一些操作JavaBean的方法

关于JavaBean的介绍就不说了，直接上代码

测试类

package com.home.test;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.PropertyUtils;

import com.home.util.BeanUtil;

public class Main {

public static void main(String[] args) throws Exception {

Person person = new Person("小飞", 23);
String propertyName1 = "name";
String propertyName2 = "age";
// 这是属性链，birthday是Date类型的，Date中有setTime(long time)方法
String propertyName3 = "birthday.time";

// 1.以下使用PropertyDescriptor操作JavaBean
BeanUtil.setProperty(person, propertyName1, "小明");
System.out.println(BeanUtil.getProperty(person, propertyName1));

// 2.使用BeanInfo操作JavaBean，方法里面一样可以获取和设置属性值
System.out.println(BeanUtil.beanToMap(person));

// 3.使用apache BeanUtils操作JavaBean
BeanUtils.setProperty(person, propertyName1, "小红");
BeanUtils.setProperty(person, propertyName3, "1111112222");
System.out.println(BeanUtils.getProperty(person, propertyName1));
System.out.println(BeanUtils.getProperty(person, propertyName3));

// BeanUtils操作中参数是String类型的 返回结果也是String类型
System.out.println(BeanUtils.getProperty(person, propertyName3).getClass().getName());

// 4.使用apache PropertyUtils操作JavaBean
PropertyUtils.setProperty(person, propertyName1, "小高");
PropertyUtils.setProperty(person, propertyName2, 25);
PropertyUtils.setProperty(person, propertyName3, 1111111111);
System.out.println(PropertyUtils.getProperty(person, propertyName1));
System.out.println(PropertyUtils.getProperty(person, propertyName2));
System.out.println(PropertyUtils.getProperty(person, propertyName3));

// 操作的是什么类型就返回什么类型
System.out.println(PropertyUtils.getProperty(person, propertyName2).getClass().getName());
}

}

Person实体：

package com.home.test;

import java.util.Date;

public class Person {
private String name;
private int age;
private Date birthday = new Date();// 这里要创建对象！

public Date getBirthday() {
return birthday;
}

public void setBirthday(Date birthday) {
this.birthday = birthday;
}

public Person(String name, int age) {
super();
this.name = name;
this.age = age;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

@Override
public String toString() {
return this.name + " " + this.age + " " + this.birthday;
}

}

自己封装的操作JavaBean的工具类BeanUtil

package com.home.util;

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;
import java.util.HashMap;
import java.util.Map;

/**
*
* @description 关于JavaBean的一些操作方法
* @author fj
* @createTime 2016年6月9日
*/
public class BeanUtil {

/**
*
* @description 使用PropertyDescriptor获取JavaBean对象的指定属性的值
* @param obj
* JavaBean对象
* @param propertyName
* 属性名
* @return get方法返回的值
* @throws IntrospectionException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static Object getProperty(Object obj, String propertyName) throws IntrospectionException, IllegalAccessException, InvocationTargetException {
PropertyDescriptor pd = new PropertyDescriptor(propertyName, obj.getClass());// 获取javaBean的属性描述
Method methodGet = pd.getReadMethod(); // 得到get方法
if (methodGet != null) {
return methodGet.invoke(obj); // 调用get方法
}
return null;
}

/**
*
* @description 使用PropertyDescriptor设置JavaBean对象的指定属性的值
* @param obj
* JavaBean对象
* @param propertyName
* 属性名
* @param value
* 需要设置的值
* @throws IntrospectionException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static void setProperty(Object obj, String propertyName, Object value)
throws IntrospectionException, IllegalAccessException, InvocationTargetException {
PropertyDescriptor pd = new PropertyDescriptor(propertyName, obj.getClass());// 获取javaBean的属性描述
Method methodSet = pd.getWriteMethod(); // 得到set方法
if (methodSet != null) {
methodSet.invoke(obj, value);// 调用set方法
}
}

/**
*
* @description 把一个对象转换为map，key为字段，value为字段的值
* @param obj JavaBean对象
* @return map
*/
public static Map<String, Object> beanToMap(Object obj) {
Map<String, Object> result = new HashMap<String, Object>();
if (obj == null) {
return result;
}
try {
Class<?> clazz = obj.getClass();
BeanInfo info = Introspector.getBeanInfo(clazz);
for (PropertyDescriptor pd : info.getPropertyDescriptors()) {
String propertyName = pd.getName();
if (propertyName.equals("class")) {
continue;
}
Method methodGet = pd.getReadMethod();
if (methodGet != null) {
result.put(propertyName, methodGet.invoke(obj));
}
}
} catch (Exception e) {
e.printStackTrace();
}
return result;
}

}