开场DataInputStream以运行速度非常慢 [英] Opening DataInputStream running very slow
本文介绍了开场DataInputStream以运行速度非常慢的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我文件上载到服务器，并根据处理的文件，我从服务器获取不同的答复。一切工作，然而获得来自服务器的应答很慢。我在调试器中检查和code以下行正在采取6秒运行。
= inStream中DataInputStream所新（connection.getInputStream（））;
我已经测试过相同的文件和code在Web浏览器，它完美的，需要大约1或2秒显示答复。这里是我的全code，我想它的确定，但也许有东西在这里是没有做好。是否有这样做的更好的办法？或者是新的DataInputStream以总是会这么慢？
私人字符串loadImageFromNetwork（字符串MYFILE）{
HttpURLConnection的连接= NULL;
DataOutputStream类outStream = NULL;
DataInputStream以inStream中= NULL;
字符串化妆=;
弦模型=;
串DISP =;
字符串lineEnd =\\ r \\ n;
串twoHyphens = - ;
字符串边界=*****; INT读取动作，方bytesAvailable，缓冲区大小; 字节[]缓冲区; INT MAXBUFFERSIZE = 1 * 1024 * 1024; 字符串urlString =HTTP：//xxxxxxxxxxxxxx/upload.php
sendBroadcast（新意图（Intent.ACTION_MEDIA_MOUNTED，Uri.parse（文件：//+ MYFILE）））; 尝试{ 的FileInputStream的FileInputStream =新的FileInputStream（新文件（MYFILE））; //打开一个URL连接到这个Servlet
网址URL =新的URL（urlString）; //打开HTTP连接的URL
连接=（HttpURLConnection类）url.openConnection（）; //允许输入
connection.setDoInput（真）; //允许输出
connection.setDoOutput（真）; //不要使用缓存副本。
connection.setUseCaches（假）; //使用POST方法。
connection.setRequestMethod（POST）; connection.setRequestProperty（连接，保持活动）; connection.setRequestProperty（内容类型，的multipart / form-data的;边界=+边界）; outStream =新的DataOutputStream类（connection.getOutputStream（））; outStream.writeBytes（twoHyphens +边界+ lineEnd）;
outStream.writeBytes（内容处置：表格数据;名称= \\UploadedFile的\\;文件名= \\+ MYFILE +\\+ lineEnd）;
outStream.writeBytes（lineEnd）; //创建最大大小的缓冲区
参考bytesAvailable = fileInputStream.available（）;
BUFFERSIZE = Math.min（方bytesAvailable，MAXBUFFERSIZE）;
缓冲区=新的字节[缓冲区大小] //读取文件，并将其写入形式... 读取动作= fileInputStream.read（缓冲液，0，缓冲区大小）; 而（读取动作大于0）{
outStream.write（缓冲液，0，缓冲区大小）;
参考bytesAvailable = fileInputStream.available（）;
BUFFERSIZE = Math.min（方bytesAvailable，MAXBUFFERSIZE）;
读取动作= fileInputStream.read（缓冲液，0，缓冲区大小）;
} //发送文件数据后necesssary多部分的表单数据...
outStream.writeBytes（lineEnd）;
outStream.writeBytes（twoHyphens +边界+ twoHyphens + lineEnd）; //关闭流
fileInputStream.close（）;
outStream.flush（）;
outStream.close（）;
}
赶上（MalformedURLException的前）{
ex.printStackTrace（）;
} 赶上（IOException异常IOE）{
ioe.printStackTrace（）;
} // ------------------读取服务器响应
尝试{ inStream中=新DataInputStream所（connection.getInputStream（））; 字符串str; 而（（海峡= inStream.readLine（））！= NULL）
{
DISP = DISP + STR; } inStream.close（）;
}
赶上（IOException异常ioex）{
ioex.printStackTrace（）;
}
返回DISP; }
解决方案
您应该移动code到从服务器读取到一个新的线程的响应。例如：
私有类ReadResponse实现Runnable {
公共无效的run（）{
// ------------------读取服务器响应
尝试{ inStream中=新DataInputStream所（connection.getInputStream（））; 字符串str; 而（（海峡= inStream.readLine（））！= NULL）
{
DISP = DISP + STR; } inStream.close（）;
}
赶上（IOException异常ioex）{
ioex.printStackTrace（）;
}
//返回DISP;
//这里你需要证明你的UI线程显示
}
}
}
和上传文件之前开始读取线程。
I am uploading a file to a server and depending on the processing on the file I get a different reply from the server. Everything is working, however getting the reply from the server is very slow. I checked in the debugger and the following line of code is taking 6 seconds to run.
inStream = new DataInputStream( connection.getInputStream() );
I have tested the same files and code over a web browser and its perfect, taking about 1 or 2 seconds to display the reply. Here is my full code, I think its ok, but maybe there is something here that is not done properly. Is there a better way of doing this? Or is a new DataInputStream always going to be so slow?
private String loadImageFromNetwork(String myfile) {
HttpURLConnection connection = null;
DataOutputStream outStream = null;
DataInputStream inStream = null;
String make = "";
String model = "";
String disp = "";
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1*1024*1024;
String urlString = "http://xxxxxxxxxxxxxx/upload.php";
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + myfile)));
try {
FileInputStream fileInputStream = new FileInputStream(new File(myfile));
// open a URL connection to the Servlet
URL url = new URL(urlString);
// Open a HTTP connection to the URL
connection = (HttpURLConnection) url.openConnection();
// Allow Inputs
connection.setDoInput(true);
// Allow Outputs
connection.setDoOutput(true);
// Don't use a cached copy.
connection.setUseCaches(false);
// Use a post method.
connection.setRequestMethod("POST");
connection.setRequestProperty("Connection", "Keep-Alive");
connection.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);
outStream = new DataOutputStream(connection.getOutputStream());
outStream.writeBytes(twoHyphens + boundary + lineEnd);
outStream.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\"" + myfile +"\"" + lineEnd);
outStream.writeBytes(lineEnd);
// create a buffer of maximum size
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
// read file and write it into form...
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0) {
outStream.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
// send multipart form data necesssary after file data...
outStream.writeBytes(lineEnd);
outStream.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
// close streams
fileInputStream.close();
outStream.flush();
outStream.close();
}
catch (MalformedURLException ex) {
ex.printStackTrace();
}
catch (IOException ioe) {
ioe.printStackTrace();
}
//------------------ read the SERVER RESPONSE
try {
inStream = new DataInputStream( connection.getInputStream() );
String str;
while (( str = inStream.readLine()) != null)
{
disp = disp + str;
}
inStream.close();
}
catch (IOException ioex){
ioex.printStackTrace();
}
return disp;
}
解决方案
You should move the code to read the response from the server to a new thread. Ex:
private class ReadResponse implements Runnable {
public void run() {
//------------------ read the SERVER RESPONSE
try {
inStream = new DataInputStream( connection.getInputStream() );
String str;
while (( str = inStream.readLine()) != null)
{
disp = disp + str;
}
inStream.close();
}
catch (IOException ioex){
ioex.printStackTrace();
}
//return disp;
//here you need to show your display on UI thread
}
}
}
and start the reading thread before uploading the file.
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