final修饰引用类型的变量时，final只会保证引用类型的变量所引用的地址不会改变，即保证该变量会一直引用同一个对象，否则会出现“Array constants can only be used in initializers”或者“The final local variable user cannot be assigned. It must be blank and not u
在使用Java局部内部类或者内部类时,若该类调用了所在方法的局部变量,则该局部变量必须使用final关键字来修饰,否则将会出现编译错误“Cannot refer to a non-final variable * inside an inner class defined in a different method” 下面通过一段代码来演示和分析原因。 public class Example { public static void ...
final修饰引用类型的变量时,final只会保证引用类型的变量所引用的地址不会改变,即保证该变量会一直引用同一个对象,否则会出现“Array constants can only be used in initializers”或者“The final local variable user cannot be assigned. It must be blank and not using a compound assignment”的异常。 import ...
在使用Java局部内部类或者内部类时,若该类调用了所在方法的局部变量,则该局部变量必须使用final关键字来修饰,否则将会出现编译错误“Cannot refer to a non-final variable * inside an inner class defined in a different method” 下面通过一段代码来演示和分析原因。 public class Example { ...
1).we protect a variable,make it can not be changed in a project . like { final static double pi = 3.1415926; } 2)保护一个方法被重写 2).we protect a method can not be covered. 3)保护一个类被继承。 3).we protect a method can not be inherited ...
* Returns the value in the current thread's copy of this * thread-local variable. If the variable has no value for the * current thread, it is first initialized to the value returned * by an invocation of the {@link #initialValue} method. ...
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 static final String java_version = "1.7.0_51"; private static final String java_runtime_name = "Java(TM) SE Runtime Environment"; private static final String java_runtime_version = "1.7...
简介:【Java异常】Variable used in lambda expression should be final or effectively final 一、背景描述 最近在使用Java8 lambda表达式的时候编辑品,会时不时遇到这样的编译报错,如下图所示: 从字面上来理解这句话,意思是:lambda表达式中使用的变量应该是final或者有效的final,也就是说,lambda 表达式只能引用标记了...
java 更换皮肤问题Cannot refer to a non-final variable inside an inner class defined in a different method 遇到一个很奇怪的错误,想为动态生成的菜单项增加事件处理。大致代码如下: public class MainMenu extends JFrame implements ActionListener{ private String[] themes={"SubstanceAutumnLookAndFeel","...
在Java 8 之前,匿名内部类在使用外部成员的时候,会报错并提示 “Cannot refer to a non-final variable arg inside an inner class defined in a different method”: 但是在 Java 8 之后,类似场景却没有再提示了: 难道是此类变量可以随便改动了吗?当然不是,当你试图修改这些变量的时候,仍然会提示错误: try...