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Common BeanUtils组件方便了对JavaBean的使用。其中的一些类方法，使我们使用JavaBean得到了便利。
使用Common BeanUtils组件需要三个Jar包，分别是
commons-beanutils-1.8.0-BETA.jar
commons-logging-1.1.1.jar
commons-logging-api-1.1.1.jar
下面用四个例子说明该组件的三个优点。
例子一:
创建三个Java文件，分别为
Address.java
Profile.java
User.java
在写一个类文件递进调用函数，命名：BeanUtilsExample1.java，源码：
import java.util.Map;
import java.util.HashMap;import java.util.GregorianCalendar;import org.apache.commons.beanutils.BeanUtils;import org.apache.commons.beanutils.PropertyUtils;
public class BeanUtilsExample1 
{
private User prepareData() {
Profile profile = new Profile(); profile.setEmail("shiyangxt@126.com"); profile.setBirthDate(new GregorianCalendar(3212, 9, 10).getTime()); Map<String, String> phone = new HashMap<String, String>(); phone.put("home", "11011011"); phone.put("office", "82826905"); profile.setPhone(phone); Address[] address = { new Address("中国", "北京", "100120", "天安门北大街888号"),
new Address("中国", "广州", "100120", "石牌村666号") }; profile.setAddress(address); User user = new User(); user.setUserId(new Long(123456789)); user.setUsername("shiyang"); user.setPassword("12345"); user.setProfile(profile); return user; } public static void main(String[] args) { BeanUtilsExample1 example = new BeanUtilsExample1(); User user = example.prepareData(); try { System.out.println("输出对象的属性值---------------------------------"); System.out.println(BeanUtils.getProperty(user, "userId")); System.out.println(BeanUtils.getProperty(user, "username"));//返回字符型 System.out.println(PropertyUtils.getProperty(user, "username"));//返回对象类型 System.out.println(BeanUtils.getProperty(user, "profile.email"));//重点 System.out .println(BeanUtils.getProperty(user, "profile.birthDate"));//重点 System.out.println(BeanUtils.getProperty(user, "profile.phone(home)"));//重点 System.out.println(BeanUtils.getProperty(user, "profile.phone(office)"));//重点 System.out.println(BeanUtils.getProperty(user, "profile.address[0].city"));//重点 System.out.println(BeanUtils.getProperty(user, "profile.address[1].city"));//重点 User user2 = new User(); BeanUtils.copyProperties(user2, user); //两层拷贝，基本类型复制值，对于引用类型（除String，封装类型外）复制地址值。 System.out.println("输出复制属性的属性值-------------------------------"); System.out.println(BeanUtils.getProperty(user, "username")); System.out .println(BeanUtils.getProperty(user, "profile.birthDate"));//重点 System.out.println(BeanUtils.getProperty(user, "profile.phone(home)"));//重点 System.out.println(BeanUtils.getProperty(user, "profile.address[0].addr"));//重点 System.out.println("输出复制属性修改以后的属性值---------------------"); BeanUtils.setProperty(user2, "userId", new Long(8888888)); PropertyUtils.setProperty(user2, "username", "ahah"); BeanUtils.setProperty(user2, "profile.email", "shiyangxt@126.com");//重点 BeanUtils.setProperty(user2, "profile.birthDate",//重点 new GregorianCalendar(1900, 2, 5).getTime()); BeanUtils.setProperty(user2, "profile.address[0]", new Address( "中国", "深圳", "600600", "深北大道111号"));//重点 System.out.println(BeanUtils.getProperty(user2, "userId")); System.out.println(BeanUtils.getProperty(user2, "username")); System.out.println(BeanUtils.getProperty(user2, "profile")); System.out.println(BeanUtils.getProperty(user2, "profile.email"));//重点 System.out.println(BeanUtils .getProperty(user2, "profile.birthDate"));//重点 System.out.println(BeanUtils.getProperty(user2, "profile.address[0].city"));//重点 System.out.println("与被复制属性值的对象的比较-------------------------------"); System.out.println(BeanUtils.getProperty(user, "userId")); System.out.println(BeanUtils.getProperty(user, "username")); System.out.println(BeanUtils.getProperty(user, "profile")); System.out.println(BeanUtils.getProperty(user, "profile.email"));//重点 System.out .println(BeanUtils.getProperty(user, "profile.birthDate"));//重点 System.out.println(BeanUtils.getProperty(user, "profile.address[0].city"));//重点 } catch (Exception e) { e.printStackTrace(); } }
