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找一找教程网。
