1缭受、反射

1.Class.forName("")
根據(jù)給定字符串加載類。
2.newInstance()
創(chuàng)建由class表示的類實例對象
3.getMethods()
返回所有的公共方法，包含父類
4.getDeclaredMethods()
返回類或接口的聲明方法包括public, protected, default (package)，不包含繼承方法
5.method.invoke(obj,args)
執(zhí)行方法，需要傳入執(zhí)行對象及參數(shù)唬渗。
執(zhí)行私有方法需要設置method.setAccessible(true);
6.getClassLoader()
獲取classLoader BootstrapLoader->ExtClassLoader->AppClassLoader

public class TestClass {
    public TestClass() {
        System.out.println("init TestClass");
    }

    private void myPrivateMethod(){
        System.out.println("this is a private method");
    }

    public void myPublicMethod(){
        System.out.println("this is a public method");
    }
}


public class ClassTest {

    @Test
    public void testClassLoader(){
        ClassLoader classLoader = Test.class.getClassLoader();
        System.out.println(classLoader);

        ClassLoader classLoader1 = classLoader.getParent();
        System.out.println(classLoader1);

        ClassLoader classLoader2 = classLoader1.getParent();
        System.out.println(classLoader2);
    }

    @Test
    public void testInstance() throws ClassNotFoundException, IllegalAccessException, InstantiationException, InvocationTargetException {
        Class<TestClass> s = (Class<TestClass>) Class.forName("TestClass");
        TestClass testInstance = s.newInstance() ;
        for(Method method: s.getMethods()){
            System.out.println(method);
        }

        System.out.println("\n");
        for(Method method: s.getDeclaredMethods()){
            System.out.println(method);
            method.setAccessible(true);
            method.invoke(testInstance,null) ;
        }
    }
}

//輸出信息
sun.misc.Launcher$AppClassLoader@18b4aac2
sun.misc.Launcher$ExtClassLoader@452b3a41
null

init TestClass
public void TestClass.myPublicMethod()
public final void java.lang.Object.wait() throws java.lang.InterruptedException
public final void java.lang.Object.wait(long,int) throws java.lang.InterruptedException
public final native void java.lang.Object.wait(long) throws java.lang.InterruptedException
public boolean java.lang.Object.equals(java.lang.Object)
public java.lang.String java.lang.Object.toString()
public native int java.lang.Object.hashCode()
public final native java.lang.Class java.lang.Object.getClass()
public final native void java.lang.Object.notify()
public final native void java.lang.Object.notifyAll()


private void TestClass.myPrivateMethod()
this is a private method
public void TestClass.myPublicMethod()
this is a public method