Develop Reference

Open Source Java HTTP Codecs

I am writing a web server from the scratch. There I need a Http codec which can decode a string request (buffer) to an Http object and encode http object into Sting (buffer).
I found three Codecs,
Apache Codecs (can't use this because this is tightly coupled with their server coding structure)
Netty Codes (can't use this because this is tightly coupled with their server coding structure)
JDrupes Codecs (Has some concurrency issues)
But non of these can be used for my purpose. Are there any other Codecs I can use?

class SimpleHttpsServer implements Runnable {
Thread process = new Thread(this);
private static int port = 3030;
private String returnMessage;
private ServerSocket ssocket;
/************************************************************************************/
SimpleHttpsServer() {
try {
ssocket = new ServerSocket(port);
System.out.println("port " + port + " Opend");
process.start();
} catch (IOException e) {
System.out.println("port " + port + " not opened due to " + e);
System.exit(1);
}
}
/**********************************************************************************/
public void run() {
if (ssocket == null)
return;
while (true) {
Socket csocket = null;
try {
csocket = ssocket.accept();
System.out.println("New Connection accepted");
} catch (IOException e) {
System.out.println("Accept failed: " + port + ", " + e);
System.exit(1);
}
try {
DataInputStream dataInputStream = new DataInputStream(new BufferedInputStream(csocket.getInputStream()));
PrintStream printStream = new PrintStream(new BufferedOutputStream(csocket.getOutputStream(), 1024),
false);
this.returnMessage = "";
InputStream inputStream = csocket.getInputStream();
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
// code to read and print headers
String headerLine = null;
while ((headerLine = bufferedReader.readLine()).length() != 0) {
System.out.println(headerLine);
}
// code to read the post payload data
StringBuilder payload = new StringBuilder();
while (bufferedReader.ready()) {
payload.append((char) bufferedReader.read());
}
System.out.println("payload.toString().length() " + payload.toString().length());
if (payload.toString().length() != 1 || payload.toString().length() != 0) {
JSONObject jsonObject = null;
try {
jsonObject = new JSONObject(payload.toString());
// Handle here your string data and make responce
// returnMessage this can store your responce message
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String httpResponse = "HTTP/1.1 200 OK\r\n\r\n" + this.returnMessage;
printStream.write(httpResponse.getBytes("UTF-8"));
printStream.flush();
}else {
/*String httpResponse = "HTTP/1.1 200 OK\r\n\r\n";
outStream.write(httpResponse.getBytes("UTF-8"));
outStream.flush();*/
}
printStream.close();
dataInputStream.close();
// csocket.close();
System.out.println("client disconnected");
} catch (IOException e) {
e.printStackTrace();
}
}
}
/************************************************************************************/
public static void main(String[] args) {
new SimpleHttpsServer();
}
}
may be this one is help you

Error writing to server

I am uploading a file from one server to another server using a Java Program 'POST' method. But I am getting below exception.
java.io.IOException: Error writing to server
at sun.net.www.protocol.http.HttpURLConnection.writeRequests(HttpURLConnection.java:582)
at sun.net.www.protocol.http.HttpURLConnection.writeRequests(HttpURLConnection.java:594)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1216)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:379)
at com.test.rest.HttpURLConnectionExample.TransferFile(HttpURLConnectionExample.java:107)
at com.test.rest.HttpURLConnectionExample.main(HttpURLConnectionExample.java:44)
I have other method who will authenticate with server. Which will be be called from below code. When I am getting response from server, I am getting above exception. To Transfer a file to server I have written below method. My sample code is below:
public static void TransferFile(){
String urlStr = "http://192.168.0.8:8600/audiofile?path=1/622080256/virtualhaircut.mp3";
File tempFile = new File("/home/MyPath/Workspace/Sample/virtualhaircut.mp3");
BufferedWriter br=null;
HttpURLConnection conn = null;
URL url;
try {
url = new URL(urlStr);
AuthenticationUser();
conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", new MimetypesFileTypeMap().getContentType(tempFile.getName()));
} catch (MalformedURLException e1) {
System.out.println("Malformed");
e1.printStackTrace();
} catch (ProtocolException e) {
System.out.println("Protocol");
e.printStackTrace();
} catch (IOException e) {
System.out.println("IO");
e.printStackTrace();
}
System.out.println("line 69");
FileInputStream fis;
OutputStream fos;
try {
System.out.println("line 75");
System.out.println("line 77");
fis = new FileInputStream(tempFile);
fos = conn.getOutputStream();
byte[] buf = new byte[1024 * 2];
int len = 0;
System.out.println("line 80");
while ((len = fis.read(buf)) > 0) {
fos.write(buf, 0, len);
System.out.println("line 85");
}
System.out.println("line 87");
buf = null;
fos.flush();
fos.close();
fis.close();
}catch (FileNotFoundException e) {
System.out.println("");
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
if (conn.getResponseCode() == 200) {
System.out.println("here");
}
} catch (IOException e) {
e.printStackTrace();
}
}

It is possible that the error ocurred because the receiving server closed the connection, maybe because your file exceeded the size limit. Have you tested with small files?

