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BeanUtils

发表于 更新于 分类于 Valine：

概述：一个可以简化封装数据时繁琐操作的工具类

使用：

  1. 加载jar包（本文使用maven）在pom文件中加入 
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    <dependency>
        <groupId>commons-beanutils</groupId>
        <artifactId>commons-beanutils</artifactId>
        <version>1.9.3</version>
    </dependency>
  2. 定义一个标准类（这里使用了Lombok）
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    import lombok.Getter;
    import lombok.Setter;
    import lombok.ToString;

    @ToString
    public class User {
        @Getter@Setter
        private int id;
        @Getter@Setter
        private String username;
        @Getter@Setter
        private String password;
    }

    用法

  3. 使用populate将map中数据封装到JavaBean中
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    public void function() throws ClassNotFoundException, InvocationTargetException, IllegalAccessException {
        User user = new User();
        Map<String,String> map = new HashMap<>();
        BeanUtils.populate(user,map);
    }/*注意key的值要一致*/
  4. 使用setproperty为JavaBean对象赋值
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    public void function() throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        Object bean = Class.forName("itcast.domain.User").getDeclaredConstructor().newInstance();
        BeanUtils.setProperty(bean,"username","张三");
        BeanUtils.setProperty(bean,"password","123456");
    }
  5. 使用getproperty来获取JavaBean对象的键值
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    public void function() throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        Object bean = Class.forName("itcast.domain.User").getDeclaredConstructor().newInstance();
        String username = BeanUtils.getProperty(bean, "username");
        String password = BeanUtils.getProperty(bean, "password");
        BeanUtils.setProperty(bean,"username","张三");
        BeanUtils.setProperty(bean,"password","123456");
    }
  6. 将bean中的值放入Map中
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    public void function()throws Exception{
        Object bean = Class.forName("itcast.domain.User").getDeclaredConstructor().newInstance();
        Map<String, String> map = BeanUtils.describe(bean);
    }
  7. 两个JavaBean对象之间的赋值
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    public void function()throws Exception{
        User user1 = new User();
        user1.setPassword("123456");
        user1.setUsername("张三");
        User user2 = new User();
        BeanUtils.copyProperties(user2,user1);
        System.out.println(user2.toString());
    }
    本文只列举了常用的几种用法，其他内容详见官方API文档