使用反射获取和设置对象的值

使用java如何获取对象的私有成员变量的值呢?

有一个bean:

public class Student2 {
	/***
	 * 学号
	 */
	private String schoolNumber;
	private String classroom;

	

	public void setSchoolNumber(String schoolNumber) {
		this.schoolNumber = schoolNumber;
	}

	public String getClassroom() {
		return classroom;
	}

	public void setClassroom(String classroom) {
		this.classroom = classroom;
	}

}

 测试:

@Test
	public void test_getObjectValue() throws SecurityException,
			IllegalArgumentException, NoSuchFieldException,
			IllegalAccessException {
		Student2 p = new Student2();
		p.setPersonName("哥斯拉");
		System.out.println(ReflectHWUtils.getObjectValue(p, "personName"));
	}

运行结果:哥斯拉 

 

getObjectValue的实现:

/***
	 * 获取指定对象的属性值
	 * 
	 * @param obj
	 * @param name
	 *            :Field
	 * @return
	 * @throws SecurityException
	 * @throws NoSuchFieldException
	 * @throws IllegalArgumentException
	 * @throws IllegalAccessException
	 */
	public static Object getObjectValue(Object obj, Field name)
			throws SecurityException, NoSuchFieldException,
			IllegalArgumentException, IllegalAccessException {

		// Field f = getSpecifiedField(obj.getClass(), name.getName());
		if (name == null) {
			System.out.println("[ReflectHWUtils.getObjectValue]"
					+ obj.getClass().getName() + " does not has field " + name);
			return null;
		}
		name.setAccessible(true);
		return name.get(obj);
	}

	/***
	 * 获取指定对象的属性值
	 * 
	 * @param obj
	 * @param propertyName
	 * @return
	 * @throws SecurityException
	 * @throws NoSuchFieldException
	 * @throws IllegalArgumentException
	 * @throws IllegalAccessException
	 */
	public static Object getObjectValue(Object obj, String propertyName)
			throws SecurityException, NoSuchFieldException,
			IllegalArgumentException, IllegalAccessException {
		if (ValueWidget.isNullOrEmpty(propertyName)) {
			return null;
		}
		Class<?> clazz = obj.getClass();
		Field name = getSpecifiedField(clazz, propertyName);
		if (ValueWidget.isNullOrEmpty(name)) {
			propertyName=ValueWidget.title(propertyName);//convert "Key2" to "key2"
			name = getSpecifiedField(clazz, propertyName);
			
			if (ValueWidget.isNullOrEmpty(name)) {
				System.out.println("[ReflectHWUtils.getObjectValue]"
						+ obj.getClass().getName() + " does not has field "
						+ propertyName);
			return null;
			}
		}
		return getObjectValue(obj, name);
	}

 

 

 

 

使用反射设置对象的值

 

@Test
	public void test_setObjectValue() throws SecurityException,
			IllegalArgumentException, NoSuchFieldException,
			IllegalAccessException {
		Student2 p = new Student2();
		ReflectHWUtils.setObjectValue(p, "classroom", "三六班");
		System.out.println(p.getClassroom());
	}

 运行结果:

 

三六班

setObjectValue 的实现:

 

/***
	 * 设置对象的属性值。
	 * 
	 * @param obj
	 * @param propertyName
	 *            : property name
	 * @param propertyValue
	 *            : value of property<br> must be String or Field
	 * @throws SecurityException
	 * @throws NoSuchFieldException
	 * @throws IllegalArgumentException
	 * @throws IllegalAccessException
	 */
	public static void setObjectValue(Object obj, Object propertyName,
			Object propertyValue) throws SecurityException,
			NoSuchFieldException, IllegalArgumentException,
			IllegalAccessException {
		if (ValueWidget.isNullOrEmpty(propertyName)
				|| ValueWidget.isNullOrEmpty (propertyValue)) {
			return;
		}
		Class<?> clazz = obj.getClass();
		Field name = null;
		if(propertyName instanceof String){
		name=getSpecifiedField(clazz, (String)propertyName);
		}else{
			name=(Field)propertyName;
		}
		name.setAccessible(true);
		name.set(obj, propertyValue);

	}

 测试类:io0007-find_progess\src\test\java\com\test\UnitTest.java

 

源代码见附件:io0007-find_progess.zip

更多源代码下载:http://pan.baidu.com/s/1kTA7vOr

评论

1 楼 wwwcomy 2014-11-12  

commons-beanutils.jar

org.apache.commons.beanutils.BeanUtils 有这个轮子了