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*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。