Question

java关于布尔的一个疑问

public class Resource {
private String name;
private int count = 1;
private boolean flag ;

public synchronized void set(String name){
if(flag){
try {
this.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
this.name = name + count;
count++;

System.out.println(Thread.currentThread().getName()
+ "The producer name is :++++++++++++++ " + this.name);

flag = true;

this.notify();

}

public synchronized void out(){
if(!flag){
try {
this.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
System.out.println(Thread.currentThread().getName() +
"The consumer name is : ---------------------------" + this.name);
flag = false;

this.notify();

}

}

这是别人举的生产消息的一个例子，我的疑问是这里直接用if(flag)进行判断，flag的初始布尔值是从哪里弄的怎么进入到if里面去？

Answer 1

如果不赋值 会有默认值为false，