JAVA反射機構は反射によりjavabeanを内省操作する

beanクラス

package com.sg.bean;

public class TestBeanReflex {
    private String x;
    private String y;
    public TestBeanReflex(String x, String y) {
        this.x = x;
        this.y = y;
    }
    public String getX() {
        return x;
    }
    public void setX(String x) {
        this.x = x;
    }
    public String getY() {
        return y;
    }
    public void setY(String y) {
        this.y = y;
    }
    }

 

 
 
テストクラス

package com.sg.bean;

import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class IntroSpectorTest {
    public static void main(String[] args) throws Exception {
        TestBeanReflex tbr = new TestBeanReflex("3", "5");

        String propertyName = "x";
        String value = "7";
        // bean 
        Object obj = getProperty(tbr, propertyName);
        System.out.println(obj);
        // bean 
        setProperty(tbr, propertyName, value);
        System.out.println(tbr.getX());
       
    }

    private static void setProperty(Object tbr, String propertyName,
            Object value) throws IntrospectionException, IllegalAccessException,
            InvocationTargetException {
        PropertyDescriptor pd = new PropertyDescriptor(propertyName, tbr.getClass());
        Method method = pd.getWriteMethod();
        method.invoke(tbr, value);
    }

    private static Object getProperty(Object tbr, String propertyName)
            throws IntrospectionException, IllegalAccessException,
            InvocationTargetException {
        /*PropertyDescriptor pd = new PropertyDescriptor(propertyName,
                tbr.getClass());
        Method method = pd.getReadMethod();
        Object obj = method.invoke(tbr);*/
       
        BeanInfo beanInfo  = Introspector.getBeanInfo(tbr.getClass());
        //getPropertyDescriptors bean 
        PropertyDescriptor[] pds = beanInfo.getPropertyDescriptors();
        Object obj  = null;
        for (PropertyDescriptor pd : pds) {
            // 
            if (pd.getName().equals(propertyName)) {
                Method method = pd.getReadMethod();
                obj = method.invoke(tbr);
                break;
            }
        }
        return obj;
    }
}