apache commons beanutils

一、引入Maven依赖

<dependency>
    <groupId>commons-beanutils</groupId>
    <artifactId>commons-beanutils</artifactId>
    <version>1.9.4</version>
</dependency>

二、常用API说明

以下使用到一些BO：

Person.java

public class Person {
    private String username;
    private int age;
    private float stature;//身高
    private boolean sex;//性别
    private List list = new ArrayList();
    private String[] friendsNames;
    private Map<String, String> maps = new HashMap<String, String>();
    private Address address;

    public Person() {

    }
    public Person(String username) {
        this.username = username;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public float getStature() {
        return stature;
    }

    public void setStature(float stature) {
        this.stature = stature;
    }

    public boolean isSex() {
        return sex;
    }

    public void setSex(boolean sex) {
        this.sex = sex;
    }

    @SuppressWarnings("unchecked")
    public List getList() {
        return list;
    }

    @SuppressWarnings("unchecked")
    public void setList(List list) {
        this.list = list;
    }

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

    public Map<String, String> getMaps() {
        return maps;
    }

    public void setMaps(Map<String, String> maps) {
        this.maps = maps;
    }

    public String[] getFriendsNames() {
        return friendsNames;
    }

    public void setFriendsNames(String[] friendsNames) {
        this.friendsNames = friendsNames;
    }

    @Override
    public String toString() {
        return "Person{" +
                "username='" + username + '\'' +
                ", age=" + age +
                ", address=" + address +
                '}';
    }
}

Address.java

public class Address {
    private String email;
    private List<String> telephone;
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public List<String> getTelephone() {
        return telephone;
    }
    public void setTelephone(List<String> telephone) {
        this.telephone = telephone;
    }

    @Override
    public String toString() {
        return "Address{" +
                "email='" + email + '\'' +
                ", telephone=" + telephone +
                '}';
    }
}

常用的API如下：

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.beanutils.BeanMap;
import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.ConstructorUtils;
import org.apache.commons.beanutils.MethodUtils;
import org.apache.commons.beanutils.PropertyUtils;

/**
 * org.apache.commons.beanutils 提供了对于JavaBean进行各种操作，克隆对象,属性等等。
 * 常用工具类：
 *  ① PropertyUtils  主要目的是利用反射机制对JavaBean的属性进行处理，减少对JavaBean的处理导致大量get/set代码堆积
 *  ② BeanUtils 属性设置、复制等
 *  ③ BeanMap 将Bean转为BeanMap
 *  ④ MethodUtils 与方法相关的反射工具类
 *  ⑤ ConstructorUtils 与构造器相关的反射工具类
 */
public class BeanUtilsDemo {

    private static void testMethodUtils(){
        try {
            Person person = new Person();

            //获取set方法
            Method setUsernameMethod = MethodUtils.getAccessibleMethod(Person.class, "setUsername", String.class);
            // 调用person的setUsername方法
            setUsernameMethod.invoke(person, "张三");

            //获取get方法
            Method getUsernameMethod = MethodUtils.getAccessibleMethod(Person.class, "getUsername", new Class[]{});
            Object invoke = getUsernameMethod.invoke(person);
            System.out.println(invoke);

            // 直接调用方法
            // exact 是"精确的"。
            // invokeExact方法在调用时要求严格的类型匹配，方法的返回值类型也在考虑范围之内
            // MethodUtils.invokeExactMethod();
            // MethodUtils.invokeExactStaticMethod();
            // MethodUtils.invokeMethod();
            // MethodUtils.invokeStaticMethod();
            Object invokeObj = MethodUtils.invokeMethod(person, "getUsername", new Class[]{});
            System.out.println(invokeObj);


        }catch (Exception e){
            System.out.println("MethodUtils Error");
            e.printStackTrace();
        }
    }

    private static void testConstructorUtils(){
        try {
            // 这个类中的方法主要分成两种，一种是得到构造方法，一种是创建对象。事实上多数时候得到构造方法的目的就是创建对象

            // 直接创建对象
            // 调用无参构造器，参数给个空数组即可; 调用有参构造器，则需要按顺序列出参数值
            Person person = ConstructorUtils.invokeConstructor(Person.class, new Object[]{});
            // Person person = ConstructorUtils.invokeConstructor(Person.class, new Object[]{"李四"});
            System.out.println(person);

