import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.net.*;
import javax.net.ssl.*;
/**
* SSLClientServlet demonstrates how to connect to a secure
* server via SSL using the Java Secure Socket Extension API.
*/
public class SSLClientServlet extends HttpServlet
{
/**
* Present the user with an HTML form that allows them to
* choose a secured resource to access and the method by which
* to access this resource (via Socket or URL object).
*/
public void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException,
IOException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("");
out.println("");
out.println("SSL Client Servlet");
out.println("");
out.println("");
out.println("SSL Client Servlet
");
out.println("");
out.println("");
out.close();
}
/**
* Requests the cotents of a secure Web site and returns the
* information non-secure back to the client.
*/
public void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException,
IOException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String secureURL = request.getParameter("SecureURL");
String socketURL = request.getParameter("SocketURL");
try
{
BufferedReader in = null;
//register JSSE SSL implementation as new security provider
java.security.Security.addProvider(
new com.sun.net.ssl.internal.ssl.Provider());
if (socketURL.equals("Socket"))
{
in = getPageViaSocket(secureURL);
}
else
{
in = getPageViaURL(secureURL);
}
String nextLine; //read input from secure connection
while ((nextLine = in.readLine()) != null)
{
out.println(nextLine); //return each line to client
}
in.close();
out.close();
}
catch (Exception e)
{
out.println("");
out.println("Network Error");
out.println("");
out.println("Connection Error
");
out.println(e.getMessage());
out.println("");
}
}
/**
* Establishes a secure socket connection to a secure resource.
* The /index.html file is then requested and the HTTP headers
* returned from the secure server are discarded before
* returning the input stream to the calling method.
*
* @param secureURL URL of secure resource to retrieve
* @return BufferedReader Input stream to secure resource
*/
private BufferedReader getPageViaSocket(String secureURL)
throws Exception
{
//open Socket to secure resource using SSLSocketFactory
Socket socket = SSLSocketFactory.getDefault().createSocket(
secureURL, 443);
//send HTTP request for /index.html to secure server
PrintWriter out = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream())));
out.println("GET http://" + secureURL +
"/index.html HTTP/1.1");
out.println();
out.flush();
//get input stream to secure resource
BufferedReader in = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
//discard all HTTP headers from input stream
String nextLine;
while ((nextLine = in.readLine()) != null)
{
if (nextLine.trim().equals(""))
{
break; //reached blank line following HTTP headers
}
}
return in; //return input stream to secure resource
}
/**
* Use the URL object to create an input stream to the secure
* resource.
*
* @param secureURL URL of secure resource to retrieve
* @return BufferedReader Input stream to secure resource
*/
private BufferedReader getPageViaURL(String secureURL) throws
Exception
{
//to avoid a MalformedURLException, this property must be set
System.setProperty("java.protocol.handler.pkgs",
"com.sun.net.ssl.internal.www.protocol");
//create URL object representing the secure resource
URL url = new URL("https://" + secureURL);
//return an input stream to the secure resource
return new BufferedReader(new InputStreamReader(
url.openStream()));
}
}