⒈  寫(xiě)一個(gè)冒泡排序方法

【參考答案】

publicstaticvoid?Bubble(int?a[]){
for?(int?i?=?0;?i?<?a.length;?i++)?{
for?(int?j?=?a.length-1;?j>i;j++)?{
if?(a[j]

⒉ 子線(xiàn)程循環(huán)10次，接著主線(xiàn)程循環(huán)100，接著又回到子線(xiàn)程循環(huán)10次，接著再回到主線(xiàn)程又循環(huán)100，如此循環(huán)50次，請(qǐng)寫(xiě)出程序。

publicclass?ThreadTest?{
publicstaticvoid?main(String[]?args)?{
new?ThreadTest().init();
}
publicvoid?init(){
final?Business?business=new?Business();
new?Thread(
new?Runnable(){
@Override
publicvoid?run()?{
for?(int?i?=?0;?i?<?50;?i++)?{
business.SubThread(i);
}
}
}
).start();
for?(int?i?=?0;?i?<?50;?i++)?{
business.MainThread(i);
}
}
privateclass?Business{
booleanbShouldSub=true;//這里相當(dāng)于定義了控制該誰(shuí)執(zhí)行的一個(gè)信號(hào)燈
publicsynchronizedvoid?MainThread(int?i){
if?(bShouldSub)?{
try?{
this.wait();
}?catch?(InterruptedException?e)?{
//?TODO?Auto-generated?catch?block
e.printStackTrace();
}
for?(int?j?=?0;?j?<?5;?j++)?{
System.err.println(Thread.currentThread().getName()+":i="+i+",j="+j);
}
bShouldSub=true;
this.notify();
}
}
publicsynchronizedvoid?SubThread(int?i1){
if?(!bShouldSub)?{
try?{
this.wait();
}?catch?(InterruptedException?e)?{
//?TODO?Auto-generated?catch?block
e.printStackTrace();
}
for?(int?j?=?0;?j?<?10;?j++)?{
System.err.println(Thread.currentThread().getName()+":i="+i1+",j="+j);
}
bShouldSub=false;
this.notify();
}
}
}
}

備注：不可能一上來(lái)就寫(xiě)出以上代碼，最初寫(xiě)出來(lái)的代碼如下，問(wèn)題在于兩個(gè)線(xiàn)程的代碼要參照同一個(gè)變量，即這兩個(gè)線(xiàn)程要共享數(shù)據(jù)，所以，把這兩個(gè)線(xiàn)程的執(zhí)行代碼搬到同一個(gè)類(lèi)中區(qū)：

publicclass?thread?{
privatestaticbooleanbShouldMain=false;
publicstaticvoid?main(String[]?args)?{
/*new?Thread(){
public?void?run()?{
for?(int?i?=?0;?i?<?50;?i++)?{
for?(int?j?=?0;?j?<?10;?j++)?{
System.out.println("i="+i+",j="+j);
}
}
}
}.start();*/
//final?String?str?=new?String("");
new?Thread(new?Runnable()?{
publicvoid?run()?{
for?(int?i?=?0;?i?<?50;?i++)?{
synchronized?(Thread.class)?{
if?(bShouldMain)?{
try?{
ThreadTest.class.wait();
}?catch?(InterruptedException?e)?{
//?TODO?Auto-generated?catch?block
e.printStackTrace();
}
}
for?(int?j?=?0;?j?<?10;?j++)?{
System.out.println(Thread.currentThread().getName()+":i="+i+",j="+j);
}
bShouldMain=true;
ThreadTest.class.notify();
}
}
}
}).start();
for?(int?i?=?0;?i?<?50;?i++)?{
if?(!bShouldMain)?{
try?{
ThreadTest.class.wait();
}?catch?(InterruptedException?e)?{
//?TODO?Auto-generated?catch?block
e.printStackTrace();
}
}
for?(int?j?=?0;?j?<5;?j++)?{
System.out.println(Thread.currentThread().getName()+":i="+i+",j="+j);
}
bShouldMain=false;
ThreadTest.class.notify();
}
}
}

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