package otherTests;

/**
 * 基本类
 * @author Phoebus
 *
 */
public class MyClass {

    public MyClass(String msg){
        System.out.println("我是 " + msg);
    }
    
    public MyClass(){
        System.out.println("我是无参数构造函数");
    }
}

 

代码 
package otherTests;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;

/**
 * 测试类
 * @author Phoebus
 *
 */
public class OtherTestsMain {
    public static void main(String[] args) throws IllegalArgumentException,
            SecurityException, InstantiationException, IllegalAccessException,
            InvocationTargetException, NoSuchMethodException {

        //获取所有构造函数
        Constructor ctor[] = MyClass.class.getDeclaredConstructors();
        for (Constructor constructor : ctor) {
            //获取构造函数的参数
            Class c[] = constructor.getParameterTypes();
            if (c.length == 1) {
                MyClass obj = (MyClass) MyClass.class.getConstructor(c)
                        .newInstance("参数构造函数");
            } else {
                //无参数构造 直接newInstance()
                MyClass obj = (MyClass) MyClass.class.newInstance();
            }
        }
    }
}