BeanUtils的使用
BeanUtils工具类,简化数据封装
* 用于封装JavaBean的
1. JavaBean:标准的Java类
1. 要求:
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setter和getter方法
2. 功能:封装数据
2. 概念:
成员变量:
属性:setter和getter方法截取后的产物
例如:getUsername() --> Username--> username
注意:如果成员变量和setter或getter方法截取后名称不一致,还是会以setter和getter方法截取后的产物获取
3. 方法:
1. setProperty()
2. getProperty()
3. populate(Object obj , Map map):将map集合的键值对信息,封装到对应的JavaBean对象中
import com.code_g.dao.UserDao;
import com.code_g.domain.User;
import org.apache.commons.beanutils.BeanUtils;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
// String username = request.getParameter("username");
// String age = request.getParameter("age");
// User user = new User(username,Integer.parseInt(age));
Map<String, String[]> map = request.getParameterMap();
User user = new User();
try {
BeanUtils.populate(user,map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
request.setAttribute("user",user);
UserDao userDao = new UserDao();
User loginUser = userDao.LoginUser(user);
if (loginUser == null){
request.getRequestDispatcher("/failServlet").forward(request,response);
}else{
request.getRequestDispatcher("/successServlet").forward(request,response);
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request,response);
}
}