Java学习11.16（人口普查3）

service和servlet层

service.java

import java.util.List;
/**
 * CourseService
 * 服务层
 * @author Hu
 *
 */

//service层相当于一个封装层，封装那些与业务相关的通用数据接口

public class service
{
    dao cdao=new dao();
    /**
     * 添加
     * @param course
     * @return
     */
    public boolean insert(Grade grade)
    {
//        boolean f=false;
//        if(!cdao.id(grade.getID()))
//        {
//            cdao.insert(grade);
//            f=true;
//        }
        cdao.insert(grade);
        return true;
    }
    
    //删除
    
    public void delete(String name)
    {
        cdao.delete(name);
        System.out.println(2);
    }
    
    //修改
    
    public void update (Grade grade)
    {
        cdao.update(grade);
    }
    
    //通过ID得到一个Course    
    
    //通过name得到一个Course    

    //查找
    
    
    //全部数据遍历
    
    public List<Grade> list()
    {
        return cdao.list();
    }

    public Grade selectByName(String name) {
        // TODO Auto-generated method stub
        return cdao.selectByName(name);
    }


}

servlet层

servlet.java

import java.io.IOException;
import java.util.List;

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 com.service;


import com.User;

@WebServlet("/servlet")
public class servlet extends HttpServlet // 继承的是 HttpServlet方法，和网页交互的方法
{
    private static final long serialVersionUID = 1L;

    service service = new service();

    // 方法选择

    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // req是Request（请求）的简写，指的是从jsp/html界面请求回数据，即 jsp/html → 底层
        // resp是Response（回答）的简写，指的是发送给jsp/html的数据，，即 底层 → jsp/html
     
        req.setCharacterEncoding("utf-8");// 设置从jsp或HTML中请求数据的值，也就是设置为中文，防止乱码
        String method = req.getParameter("method");// getParameter()获取的是客户端设置的数据。
        if ("insert".equals(method)) {
            insert(req, resp);
        }
//        // 增
        else if ("delete".equals(method)) {
            delete(req, resp);
        }
//        // 删
        else if ("update".equals(method)) {
            update(req, resp);
        }
        // 改
        else if ("list".equals(method)) {
            list(req, resp);
        }else if ("add1".equals(method)) {
            add1(req, resp);
        }
        // 查
    }

    // 添加

    private void insert(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
        // 首先读取前端网页数据并将数据存入我创建的grade存储空间里，即 jsp/html → servlet

        req.setCharacterEncoding("utf-8"); // 从网页获得数据
        //String name = req.getParameter("name");
        //String sex = req.getParameter("sex");
        // 因为req.getParameter只能获得String类型的数据
        // 所以下面需要用Integer.parseInt（req.getParameter()）来把String类型的数据转换成我们所需的int数据
        String Name = req.getParameter("name");
        String Sex = req.getParameter("sex");
        String nation = req.getParameter("nation");
        String ID = req.getParameter("ID");
        String hometype = req.getParameter("hometype");
        String roomtype = req.getParameter("roomtype");
        String roomnumber = req.getParameter("roomnumber");
        String xueli = req.getParameter("xueli");
        String square = req.getParameter("square");
        String s[]=new String[10];
       
        s[0]="";
        s = req.getParameterValues("category");
      
        Grade grade = new Grade(hometype,roomtype,square,roomnumber,Name,ID,Sex,nation,xueli);

        // 其次进行把grade里的数据与添加到数据库里，即 servlet → mysql数据库
        // 并跳转，req.getRequestDispatcher("add.jsp").forward(req,
        // resp);这一步是跳转到前端jsp/html界面

        if (service.insert(grade)) // 如果添加成功
        {
            req.setAttribute("message", "添加"+grade.getname()+"成功");
            // 这里表示，在req的作用域中设置一个massage变量,变量内容是：添加成功
            // 然后，当跳转到它下一个界面时，这个作用域里的值可以通过Object message
            // =request.getAttribute("message")拿出来使用
            req.getRequestDispatcher("index.jsp").forward(req, resp);
            // 处理完了，分发到下一个JSP页面或者下一个Action继续处理。
        } else {
            req.setAttribute("message", "添加失败！");
            req.getRequestDispatcher("insert.jsp").forward(req, resp);
        }
    }

    // 删除delete

    private void delete(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
        req.setCharacterEncoding("UTF-8");
        String name = req.getParameter("name");
        service.delete(name); // 进行数据库的删除操作
        req.setAttribute("message", "删除成功");
        req.getRequestDispatcher("index.jsp").forward(req, resp);
    }

