ThreadLocal變量自動與當前線程相關聯，替代Map，HashMap結構：

package cn.qy.heima2;import java.util.Random;public class ThreadLocalTest {private static ThreadLocal<Integer> xLocal= new ThreadLocal<Integer>();public static void main(String[] args) {// TODO Auto-generated method stubfor(int i=0;i<2;i++){new Thread(new Runnable() { @Overridepublic void run() {// TODO Auto-generated method stubint data=new Random().nextInt(); System.out.println(Thread.currentThread().getName()+"has put data:"+data); xLocal.set(data); //xLocal與當前線程相關，進行數據存放 new A().get();new B().get();}}).start(); }} static class A { public void get() { int data=xLocal.get(); //xLocal與當前線程相關，進行數據取出 System.out.println("A from"+Thread.currentThread().getName()+"get data:"+data); } } static class B { public void get() { int data=xLocal.get(); System.out.println("B from"+Thread.currentThread().getName()+"get data:"+data); } } }

?將多個共享變量封裝為一個對象放入ThreadLocal變量里面：

package cn.qy.heima2; import java.util.Random; public class ThreadLocalTest {private static ThreadLocal<Integer> xLocal= new ThreadLocal<Integer>();private static ThreadLocal<MyThreadScopeData> mythreadScopedata=new ThreadLocal<MyThreadScopeData>();public static void main(String[] args) {// TODO Auto-generated method stubfor(int i=0;i<2;i++){new Thread(new Runnable() { @Overridepublic void run() {// TODO Auto-generated method stubint data=new Random().nextInt(); System.out.println(Thread.currentThread().getName()+"has put data:"+data); xLocal.set(data); //xLocal與當前線程相關，進行數據存放MyThreadScopeData mydata= new MyThreadScopeData();mydata.setName("qianyong"+data);mydata.setAge(data);mythreadScopedata.set(mydata);new A().get();new B().get();}}).start(); }} static class A { public void get() { int data=xLocal.get(); //xLocal與當前線程相關，進行數據取出 System.out.println("A from"+Thread.currentThread().getName()+"get data:"+data); MyThreadScopeData mydata=mythreadScopedata.get(); System.out.println("A from"+Thread.currentThread().getName()+",get myName:"+mydata.getName()+",get myAge:"+mydata.getAge()); } } static class B { public void get() { int data=xLocal.get(); System.out.println("B from"+Thread.currentThread().getName()+"get data:"+data); MyThreadScopeData mydata=mythreadScopedata.get(); System.out.println("B from"+Thread.currentThread().getName()+",get myName:"+mydata.getName()+",get myAge:"+mydata.getAge()); } } }class MyThreadScopeData { private String name; private int age; public String getName() {return name; } public void setName(String name) {this.name = name; } public int getAge() {return age; } public void setAge(int age) {this.age = age; } }

運行結果：

Thread-0has put data:-2141728227 Thread-1has put data:1848865996 A fromThread-1get data:1848865996 A fromThread-1,get myName:qianyong1848865996,get myAge:1848865996 A fromThread-0get data:-2141728227 A fromThread-0,get myName:qianyong-2141728227,get myAge:-2141728227 B fromThread-1get data:1848865996 B fromThread-1,get myName:qianyong1848865996,get myAge:1848865996 B fromThread-0get data:-2141728227 B fromThread-0,get myName:qianyong-2141728227,get myAge:-2141728227

通過ThreadLocal變量創建與某一線程相關聯的單例對象：

package cn.qy.heima2; import java.util.Random; public class ThreadLocalTest {private static ThreadLocal<Integer> xLocal= new ThreadLocal<Integer>();private static ThreadLocal<MyThreadScopeData> mythreadScopedata=new ThreadLocal<MyThreadScopeData>();public static void main(String[] args) {// TODO Auto-generated method stubfor(int i=0;i<2;i++){new Thread(new Runnable() { @Overridepublic void run() {// TODO Auto-generated method stubint data=new Random().nextInt(); System.out.println(Thread.currentThread().getName()+"has put data:"+data); xLocal.set(data); //xLocal與當前線程相關，進行數據存放/*MyThreadScopeData mydata= new MyThreadScopeData();mydata.setName("qianyong"+data);mydata.setAge(data);mythreadScopedata.set(mydata);*/MyThreadScopeData.getThreadInstance().setName("qianyong"+data);MyThreadScopeData.getThreadInstance().setAge(data);new A().get();new B().get();}}).start(); }} static class A { public void get() { int data=xLocal.get(); //xLocal與當前線程相關，進行數據取出 System.out.println("A from"+Thread.currentThread().getName()+",get data:"+data); /*MyThreadScopeData mydata=mythreadScopedata.get(); System.out.println("A from"+Thread.currentThread().getName()+",get myName:"+mydata.getName()+",get myAge:"+mydata.getAge());*/ MyThreadScopeData mydata=MyThreadScopeData.getThreadInstance(); System.out.println("A from"+Thread.currentThread().getName()+",get myName:"+mydata.getName()+",get myAge:"+mydata.getAge()); } } static class B { public void get() { int data=xLocal.get(); System.out.println("B from"+Thread.currentThread().getName()+",get data:"+data); /*MyThreadScopeData mydata=mythreadScopedata.get(); System.out.println("B from"+Thread.currentThread().getName()+",get myName:"+mydata.getName()+",get myAge:"+mydata.getAge());*/ MyThreadScopeData mydata=MyThreadScopeData.getThreadInstance(); System.out.println("B from"+Thread.currentThread().getName()+",get myName:"+mydata.getName()+",get myAge:"+mydata.getAge()); } } }class MyThreadScopeData { private MyThreadScopeData() {}; public static /*synchronized*/ MyThreadScopeData getThreadInstance() {MyThreadScopeData instance=map.get();if(instance==null){instance = new MyThreadScopeData();map.set(instance);}return instance; } //private static MyThreadScopeData instance=null; //創建單例,饑漢模式 //new MyThreadScopeData(); 創建單例，飽漢模式private static ThreadLocal<MyThreadScopeData> map=new ThreadLocal<MyThreadScopeData>();private String name; private int age; public String getName() {return name; } public void setName(String name) {this.name = name; } public int getAge() {return age; } public void setAge(int age) {this.age = age; } }

?

轉載于:https://www.cnblogs.com/dddyg/p/10715760.html

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