nmeasentence.java

国外的一个开源gps模拟器源代码

/*
 * Copyright (c) 2007 by the University of Applied Sciences Northwestern Switzerland (FHNW)
 * 
 * This program can be redistributed or modified under the terms of the
 * GNU General Public License as published by the Free Software Foundation.
 * This program is distributed without any warranty or implied warranty
 * of merchantability or fitness for a particular purpose.
 *
 * See the GNU General Public License for more details.
 */

package ch.fhnw.imvs.gpssimulator.nmea;

import java.util.Calendar;
import java.util.TimeZone;

import ch.fhnw.imvs.gpssimulator.data.GPSData;

public abstract class NMEASentence {
	
    private final char[] hex = new char[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C','D', 'E', 'F'}; 

    public abstract String getName();
    
    private boolean linePrinted;
    public boolean isLinePrinted(){return linePrinted;}
	public void setLinePrinted(boolean linePrinted){this.linePrinted = linePrinted;}
    
    private boolean printContent;
	public void setPrintContent(boolean printContent){this.printContent = printContent;}
    
    private boolean printChecksum;
	public void setPrintChecksum(boolean printChecksum){this.printChecksum = printChecksum;}
   
	
	protected void append(StringBuffer buf, double arg){
		buf.append("," + arg);
	}
	protected void append(StringBuffer buf, int arg){
		buf.append("," + arg);
	}
	protected void append(StringBuffer buf, String arg){
		buf.append(","); buf.append(arg);
	}

	
	protected abstract String getSentence(boolean content);
	public final String getSentence(){
		String s = getSentence(printContent);
		if(printChecksum) s = addCheckSum(s);
		return s;
	}
	
	private String addCheckSum(String string){
        byte[] buf = string.getBytes();
        int sum = buf[0];
        for(int i=1; i < buf.length; i++){
        	sum ^= buf[i];
        }
        return string + "*" + hex[sum/16] + hex[sum%16];
	}

    public String getTimestamp() {
    	Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
    	
    	int hour_of_day = calendar.get(Calendar.HOUR_OF_DAY);
    	String cookedHour_of_day;
    	if (hour_of_day < 10) {
    		cookedHour_of_day = "0" + hour_of_day;
    	} else {
    		cookedHour_of_day = "" + hour_of_day;
    	}
    	
    	int minutes = calendar.get(Calendar.MINUTE);
    	String cookedMinutes;
    	if (minutes < 10) {
    		cookedMinutes = "0" + minutes;
    	} else {
    		cookedMinutes = "" + minutes;
    	}
    	
    	int seconds = calendar.get(Calendar.SECOND);
    	String cookedSeconds;
    	if (seconds < 10) {
    		cookedSeconds = "0" + seconds;
    	} else {
    		cookedSeconds = "" + seconds;
    	}
    	
    	int milliseconds = calendar.get(Calendar.MILLISECOND);
    	String cookedMilliseconds;
    	if (milliseconds > 99) {
    		cookedMilliseconds = ("" + milliseconds).substring(0, 2);
    	} else {
    		cookedMilliseconds = "" + milliseconds;
    	}

    	return cookedHour_of_day + cookedMinutes + cookedSeconds + "." + cookedMilliseconds;
    }
    
    public String getDatestamp() {
    	Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
    	
    	int day_of_month = calendar.get(Calendar.DAY_OF_MONTH);
    	
    	String cookedDay_of_month;
    	if (day_of_month < 10) {
    		cookedDay_of_month = "" + 0 + day_of_month;
    	} else {
    		cookedDay_of_month = "" + day_of_month;
    	}
    	
    	int month = calendar.get(Calendar.MONTH) + 1;
    	String cookedMonth;
    	if (month < 10) {
    		cookedMonth = "" + 0 + month;
    	} else {
    		cookedMonth = "" + month;
    	}
    	return "" + cookedDay_of_month + cookedMonth + ("" + calendar.get(Calendar.YEAR)).substring(2, 4);
    }

	public synchronized static double getNMEALatitude() {
		double degree = (int)GPSData.getLatitude();
		double minute = (int)(GPSData.getLatitude()*60 - degree*60);
		double second = GPSData.getLatitude()*60 - (int)(GPSData.getLatitude()*60);

		return (double) Math.round((degree*100 + minute + second)*100)/100;
	}
	
	public synchronized static double getNMEALongitude() {
		double degree = (int)GPSData.getLongitude();
		double minute = (int)(GPSData.getLongitude()*60 - degree*60);
		double second = GPSData.getLongitude()*60 - (int)(GPSData.getLongitude()*60);

		return (double) Math.round((degree*100 + minute + second)*100)/100;
	}
}