BeanUtils工具类

• 封装JavaBean(标准的Java类)

• 注意：

  1. 类必须被public修饰
  2. 必须提供空参的构造器
  3. 成员变量必须使用private修饰
  4. 提供公共的setter和getter方法

• 类中的属性：setter和getter方法截取后的产物

  例如：getUsername() —->Username—–>username

  代码理解

  //UserTest类
  public class UserTest {
      public String getHehe() {
          return gender;
      }
      public void setHehe(String gender) {
          this.gender = gender;
      }
      @Override
      public String toString() {
          return "UserTest{" +
                  "gender='" + gender + '\'' +
                  '}';
      }
      private String gender;
  }
  //测试
  public class BeanUtilsTest {
      @Test
      public void test(){
          UserTest user = new UserTest();
          try {
              BeanUtils.setProperty(user,"hehe","hxx");
              System.out.println(user);
              String hehe = BeanUtils.getProperty(user, "hehe");
              System.out.println(hehe);
          } catch (IllegalAccessException e) {
              e.printStackTrace();
          } catch (InvocationTargetException e) {
              e.printStackTrace();
          } catch (NoSuchMethodException e) {
              e.printStackTrace();
          }
      }
  }
  public class BeanUtilsTest {
      @Test
      public void test(){
          UserTest user = new UserTest();
          try {
         	 	//这里传的是根据setHehe和getHehe方法得到的hehe，进而给gender赋值
              BeanUtils.setProperty(user,"hehe","hxx");
              System.out.println(user);
              String hehe = BeanUtils.getProperty(user, "hehe");
              System.out.println(hehe);
          } catch (IllegalAccessException e) {
              e.printStackTrace();
          } catch (InvocationTargetException e) {
              e.printStackTrace();
          } catch (NoSuchMethodException e) {
              e.printStackTrace();
          }
      }
  }

• 方法

  1. setProperty(属性名，属性值)
  2. getProperty(属性名，属性值)
  3. populate(Object obj,Map map)：将map集合的键值对信息，封装到对应的JavaBean对象