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package net.xsoftlab.baike;
import java.lang.reflect.Constructor;
public class TestReflect {
public static void main(String[] args) throws Exception {
Class<?> class1 = null;
class1 = Class.forName("net.xsoftlab.baike.User");
// 第一种方法，实例化默认构造方法，调用set赋值
User user = (User) class1.newInstance();
user.setAge(20);
user.setName("Rollen");
System.out.println(user);
// 结果 User [age=20, name=Rollen]
// 第二种方法 取得全部的构造函数 使用构造函数赋值
Constructor<?> cons[] = class1.getConstructors();
// 查看每个构造方法需要的参数
for (int i = 0; i < cons.length; i++) {
Class<?> clazzs[] = cons[i].getParameterTypes();
System.out.print("cons[" + i + "] (");
for (int j = 0; j < clazzs.length; j++) {
if (j == clazzs.length - 1)
System.out.print(clazzs[j].getName());
else
System.out.print(clazzs[j].getName() + ",");
}
System.out.println(")");
}
// 结果
// cons[0] (java.lang.String)
// cons[1] (int,java.lang.String)
// cons[2] ()
user = (User) cons[0].newInstance("Rollen");
System.out.println(user);
// 结果 User [age=0, name=Rollen]
user = (User) cons[1].newInstance(20, "Rollen");
System.out.println(user);
// 结果 User [age=20, name=Rollen]
}
}
class User {
private int age;
private String name;
public User() {
super();
}
public User(String name) {
super();
this.name = name;
}
public User(int age, String name) {
super();
this.age = age;
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "User [age=" + age + ", name=" + name + "]";
}
}
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