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文章目录
1.BeanUtils位于org.apache.commons.beanutils.BeanUtils常用方法：populate示例常用方法：cloneBean示例：常用方法：copyProperties(Object dest, Object orig)示例：
2.BeanUtils位于org.springframework.beans.BeanUtils常用方法：copyProperties示例：copyProperties(Object source, Object target)示例 copyProperties(Object source, Object target, String... ignoreProperties)
1.BeanUtils位于org.apache.commons.beanutils.BeanUtils
依赖：
commons-beanutils
commons-beanutils
1.9.4
常用方法：populate
static void populate(Object bean, Map properties)
Populate the JavaBeans properties of the specified bean, based on the specified name/value pairs.
这个方法会遍历map中的key，如果bean中有这个属性，就把这个key对应的value值赋给bean的属性。
示例
/**
* org.apache.commons.beanutils.BeanUtils populate(Object bean, Map properties)
*/
@Test
public void testBeanUtilsFromCommons1() throws InvocationTargetException, IllegalAccessException {
Person person = new Person();
HashMap map = new HashMap();
map.put("id", "10086");
map.put("username", "张三");
map.put("address", "地址");
BeanUtils.populate(person, map);
System.out.println(JSON.toJSONString(person));
}
@Data
public class Person {
private Long id;
private String username;
private int age;
public Person(Long id, String username, int age) {
this.id = id;
this.username = username;
this.age = age;
}
public Person() {
}
}
结果：
age是int类型，没有赋值时默认值为0， Person没有address属性，所以不赋值。id为Long类型，但是map中为String类型，类型不一样也能得到值，说明内部进行了类型转换 
常用方法：cloneBean
static Object cloneBean(Object bean)
Clone a bean based on the available property getters and setters, even if the bean class itself does not implement Cloneable.
基于可用的属性getter和setter克隆bean，即使bean类本身没有实现Cloneable。
示例：
/**
* org.apache.commons.beanutils.BeanUtils cloneBean(Object bean)
*/
@Test
public void testBeanUtilsFromCommons2() throws InvocationTargetException, NoSuchMethodException, InstantiationException, IllegalAccessException {
Person person1 = new Person(10086L, "张三", 20);
Person person2 = (Person)BeanUtils.cloneBean(person1);
System.out.println("person1:" + JSON.toJSONString(person1));
System.out.println("person2:" + JSON.toJSONString(person2));
System.out.println(person1.equals(person2));
person2.setId(888L);
System.out.println("person1:" + JSON.toJSONString(person1));
System.out.println("person2:" + JSON.toJSONString(person2));
}
结果： cloneBean将拷贝一份对象，此时person1.equals(person2) 为true， 对person2的id再赋值，不影响person1，说明是两个对象互不影响 
常用方法：copyProperties(Object dest, Object orig)
static void copyProperties(Object dest, Object orig)
Copy property values from the origin bean to the destination bean for all cases where the property names are the same.
对于所有属性名称相同的情况，将属性值从源bean复制到目标bean。
示例：
/**
* org.apache.commons.beanutils.BeanUtils copyProperties(Object dest, Object orig)
*/
@Test
public void testBeanUtilsFromCommons3() throws InvocationTargetException, IllegalAccessException {
Person person1 = new Person(10086L, "张三", 20);
Person person2 = new Person();
BeanUtils.copyProperties(person2, person1);
System.out.println("person1:" + JSON.toJSONString(person1));
System.out.println("person2:" + JSON.toJSONString(person2));
}
结果： 
2.BeanUtils位于org.springframework.beans.BeanUtils
JavaBeans 的静态便捷方法：用于实例化 bean、检查 bean 属性类型、复制 bean 属性等。
常用方法：copyProperties
修饰符和类型 方法及说明
static void copyProperties(Object source, Object target)
将给定源 bean 的属性值复制到目标 bean。
static void copyProperties(Object source, Object target, Class editable)
将给定源 bean 的属性值复制到给定目标 bean 中，仅设置给定“可编辑”类（或接口）中定义的属性。
static void copyProperties(Object source, Object target, String... ignoreProperties)
将给定源 bean 的属性值复制到给定目标 bean 中，忽略给定的“ignoreProperties”。
示例：copyProperties(Object source, Object target)
/**
* org.springframework.beans.BeanUtils copyProperties(Object source, Object target)
*/
@Test
public void testBeanUtilsFromSpringframework1(){
Person person = new Person(10086L, "张三", 20);
Person person2 = new Person();
BeanUtils.copyProperties(person, person2);
System.out.println(JSON.toJSONString(person2));
}
结果： 
示例 copyProperties(Object source, Object target, String… ignoreProperties)
/**
* org.springframework.beans.BeanUtils
* static void copyProperties(Object source, Object target, String... ignoreProperties)
*/
@Test
public void testBeanUtilsFromSpringframework2(){
Person person = new Person(10086L, "张三", 20);
Person person2 = new Person();
BeanUtils.copyProperties(person, person2, "username");
System.out.println(JSON.toJSONString(person2));
}
结果： 
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