutputStream.write(("
--" + BOUNDARY + "--
").getBytes());
    }

    public void addFile(final String key, final File file) {
        VolleyLog.e("addFile");
        InputStream inputStream = null;

        try {
            mOutputStream.write(("
--" + BOUNDARY + "
").getBytes());

            StringBuilder stringBuilderContentDisposition = new StringBuilder();
            stringBuilderContentDisposition.append("Content-Disposition: ");
            stringBuilderContentDisposition.append("form-data; ");
            stringBuilderContentDisposition.append("name="" + key + ""; ");
            stringBuilderContentDisposition.append("filename="" + file.getName() + ""
");
            mOutputStream.write(stringBuilderContentDisposition.toString().getBytes());

            StringBuilder stringBuilderContentType = new StringBuilder();
            stringBuilderContentType.append("Content-Type: ");
            stringBuilderContentType.append(new MimetypesFileTypeMap().getContentType(file).toString());
            stringBuilderContentType.append("

");
            mOutputStream.write(stringBuilderContentType.toString().getBytes());

            inputStream = new FileInputStream(file);
            final byte[] buffer = new byte[1024];
            int len = 0;
            while ((len = inputStream.read(buffer)) != -1) {
                VolleyLog.e("len --> %s", String.valueOf(len));
                mOutputStream.write(buffer, 0, len);
            }
            VolleyLog.e("===last====len --> %s", String.valueOf(len));

            mOutputStream.flush();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            closeSilently(inputStream);
        }
    }

    private void closeSilently(Closeable closeable) {
        try {
            if (closeable != null) {
                closeable.close();
            }
        } catch (final IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public boolean isRepeatable() {
        return false;
    }

    @Override
    public boolean isChunked() {
        return false;
    }

    @Override
    public long getContentLength() {
        return mOutputStream.toByteArray().length;
    }

    @Override
    public Header getContentType() {
        return new BasicHeader("Content-Type", "multipart/form-data; boundary=" + BOUNDARY);
    }

    @Override
    public Header getContentEncoding() {
        return null;
    }

    @Override
    public InputStream getContent() throws IOException, UnsupportedOperationException {
        return new ByteArrayInputStream(mOutputStream.toByteArray());
    }

    @Override
    public void writeTo(OutputStream outputStream) throws IOException {
        writeLastBoundary();
        outputStream.write(mOutputStream.toByteArray());
    }

    @Override
    public boolean isStreaming() {
        return false;
    }

    @Override
    public void consumeContent() throws IOException {

    }
}

现在来解释一下，首先这是支持多文件上传的，数据格式一共包括四部分，Content-Type，First boundary，文件二进制数据[]，及Last boundary。可以有多个文件，使用addFile方法插入，文件之间需要有分隔符Boundary。每个文件需要有Content-Disposition及Content-Type

然后再自定义一个Request，根据需要使用不同的构造方法

package cc.dewdrop.volleydemo.utils;

import com.android.volley.AuthFailureError;
import com.android.volley.NetworkResponse;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.Response.Listener;
import com.android.volley.Response.ErrorListener;
import com.android.volley.toolbox.HttpHeaderParser;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Map;

/**
 * Created by Tingkuo on 12/2/2015.
 */
public class FileUploadRequest extends Request<String> {
    private final Listener<String> mListener;

    private FileUploadEntity mFileUploadEntity = new FileUploadEntity();
    private Map<String, String> mHeaders = new HashMap<>();


    public FileUploadRequest(String url, Listener<String> listener) {
        this(url, listener, null);
    }

    public FileUploadRequest(String url, Listener<String> listener, ErrorListener errorListener) {
        this(Method.POST, url, listener, errorListener);
    }

    public FileUploadRequest(int method, String url, Listener<String> listener, ErrorListener errorListener) {
        super(method, url, errorListener);
        this.mListener = listener;
    }

    public FileUploadEntity getFileUploadEntity() {
        return mFileUploadEntity;
    }

    @Override
    public String getBodyContentType() {
        return mFileUploadEntity.getContentType().getValue();
    }

    public void addHeader(String key, String value) {
        mHeaders.put(key, value);
    }

    @Override
    public Map<String, String> getHeaders() throws AuthFailureError {
        return mHeaders;
    }

    @Override
    public byte[] getBody() throws AuthFailureError {
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        try {
            mFileUploadEntity.writeTo(outputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return outputStream.toByteArray();
    }

    @Override
    protected Response<String> parseNetworkResponse(NetworkResponse response) {
        String parsed = "";
        try {
            parsed = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
        } catch (UnsupportedEncodingException e) {
            parsed = new String(response.data);
        }
        return Response.success(parsed, HttpHeaderParser.parseCacheHeaders(response));
    }

    @Override
    protected void deliverResponse(String response) {
        if (mListener != null) {
            mListener.onResponse(response);
        }
    }
}

代码是放在Volley中其他类型Request来写的，没什么好说的。

最后就是如何调用

    private void simpleUploadFile() {
        File file = new File(Environment.getExternalStorageDirectory().getPath() + "/upload.png");

        fileUploadRequest = new FileUploadRequest(
                Request.Method.POST,
                urlList.get(2),
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        textViewInfo.setText("Post Succeed:
" + response.replace("<br>", "
"));
                        Log.e(TAG, response);
                        dialog.dismiss();
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        textViewInfo.setText("Post Failed:
" + error.getMessage());
                        Log.e(TAG, error.getMessage());
                        dialog.dismiss();
                    }
                }
        );
        fileUploadRequest.addHeader("User-Agent", "Android 5.1.1");
        FileUploadEntity fileUploadEntity = fileUploadRequest.getFileUploadEntity();
        fileUploadEntity.addFile("file[]", file);
        fileUploadEntity.addFile("file[]", file);
        fileUploadEntity.addFile("file[]", file);
        fileUploadEntity.addFile("file[]", file);
        fileUploadEntity.addFile("file[]", file);
        requestQueue.add(fileUploadRequest);

        dialog.show();
    }

实例化一个新的Request对象，传入Method，Url，然后通过Request对象来获取Entity，通过addFile()方法来传入需要上传的文件，最后加入requestQueue，使用方法与其他类型Request相同。

备注：

需要添加以下依赖：

    compile 'org.apache.httpcomponents:httpcore:4.4.4'
    compile 'org.apache.httpcomponents:httpmime:4.5.1'
    compile files('libs/volley.jar')
    compile files('libs/activation.jar')