Java一个线程中传递数组时抛出空指针异常，疑似数组没传进来？求助，谢谢！

stshow 2013-01-01 06:07:00

在写一个排序算法演示程序

先在主窗体中的Listener中调用engine：

private class StartListener implements ActionListener{

                public void actionPerformed(ActionEvent e){



                        

                        int[] unsort=UnsortGenerator();  //函数返回给unsort一个数组

                        

                        

                        engine.setArray(unsort);

                        engine.setAlgorithm(getAlgorithm());

                        engine.setSleepTime(jslSpeed.getValue()*50);

                        engine.setHistogram(histogram);  //Histogram是用来画柱状图的

                        engine.run();

                }

        }

然后在Engine中：

private SelectionSort selectionSort=new SelectionSort();

...

if (thread != null && thread.getState() != Thread.State.TERMINATED)

                                return;

                        

                        thread=new Thread(selectionSort);

                        selectionSort.setArray(unsort);

                        thread.start();

在SelectionSort中：

public class SelectionSort implements Runnable{

        private int[] unsort;

        private Histogram histogram;

        private int sleepTime;

        

        public void run(){

                selectionSort();

        }



        public void setArray(int[] unsort){

                this.unsort=unsort;

        }

        

        private void selectionSort(){

                

                int key=0;

                int count=0;

                while(count<unsort.length-1){

                        for(int i=key+1;i<unsort.length;i++){

                                if(unsort[key]>unsort[i])

                                        key=i;

                        }       

                        int temp=unsort[count];

                        unsort[count]=unsort[key];

                        unsort[key]=temp;

                        

                        count++;

                        key=count;

                        

                        for(int i=0;i<unsort.length;i++)

                                System.out.printf("%d ",unsort[i]);

                        System.out.print('\n');//这里可以输出正常数组



                        histogram.showHistogram(unsort);//这里会抛出异常



                        try {

                                Thread.sleep(sleepTime);

                        } catch (Exception ex) {

                                ex.printStackTrace();

                        }

                }

        }

}