            // 获取构造器后，再创建对象
            Constructor accessibleConstructor = ConstructorUtils.getAccessibleConstructor(Person.class, new Class[]{String.class});
            if(null != accessibleConstructor){
                Person newInstance = (Person) accessibleConstructor.newInstance("李四");
                System.out.println(newInstance.getClass());
                System.out.println(newInstance);
            }

        }catch (Exception e){
            System.out.println("ConstructorUtils Error");
            e.printStackTrace();
        }
    }

    private static void testBeanMap(){
        try {
            Person person = new Person();
            person.setUsername("李四");
            person.setAge(22);
            person.setStature(173.5f);
            person.setSex(false);

            Address address = new Address();
            address.setEmail("jhlishero@163.com");
            person.setAddress(address);

            // 将Bean转为Map
            BeanMap beanMap = new BeanMap(person);
            System.out.println(beanMap.get("username"));

            // 克隆, 深拷贝
            BeanMap copyBeanMap = (BeanMap)beanMap.clone();
            System.out.println(copyBeanMap.get("address"));

        }catch (Exception e){
            System.out.println("BeanMap Error");
            e.printStackTrace();
        }
    }

    private static void testBeanUtils(){
        Person person = new Person();
        try {
            //simple property
            BeanUtils.setProperty(person, "username", "李四");
            BeanUtils.setProperty(person, "age", 22);
            BeanUtils.setProperty(person, "stature", 173.5f);
            BeanUtils.setProperty(person, "sex", new Boolean(false));

            //index property
            //List
            List list = new ArrayList();
            list.add("list value 0");
            list.add("list value 1");
            BeanUtils.setProperty(person, "list", list);
            //将list设置到person之后，可以对里面的值进行修改
            String listValue2 = "new list value 1";
            BeanUtils.setProperty(person, "list[1]", listValue2);

            //数组
            String[] str = {"张三", "王五", "赵钱"};
            person.setFriendsNames(str);
            BeanUtils.setProperty(person, "friendsNames[2]", "new赵钱");

            //nest property
            Address address = new Address();
            address.setEmail("jhlishero@163.com");
            List<String> telephoneList = new ArrayList<String>();
            telephoneList.add("12345678911");
            telephoneList.add("92345678911");
            address.setTelephone(telephoneList);
            person.setAddress(address);
            BeanUtils.setProperty(person, "address.telephone[1]", "nest 11111111");
            BeanUtils.setProperty(person, "address.email", "new_jhlishero@163.com");

            System.out.println(BeanUtils.getSimpleProperty(person, "username"));
            System.out.println(BeanUtils.getSimpleProperty(person, "age"));
            System.out.println(BeanUtils.getSimpleProperty(person, "stature"));
            System.out.println(BeanUtils.getSimpleProperty(person, "sex"));
            System.out.println(BeanUtils.getSimpleProperty(person, "list"));
            //list
            System.err.println(BeanUtils.getIndexedProperty(person, "list[0]"));
            System.err.println(BeanUtils.getIndexedProperty(person, "list", 1));
            //数组
            System.out.println(BeanUtils.getIndexedProperty(person, "friendsNames[0]"));
            System.out.println(BeanUtils.getIndexedProperty(person, "friendsNames", 1));
            System.out.println(BeanUtils.getIndexedProperty(person, "friendsNames[2]"));

            //nest--嵌套输出
            System.out.println(BeanUtils.getNestedProperty(person, "address.email"));
            System.out.println(BeanUtils.getNestedProperty(person, "address.telephone[0]"));
            System.out.println(BeanUtils.getNestedProperty(person, "address.telephone[1]"));

            //也可以使用如下方法获取值
            System.out.println(BeanUtils.getProperty(person, "address.telephone[1]"));

            //复制属性
            // 浅拷贝： 只是调用子对象的set方法，并没有将所有属性拷贝。(也就是说，引用的一个内存地址)
            // 深拷贝： 将子对象的属性也拷贝过去。
            // org.springframework.beans.BeanUtils.copyProperties 是浅拷贝
            // org.apache.commons.beanutils.BeanUtils是深拷贝
            Person copyPerson = new Person();
            BeanUtils.copyProperties(copyPerson, person);
            System.out.println(copyPerson.getAddress());

            // 遍历map<key, value>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。
            Person mpPerson = new Person();
            Map<String, String> personMap = new HashMap();
            personMap.put("username", "宋江");
            personMap.put("sex", "true");
            BeanUtils.populate(mpPerson, personMap);
            System.out.println(mpPerson.getUsername());

