frontcontroller.java

编写rest实例 rest分布式框架在app中的应用

package com.jeffhanson.rest.server.http;

import com.jeffhanson.rest.core.*;
import com.jeffhanson.rest.server.ContextNotFoundException;
import com.jeffhanson.rest.server.ContextRequestException;

import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class for Servlet: FrontController
 * 
 */
public class FrontController extends javax.servlet.http.HttpServlet
  implements javax.servlet.Servlet
{
  private static final long serialVersionUID = 1850220150861735628L;
  private static final String SC_ATTR = "SERVER_COMPONENT";

  /*
   * (non-Java-doc)
   * 
   * @see javax.servlet.http.HttpServlet#HttpServlet()
   */
  public FrontController()
  {
    super();
  }
  
  public HTTPServerComponent resolveServerComponent(int port,
                                                    String contextRootPath,
                                                    String contextPath)
    throws ServletException
  {
    ServletContext servletCtx = getServletConfig().getServletContext();
    HTTPServerComponent serverComponent =
      (HTTPServerComponent)servletCtx.getAttribute(SC_ATTR);
    
    if (serverComponent == null)
    {
      try
      {
        HTTPConnector connector =
         (HTTPConnector)Connectors.getConnector(Protocol.HTTP);
        serverComponent =
         (HTTPServerComponent)connector.addServer(port);
        System.out.println("FrontController adding context [" + contextPath
                           + "] with root [" + contextRootPath + "]");
        serverComponent.addContext(contextRootPath, contextPath);
        servletCtx.setAttribute(SC_ATTR, serverComponent);
      }
      catch (ConnectorException e)
      {
        e.printStackTrace();
        throw new ServletException(e);
      }
    }
    
    return serverComponent;
  }

  /*
   * (non-Javadoc)
   * 
   * @see javax.servlet.http.HttpServlet#doDelete(javax.servlet.http.HttpServletRequest,
   *      javax.servlet.http.HttpServletResponse)
   */
  protected void doDelete(HttpServletRequest request,
                          HttpServletResponse response)
      throws ServletException,
        IOException
  {
    System.out.println("FrontController.doDelete() called");
    
    HTTPServerComponent serverComponent =
      resolveServerComponent(request.getServerPort(),
                             this.getServletContext().getRealPath("/"),
                             HTTPServerComponent.ContextPathFromRequest(request, this));
    
    try
    {
      serverComponent.getContext(request, this).handleDelete(new HTTPRequest(request));
    }
    catch (ContextNotFoundException e)
    {
      e.printStackTrace();
      throw new ServletException("Error: " + e);
    }
    catch (ContextRequestException e)
    {
      e.printStackTrace();
      throw new ServletException("Error: " + e);
    }
    
    response.getWriter().println("Success");
  }

  /*
   * (non-Java-doc)
   * 
   * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request,
   *      HttpServletResponse response)
   */
  protected void doGet(HttpServletRequest request,
                       HttpServletResponse response)
      throws ServletException,
             IOException
  {
    /*
    System.out.println("FrontController.doGet() - request LocalName [" + request.getLocalName() + "]");
    System.out.println("FrontController.doGet() - request PathInfo [" + request.getPathInfo() + "]");
    System.out.println("FrontController.doGet() - request PathTranslated [" + request.getPathTranslated() + "]");
    System.out.println("FrontController.doGet() - request RequestURI [" + request.getRequestURI() + "]");
    System.out.println("FrontController.doGet() - request ServerName [" + request.getServerName() + "]");
    System.out.println("FrontController.doGet() - request ServletPath [" + request.getServletPath() + "]");
    System.out.println("FrontController.doGet() - request RequestURL [" + request.getRequestURL() + "]");
    System.out.println("FrontController.doGet() - servlet ServletName [" + this.getServletName() + "]");
    System.out.println("FrontController.doGet() - ServletConfig ServletName [" + this.getServletConfig().getServletName() + "]");
    System.out.println("FrontController.doGet() - ServletContext RealPath [" + this.getServletContext().getRealPath("/") + "]");
    */
    
    System.out.println("FrontController.doGet() called");
    
    HTTPServerComponent serverComponent =
      resolveServerComponent(request.getServerPort(),
                             this.getServletContext().getRealPath("/"),
                             HTTPServerComponent.ContextPathFromRequest(request, this));
    
    Representation representation = null;
    
    try
    {
      representation = serverComponent.getContext(request, this).handleGet(new HTTPRequest(request));
    }
    catch (Exception e)
    {
      e.printStackTrace();
      throw new ServletException("Error: " + e);
    }
    
    new HTTPResponse(response).write(representation.getContentType(),
                                     representation.getInputStream());
  }

  /*
   * (non-Java-doc)
   * 
   * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request,
   *      HttpServletResponse response)
   */
  protected void doPost(HttpServletRequest request,
                        HttpServletResponse response)
      throws ServletException,
             IOException
  {
    System.out.println("FrontController.doPost() called");
    
    HTTPServerComponent serverComponent =
      resolveServerComponent(request.getServerPort(),
                             this.getServletContext().getRealPath("/"),
                             HTTPServerComponent.ContextPathFromRequest(request, this));
    
    try
    {
      serverComponent.getContext(request, this).handlePost(new HTTPRequest(request));
    }
    catch (ContextNotFoundException e)
    {
      e.printStackTrace();
      throw new ServletException("Error: " + e);
    }
    catch (ContextRequestException e)
    {
      e.printStackTrace();
      throw new ServletException("Error: " + e);
    }
    
    response.getWriter().println("Success");
  }

  /*
   * (non-Javadoc)
   * 
   * @see javax.servlet.http.HttpServlet#doPut(javax.servlet.http.HttpServletRequest,
   *      javax.servlet.http.HttpServletResponse)
   */
  protected void doPut(HttpServletRequest request,
                       HttpServletResponse response)
      throws ServletException,
             IOException
  {
    System.out.println("FrontController.doPut() called");
    
    HTTPServerComponent serverComponent =
      resolveServerComponent(request.getServerPort(),
                             this.getServletContext().getRealPath("/"),
                             HTTPServerComponent.ContextPathFromRequest(request, this));
    
    try
    {
      serverComponent.getContext(request, this).handlePut(new HTTPRequest(request));
    }
    catch (ContextNotFoundException e)
    {
      e.printStackTrace();
      throw new ServletException("Error: " + e);
    }
    catch (ContextRequestException e)
    {
      e.printStackTrace();
      throw new ServletException("Error: " + e);
    }
    
    response.getWriter().println("Success");
  }
}