小编Ale*_*lex的帖子

假设我们有一个类：

public class MyClass extends AbstractClass {

    private AnotherObject ao = null;

    public MyClass() {
        super();
    }

    @Override
    protected void init() {
        ao = new AnotherObject();
        if (ao != null) {
            log.info("NOT NULL");
        }
    }

    @Override
    protected void doSomething() {
        if (ao == null) {
            log.info("It is NULL.");
        }
        ao.doIt(); //NullPointerException here
    }
}

以及相应的抽象类：

public class AbstractClass implements Runnable {
    Thread myThread = null;
    
    AbstractClass () {
        init();
        myThread = new Thread(this, "ThreadName");
        myThread.start();
    }

    public void run() { …