    // 修改update

    private void update(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
        req.setCharacterEncoding("utf-8");
        
       
        
        
        String name = req.getParameter("name");
        String sex = req.getParameter("sex");
        String nation = req.getParameter("nation");
        String ID = req.getParameter("ID");
        String hometype = req.getParameter("hometype");
        String roomtype = req.getParameter("roomtype");
        String roomnumber = req.getParameter("roomnumber");
        String xueli = req.getParameter("xueli");
        String square = req.getParameter("square");
        String s[]=new String[10];
        s[0]="";
        s = req.getParameterValues("category");
        
        
        
        Grade user = new Grade(hometype,roomtype,square,roomnumber,name,ID,sex,nation,xueli);
        service.update(user);// 进行数据库的修改操作
        req.setAttribute("message", "修改成功");
        req.setAttribute("user", user);
        req.getRequestDispatcher("delete.jsp").forward(req, resp);
        // ?method=list表示传一个叫做method的参数，他的值是list,你可以在Servlet中用request.getParam...获取到。
    }

    // 全部

      private void add1(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
            req.setCharacterEncoding("utf-8");
            String username = req.getParameter("username");
            String password = req.getParameter("password");

            User user = new User(username,password);

            dao dao =new dao();
            boolean f=dao.add1(user);
            if(f) {
                req.setAttribute("message", "登录成功！");
                req.getRequestDispatcher("index.jsp").forward(req,resp);
            } else {
                
                req.setAttribute("message", "用户名或者账号错误！");
                req.getRequestDispatcher("denglu.jsp").forward(req,resp);
            }
        }
    
    private void list(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
        req.setCharacterEncoding("utf-8");
        List<Grade> grade_list = service.list();

        req.setAttribute("grade_list", grade_list);

        req.getRequestDispatcher("list.jsp").forward(req, resp);
    }

}

findservlet.java

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

 

/**
 * Servlet implementation class findservlet
 */
@WebServlet("/findservlet")
public class findservlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    service service=new service();
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //req是Request（请求）的简写，指的是从jsp/html界面请求回数据，即 jsp/html → 底层
        //resp是Response（回答）的简写，指的是发送给jsp/html的数据，，即 底层 → jsp/html
        
        req.setCharacterEncoding("utf-8");//设置从jsp或HTML中请求数据的值，也就是设置为中文，防止乱码
        String method=req.getParameter("method");
        if(method.equals("selectByName1")) {
            selectByName1(req,resp);
        }else if(method.equals("selectByName2")) {
            selectByName2(req,resp);
        }else if(method.equals("selectByName3")) {
            selectByName3(req,resp);
        }
}
        
    private void selectByName1(HttpServletRequest req,HttpServletResponse resp)throws IOException, ServletException {
        req.setCharacterEncoding("utf-8");
        String name=req.getParameter("name");
        System.out.println(name+"....");
        Grade user=service.selectByName(name);
    if(user==null) {
        req.setAttribute("message", "未找到此人！");
        req.getRequestDispatcher("find.jsp").forward(req,resp);
    }else {
        System.out.println("**"+user.getname());
        req.setAttribute("user", user);
        req.getRequestDispatcher("delete.jsp").forward(req,resp);
    }
        //?method=list表示传一个叫做method的参数，他的值是list,你可以在Servlet中用request.getParam...获取到。
    }
    private void selectByName2(HttpServletRequest req,HttpServletResponse resp)throws IOException, ServletException {
        req.setCharacterEncoding("utf-8");
        String name=req.getParameter("name");
        Grade user=service.selectByName(name);
        if(user==null) {
            req.setAttribute("message", "未找到此人！");
            req.getRequestDispatcher("find.jsp").forward(req,resp);
        }else {
        req.setAttribute("user", user);
        
        req.getRequestDispatcher("update.jsp").forward(req,resp);
        }
        //?method=list表示传一个叫做method的参数，他的值是list,你可以在Servlet中用request.getParam...获取到。
    }
    private void selectByName3(HttpServletRequest req,HttpServletResponse resp)throws IOException, ServletException {
        req.setCharacterEncoding("utf-8");
        String name=req.getParameter("name");
        System.out.println("--"+name);
        Grade user=service.selectByName(name);
        if(user==null) {
            req.setAttribute("message", "未找到此人！");
            req.getRequestDispatcher("find.jsp").forward(req,resp);
        }else{
        req.setAttribute("user", user);
        req.getRequestDispatcher("delete.jsp").forward(req,resp);
        }
        //?method=list表示传一个叫做method的参数，他的值是list,你可以在Servlet中用request.getParam...获取到。
    }
}