Java中的Class对象

Java中的Class对象

Java中的Class对象- -

                                      

Java程序在运行时每个类都会对应一个Class对象,可以从Class对象中得到与类相关的信息,例如:

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public class MyClass {

public static void main(String[] args) {

String name = "ZhuJun";

Class c = name.getClass();

System.out.println("getName: " + c.getName());

System.out.println("isInterface: " + c.isInterface());

System.out.println("isPrimitive: " + c.isPrimitive());

System.out.println("isArray: " + c.isArray());

System.out.println("SuperClass: " + c.getSuperclass().getName());

}

}

输出结果:

getName: java.lang.String

isInterface: false

isPrimitive: false

isArray: false

SuperClass: java.lang.Object

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对于简单类型boolean, byte, char, short, int, long, float, double以及关键字void,可以通过类常量class取得对应的Class对象,例如:

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public class MyClass {

public static void main(String[] args) {

System.out.println(boolean.class.getName());

System.out.println(boolean.class.isPrimitive());

System.out.println(void.class.getName());

}

}

输出结果:

boolean

true

void

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Class类有一个forName()静态方法,可以根据传入的类名称(Class Name)得到相应类的实例,例如:

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class TestClass {

void say(){

System.out.println("This is instance of TestClass"):

}

}

public class Main {

public static void main(String[] args) {

try {

Class c = Class.forName("TestClass");

TestClass testClass = c.newInstance();

testClass.say();

}

catch(ClassNotFoundException e) {

e.printStackTrace();

}

}

}

输出结果:

This is instance of TestClass

 

 

 

评论

1 楼 byandby 2010-04-24  

Class类有一个forName()静态方法,可以根据传入的类名称(Class Name)得到相应类的实例 ? 得到实例?  真的?