java - 匿名类和外部私有(private)字段

Question

在一个方法中定义一个新的匿名类，然后将一个实例分配给一个外部类的私有(private)字段是否合法，就像下面的代码中所评论的那样？我正在学习 Java 并试图了解这背后的原因。谢谢!

public class Outer{
    private int id;
    private String name;
    private SwingWorker doSomething; //Is it ok not to include it in the constructor?  
 public Outer (int id, String name){

    //constructor, but didn't include the instance doSomething
 }
 public void fuctionOne(){
    Swingworker doSomething =new SwingWorker<int, Void>(){
        protected int DoInBackground(){
          ...........// created an anonymous class and override methods 

Answer 1

 public void fuctionOne(){
    Swingworker doSomething = new SwingWorker<int, Void>(){
        protected int DoInBackground(){...

您在这里定义和初始化一个局部变量，而不是分配给 Outer 类的成员。

如果你想初始化Outer的doSomething成员，做

 public void fuctionOne(){
    doSomething = new SwingWorker<int, Void>(){
        protected int DoInBackground(){...

通常，您不必在构造函数中初始化类的所有成员。如果您不初始化它们，它们将获得默认值(在引用类型的情况下为 null)。您只需确保在实际使用它们之前对它们进行初始化。