黑马程序员---PropertyDescriptor和BeansUtil

来源：互联网发布：python可以做什么编辑：程序博客网时间：2024/05/17 21:44

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我们有一个注册页面，主题部分如下：

针对此注册页面，我们见一个javaBean

public class Student {

private String username;
private String password;
private String age;
private String birthday;
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 String getAge() {
  return age;
}
public void setAge(String age) {
  this.age = age;
}
public String getBirthday() {
  return birthday;
}
public void setBirthday(String birthday) {
  this.birthday = birthday;
}
@Override
public String toString() {
  return "Student [age=" + age + ", birthday=" + birthday + ", password="
    + password + ", username=" + username + "]";
}
}

用PropertyDescriptor完成填充javaBean

　Student student = new Student();
  Map<String,String[]> map = request.getParameterMap();//得到页面参数组成的的map
  for(Map.Entry<String, String[]> o: map.entrySet())
  {
   String key = o.getKey();
   try {
    PropertyDescriptor pd = new PropertyDescriptor(key, Student.class);//用参数名和javaBean实例化PropertyDescriptor

    Method m = pd.getWriteMethod();//通过对参数名的反射得到setter方法
    m.invoke(student, o.getValue());
   } catch (Exception e) {
    throw new RuntimeException(e);
   }
  }
  System.out.println(student);

这样就把页面的数据存入了javaBean中，不过页面参数名一定要和javaBean中的一致。

BeanUtils把这些封装到了populate(...)中。

Student student = new Student();
  Map<String,String[]> map = request.getParameterMap();
  try {
   BeanUtils.populate(student, map);
  } catch (Exception e) {
   throw new RuntimeException(e);
  }
  System.out.println(student);

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详细请查看：http://edu.csdn.net/heima