mainapplet.java

java+mapxtreme 开发校园房管系统

package com.oyc.mapxtreme.applet;

import java.awt.Color;
import java.io.IOException;

import javax.swing.JApplet;

import netscape.javascript.JSObject;

import com.oyc.mapxtreme.applet.util.AppletRequest;

/**
 * 显示地图的Applet
 * @author 三峡大学理学院 欧阳超
 * 
 */
public class MainApplet extends JApplet {

	//默认地图servlet,工程根目录
	private String m_servletName = "http://localhost/MyGISApplet/servlet/mapper";
	private String m_basePath = "http://localhost/MyGISApplet/";
	
	//画布大小,默认值为500,500
	private int mapWidth = 500;
	private int mapHeight = 500;
	
	//绘制地图的画布对象
	private MapWindow m_map;
	
	//请求对象
	private AppletRequest request;
	//地图字节数据
	byte[] buff = null;

	//url变量,每次请求地图servlet时,重新给它赋值
	private String m_url = null;
	
	public void init() {
		//读取地图servlet url
		String servletURL = this.getParameter("servleturl");
		if (servletURL != null && servletURL.length() > 0) {
			this.m_servletName = servletURL;
		}
		
		//读取工程根目录
		String basePath = this.getParameter("basePath");
		if (basePath != null && basePath.length() > 0) {
			this.m_basePath = basePath;
		}
		
		//读取画布大小
		String strParam = this.getParameter("canvasWidth");
		if(strParam != null){
			this.mapWidth = Integer.parseInt(strParam);
		}
		strParam = this.getParameter("canvasHeight");
		if(strParam != null){
			this.mapHeight = Integer.parseInt(strParam);
		}
		
		//读取地图初始视野
		strParam = this.getParameter("oldZoom");
		if(strParam != null){
			MapState.setOldZoom(Double.parseDouble(strParam));
			MapState.setCurZoom(Double.parseDouble(strParam));
		}

		//创建地图窗口
		m_map = new MapWindow(this, this.m_servletName, this.mapWidth, this.mapHeight);
		m_map.setBounds(0, 0, mapWidth, mapHeight);
		m_map.setBackground(Color.lightGray);
		
		// 创建请求对象
		request = new AppletRequest();
		
		this.setLayout(null);
		add(m_map, null);
		
		m_url = m_servletName + "?method=fullMap";
		this.adjustMapBySelf(m_url);
	}
	
	/**
	 * 外部javascript调用,设置当前工具
	 * @param tool 取值0,1,2,3,4,5,6,代表无工具,放大,缩小,平移,测距离,信息访问,范围查询
	 */
	public void setCommandTool(int tool){
		this.m_map.setCommandTool(tool);
	}
	
	/**
	 * 内部调用,发送get请,校正地图
	 * @param url 绝对url,形如http://localhost/project/servletName
	 */
	public void adjustMapBySelf(String url){
		try {
			buff = request.sendGetRequest(url);
		} catch (IOException e) {
			e.printStackTrace();
		}
		m_map.updateMap(this.getToolkit().createImage(buff));
	}
	
	/**
	 * 发送get请求,校正地图,通常由外部javascript调用
	 * @param url 相对工程根目录的url
	 */
	public void adjustMap(String url){
		this.m_url = this.m_basePath + url;
		try {
			buff = request.sendGetRequest(m_url);
		} catch (IOException e) {
			e.printStackTrace();
		}
		m_map.updateMap(this.getToolkit().createImage(buff));
	}
	
	/**
	 * 发送post请求,校正地图,通常由外部javascript调用
	 * @param url       相对工程根目录的url
	 * @param parameter 参数列表
	 */
	public void adjustMap(String url, String parameter){
		this.m_url = this.m_basePath + url;
		try {
			buff = request.sendPostRequest(m_url, parameter);
		} catch (IOException e) {
			e.printStackTrace();
		}
		m_map.updateMap(this.getToolkit().createImage(buff));
	}
	
	/**
	 * 调用外部javascript代码
	 * @param method 要调用的方法名
	 */
	public void invokeJavascript(String method){
		try {
			JSObject.getWindow(this).eval(method);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 初始化地图状态,即将地图视野重新设为起始值
	 *
	 */
	public void initMapState(){
		MapState.setCurZoom(MapState.getOldZoom());
	}
	
	/**
	 * 清除地图上所有绘的图形
	 *
	 */
	public void clearMap(){
		this.m_map.clear();
	}

}