Java Language Networking Socket example - reading a web page using a simple socket
Example
import java.io.*;
import java.net.Socket;
public class Main {
public static void main(String[] args) throws IOException {//We don't handle Exceptions in this example
//Open a socket to stackoverflow.com, port 80
Socket socket = new Socket("stackoverflow.com",80);
//Prepare input, output stream before sending request
OutputStream outStream = socket.getOutputStream();
InputStream inStream = socket.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(inStream));
PrintWriter writer = new PrintWriter(new BufferedOutputStream(outStream));
//Send a basic HTTP header
writer.print("GET / HTTP/1.1\nHost:stackoverflow.com\n\n");
writer.flush();
//Read the response
System.out.println(readFully(reader));
//Close the socket
socket.close();
}
private static String readFully(Reader in) {
StringBuilder sb = new StringBuilder();
int BUFFER_SIZE=1024;
char[] buffer = new char[BUFFER_SIZE]; // or some other size,
int charsRead = 0;
while ( (charsRead = rd.read(buffer, 0, BUFFER_SIZE)) != -1) {
sb.append(buffer, 0, charsRead);
}
}
}
You should get a response that starts with HTTP/1.1 200 OK, which indicates a normal HTTP response, followed by the rest of the HTTP header, followed by the raw web page in HTML form.
Note the readFully() method is important to prevent a premature EOF exception. The last line of the web page may be missing a return, to signal the end of line, then readLine() will complain, so one must read it by hand or use utility methods from Apache commons-io IOUtils
This example is meant as a simple demonstration of connecting to an existing resource using a socket, it's not a practical way of accessing web pages. If you need to access a web page using Java, it's best to use an existing HTTP client library such as Apache's HTTP Client or Google's HTTP Client