}
从中可以看出，
调用一个属性中的方法，只需要加一个“.”即可。精简了操作。
还可以拷贝属性，但要注意是二层拷贝。
还要注意BeanUtils和PropertyUtils的区别。
例子二:
动态创建属性
文件名：BeanUtilsExample2，源码：
import java.util.GregorianCalendar;import org.apache.commons.beanutils.LazyDynaBean;import org.apache.commons.beanutils.BeanUtils;public class BeanUtilsExample2 { //动态创建属性 public static void main(String args[]) throws Exception { LazyDynaBean hh = new LazyDynaBean(); hh.set("country", "中国"); hh.set("city", "北京"); hh.set("postCode", "100120"); hh.set("addr", "aaaaaaa"); LazyDynaBean bb = new LazyDynaBean(); bb.set("phone", "home", "11011011"); bb.set("phone", "office", "111111"); bb.set("email", "sh@126.com"); bb.set("address", 0, hh); bb.set("birthDate", new GregorianCalendar(1990, 3, 29).getTime()); LazyDynaBean tt = new LazyDynaBean(); tt.set("userId", new Long(8888888)); tt.set("gggg", "施杨"); tt.set("password", "sgsgsgsg"); tt.set("dddd", bb); System.out.println(BeanUtils.getProperty(tt, "gggg")); System.out.println(BeanUtils.getProperty(tt, "dddd.birthDate")); System.out.println(BeanUtils.getProperty(tt, "dddd.address[0].addr")); System.out .println(BeanUtils.getProperty(tt, "dddd.phone(office)")); }}
例子三:
连接Mysql数据库
文件名BeanUtilsExample3.java源码：
import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.util.Iterator;import org.apache.commons.beanutils.DynaBean;import org.apache.commons.beanutils.ResultSetDynaClass;public class BeanUtilsExample3 { public static void main(String args[]) throws Exception { Connection conn = getConnection(); PreparedStatement ps = conn .prepareStatement("select id,title,time from guestbook2 order by id desc"); ResultSet rs = ps.executeQuery(); ResultSetDynaClass rsdc = new ResultSetDynaClass(rs);//重点，二次封装，对连接对象有依赖 Iterator itr = rsdc.iterator(); while (itr.hasNext()) { DynaBean bean = (DynaBean) itr.next(); System.out.print(bean.get("id") + "\t"); System.out.print(bean.get("title") + "\t"); System.out.println(bean.get("time")); } conn.close(); } private static Connection getConnection() { String url = "jdbc:mysql://localhost:3306/guestbook"; String username = "root"; String password = "hicc"; Connection conn = null; try { Class.forName("com.mysql.jdbc.Driver"); conn = DriverManager.getConnection(url, username, password); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } return conn; }}
例子四:
文件BeanUtilsExample4.java，源码：
import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.util.Iterator;import org.apache.commons.beanutils.DynaBean;import org.apache.commons.beanutils.RowSetDynaClass;public class BeanUtilsExample4 { public static void main(String args[]) throws Exception { Connection conn = getConnection(); PreparedStatement ps = conn .prepareStatement("select id,title,time from guestbook2 order by id desc"); ResultSet rs = ps.executeQuery(); RowSetDynaClass rsdc = new RowSetDynaClass(rs); //重点，与ResultSetDynaClass的区别 conn.close();//重点，关闭连接后仍能读取 Iterator itr = rsdc.getRows().iterator(); while (itr.hasNext()) { DynaBean bean = (DynaBean) itr.next(); System.out.print(bean.get("id") + "\t"); System.out.print(bean.get("title") + "\t"); System.out.println(bean.get("time")); } } private static Connection getConnection() { String url = "jdbc:mysql://localhost:3306/guestbook"; String username = "root"; String password = "hicc"; Connection conn = null; try { Class.forName("com.mysql.jdbc.Driver"); conn = DriverManager.getConnection(url, username, password); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } return conn; }}
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