小编Mar*_*ler的帖子

我增强/测试了我在使用Singleton类初始化/访问的ArrayList上找到的编码

import java.util.ArrayList;

public class SingletonArrayList {

    private static SingletonArrayList mInstance;
    private static ArrayList<String> list = null;

    public static SingletonArrayList getInstance() {
        if (mInstance == null)
            mInstance = new SingletonArrayList();
        SingletonArrayList.list.add("a");
        SingletonArrayList.list.add("b");
        SingletonArrayList.list.add("c");
        return mInstance;
    }

    private SingletonArrayList() {
        list = new ArrayList<String>();
    }

    // retrieve array from anywhere
    public ArrayList<String> getArray() {
        return SingletonArrayList.list;
    }

}

然后我做了一个测试类,我将上述单例调用两次:

import java.util.ArrayList;

public class TestSingletonArrayList {

    public static void main(String[] args) {


        ArrayList<String> array = SingletonArrayList.getInstance().getArray();
        for (int i = …