代码片段

单例模式

//单例模式
public class SimpleDemo {
    private static  SimpleDemo instance;
    private SimpleDemo (){}
    public static SimpleDemo getInstance(){
        if (instance == null){
            synchronized (SimpleDemo.class){
                if (instance == null){
                    instance = new SimpleDemo();
                }
            }
        }
        return instance;
    }
}

获取Keystore 证书指纹

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