java 中getDeclaredFields() 与getFields() 的区别

java 中getDeclaredFields() 与getFields() 的区别

 

getDeclaredFields()返回Class中所有的字段，包括私有字段。例证：

package com.test.bean;

import java.sql.Timestamp;

public class Person2 {
    private int id;
    private int age;
    private String personName;
    private Timestamp birthdate;
    public String identitify;
    protected String address;
    String phone;

}
@Test
    public void test_getDeclaredFields() {
        Field[]fields=Person2.class.getDeclaredFields();
        for (int i = 0; i < fields.length; i++) {
            Field field = fields[i];
            System.out.println(field.getName());
        }
    }

package com.test.bean;

import java.sql.Timestamp;

public class Person2 {
	private int id;
	private int age;
	private String personName;
	private Timestamp birthdate;
	public String identitify;
	protected String address;
	String phone;
	
}
@Test
	public void test_getDeclaredFields() {
		Field[]fields=Person2.class.getDeclaredFields();
		for (int i = 0; i < fields.length; i++) {
			Field field = fields[i];
			System.out.println(field.getName());
		}
	}

 运行结果：

id

age

personName

birthdate

identitify

address

phone

 

getFields  只返回公共字段，即有public修饰的字段。例证：

@Test
    public void test_getDeclaredFields() {
        Field[]fields=Person2.class.getFields();
        for (int i = 0; i < fields.length; i++) {
            Field field = fields[i];
            System.out.println(field.getName());
        }
    }

@Test
	public void test_getDeclaredFields() {
		Field[]fields=Person2.class.getFields();
		for (int i = 0; i < fields.length; i++) {
			Field field = fields[i];
			System.out.println(field.getName());
		}
	}

 运行结果如下：

identitify

 

总结：

（1）getDeclaredFields()返回Class中所有的字段，包括私有字段；

（2）getFields  只返回公共字段，即有public修饰的字段