反射：java.lang.reflect
要被加載的類：
package eg.fortest;
public class WaitingforLoader {
private String str;
static{
System.out.println("loading WaitingforLoader");
}
public WaitingforLoader() {
str="empty";
System.out.println("Constructor of WaitingforLoader without anything.");
}
public WaitingforLoader(String str) {
this.str=str;
System.out.println("Constructor of WaitingforLoader with "+str);
}
public void getStr(int i){
System.out.println("str="+str);
}
}
加載運行的類：
package factory.classfactory;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
//import eg.fortest.WaitingforLoader;不需要這條語句
public class LoadMyClass {
public static void main(String[] args)
throws ClassNotFoundException,
InstantiationException,IllegalAccessException,
NoSuchMethodException, SecurityException,
IllegalArgumentException, InvocationTargetException
{
System.out.println("Program start.");
/**
* 類的加載、鏈接、初始化。
*/
Class<?> clazz = Class.forName("eg.fortest.WaitingforLoader");
/**
* 對象的創建
*/
Object myvar1 = clazz.newInstance();
Constructor cor=clazz.getConstructor(String.class);
Object myvar2 =cor.newInstance("string Parameter");
/**
* 方法調用
*/
Method m =clazz.getMethod("getStr",int.class);
m.invoke(myvar2, 1);
}
}
輸出的結果：
Program start.
loading WaitingforLoader
Constructor of WaitingforLoader without anything.
Constructor of WaitingforLoader with string Parameter
str=string Parameter
