interrupt

对thread对象设置中断标记，但不会执行中断操作。没有返回值。

interrupted & isInterrupted

简单看一下源码，interrupted()方法中调用了isInterrupted()

public static boolean interrupted() {
return currentThread().isInterrupted(true);
}

那么再看isInterrupted,不带参数的isInterrupted()调用了带参数的isInterrupted(false),
（带参数的isInterrupted方法是个native方法，所以就不深究了），看注释可以知道：这个boolean类型的参数ClearInterrupted就是是否reset中断标记的。

也就是说，interrupted()会重置中断标记，而isInterrupted()不会重置。
另一个区别是，interrupted()是一个static方法，用在当前线程；而isInterrupted()是一个instance方法，用在线程实例对象。

public boolean isInterrupted() {
return isInterrupted(false);
}
/**
* Tests if some Thread has been interrupted.  The interrupted state
* is reset or not based on the value of ClearInterrupted that is
* passed.
*/
private native boolean isInterrupted(boolean ClearInterrupted);

总结一下
interrupted(): static方法，检查当前线程的中断标记（返回值类型为boolean），并且会重置中断标记为false
isInterrupted(): 实例方法，检查实例线程的中断标记（返回值类型同样为boolean），但不会重置中断标记

Demo

Demo 1
只在main中调用t.interrupt(), 设置中断标记，但它本身不执行中断，所以输出
Entering thread
Running in C
Running in C
Running in C
…
直到生命尽头

public class GeneralInterrupt implements Runnable {
@Override
public void run() {
System.out.println("Entering thread");
while(true){
System.out.println("Running in C");
}
}

public static void main(String[] args) {
GeneralInterrupt si = new GeneralInterrupt();
Thread t = new Thread(si);
t.start();
try{
Thread.sleep(1000);
}catch (InterruptedException x){
System.out.println("interrupted");
}
t.interrupt();
}
}

Demo 2
main函数没有变化，run中使用中断标记控制循环。
对于第一个循环来说，当中断发生时，Thread.interrupted()为true，跳出第一个循环，同时Thread.interrupted()会将中断标记置为false，这样进入第二个循环Thread.currentThread().isInterrupted()值为false，然后无限循环。
输出
Entering thread
Running in C1
Running in C1
…
…
Running in C1
Running in C2
Running in C2
…
…

public class GeneralInterrupt implements Runnable {
@SuppressWarnings("static-access")
@Override
public void run() {
System.out.println("Entering thread");
//		while(true){
//			System.out.println("Running in C");
//		}
while(!(Thread.interrupted())){
//while(!(Thread.currentThread().isInterrupted())){
System.out.println("Running in C1");
}
while(!Thread.currentThread().isInterrupted()){
System.out.println("Running in C2");
}
System.out.println("Leaving thread");
}
//main没变
public static void main(String[] args) {
GeneralInterrupt si = new GeneralInterrupt();
Thread t = new Thread(si);
t.start();
try{
Thread.sleep(1000);
}catch (InterruptedException x){
System.out.println("interrupted");
}
t.interrupt();
}
}

Demo 3:
对Demo2来说只是把第一个循环中检查中断的语句换成Thread.currentThread().isInterrupted()，这意味着当中断发生时，它不会重置中断标记，所以当下一个循环检查中断标记仍然是false，就不会进入第二个循环。
输出
Entering thread
Running in C1
Running in C1
…
…
Leaving thread

public class GeneralInterrupt implements Runnable {
@SuppressWarnings("static-access")
@Override
public void run() {
System.out.println("Entering thread");
//		while(true){
//			System.out.println("Running in C");
//		}
//while(!(Thread.interrupted())){
while(!(Thread.currentThread().isInterrupted())){
System.out.println("Running in C1");
}
while(!Thread.currentThread().isInterrupted()){
System.out.println("Running in C2");
}
System.out.println("Leaving thread");
}

public static void main(String[] args) {
GeneralInterrupt si = new GeneralInterrupt();
Thread t = new Thread(si);
t.start();
try{
Thread.sleep(1000);
}catch (InterruptedException x){
System.out.println("interrupted");
}
t.interrupt();
}
}