JavaBean的属性用反射访问的基础知识
2017-10-21 本文已影响0人
exmexm
1、简单利用配置文件以及反射生成一个实体类：
配置 文件内容：
image.png
代码实现：
package com.winney.dayst;
import java.io.IOException;
import java.util.Properties;
import java.util.Set;
public class Winney {
public static void main(String[] args) {
Properties pros = new Properties();
try {
pros.load(Winney.class.getResourceAsStream("classConfig.properties"));
} catch (IOException e) {
e.printStackTrace();
throw new RuntimeException("加载配置文件失败!");
}
String className = pros.getProperty("className");
try {
Set<String> set = (Set) Class.forName(className).newInstance();
set.add("winney");
set.add("hello");
System.out.println(set.toString());
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
}
2、利用通过javaBean的属性描述new一个propertyDescriptor，然后利用propertyDescriptor.getReadMethod或者propertyDescriptor.getWriteMethod获得setter和getter方法。
代码如下:
public class TestSetAGet {
public static void main(String[] args)
throws IntrospectionException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
Person person = new Person("01", "person Wang");
// 输出person的name属性 name->Name,getName->
String propertyName = "Name";
PropertyDescriptor pd = new PropertyDescriptor(propertyName, person.getClass());
Method getMethod = pd.getReadMethod();
String retVal = (String) getMethod.invoke(person, null);
System.out.println(retVal);
// 设置person的name setName
Method setMethod = pd.getWriteMethod();
retVal = (String) setMethod.invoke(person, "person LI");
System.out.println(getMethod.invoke(person, null));
}
}