Read first text line of an URL

I am trying to read the first line of a URL.
Then i want to use that as a string later in the code.
Anyone can help me?
I already tried it with
public static String main(String[] args) {
try {
URL url = new URL("myurlhere");
// read text returned by server
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
String line;
while ((line = in.readLine()) != null) {
return line;
}
in.close();
}
catch (MalformedURLException e) {
System.out.println("Malformed URL: " + e.getMessage());
}
catch (IOException e) {
System.out.println("I/O Error: " + e.getMessage());
}
return null;
}
I just can't get a string out of it.

You can consider using jsoup for your purpose:
try {
Document doc = Jsoup.connect("http://popofibo.com/pop/swaying-views-of-our-past/").get();
Elements paragraphs = doc.select("p");
for(Element p : paragraphs) {
System.out.println(p.text());
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Output:
It is indeed difficult to argue over the mainstream ideas of evolution of human civilizations...

If you want to read from a file on the internet using a URL you should use URLConnection
here is a simple example:
String string = "";
try {
URLConnection connection = new URL(
"http://myurl.org/mypath/myfile")
.openConnection();
Scanner scanner = new Scanner(connection.getInputStream());
while (scanner.hasNext()) {
string += scanner.next() + " ";
}
scanner.close();
} catch (IOException e) {
e.printStackTrace();
}
// Do something with the string.

application closed on http post process [duplicate]

This question already has answers here:
How can I fix 'android.os.NetworkOnMainThreadException'?
(66 answers)
Closed 9 years ago.
aim trying process http post for user login information by remote server
my code works good on 2.3.3 but on 4.1 and 4.2 the application is force closed
my AndroidManifest.xml file has
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17"
android:maxSdkVersion="17" />
and the code aim using for http post process is
public class postdata {
public static final String Logger = postdata.class.getName();
private static String slurp(InputStream in) throws IOException {
StringBuffer out = new StringBuffer();
byte[] b = new byte[4096];
for (int n; (n = in.read(b)) != -1;) {
out.append(new String(b, 0, n));
}
return out.toString();
}
public static String post_string(String url, String urlParameters) throws IOException {
HttpURLConnection conn = null;
try {
conn = (HttpURLConnection) new URL(url).openConnection();
} catch (MalformedURLException e) {
Log.e(Logger, "MalformedURLException While Creating URL Connection - " + e.getMessage());
throw e;
} catch (IOException e) {
Log.e(Logger, "IOException While Creating URL Connection - " + e.getMessage());
throw e;
}
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", Integer.toString(urlParameters.length()));
OutputStream os = null;
try {
os = conn.getOutputStream();
} catch (IOException e) {
Log.e(Logger, "IOException While Creating URL OutputStream - " + e.getMessage());
throw e;
}
try {
os.write(urlParameters.toString().getBytes());
} catch (IOException e) {
Log.e(Logger, "IOException While writting URL OutputStream - " + e.getMessage());
throw e;
}
InputStream in = null;
try {
in = conn.getInputStream();
} catch (IOException e) {
Log.e(Logger, "IOException While Creating URL InputStream - " + e.getMessage());
throw e;
}
String output = null;
try {
output = slurp(in);
} catch (IOException e) {
Log.e(Logger, "IOException While Reading URL OutputStream - " + e.getMessage());
throw e;
} finally {
try {
os.close();
in.close();
} catch (IOException e) {
Log.e(Logger, "IOException While Closing URL Output and Input Stream - " + e.getMessage());
}
}
conn.disconnect();return output;
}
}
how to make my code work on all android versions without problem ?

You may be trying to perform Network operations on UI thread, please move your Network related operations to a background Thread, preferably an AsyncTask, see this example on how to do it correctly.

Twitter request with java connection fails

I can pull the user's statuses with no problem with cURL, but when I connect with Java, the xml comes out truncated and my parser wants to cry. I'm testing with small users so it's not choke data or anything.
public void getRuserHx(){
System.out.println("Getting user status history...");
String https_url = "https://twitter.com/statuses/user_timeline/" + idS.rootUser + ".xml?count=100&page=[1-32]";
URL url;
try {
url = new URL(https_url);
HttpsURLConnection con = (HttpsURLConnection)url.openConnection();
con.setRequestMethod("GET");
con.setReadTimeout(15*1000);
//dump all the content into an xml file
print_content(con);
}
catch (MalformedURLException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
System.out.println("Finished downloading user status history.");
}
private void print_content(HttpsURLConnection con){
if(con!=null){
try {
BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
File userHx = new File("/" + idS.rootUser + "Hx.xml");
PrintWriter out = new PrintWriter(idS.hoopoeData + userHx);
String input;
while ((input = br.readLine()) != null){
out.println(input);
}
br.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
This request doesn't need auth. Sorry about my ugly code. My professor says input doesn't matter so my I/O is a trainwreck.

You have to flush the output stream when you write the content out. Did you flush or close the output stream?