Java 反射之访问属性_java反射实现框架加入属性方法-优快云博客

本文深入探讨了Java反射机制的应用，包括获取类的所有字段、修改私有变量及设置泛型类型等高级操作。通过实例演示了如何使用反射来访问和修改对象的属性。

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package com.reflect;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.lang.reflect.TypeVariable;

import com.entity.Course;

public class TestField
{
	/**
	 * 
	 * @param args
	 */
	public static void testGetDeclaredFields()
	{
		try
		{
			Class c=Class.forName("com.entity.Student");
			Field[] fields=c.getDeclaredFields();
			for(Field field:fields)
			{
				System.out.println(field.getName());
				System.out.println(field.getModifiers());
				if(field.getModifiers()==Modifier.PRIVATE)
				{
					System.out.println("private");
				}
				
			}
		} catch (ClassNotFoundException e)
		{
			e.printStackTrace();
		} 
	}
	public static void testField()
	{
		try
		{
			Class c=Class.forName("com.entity.Student");
			Object obj=c.newInstance();
			Field field=c.getDeclaredField("money");
			//强制访问
			field.setAccessible(true);
			field.setInt(obj, 1000);
			System.out.println(field.getInt(obj));
			
			field=c.getDeclaredField("address");
			field.setAccessible(true);
			field.set(obj, "北京");
			System.out.println(field.get(obj));
			
			field=c.getDeclaredField("course");
			field.setAccessible(true);
			field.set(obj, new Course("里哈",90));
			Course course=(Course)field.get(obj);
			System.out.println(course.getName()+","+course.getScore());
			
			
		} catch (Exception e)
		{
			e.printStackTrace();
		} 
	}
	public static void testType()
	{
		try
		{
			Class c=Class.forName("com.entity.Student");
			Object obj=c.newInstance();
			Field field=c.getDeclaredField("name");
			System.out.println(field.getType());
			System.out.println(field.getType().getSimpleName());
			if("java.lang.String".equals(field.getType().getName()))
			{
				System.out.println(true);
			}
			
		} catch (Exception e)
		{
			e.printStackTrace();
		} 
	}
	public static void main(String[] args)
	{
		testGetDeclaredFields();
	}
}





package com.entity;

public class Course
{
	private int id;
	private String name;
	private int score;
	
	public Course()
	{
		super();
	}
	public Course(String name, int score)
	{
		super();
		this.name = name;
		this.score = score;
	}
	public String getName()
	{
		return name;
	}
	public void setName(String name)
	{
		this.name = name;
	}
	public int getScore()
	{
		return score;
	}
	public void setScore(int score)
	{
		this.score = score;
	}
	public int getId()
	{
		return id;
	}
	public void setId(int id)
	{
		this.id = id;
	}
	
	
}





package com.entity;

public class Student
{
	private String name;
	private int age;
	private int money;
	private String address;
	private Course course;
	
	public Student()
	{
		super();
		System.out.println("student");
	}
	public Student(String name, int age)
	{
		super();
		this.name = name;
		this.age = age;
		System.out.println(this.name+","+this.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;
	}
	
	private String getHello()
	{
		return "hello";
	}
	
}





student2.xml 

<?xml version="1.0" encoding="UTF-8"?>

<data> 
  <student> 
    <name>李军</name>  
    <age>29</age> 
  </student>  
  <student> 
    <name>李浩</name>  
    <age>21</age> 
  </student> 
</data>

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