运用IntrosPector(内省）获取和操作javabean的属性

超、凢脫俗 2022-02-03 00:05 366阅读 0赞

# 什么是javabean？ #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDA1NjY2_size_16_color_FFFFFF_t_70]

# 自省可以干什么？ #

**我们在获取javabean的属性的时候通常用new对象的形式来调用，这种方法使得代码的通用性变得特别差，所以就得用内省，它的用途和反射差不多，都是提高代码的重用性，使得代码变得十分灵活。**

# 要测试javabean #

package TestIntrosPector;
    
    public class People { 
    	private int age;
    	private String name;
    	private char sex='女';
    	
    	public People() { 
    		super();
    	}
    	public People(int age, String name, char sex) { 
    		super();
    		this.age = age;
    		this.name = name;
    		this.sex = sex;
    	}
    	public String getWaihao() { 
    		return "我的外号是二狗"+name;
    	}
    	public int getAge() { 
    		System.out.println("我的芳龄");
    		return age;
    	}
    	public void setAge(int age) { 
    		this.age = age;
    	}
    	public String getName() { 
    		System.out.println("原名王尼玛");
    		return name;
    	}
    	public void setName(String name) { 
    		this.name = name;
    	}
    	public char getSex() { 
    		System.out.println("默认人妖");
    		return sex;
    	}
    	public void setSex(char sex) { 
    		this.sex = sex;
    	}
    	
    }

# 自省工具类 #

package TestIntrosPector;
    
    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 IntrosPectorDemo { 
    	public static void main(String[] args) throws IntrospectionException, IllegalAccessException, IllegalArgumentException, InvocationTargetException { 
    		//1.通过intropestor分析出字节码对象的信息beaninfo
    		BeanInfo bean=Introspector.getBeanInfo(People.class, Object.class);//左闭右开，过滤父类的benninfo
    		//2.通过调用getpro....方法获取对象的属性描述器
    		PropertyDescriptor[] pro=bean.getPropertyDescriptors();
    		for (PropertyDescriptor property : pro) { 
    			String name=property.getName();//3.获取属性的名称，getname继承父类的方法
    			//4.得到属性的类型
    			System.out.println("属性类型："+property.getPropertyType());
    			System.out.println("属性名字："+name);
    			if(name.equals("waihao")) { 
    				Method meth=property.getReadMethod();//获取读属性的方法get
    				Object obj=meth.invoke(new People());//执行对象的属性的get方法
    				System.out.println(obj);
    			}
    			System.out.println("获取属性的set方法"+property.getWriteMethod());//
    			System.out.println("获取属性的个体方法"+property.getReadMethod());//
    			System.out.println("--------------------");			
    		}
    	}
    }

# 测试效果 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDA1NjY2_size_16_color_FFFFFF_t_70 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDA1NjY2_size_16_color_FFFFFF_t_70]: /images/20220203/140b147224414242b46936024eae79cc.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDA1NjY2_size_16_color_FFFFFF_t_70 1]: /images/20220203/526b176aa7a9493ebc7fcf9c78237aae.png