Monday, September 11, 2006

downloading a web page using java code

U can use the following code to call the following methods and classes:



HttpURLConnection conn = getHttpURLConnectionUsingProxy(“http://www.google.com” "", "", "11.11.11.11", "80");

conn.connect();

InputStream xmlStream = null;

xmlStream = conn.getInputStream();



The code follows:



public HttpURLConnection getHttpURLConnectionUsingProxy(String urlstring, String username, String password, String proxyHost, String proxyPort){

String input = username + ":" + password;

String encoding = base64Encode(input);



// Enable the properties used for proxy support

System.getProperties().put("proxySet", "true" );

System.getProperties().put("proxyHost",proxyHost);

System.getProperties().put("proxyPort", proxyPort);



HttpURLConnection connection = null;

try{

URL url = new URL(urlstring);

connection = (HttpURLConnection)url.openConnection();

// Set up the connection so it knows you are sending

// proxy user information

connection.setRequestProperty( "Proxy-Authorization", encoding );

}catch(MalformedURLException murle){

System.out.println("MalformedURLException: " + murle.getMessage());

}catch(IOException ioe){

System.out.println("IOException: " + ioe.getMessage());

}

if (connection==null) System.out.println("Returning null connection");

return connection;



}



public String base64Encode(String s){



ByteArrayOutputStream bOut = new ByteArrayOutputStream();

Base64OutputStream out = new Base64OutputStream(bOut);

try{

out.write(s.getBytes());

out.flush();

}catch (IOException exception){

}

return bOut.toString();

}





A separate class:



public class Base64OutputStream extends FilterOutputStream {

private int col = 0;

private int i = 0;

private int[] inbuf = new int[3];



public Base64OutputStream(OutputStream out){

super(out);

}



public void write(int c) throws IOException{

inbuf[i] = c;

i++;

if (i==3){

super.write(toBase64[(inbuf[0] & 0xFC) >> 2]);

super.write(toBase64[((inbuf[0] & 0x03) << 4) | ((inbuf[1] & 0xF0) >> 4)]);

super.write(toBase64[((inbuf[1] & 0x0F) << 2) | ((inbuf[2] & 0xC0) >> 6)]);

super.write(toBase64[inbuf[2] & 0x3F]);

col += 4;

i = 0;

if (col >= 76){

super.write('\n');

col = 0;

}

}

}



public void flush() throws IOException{

if (i==1){

super.write(toBase64[(inbuf[0] & 0xFC) >> 2]);

super.write(toBase64[(inbuf[0] & 0x03) << 4]);

super.write('=');

super.write('=');

}else if (i==2){

super.write(toBase64[(inbuf[0] & 0xFC) >> 2]);

super.write(toBase64[((inbuf[0] & 0x03) << 4) | ((inbuf[1] & 0xF0) >> 4)]);

super.write(toBase64[(inbuf[1] & 0x0F) << 2]);

super.write('=');

}

}



private char[] toBase64 = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',

'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',

'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',

'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',

'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',

'o', 'p', 'q', 'r', 's', 't', 'u', 'v',

'w', 'x', 'y', 'z', '0', '1', '2', '3',

'4', '5', '6', '7', '8', '9', '+', '/'

};



}

Thanks to chaya Infosys, chennai

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