直接获取对象的某个值
et.createCell(BeanUtils.getProperty(o, eh.getFieldName()));
简单为对象某个字段赋值
c.setCellValue(BeanUtils.getProperty(datas.get(i),headers.get(j).getFieldName()));
beanUtils的底层是内省。下面是又一个小例子，实现了map和bean的映射注入
package com.itcast.domain;
public class Student {
private String username;
private String password;
private int age;
public Student() {
super();
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
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 Student(String username, String password, int age) {
super();
this.username = username;
this.password = password;
this.age = age;
}
@Override
public String toString() {
return "Student [username=" + username + ", password=" + password
+ ", age=" + age + "]";
}
}
package com.itcast.test;
import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.beanutils.BeanUtils;
import org.junit.Test;
import com.itcast.domain.Student;
import com.itcast.utils.CommonUtils;
@SuppressWarnings({"rawtypes","unused"})
public class Test01 {
@Test
public void fun1() throws Exception{
Class cla=Class.forName("com.itcast.domain.Student");
Object stu=cla.newInstance();
BeanUtils.setProperty(stu, "username", "guodaxia");
BeanUtils.setProperty(stu, "password", "12345");
BeanUtils.setProperty(stu, "age", "21");//这个类会自动进行类型转换注入
//System.out.println(stu);
int age=Integer.valueOf(BeanUtils.getProperty(stu, "age"));//getProperty得到的都是String类型
System.out.println(age);
}
/*
*把map中的属性直接封装到一个bean中
*
* Map:{"username":"zhangsan","password","123"}
* 我们要把map的数据封装到一个javaBean中，要求map的key域bean的属性名相同！
*/
@Test
public void fun2() throws Exception{//将Map的内容直接写入一个bean中
Map<String,String> map=new HashMap<String,String>();
map.put("username", "guodaxia");
map.put("password","961012gz");
map.put("age", "21");
Student stu=new Student();
BeanUtils.populate(stu, map);
System.out.println(stu);
}
@Test
public void fun3(){
Map<String,String> map=new HashMap<String,String>();
map.put("username", "guodaxia");
map.put("password","961012gz");
map.put("age", "21");
Student stu=CommonUtils.toBean(map,Student.class);
System.out.println(stu);
}
}
package com.itcast.utils;
import java.util.Map;
import java.util.UUID;
import org.apache.commons.beanutils.BeanUtils;
public class CommonUtils {
/**
* 生成不重复的32位长的大写字符串
* @return
*/
public static String uuid(){
return UUID.randomUUID().toString().replace("-", "").toUpperCase();
}
/**
* 把map转换成指定类型的javabean对象
* @param map
* @param clazz
* @return
*/
public static <T> T toBean(Map<String, String> map,Class<T> clazz){
try {
T bean = clazz.newInstance();
BeanUtils.populate(bean, map);
return bean;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}