java必知必会之SecureSocket

SSL，Secure Sockets Layer，安全Socket层
TLS，Transport Layer Security，传输层安全协议

package network.secure;
import java.io.*;
import javax.net.ssl.*;
public class HTTPSClient {
    
  public static void main(String[] args) {
    
    if (args.length == 0) {
      System.out.println("Usage: java HTTPSClient2 host");
      return;
    }       
    
    int port = 443; // default https port
    String host = args[0];
    
    SSLSocketFactory factory 
        = (SSLSocketFactory) SSLSocketFactory.getDefault();
    SSLSocket socket = null;
    try {         
      socket = (SSLSocket) factory.createSocket(host, port);
      // enable all the suites
      String[] supported = socket.getSupportedCipherSuites();
      socket.setEnabledCipherSuites(supported);
      Writer out = new OutputStreamWriter(socket.getOutputStream(), "UTF-8");
      // https requires the full URL in the GET line
      out.write("GET http://" + host + "/ HTTP/1.1
");
      out.write("Host: " + host + "
");
      out.write("
");
      out.flush(); 
      
      // read response
      BufferedReader in = new BufferedReader(
          new InputStreamReader(socket.getInputStream()));
      
      // read the header
      String s;
      while (!(s = in.readLine()).equals("")) {
        System.out.println(s);
      }
      System.out.println();
      
      // read the length
      String contentLength = in.readLine();
      int length = Integer.MAX_VALUE;
      try {
        length = Integer.parseInt(contentLength.trim(), 16);
      } catch (NumberFormatException ex) {
        // This server doesn"t send the content-length
        // in the first line of the response body
      }
      System.out.println(contentLength);
      
      int c;
      int i = 0;
      while ((c = in.read()) != -1 && i++ < length) {
        System.out.write(c);
      }
      
      System.out.println();
    } catch (IOException ex) {
      System.err.println(ex);
    } finally {
        try {
          if (socket != null) socket.close();
        } catch (IOException e) {}
    }
  }
}