Android Volley扩展实现支持进度条的文件上传功能

volley是一个轻量级的开源网络通信框架，开源的好处就是可以自由定制自己需要的jar包。volley里网络通信时android2.3以上用的HttpUrlConnection,2.3以下用的HttpClient，我做的改动只考虑了2.3以上，不支持2.3版本以下。HttpUrlConnection默认传输数据是将数据全部写到内存中再发送到服务端，Volley就是采用默认的方式，这样在上传大文件时很容易就out of memory，有一种解决办法是设置每次传输流的大小：

已知文件大小：connection .setFixedLengthStreamingMode（long l）;

不知道文件大小：connection.setChunkedStreamingMode(1024); //建议使用

android的文件上传一般都是模拟表单，也可以直接socket传，我这里是集成了表单上传，下面是关键类：

public class MultipartRequest extends Request<String> {
 private final Listener<String> mListener;
 private Map<String, String> headerMap;
 private Map<String, String> mParams;
 private FormFile[] files;
 private String BOUNDARY = "---------7dc05dba8f3e19";
 
 public MultipartRequest(String url, Listener<String> listener, Map<String, String> params, FormFile[] files) {
 this(Method.POST, url, listener, params, files);
 }
 
 public MultipartRequest(int method, String url, Listener<String> listener, Map<String, String> params, FormFile[] files) {
 super(method, url, listener);
 mListener = listener;
 mParams = params;
 this.files = files;
 }
 
 @Override
 public Map<String, String> getHeaders() throws AuthFailureError {
 headerMap = new HashMap<String, String>();
 headerMap.put("Charset", "UTF-8");
 //Keep-Alive
 headerMap.put("Connection", "Keep-Alive");
 headerMap.put("Content-Type", "multipart/form-data; boundary=" + BOUNDARY);
 return headerMap;
 }
 
 @Override
 public byte[] getBody() throws AuthFailureError {
 //传参数
 StringBuilder sb = new StringBuilder();
 for (Map.Entry<String, String> entry : mParams.entrySet()) {
  // 构建表单字段内容
  sb.append("--");
  sb.append(BOUNDARY);
  sb.append("\r\n");
  sb.append("Content-Disposition: form-data; name=\"" + entry.getKey() + "\"\r\n\r\n");
  sb.append(entry.getValue());
  sb.append("\r\n");
 }
 return sb.toString().getBytes();
 }
 
 @Override
 public void handRequest(OutputStream out) {
 DataOutputStream dos = (DataOutputStream) out;
 try {
  //发送文件数据
  if (files != null) {
  for (FormFile file : files) {
   // 发送文件数据
   StringBuilder split = new StringBuilder();
   split.append("--");
   split.append(BOUNDARY);
   split.append("\r\n");
   split.append("Content-Disposition: form-data;name=\"" + file.getParameterName() + "\";filename=\"" + file.getFilname() + "\"\r\n");
   split.append("Content-Type: " + file.getContentType() + "\r\n\r\n");
   dos.write(split.toString().getBytes());
   if (file.getInStream() != null) {
   byte[] buffer = new byte[1024];
   int len = -1;
   int count = 0;
   while ((len = file.getInStream().read(buffer)) != -1) {
    dos.write(buffer, 0, len);
    count += len;
    if (mListener != null) {
    mListener.onProgressChange(file.getFileSize(), count);
    }
   }
   count = 0;
   file.getInStream().close();
   } else {
   dos.write(file.getData(), 0, file.getData().length);
   }
   dos.write("\r\n".getBytes());
  }
  }
  dos.writeBytes("--" + BOUNDARY + "--\r\n");
  dos.flush();
 } catch (IOException e) {
  mListener.onError(new VolleyError(e.toString()));
  try {
  dos.close();
  } catch (IOException e1) {
  e1.printStackTrace();
  }
 }
 }
 
 @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) {
 mListener.onSuccess(response);
 }
 
 @Override
 public void deliverError(VolleyError error) {
 mListener.onError(error);
 }
}

附上demo连接：Android实现文件上传功能

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持小牛知识库。