htmlembeddedmapservlet.java

java开发的MAP

/*
 * HTMLEmbeddedMapServlet.java
 *
 * NOTE: Before you run this servlet, you must configure it.
 * You can configure it by assigning explicit values to the
 * member variables (m_mxtURL, m_fileToLoad)
 * defined below; see "TODO" comments below.	Or, instead of
 * hard-coding these values into this source file, you can
 * provide those five values by defining corresponding
 * init parameters in your servlet administrator.
 * COPYRIGHT 1999-2003, MapInfo Corporation
 *
 * Version 4.7.0
 *
 * Revision history:
 *
 *   MapXtreme version 4.7: replaced (deprecated) Layer with FeatureLayer.
 *   Various modifications so that all strings displayed in the generated HTML
 *   page are in the client language.
 */

import com.mapinfo.devsupport.servlet.FieldReader;
import com.mapinfo.devsupport.servlet.MapToolkit;
import com.mapinfo.mapdefcontainer.JDBCMapDefContainer;
import com.mapinfo.mapj.MapJ;
import com.mapinfo.mapxtreme.client.MapXtremeImageRenderer;
import com.mapinfo.util.DoublePoint;
import com.mapinfo.util.DoubleRect;
import com.mapinfo.xmlprot.mxtj.ImageRequestComposer;

import java.awt.Color;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Hashtable;
import java.util.Random;
import java.io.*;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;

/*
 * This is an example of an HTTP Map Servlet that extends the HttpServlet
 * class and contains MapJ objects
 */
public class HTMLEmbeddedMapServlet extends HttpServlet implements Serializable{

	// Host Configuration

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	// TODO: Specify the URL of the MapXtremeServlet that will
	// service our mapping requests.
	//
	// Or, instead of specifying a literal string value here, you can
	// specify this value using an init parameter called 'mapxtremeurl'.  
	private String m_mxtURL =
		"http://localhost:8080/mapxtreme47/mapxtreme";

	// TODO: If you want to initialize the map based on a file -- either 
	// a geoset (.gst file) or an XML-based map definition (.mdf file) -- 
	// specify the name of the file, including the full path.  
	// Or you can specify this value using an init parameter called 'filetoload'.
	// For example, on Windows, this string might look like "C:\\maps\\world.gst". 
	private String m_fileToLoad = null;

	// TODO: If you plan to load a geoset (.gst file) instead of a map 
	// definition, then specify the "maps path" -- the directory path 
	// where map layers (.TAB files) are stored.  Note that this is a
	// directory on the server where MapXtremeServlet is running, which
	// could be a different server than the server that is running 
	// this servlet.  For example, if you are calling a MapXtremeServlet 
	// that is running on a Windows system, with map layers installed on 
	// drive C:, you might specify a path such as "C:\\data\\maps".
	// If you will load a map definition instead of a geoset file,
	// the m_mapPath variable is ignored.
	// If you leave this variable set to null, and you load a .gst file,
	// the program will assume that map layers are in the same directory
	// as the .gst file that you are loading. 
	// Or you can specify this value using an init parameter called 'mappath'.	
	private String m_mapPath = null;

	// TODO: If you want to load an XML-based map definition 
	// from a JDBC source, initialize the following two objects 
	// (in which case the m_fileToLoad variable will be ignored):
	private JDBCMapDefContainer m_jdbcContainer = null; 
	private String m_mapName = null; 
	
	// TODO (Optional): You can re-configure the servlet so that it creates a
	// GIF file on the web server, instead of its default behavior of streaming
	// the image directly down to the browser.	(For example, you might
	// want to do performance testing, to compare the execution speed of
	// streaming the image vs. creating and downloading GIF files.)
	// If you want to create a server-side GIF instead of streaming the
	// image directly to the browser, then change m_bGenerateImageFile to true.
	// Or you can specify this value using an init parameter 'generateimagefile'.
	// NOTE: If you set m_bGenerateImageFile to true, you will also need to
	// set the m_mapImageURL and m_mapImagePath settings; see comments below.
	private boolean m_bGenerateImageFile = false;

	// TODO (optional): You can specify a path where the servlet can create and
	// delete GIF image files, such as "C:\\JavaWebServer2.0\\public_html\\".
	// **** This setting is only used if m_bGenerateImageFile is set to true. ****
	// Or you can specify this value using an init parameter called 'mapimagepath'.
	// NOTE: This string should end with the path separator for the OS
	// on which the servlet will be deployed.
	private String m_mapImagePath = null;

