BeanUtils框架的简单运用

Sun公司的内省API过于繁琐，所以Apache组织结合很多实际开发中的应用场景开发了一套简单、易用的API操作Bean的属性——BeanUtils

Beanutils工具包的常用类：

•BeanUtils

•PropertyUtils

•ConvertUtils.regsiter(Converter convert, Class clazz)

•自定义转换器

 

首先我们需要导入两个Jar包 一 二

 

package com.cn.gbx;

import java.util.Date;

public class Person {
	
	private String name;
	private String password;
	private int age;
	private Date date = null;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public Date getDate() {
		return date;
	}
	public void setDate(Date date) {
		this.date = date;
	}
	
	@Override
	public String toString() {
		return name + " " + password + " " + age + " " + date.toLocaleString();
	} 
}

　　

package com.cn.gbx;

import java.lang.reflect.InvocationTargetException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.ConversionException;
import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.Converter;
import org.apache.commons.beanutils.locale.converters.DateLocaleConverter;
import org.junit.Test;

public class BeanUtilsDemo {
	@Test
	public void test1() throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
		Person p = new Person();
		BeanUtils.setProperty(p, "name", "gbx");
		System.out.println(p.getName());
		
		String name = null;
		BeanUtils.getMappedProperty("name", name);
		System.out.println(name);
	}
	
	@Test
	public void test2() throws IllegalAccessException, InvocationTargetException {
		
		//为BeanUtils 注册转自己的换器     String to Date
		ConvertUtils.register(new Converter() {
			@Override
			public Object convert(Class type, Object value) {
				if (value == null) {
					return null;
				}
				if (!(value instanceof String)) {
					throw new ConversionException("只支持String的转换");
				}
				String str = (String) value;
				if ("".equals(str.trim())) {
					return null;
				}
				SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd");
				Date date = null;
				try {
					date = sf.parse(str);
				} catch (ParseException e) { 
					throw new RuntimeException(e); //异常连不可断
				}
				return date;
			}
		},
		Date.class);
		
		String name = "gbx";
		String age = "23";
		String password = "123";
		String birth = "1990-11-14";
		
		Person p = new Person();
		BeanUtils.setProperty(p, "name", name);
		BeanUtils.setProperty(p, "age", age);   // BeanUtils自动帮我们完成了转换， 自动的只支持八中基本数据类型
		BeanUtils.setProperty(p, "password", password);
		
		//非八种基本数据类型 我们需要注册自己的转换器
		BeanUtils.setProperty(p, "date", birth);
		
		System.out.println(p);
	}
	
	@Test
	public void test3() throws IllegalAccessException, InvocationTargetException {
		String name = "gbx";
		String age = "23";
		String password = "123";
		String birth = "1990-11-14";
		
		//注册系统为我们提供的转换器
		ConvertUtils.register(new DateLocaleConverter(), Date.class);
		
		Person p = new Person();
		BeanUtils.setProperty(p, "name", name);
		BeanUtils.setProperty(p, "age", age);   // BeanUtils自动帮我们完成了转换， 自动的只支持八中基本数据类型
		BeanUtils.setProperty(p, "password", password);
		
	
		BeanUtils.setProperty(p, "date", birth);
		
		System.out.println(p);
	}
	
	//这样可以直接把表单提交 request交给对象了
	@Test
	public void test4() throws IllegalAccessException, InvocationTargetException {
		ConvertUtils.register(new DateLocaleConverter(), Date.class);
		Person p = new Person();
		Map<String, String> info = new HashMap<String, String>();
		info.put("name", "gbx");
		info.put("age","23");
		info.put("password","123");
		info.put("date", "1990-11-14");
		
		BeanUtils.populate(p, info); // 。。。
		System.out.println(info);
	}
	

}