Question

我真的不明白以下static阻止。我在使用方法和变量时理解static关键字，但我不确切知道下面代码中静态关键字的用途是什么。

static
    {
        sURIMatcher.addURI("contacts", "people", PEOPLE);
        sURIMatcher.addURI("contacts", "people/#", PEOPLE_ID);
        sURIMatcher.addURI("contacts", "people/#/phones", PEOPLE_PHONES);
        sURIMatcher.addURI("contacts", "people/#/phones/#", PEOPLE_PHONES_ID);
        sURIMatcher.addURI("contacts", "people/#/contact_methods", PEOPLE_CONTACTMETHODS);
        sURIMatcher.addURI("contacts", "people/#/contact_methods/#", PEOPLE_CONTACTMETHODS_ID);
        sURIMatcher.addURI("contacts", "deleted_people", DELETED_PEOPLE);
        sURIMatcher.addURI("contacts", "phones", PHONES);
        sURIMatcher.addURI("contacts", "phones/filter/*", PHONES_FILTER);
        sURIMatcher.addURI("contacts", "phones/#", PHONES_ID);
        sURIMatcher.addURI("contacts", "contact_methods", CONTACTMETHODS);
        sURIMatcher.addURI("contacts", "contact_methods/#", CONTACTMETHODS_ID);
        sURIMatcher.addURI("call_log", "calls", CALLS);
        sURIMatcher.addURI("call_log", "calls/filter/*", CALLS_FILTER);
        sURIMatcher.addURI("call_log", "calls/#", CALLS_ID);
    }

Answer 1

这在Java中称为静态初始化程序块。这将在类加载时执行。红色这个oracle tutorial。

静态初始值设定项可用于初始化类的类变量。

Answer 2

来自Java Language Specification：

在类中声明的类中声明的静态初始化程序初始化（§12.4.2）。与课程的任何字段初始化程序一起使用变量（§8.3.2），静态初始化器可用于初始化类的类变量。

StaticInitializer:
     static Block

android中的static关键字

2 个答案: