j2me_thread.java

演示win32的socket 通讯 八皇后的改进算法 并发Concurrency的JAVA实现 applet演示鼠标的点击时间和显示图象 手机J2ME的多线程演示

import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
import java.util.*;
public class J2me_Thread extends MIDlet
{
	private Display display;
	ShowCanvas canvas;
	public J2me_Thread()
	{
		display = Display.getDisplay(this);
		canvas = new ShowCanvas(display);
	}
	public void startApp(){
		System.out.println("startApp is called.");
		canvas.start();
	}
	public void pauseApp(){
		System.out.println("pauseApp is called.");
	}
	public void destroyApp(boolean unconditional){
		System.out.println("destroyApp is called.");
	}
}


class ShowCanvas extends Canvas 
{
	Thread firstThread,secondThread;
	Display display;
	Ceremony ceremony;
	DrawQueen queen;
	int threadNum;
	public ShowCanvas(Display d)
	{
		display = d;		// save the display
		threadNum=3;
		// initialize the array of balls
		ceremony = new Ceremony(this);
		queen = new DrawQueen(this);
	}

    void start() {
		display.setCurrent(this);
		Thread t1 = new Thread(ceremony);
		Thread t2 = new Thread(queen);
		t1.start();
		t2.start();
		repaint();
    }
	public void paint(Graphics g)
	{
		int height=getHeight();
		int width=getWidth();
		int x=15;
		g.setColor(255,255,255);
		g.fillRect(0,0,getWidth(),getHeight());
		ceremony.paint(g);
		queen.paint(g);
	}
}

class Ceremony implements Runnable
{
	Graphics g;
	Canvas canvas;
	int lastxs=0;
	int lastys=0;
	int lastxm=0;
	int lastym=0;
	int lastxh=0;
	int lastyh=0;
	int hour, minute, second;
	Ceremony(Canvas c) {
		super();
		canvas = c;
	}
	public void run() {
		
		while (true) {
			canvas.repaint();
			// use the delay to control the speed of the ball
			try {
				Thread.sleep(100);
				} catch (InterruptedException e) {}
		}
	}

    /**
     * Paint the ball.
     */
    void paint(Graphics g) {
	 int xh,yh,xm,ym,xs,ys,s,m,h,xcenter,ycenter;
	  Calendar dat=Calendar.getInstance();
	 
	  s=dat.get(Calendar.SECOND);
	  m=dat.get(Calendar.MINUTE);
	  h=dat.get(Calendar.HOUR);
	  hour=h%12;  minute=m;  second=s;
	  show(g, 120,200,50);
}
     void show(Graphics g,int center_x,int center_y,int radius) {
        int hrs_nid_len=(int)(radius*0.5), min_nid_len=(int)(radius*0.7), sec_nid_len=(int)(radius*0.85);
        double theta;
		g.setColor(255,0,0);
        g.drawArc(center_x-radius,center_y-radius,radius*2,radius*2,0,360);
        theta=(double)(hour*60*60+minute*60+second)/43200.0*2.0*Math.PI;
		g.setColor(255,0,0);
        drawNiddle(g,center_x,center_y,hrs_nid_len,theta);
        theta=(double)(minute*60+second)/3600.0*2.0*Math.PI;
		g.setColor(0,255,0);
        drawNiddle(g,center_x,center_y,min_nid_len,theta);
        theta=(double)second/60.0*2.0*Math.PI;
		g.setColor(0,0,255);
        drawNiddle(g,center_x,center_y,sec_nid_len,theta);
     }
     private void drawNiddle(Graphics g,int x,int y,int len,double theta) {
       // g.setColor(c);
        g.drawLine(x,y,(int)(x+len*Math.sin(theta)),(int)(y-len*Math.cos(theta)));
     }
}


class DrawQueen implements Runnable
{
    Thread  myThread;
	int N=0;
	Graphics g;
	Canvas canvas;
	int x,y;
    public DrawQueen(Canvas c)
    {
        super();
		canvas = c;
		this.x=x;
		this.y=y;
    }
   public void run() {
		
		while (true) {
			canvas.repaint();
			// use the delay to control the speed of the ball
			try {
				Thread.sleep(100);
				} catch (InterruptedException e) {}
		}
	}


    public void paint(Graphics g)
    {
	
	g.setColor(0,0,0);
	int n=8;
	
	boolean col[]=new boolean[8];
	boolean bias[]=new boolean[16];
	boolean isget=false;
	int k=0,m=0,odd=0,oddnum=0,b;
	int leftBias[]=new int[16];
	int a[]=new int[8];
	for(m=0;m<9;m++){g.drawLine(18+m*15, 18, 18+m*15, 140);}	
	for(m=0;m<9;m++){g.drawLine(18, 18+m*15,140, 18+m*15); }	
	for(k=0;k<n;k++)
	{
		col[k]=true;
		bias[k]=true;
		bias[k+n]=true;
		leftBias[k+n]=0;
		leftBias[k]=0;
	}
	if(n%2!=0)
	{
		odd=n/2;
	}
	else
	{
		odd=-1;
	}
	k=0;
	m=0;
	int i=0,j=0;
	 for(i=0;i<n+1;i++)
		{
			if(isget)
				break;
			if(j==n)              //退到的行已经在最后一列
			{
				b=i-2;
				col[a[b]]=true;  //把退到行的列置为有效
				bias[a[b]-b+n]=true;
				leftBias[a[b]+b]--;
				j=a[b]+1;
				i=b;
			}
			else
			{
				j=0;
			}
			for(;j<n;j++)
			{
				if(i==0)                           //如果是零行就顺次摆放
				{
					if(k>=n/2)
					{
							if(odd==-1)                    //如果皇后数是奇数
							{
								return ;
							}
							else if(k==n/2+1)              //如果皇后数是偶数
							{
								return ;
							}
					}
					col[k]=false;                  //被占用的列被标记
					bias[k-i+n]=false;             //右斜线被标记
					leftBias[i+j]++;
					a[i]=k++;break;
				}
				else
				{
					if(!bias[j-i+n]||!col[j]||leftBias[i+j]!=0)      //j列是否已使用和，此斜线是否被用
					{
						continue;
					}
					a[i]=j;
					if(i==n-1)                        //找到最后一个点，成功一个 
						{
							m++;                  
							//记录成功数
							if(m==(N%45+1))
							{
								for(int w=0;w<8;w++)
									{
										g.setColor(23,45,67);
										g.fillArc(23+w*15, 23+a[w]*15, 8, 8, 0, 360);
										
									}
								isget=false;
								N++;
								return;
							}
							
						}
						else{
							col[j]=false;
							bias[j-i+n]=false;
							leftBias[i+j]++;
							break;
						}
					}
				}
			}
    }
}