局部内部类对外部属性和变量的访问测试

package test;
/**
 * 
 * 局部内部类能不能访问外围方法或者属性的值 ？
 * 
 * 局部内部类可以访问属性 ，但是不能访问非final的局部变量 
 *
 */
public class Test1 {
    private String attribute ;
    public void f(){
        final String localAttribute = "" ;
        class InnerClass {
            public InnerClass(){
                System.out.println("attribute " + attribute );
                attribute = attribute + "" ;
                //Cannot refer to 
                //the non-final local variable localAttribute 
                //defined in an enclosing scope
                System.out.println("localAttribute " + localAttribute );
                localAttribute = localAttribute + "" ;
            }
        }
    }
}
/**
 * 测试任意代码块中的内部类访问属性和局部变量 
 */
class TestIfLocalClass {
    private String attribute ;
    public TestIfLocalClass(){
        final String localAttribute = "" ;
        if(true){
            class IfLocalClass {
                public IfLocalClass(){
                    System.out.println(attribute);
                    attribute = attribute + "" ;
                    System.out.println(localAttribute);
                    localAttribute = localAttribute + "" ;
                }
            }
        }
    }
}
/**
 * 测试匿名内部类对外围属性和本地变量的访问 
 */
interface TestAnonymousClass{
    public void f() ;
}
class TestAClass{
    private String attribute ;
    public TestAnonymousClass f(){
        final String localAttribute = "" ;
        return new TestAnonymousClass(){
            @Override
            public void f() {
                System.out.println(attribute);
                attribute = attribute + "" ;
                System.out.println(localAttribute);
                localAttribute = localAttribute + "" ;
            }
        } ;
    }
}

通过上面的测试可得，局部内部类能够访问和修改外部类的属性但是不能访问非final修饰的局部变量，可以访问final修饰的局部变量但是不能修改其值。