branch-0.23.1/hadoop-common-project/hadoop-auth-examples/src/main/java/org/apache/hadoop/security/authentication/examples/WhoServlet.java

/**
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License. See accompanying LICENSE file.
 */
package org.apache.hadoop.security.authentication.examples;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.Writer;
import java.text.MessageFormat;

/**
 * Example servlet that returns the user and principal of the request.
 */
public class WhoServlet extends HttpServlet {

  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    resp.setContentType("text/plain");
    resp.setStatus(HttpServletResponse.SC_OK);
    String user = req.getRemoteUser();
    String principal = (req.getUserPrincipal() != null) ? req.getUserPrincipal().getName() : null;
    Writer writer = resp.getWriter();
    writer.write(MessageFormat.format("You are: user[{0}] principal[{1}]\n", user, principal));
  }

  @Override
  protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    doGet(req, resp);
  }
}