publicclassMyClass{publicstaticintmyStaticVariable=initializeStaticVariable();privatestaticintinitializeStaticVariable(){// 初始化静态变量的值return30;}} 1. 2. 3. 4. 5. 6. 7. 8. 2.4 构造方法 在Java中,静态成员变量的初始化早于对象的
静态初始化块是一段用static关键字修饰的代码块,在类被加载时执行。通过使用静态初始化块,我们可以在初始化静态变量时执行一些复杂的逻辑。示例如下: publicclassMyClass{publicstaticintmyStaticVariable;static{// 执行一些复杂的逻辑myStaticVariable=calculateValue();}privatestaticintcalculateValue(){// 计算变量的...
static{//can be used to initialize resources when class is loadedSystem.out.println("StaticExamplestaticblock");//can access only static variables and methodsstr="Test"; setCount(2); } 4、静态类 Java可以嵌套使用静态类,但是静态类不能用于嵌套的顶层。 静态嵌套类的使用与其他顶层类一样,嵌套只是...
2. Java Static Method: A static method belongs to a class rather than a object. A static method could be invoked without creating an object. Static method could access and change static data value. 3. Static Block: It is used to initialize static data member. It is executed before main ...
The Initialize-On-Demand Holder Class idiom private static class LazySomethingHolder{ public static Something something = new Something(); }... public static Something getInstance() { return LazySomethingHolder.something;} 上述方式是线程安全的,因为类的初始化是线程安全的。上述方式也是懒初始化的,因为...
LogManager.shutdown(); } /** * Initialize Log4J from the given file location,...
用@EnabledIfEnvironmentVariable标记方法表示需要传入环境变量DEBUG=true才能执行的测试。 运行测试代码,可以看到测试结果。 Config.java 代码语言:javascript 代码运行次数:0 运行 AI代码解释 publicclassConfig{publicStringgetConfigFile(String filename){String os=System.getProperty("os.name").toLowerCase();if(os...
();}/** Private constructor. Only the Java Virtual Machine creates Class objects. //私有构造器,只有JVM才能调用创建Class对象* This constructor is not used and prevents the default constructor being* generated.*/private Class(ClassLoader loader) {// Initialize final field for classLoader. The ...
*/ 在System类中的注释可以知道,调用了initializeSystemClass方法,在此方法中调用了Version对象的init静态方法 sun.misc.Version.init(); 因此sun.misc.Version类会在JDK类库的初始化过程中被加载并初始化。查看Version类定义的私有静态字符串常量如下: private static final String launcher_name = "java"; private ...
public static void main(String args[]) { Zhui zui;GraphicObject tuxing;tuxing = new TiXing(2, 3, 4);System.out.println("梯形的面积是" + tuxing.getArea());zui = new Zhui(tuxing, 30);System.out.println("梯形底的锥的体积是" + zui.getVolum());tuxing = new Circle(10...