	// TODO (optional): You can specify the beginning part of a URL to a GIF
	// image on the web server.	For example, "http://localhost/"	or
	// or "http://locahost:8080/"	or	"http://localhost/images/" .
	// **** This setting is only used if m_bGenerateImageFile is set to true. ****
	// Or you can specify this value using an init parameter called 'mapimageurl'.
	private String m_mapImageURL = null;

	// Define a constant for each type of image format we support 
	public static final int IMAGE_FORMAT_GIF = 0;
	public static final int IMAGE_FORMAT_JPG = 1;
	public static final int IMAGE_FORMAT_PNG = 2;	
	public static final int IMAGE_FORMAT_BMP = 3;

	// Define constants to control various rendering options
	public static final int NUM_OF_COLORS = 256;
	public static final Color BACKGROUND_COLOR = Color.blue;
	
	// Specify which type of map image to generate: 
	private int m_imageFormat = IMAGE_FORMAT_GIF; 
	private String m_imageExtension = ".gif"; 

	// TODO (optional):	Set the following booleans to true or false 
	// to control whether the corresponding items are included on 
	// the HTML page that the user sees.	 Or you can specify these
	// values using init parameters named includescalebar, 
	// includelayercontrol, includetogglesize, and includezoomwidth.	
	private boolean m_bIncludeScalebar = true;
	private boolean m_bIncludeLayerControl = true;	
	private boolean m_bIncludeToggleSize = true;
	private boolean m_bIncludeZoomWidth = true;	
	
	// TODO (optional): You can set m_bDebug to true if you want error messages
	// to include debugging information, or false otherwise.	Or you can set
	// this variable by setting a 'debug' init parameter to 'true'.
	private boolean m_bDebug = false;

	// A string used to report status information when m_bDebug is true.
	private String m_debugMessage = "";

	// A string to hold the URL used to invoke this servlet.
	// You do not need to specify this explicitly; if you leave it
	// set to null, we will determine it at runtime.
	private String m_thisServletURL = null;

	// Temporary image file handling
	private static final String m_imagePrefix = "servmap";
	private static int m_imageCounter = 0;

	// Define the names used for the form fields
	//	Submit buttons on the Layer Settings page:
	private static final String FF_LS_APPLY	= "lsapply";
	private static final String FF_LS_CANCEL = "lscancel";

	// A string used to append parameters to an URL
	// (such as the URL you click to bring up Layer Control)
	private static final String FF_REQUEST_TYPE = "reqtype";

	// Map Image:
	private static final String FF_MAP_IMAGE = "mapImage";
	private static final String FF_MAP_IMAGE_X = FF_MAP_IMAGE + ".x";
	private static final String FF_MAP_IMAGE_Y = FF_MAP_IMAGE + ".y";

	// Define identifiers that represent hidden form fields,
	// which store the map's center and zoom so that the old
	// center and zoom can be restored even after a session expires.
	private static final String FF_OLD_X = "fx";
	private static final String FF_OLD_Y = "fy";
	private static final String FF_OLD_ZOOM = "fzoom";
	private static final String	FF_OLD_SIZE_LARGE = "flarge";

	// Strings used with a Hashtable of user selections
	private static final String HT_SUBMIT_BUTTON = "submitButton";
	private static final String HT_SCREEN_LOCATION = "screenLocation";
	private static final String HT_OLD_MAP_LOCATION = "oldmapcenter";

	// Dimensions for a "small" (default sized) map image, in pixels
	private static final int MAP_WIDTH_SMALL = 400;
	private static final int MAP_HEIGHT_SMALL = 400;
	// Dimensions for a "large" map image
	private static final int MAP_WIDTH_LARGE = 550;
	private static final int MAP_HEIGHT_LARGE = 550;

	// Name for a session attribute that will store our MapJ object.
	// Make sure this attribute name is unique (among attributes used
	// by all the servlets in this context) or else this servlet may 
	// interfere with another servlet attempting to use the same name.
	private static final String MAPJ_ATTR = "mapinfo.mapj.htmlmap"; 
	