        } catch (Exception e) {
            System.out.println("BeanUtils Error");
            e.printStackTrace();
        }
    }

    private static void testPropertyUtils(){
        Person person = new Person();
        try {
            //simple property
            PropertyUtils.setSimpleProperty(person, "username", "李四");
            PropertyUtils.setSimpleProperty(person, "age", 22);
            PropertyUtils.setSimpleProperty(person, "stature", 173.5f);
            PropertyUtils.setSimpleProperty(person, "sex", new Boolean(false));

            //index property
            //List
            List list = new ArrayList();
            list.add("list value 0");
            list.add("list value 1");
            PropertyUtils.setSimpleProperty(person, "list", list);
            //将list设置到person之后，可以对里面的值进行修改
            String listValue2 = "new list value 1";
            PropertyUtils.setIndexedProperty(person, "list[1]", listValue2);

            //数组
            String[] str = {"张三", "王五", "赵钱"};
            person.setFriendsNames(str);
            PropertyUtils.setIndexedProperty(person, "friendsNames[2]", "new赵钱");

            //Map
            Map<String, String> map = new HashMap();
            map.put("key1", "vlaue1");
            map.put("key2", "vlaue2");
            map.put("key3", "vlaue3");
            person.setMaps(map);
            PropertyUtils.setMappedProperty(person, "maps", "key1", "new value1");
            PropertyUtils.setMappedProperty(person, "maps(key2)", "maps(key2) value");

            //nest property
            Address address = new Address();
            address.setEmail("jhlishero@163.com");
            List<String> telephoneList = new ArrayList<String>();
            telephoneList.add("12345678911");
            telephoneList.add("92345678911");
            address.setTelephone(telephoneList);
            person.setAddress(address);
            PropertyUtils.setNestedProperty(person, "address.telephone[1]", "nest 11111111");
            PropertyUtils.setNestedProperty(person, "address.email", "new_jhlishero@163.com");

            System.out.println(PropertyUtils.getSimpleProperty(person, "username"));
            System.out.println(PropertyUtils.getSimpleProperty(person, "age"));
            System.out.println(PropertyUtils.getSimpleProperty(person, "stature"));
            System.out.println(PropertyUtils.getSimpleProperty(person, "sex"));
            System.out.println(PropertyUtils.getSimpleProperty(person, "list"));
            //list
            System.err.println(PropertyUtils.getIndexedProperty(person, "list[0]"));
            System.err.println(PropertyUtils.getIndexedProperty(person, "list", 1));
            //数组
            System.out.println(PropertyUtils.getIndexedProperty(person, "friendsNames[0]"));
            System.out.println(PropertyUtils.getIndexedProperty(person, "friendsNames", 1));
            System.out.println(PropertyUtils.getIndexedProperty(person, "friendsNames[2]"));

            //Map
            System.err.println(PropertyUtils.getMappedProperty(person, "maps(key1)"));
            System.err.println(PropertyUtils.getMappedProperty(person, "maps", "key2"));
            System.err.println(PropertyUtils.getMappedProperty(person, "maps(key3)"));

            //nest--嵌套输出
            System.out.println(PropertyUtils.getNestedProperty(person, "address.email"));
            System.out.println(PropertyUtils.getNestedProperty(person, "address.telephone[0]"));
            System.out.println(PropertyUtils.getNestedProperty(person, "address.telephone[1]"));

            //也可以使用如下方法获取值
            System.out.println(PropertyUtils.getProperty(person, "address.telephone[1]"));

            //复制属性
            // 浅拷贝： 只是调用子对象的set方法，并没有将所有属性拷贝。(也就是说，引用的一个内存地址)
            // 深拷贝： 将子对象的属性也拷贝过去。
            // org.apache.commons.beanutils.PropertyUtils
            Person copyPerson = new Person();
            PropertyUtils.copyProperties(copyPerson, person);
            System.out.println(copyPerson.getList().size());


        } catch (Exception e) {
            System.out.println("PropertyUtils Error");
            e.printStackTrace();
        }
    }

    public static void main(String[] args){
        //BeanUtilsDemo.testPropertyUtils();
        //BeanUtilsDemo.testBeanUtils();
        //BeanUtilsDemo.testBeanMap();
        //BeanUtilsDemo.testConstructorUtils();
        BeanUtilsDemo.testMethodUtils();
    }

}