Java多线程处理List数据

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.lang.ArrayUtils;

public class Test_4 {
    /**
     * 多线程处理list
     *
     * @param data  数据list
     * @param threadNum  线程数
     */
    public synchronized void handleList(List data, int threadNum) {
        int length = data.size();
        int tl = length % threadNum == 0 ? length / threadNum : (length
                / threadNum + 1);
 
        for (int i = 0; i < threadNum; i++) {
            int end = (i + 1) * tl;
            HandleThread thread = new HandleThread("线程[" + (i + 1) + "] ",  data, i * tl, end > length ? length : end);
            thread.start();
        }
    }
 
    class HandleThread extends Thread {
        private String threadName;
        private List data;
        private int start;
        private int end;
 
        public HandleThread(String threadName, List data, int start, int end) {
            this.threadName = threadName;
            this.data = data;
            this.start = start;
            this.end = end;
        }
 
        public void run() {
            //这里处理数据
            List subList = data.subList(start, end);
            for(int a=0; a data = new ArrayList();
        for (int i = 0; i < 1517; i++) {
            data.add("item" + i);
        }
        test.handleList(data, 6);
        System.out.println(ArrayUtils.toString(data));
    }
}