	/**
	* This method initializes the servlet, and also initializes various
	* member variables using initialization parameters, if those
	* parameters have been provided.	(You are not required to set up
	* initialization parameters; instead, you can simply specify
	* the desire, explicit values -- see the "TODO" comments above.
	* However, you might want to provide the following settings
	* through initialization parameters, so that you can change
	* the values without recompiling.)
	*
	* @param config ServletConfig servlet initialization parameter
	*
	* @exception ServletException if detected when handling the request
	*/
	public void init(ServletConfig config)
			throws ServletException
	{
		super.init(config);

		// If the servlet set-up has provided initialization parameters,
		// use those parameters to override the hard-coded values
		// declared above.
		String strParam = getInitParameter("mapxtremeurl");
		if (strParam != null) {
			m_mxtURL = strParam;
		}
		strParam = getInitParameter("filetoload");
		if (strParam != null	&&	strParam.length() > 0) {
			m_fileToLoad = strParam;
		}
		strParam = getInitParameter("mappath");
		if (strParam != null	&&	strParam.length() > 0) {
			m_mapPath = strParam;
		}
		strParam = getInitParameter("generateimagefile");
		if (strParam != null) {
			if (strParam.equalsIgnoreCase("true")) {
				m_bGenerateImageFile = true;
			} else if (strParam.equalsIgnoreCase("false")) {
				m_bGenerateImageFile = false;
			}
		}
		strParam = getInitParameter("mapimagepath");
		if (strParam != null	&&	strParam.length() > 0) {
			m_mapImagePath = strParam;
		}
		strParam = getInitParameter("mapimageurl");
		if (strParam != null	&&	strParam.length() > 0) {
			m_mapImageURL = strParam;
		}
		strParam = getInitParameter("imageformat");
		if (strParam != null) {
			if (strParam.equalsIgnoreCase("jpg") || 
					strParam.equalsIgnoreCase("jpeg") )	{ 
				m_imageFormat = IMAGE_FORMAT_JPG;
				m_imageExtension = ".jpg";
			} else if (strParam.equalsIgnoreCase("png") )	{
				m_imageFormat = IMAGE_FORMAT_PNG; 
				m_imageExtension = ".png";
			} else if (strParam.equalsIgnoreCase("bmp") )	{
				m_imageFormat = IMAGE_FORMAT_BMP; 
				m_imageExtension = ".bmp";				
			}	else {
				m_imageFormat = IMAGE_FORMAT_GIF; 
				m_imageExtension = ".gif";
			}
		}		
		strParam = getInitParameter("debug");
		if (strParam != null) {
			if (strParam.equalsIgnoreCase("true")) {
				m_bDebug = true;
			} else if (strParam.equalsIgnoreCase("false")) {
				m_bDebug = false;
			}
		}
		// Process the four boolean settings that control whether we include
		// various map elements (Scalebar, etc.) on the page. 
		strParam = getInitParameter("includelayercontrol");
		if (strParam != null) {
			if (strParam.equalsIgnoreCase("true")) {
				m_bIncludeLayerControl = true;
			} else if (strParam.equalsIgnoreCase("false")) {
				m_bIncludeLayerControl = false;
			}
		}		
		strParam = getInitParameter("includescalebar");
		if (strParam != null) {
			if (strParam.equalsIgnoreCase("true")) {
				m_bIncludeScalebar = true;
			} else if (strParam.equalsIgnoreCase("false")) {
				m_bIncludeScalebar = false;
			}
		}			
		strParam = getInitParameter("includezoomwidth");
		if (strParam != null) {
			if (strParam.equalsIgnoreCase("true")) {
				m_bIncludeZoomWidth = true;
			} else if (strParam.equalsIgnoreCase("false")) {
				m_bIncludeZoomWidth = false;
			}
		}				 
		strParam = getInitParameter("includetogglesize");
		if (strParam != null) {
			if (strParam.equalsIgnoreCase("true")) {
				m_bIncludeToggleSize = true;
			} else if (strParam.equalsIgnoreCase("false")) {
				m_bIncludeToggleSize = false;
			}
		}						
		// If either the imagePath setting or the imageURL setting
		// is null,	we will not be able to generate image files that
		// can be located by the user's browser.	In this case,
		// stream the image down to the client directly.
		if (m_mapImagePath == null || m_mapImageURL == null) {
			m_bGenerateImageFile = false;
		}
	}

	/**
	 *	service	-- handle both GET and POST requests.
	 *
	 * @param req HttpServletRequest that encapsulates the request to
	 * the servlet
	 * @param res HttpServletResponse that encapsulates the response
	 * from the servlet