多线程学习

package com.service.cone;

public class EnergySystem {

    //总能量
    private final double[] energyBoxs;
    
     private final Object obj = new Object();
    
    //个数和每个能量块的能量值
    public EnergySystem(int n,double initialEnergy ) {
        energyBoxs = new double[n];
        for (int i = 0; i < energyBoxs.length; i++) {
            energyBoxs[i] = initialEnergy;
        }
    }

    //能量转移
    public void transfer(int from,int to,double amount) {
        
        synchronized (obj) {
            
//            if(energyBoxs[from]<amount){
//                return;
//            }
            
            while(energyBoxs[from]<amount){
                try {
                    //
                    obj.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            
            System.out.print(Thread.currentThread().getName());
            energyBoxs[from]-=amount;
            System.out.printf("从%d转移 %10.2f单位能量到 %d",from,amount,to);
            energyBoxs[to]+=amount;
            System.out.printf("能量总和：%10.2f%n",getTotalEnergies());
            //
            obj.notifyAll();
        }
    }

    //返回总能量
    public double getTotalEnergies() {
        double sum = 0;
        for (double amount :energyBoxs) {
            sum+=amount;
        }
        return sum;
    }
    
    //返回长度
    public int getBoxAmount() {
        return energyBoxs.length;
    }
    
}

package com.service.cone;

public class EnergySystemTest {

    //能量块的个数
    public static final int BOX_AMOUNT = 100;
    //每个能量块的初始化能量值
    public static final double INITIAL_ENERGY = 1000;
    
    
    
    public static void main(String[] args) {

        EnergySystem eng = new EnergySystem(BOX_AMOUNT,INITIAL_ENERGY);
        
        for (int i = 0; i < BOX_AMOUNT; i++) {
            
            EnergyTransferTask task = new EnergyTransferTask(eng, i, INITIAL_ENERGY);
            
            Thread t = new Thread(task,"TransferThread_"+i);
            t.start();
                    
        }
        
    }

}

package com.service.cone;

public class EnergyTransferTask implements Runnable {

    private EnergySystem energySystem;

    //下标
    private int fromBox;
    
    //每次转换的最大能量
    private double maxAmount;
    
    //休眠时间
    private int Delay = 10;
    
    
    public EnergyTransferTask(EnergySystem energySystem,int from,double max) {
        
        this.energySystem = energySystem;
        this.fromBox = from;
        this.maxAmount = max;
    }
    
    
    @Override
    public void run() {

        try {
            while(true){
                
//                static double random() 
//                返回带正号的 double 值，该值大于等于 0.0 且小于 1.0。
                
                int toBox = (int)(energySystem.getBoxAmount()*Math.random());
                
                double amount = maxAmount*Math.random();
                
                energySystem.transfer(fromBox, toBox, amount);
                
                Thread.sleep((int)(Delay*Math.random()));
                
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        
    }

}