MultipartEntity.java

/**
 * Copyright (c) 2012-2013, Michael Yang 杨福海 (www.yangfuhai.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.tsz.afinal.http;

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

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

/**
 * 参考 http://blog.rafaelsanches.com/2011/01/29/upload-using-multipart-post-
 * using-httpclient-in-android/  拿来主义...   :)
 * @author michael yang （www.yangfuhai.com）
 */
class MultipartEntity implements HttpEntity {
	
    private final static char[] MULTIPART_CHARS = "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();

    private String boundary = null;

    ByteArrayOutputStream out = new ByteArrayOutputStream();
    boolean isSetLast = false;
    boolean isSetFirst = false;

    public MultipartEntity() {
        final StringBuffer buf = new StringBuffer();
        final Random rand = new Random();
        for (int i = 0; i < 30; i++) {
            buf.append(MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)]);
        }
        this.boundary = buf.toString();

    }

    public void writeFirstBoundaryIfNeeds(){
        if(!isSetFirst){
            try {
                out.write(("--" + boundary + "\r\n").getBytes());
            } catch (final IOException e) {
                e.printStackTrace();
            }
        }

        isSetFirst = true;
    }

    public void writeLastBoundaryIfNeeds() {
        if(isSetLast){
            return;
        }

        try {
            out.write(("\r\n--" + boundary + "--\r\n").getBytes());
        } catch (final IOException e) {
            e.printStackTrace();
        }

        isSetLast = true;
    }

    public void addPart(final String key, final String value) {
        writeFirstBoundaryIfNeeds();
        try {
            out.write(("Content-Disposition: form-data; name=\"" +key+"\"\r\n\r\n").getBytes());
            out.write(value.getBytes());
            out.write(("\r\n--" + boundary + "\r\n").getBytes());
        } catch (final IOException e) {
            e.printStackTrace();
        }
    }

    public void addPart(final String key, final String fileName, final InputStream fin, final boolean isLast){
        addPart(key, fileName, fin, "application/octet-stream", isLast);
    }

    public void addPart(final String key, final String fileName, final InputStream fin, String type, final boolean isLast){
        writeFirstBoundaryIfNeeds();
        try {
            type = "Content-Type: "+type+"\r\n";
            out.write(("Content-Disposition: form-data; name=\""+ key+"\"; filename=\"" + fileName + "\"\r\n").getBytes());
            out.write(type.getBytes());
            out.write("Content-Transfer-Encoding: binary\r\n\r\n".getBytes());

            final byte[] tmp = new byte[4096];
            int l = 0;
            while ((l = fin.read(tmp)) != -1) {
                out.write(tmp, 0, l);
            }
            if(!isLast)
                out.write(("\r\n--" + boundary + "\r\n").getBytes());
            out.flush();
        } catch (final IOException e) {
            e.printStackTrace();
        } finally {
            try {
                fin.close();
            } catch (final IOException e) {
                e.printStackTrace();
            }
        }
    }

    public void addPart(final String key, final File value, final boolean isLast) {
        try {
            addPart(key, value.getName(), new FileInputStream(value), isLast);
        } catch (final FileNotFoundException e) {
            e.printStackTrace();
        }
    }

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

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

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

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

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

    @Override
    public void writeTo(final OutputStream outstream) throws IOException {
        outstream.write(out.toByteArray());
    }

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

    @Override
    public void consumeContent() throws IOException,
    UnsupportedOperationException {
        if (isStreaming()) {
            throw new UnsupportedOperationException(
            "Streaming entity does not implement #consumeContent()");
        }
    }

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