java多线程问题集锦(二)

用多线程的方式实现对一个数随机自增N次，随机自减M次，最后打印出这个数字（不能用原子操作类AtomicInteger）。

?

?

package com.test;public class TestThreadTwo {public static void main(String[] args) {int num = 0;int total = 0;int increase_count = 4000;int decrease_count = 3000;int sum_count = increase_count + decrease_count;OperatorTwo o = new OperatorTwo(num, total);//打印监控线程启动new PrintThread(o, sum_count).start();//所有加减线程启动for(int i =0;i<increase_count;i++){new IncreaseThreadTwo(o).start();}for(int i =0;i<decrease_count;i++){new DecreaseThreadTwo(o).start();}}}class OperatorTwo {private int num;private int total;public OperatorTwo(int num, int total) {this.num = num;}public int getNum() {return num;}public int getTotal() {return total;}public synchronized void increase() {num++;}public synchronized void decrease() {num--;}public synchronized void increaseTotal() {total++;}}class IncreaseThreadTwo extends Thread {private OperatorTwo o;public IncreaseThreadTwo(OperatorTwo o) {this.o = o;}@Overridepublic void run() {try {Thread.sleep((long) (Math.random() * 100));} catch (InterruptedException e) {e.printStackTrace();}o.increase();o.increaseTotal();}}class DecreaseThreadTwo extends Thread {private OperatorTwo o;public DecreaseThreadTwo(OperatorTwo o) {this.o = o;}@Overridepublic void run() {try {Thread.sleep((long) (Math.random() * 100));} catch (InterruptedException e) {e.printStackTrace();}o.decrease();o.increaseTotal();}}class PrintThread extends Thread{private OperatorTwo o;private int sum_count;public PrintThread(OperatorTwo o,int sum_count) {this.o = o;this.sum_count=sum_count;}@Overridepublic void run() {while(true){if(o.getTotal()==sum_count){System.out.println("最终结果:"+o.getNum());break;}}}}

?

package com.test;import java.util.ArrayList;import java.util.Collections;import java.util.List;import java.util.ListIterator;public class TestThreadOne {public static void main(String[] args) {int num = 0;int increase_count = 40000;int decrease_count = 30000;Operator o = new Operator(num);List<Thread> threads = new ArrayList<Thread>(); for (int i = 0; i < increase_count; i++) {Thread t = new IncreaseThreadO(o);threads.add(t);t.start();}for (int i = 0; i < decrease_count; i++) {Thread t = new DecreaseThreadO(o);threads.add(t);t.start();}/*List<Thread> ts = new ArrayList<Thread>();while(threads.size()>0){for(Thread t : threads){if(t.isAlive()){ts.add(t);}}threads.clear();threads.addAll(ts);ts.clear();}*/int sum = increase_count + decrease_count;int count = 0;ListIterator<Thread> it = null;while(count<sum){it = threads.listIterator();while(it.hasNext()){Thread t =it.next();if(t!=null&&!t.isAlive()){count++;it.set(null);}}}System.out.println("最终结果"+o.getNum());}}class Operator {private int num;public Operator(int num) {this.num = num;}public int getNum() {return num;}public synchronized void increase() {num++;}public synchronized void decrease() {num--;}}class IncreaseThreadO extends Thread {private Operator o;public IncreaseThreadO(Operator o) {this.o = o;}@Overridepublic void run() {try {Thread.sleep((long)(Math.random()*100));} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}o.increase();}}class DecreaseThreadO extends Thread {private Operator o;public DecreaseThreadO(Operator o) {this.o = o;}@Overridepublic void run() {try {Thread.sleep((long)(Math.random()*100));} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}o.decrease();}}

?

package com.test;import java.util.ArrayList;import java.util.List;public class TestThreadOne {public static void main(String[] args) {int num = 0;int increase_count = 4000;int decrease_count = 3000;Operator o = new Operator(num);List<Thread> threads = new ArrayList<Thread>(); for (int i = 0; i < increase_count; i++) {Thread t = new IncreaseThreadO(o);threads.add(t);t.start();}for (int i = 0; i < decrease_count; i++) {Thread t = new DecreaseThreadO(o);threads.add(t);t.start();}List<Thread> ts = new ArrayList<Thread>();while(threads.size()>0){for(Thread t : threads){if(t.isAlive()){ts.add(t);}}threads.clear();threads.addAll(ts);ts.clear();}System.out.println("最终结果"+o.getNum());}}class Operator {private int num;public Operator(int num) {this.num = num;}public int getNum() {return num;}public synchronized void increase() {num++;}public synchronized void decrease() {num--;}}class IncreaseThreadO extends Thread {private Operator o;public IncreaseThreadO(Operator o) {this.o = o;}@Overridepublic void run() {try {Thread.sleep((long)(Math.random()*100));} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}o.increase();}}class DecreaseThreadO extends Thread {private Operator o;public DecreaseThreadO(Operator o) {this.o = o;}@Overridepublic void run() {try {Thread.sleep((long)(Math.random()*100));} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}o.decrease();}}