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public class ThreadScopeShareData {
// private static int data = 0;
private static Map<Thread, Integer> threadData = new HashMap<Thread,Integer>();
public static void main(String[] args) {
for(int i =0;i<2;i++){
new Thread(new Runnable() {
@Override
public void run() {
int data = new Random().nextInt();
threadData.put(Thread.currentThread(), data);
System.out.println(Thread.currentThread().getName()
+ " has put data : " + data);
new A().get();
new B().get();
}
}).start();
}
}
static class A {
public void get() {
int data = threadData.get(Thread.currentThread());
System.out.println(" A from " + Thread.currentThread().getName()
+ " get data : " + data);
}
}
static class B {
public void get() {
int data = threadData.get(Thread.currentThread());
System.out.println(" B from " + Thread.currentThread().getName()
+ " get data : " + data);
}
}
}
Thread-0 has put data : 17163974
Thread-1 has put data : 1317343157
A from Thread-0 get data : 17163974
Exception in thread "Thread-1" java.lang.NullPointerException
at Thread.ThreadScopeShareData$A.get(ThreadScopeShareData.java:29)
at Thread.ThreadScopeShareData$1.run(ThreadScopeShareData.java:20)
at java.lang.Thread.run(Thread.java:744)
B from Thread-0 get data : 17163974