反射によるオブジェクトの作成(パラメータ付きおよびパラメータなしの構築方法)
3068 ワード
1、エンティティークラスを作成する
2、定義によるクラスのインスタンス化
package adtec.reflect;
public class Person {
String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
//
public Person(String name) {
super();
this.name = name;
}
//
public Person(){
}
public void run(){
System.out.println(getName() + " is running");
}
public void eat(){
System.out.println(getName() + " is eating rice");
}
}
2、定義によるクラスのインスタンス化
package adtec.reflect;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import org.junit.Test;
public class ReflectPerson {
/**
* ,
*/
@Test
public void noParamContruct(){
String classStr = "adtec.reflect.Person";
ClassLoader c1 = ClassLoader.getSystemClassLoader();
Class clazz;
try {
clazz = c1.loadClass(classStr);
Person person = (Person)clazz.newInstance();
person.eat();
person.run();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
/**
* ,
*/
@Test
public void haveParamContruct(){
String classStr = "adtec.reflect.Person";
ClassLoader c1 = ClassLoader.getSystemClassLoader();
try {
Class clazz = c1.loadClass(classStr);
Constructor construct = clazz.getConstructor(String.class);
Person person = (Person)construct.newInstance("huangbiao");
person.eat();
person.run();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (SecurityException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
/**
* Class
*/
@Test
public void newObjectByClass(){
String classStr = "adtec.reflect.Person";
try {
Person person = (Person)Class.forName(classStr).newInstance();
person.eat();
person.run();
} catch (InstantiationException | IllegalAccessException
| ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}