java反射给实体类赋值

给实体类赋值有两种方法,一个是通过Field.set()方法,另一个是Method.invoke();

至于两种方法的区别,还想请教:

我知道的:set直接给属性赋值,invoke通过调用属性的set方法赋值

好了上代码:

实体类:

package testReflect;

public class UserEntity {
private int id;
private String name;
private boolean male;
private boolean isMale;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean getMale() {
return male;
}
public void setMale(boolean male) {
this.male = male;
// this.isMale = male;
}
public boolean isMale() {
return isMale;
}
}

实现类
package testReflect;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class TestSetAndInvoke {
public static UserEntity testSet() throws SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException{
UserEntity ue = new UserEntity();
//UserEntity.class和ue.getClass()有什么不同?
//.class是属性 ue.getClass()需要实例化 是方法
Field f1= UserEntity.class.getDeclaredField("id");
Field f2= ue.getClass().getDeclaredField("name");
//该属性没有set方法
Field f3= ue.getClass().getDeclaredField("isMale");
//该属性有set方法
Field f4= ue.getClass().getDeclaredField("male");
//私有属性设置可访问
f1.setAccessible(true);
f2.setAccessible(true);
f3.setAccessible(true);
f4.setAccessible(true);
//给ue的f1(id属性)设置值为1
f1.set(ue, 1);
//给ue的f2(name属性)设置值为kon
f2.set(ue, "kon");
//给ue的f3(isMale属性)设置值为true
f3.set(ue, true);
//给ue的f4(male属性)设置值为true
f4.set(ue, true);

return ue;
}

public static UserEntity testInvoke() throws InvocationTargetException, IllegalArgumentException, IllegalAccessException{
UserEntity ue = new UserEntity();
Method[] allMethods= UserEntity.class.getDeclaredMethods();
//获得的allMethods是无顺序的;
for (Method method : allMethods) {
if(method.getName().startsWith("get")){
System.out.println(method.getName());
}else{
System.out.println(method.getName());
if("setId".equals(method.getName())){
method.invoke(ue,1);
}else if("setName".equals(method.getName())){
method.invoke(ue,"kon");
}else if("setMale".equals(method.getName())){
method.invoke(ue,true);
}else{
System.out.println("不用设置");
}
}
}

return ue;
}

public static void main(String[] args) throws SecurityException, IllegalArgumentException, NoSuchFieldException, IllegalAccessException, InvocationTargetException {
// UserEntity ue = testSet();
UserEntity ue = testInvoke();
System.out.println(ue.getId()+":"+ue.getName()+" isMale--> "+ue.isMale()+" male: "+ue.getMale());
}
}


输出结果
1:kon isMale--> true male: true

isMale

不用设置

setId

setMale

getMale

getName

getId

setName

1:kon isMale--> false male: true