Android中的文件上传下载

Android中的文件上传下载

一、文件上传

1. 使用HttpUrlConnection

//此处省略线程操作和Handler通信
File file = new File(etUpload.getText().toString());
FileInputStream in = new FileInputStream(file);
URL url = new URL(path);
// 开启连接
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
// 设置请求方式
conn.setRequestMethod("POST");
//设置文件大小
conn.setChunkedStreamingMode(0);
// 设置超时
conn.setConnectTimeout(10000);
// 设置发送内容
conn.setDoInput(true);
byte[] buffer = new byte[1024];
int len = 0;
while ((len = in.read(buffer)) != -1) {
    conn.getOutputStream().write(buffer, 0, len);
}
in.close();

2. 使用AsyncHttpClient

//创建client
AsyncHttpClient client = new AsyncHttpClient();
//准备请求
RequestParams params = new RequestParams();
params.put("file", new File(etUpload.getText().toString()));
//发出请求
client.post(path, params, new AsyncHttpResponseHandler(){
    @Override
    public void onSuccess(int statusCode, String content) {
        //获取响应体
        Toast.makeText(MainActivity02.this, "发送成功！", Toast.LENGTH_SHORT).show();
    }
    @Override
    public void onFailure(Throwable error, String content) {
        //获取响应体
        Toast.makeText(MainActivity02.this, "发送失败！", Toast.LENGTH_SHORT).show();
    }
});

二、文件下载

1. 多线程下载过程

1. 获取连接
2. 准备请求信息
3. 获取服务端文件大小
4. 客户端创建同等大小的随机访问文件
5. 创建多线程，分配任务
6. 分段请求资源并写入到随机访问文件中
7. 通知下载完毕并断开连接

2. 多线程下载（HttpUrlConnection）

public void downloadImage(View v) {
    new Thread() {
        public void run() {
            HttpURLConnection conn = null;
            try {
                // 获取连接
                URL url = new URL(path);
                conn = (HttpURLConnection) url.openConnection();
                // 准备请求信息，请求方式，最大延时
                conn.setRequestMethod("GET");
                conn.setReadTimeout(10000);
                // 获取响应信息
                if (conn.getResponseCode() == 200) {

                    // 获取服务端文件大小
                    int length = conn.getContentLength();
                    // 客户端新建同等大小的文件
                    RandomAccessFile raf = new RandomAccessFile(fileName,
                            "rw");
                    raf.setLength(length);
                    raf.close();
                    // 创建多线程，分配任务
                    int threadCount = 3;// 线程数量
                    int blockSize = length / threadCount;// 每个线程负责的任务量
                    for (int i = 0; i < threadCount; i++) {
                        int start = i * blockSize;// 开始读取位置
                        int end = (i + 1) * blockSize - 1;// 结束读取位置
                        if (i == threadCount - 1) {
                            end = length;
                        }
                        // 多线程下载
                        new AsyncDownload(i, start, end).start();
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (conn != null){
                    conn.disconnect();// 断开连接
                }
            }
        }
    }.start();
}

private class AsyncDownload extends Thread {
    int threadIndex;
    int start;
    int end;
    AsyncDownload(int threadIndex, int start, int end) {
        this.threadIndex = threadIndex;
        this.start = start;
        this.end = end;
    }
    @Override
    public void run() {
        HttpURLConnection conn=null;
        try {
            URL url = new URL(path);
            // 获取连接
            conn = (HttpURLConnection) url.openConnection();
            // 准备请求
            conn.setRequestMethod("GET");
            conn.setRequestProperty("range", "bytes=" + start + "-" + end);
            conn.setReadTimeout(10000);
            // 获取响应,请求码表示请求一段信息完毕
            if (conn.getResponseCode() == 206) {
                // 获取对应的字节流并写入文件
                InputStream is = conn.getInputStream();
                RandomAccessFile raf = new RandomAccessFile(fileName, "rw");
                raf.seek(start);
                byte[] buff = new byte[1024];
                int len = 0;
                while ((len = is.read(buff)) != -1) {
                    raf.write(buff, 0, len);
                }
                // 关闭流
                raf.close();
                System.out.println("第" + threadIndex + "个线程下载完毕");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (conn != null) {
                // 关闭连接
                conn.disconnect();
            }
            //使用唯一的对象加同步，保证runningThread数据的正确性
            synchronized (MainActivity.class) {
                runningThread--;
                if (runningThread == 0) {
                    Message msg = new Message();
                    msg.what = DOWNLOAD_FINISH;
                    mHandler.sendMessage(msg);
                }
            }
        }
    }
}

3. 多线程下载（AsyncHttpClient）

使用BinaryHttpResponseHandler

public void downloadImage(View v) {
// 建立一个访问client
AsyncHttpClient client = new AsyncHttpClient();
// 发出请求
client.get(path, new BinaryHttpResponseHandler(){
    @Override
    public void onSuccess(byte[] binaryData) {
            try {
                //获取文件并保存
                FileOutputStream out = new FileOutputStream(new File(fileName));
                out.write(binaryData);
                out.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}