Java反射(三)在运行时利用反射分析对象

时间:2021-09-27 09:21:47

在运行时利用反射分析对象,其实就是利用反射来获得或者设置类的域。举例如下:

有一个Student类:

package testreflection;

public class Student {
	private String stuNum;

	public Student(String stuNum) {
		this.stuNum = stuNum;
	}
}

利用反射来获得和设置Student类的stuNum域的测试代码如下:

package testreflection;

import java.lang.reflect.Field;

public class ObjectAnalyzerTest {

	public static void main(String[] args) {
		Student student = new Student("20101120244");
		Class cl = student.getClass();
		try {
			Field field = cl.getDeclaredField("stuNum");
			// 这一句对于访问私有域的值是必须的
			field.setAccessible(true);
			// 获得域
			Object object = field.get(student);
			System.out.println(object);
			
			// 设置域
			field.set(student, "20121120064");
			Object object1 = field.get(student);
			System.out.println(object1);
		} catch (NoSuchFieldException e) {
			e.printStackTrace();
		} catch (SecurityException e) {
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}

	}

}

运行ObjectAnalyzerTest结果如下:

20101120244
20121120064