代码在修改更新上有一些缺陷，应该先把相应的要修改的部分查询显示显示出来再进行修改。其实完成增删改查的原理与登录注册是一样的。 1.首先建student类。 public class Studentmodel {private int id;private String name;private String grade;private Str
public class Studentmodel {
private int id;
private String name;
private String grade;
private String gender;
private int age;
private String address;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGrade() {
return grade;
}
public void setGrade(String grade) {
this.grade = grade;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
package cn.edu.hpu.service;
import cn.edu.hpu.model.Studentmodel;
public interface Student {
public boolean addStu(Studentmodel studentmodel);
public boolean delStu(int id);
public boolean updStu(int id,Studentmodel studentmodel);
public Studentmodel selStu(int id);
}
package cn.edu.hpu.service;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.mysql.jdbc.Connection;
import cn.edu.hpu.model.Studentmodel;
import cn.edu.hpu.util.Util;
public class StudentImpl implements Student {
@Override
public boolean addStu(Studentmodel studentmodel) {
boolean flag=false;
String sql="insert into student1(id,name,grade,gender,age,address) value(?,?,?,?,?,?)";
Connection conn=Util.getConnection();
PreparedStatement pst;
try {
pst = conn.prepareStatement(sql);
pst.setInt(1, studentmodel.getId());
pst.setString(2, studentmodel.getName());
pst.setString(3, studentmodel.getGrade());
pst.setString(4, studentmodel.getGender());
pst.setInt(5, studentmodel.getAge());
pst.setString(6, studentmodel.getAddress());
pst.executeUpdate();
flag=true;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return flag;
}
@Override
public boolean delStu(int id) {
boolean flag=false;
String sql="delete from student1 where id="+id;
Connection conn=Util.getConnection();
try {
PreparedStatement pst=conn.prepareStatement(sql);
pst.executeUpdate();
flag=true;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return flag;
}
@Override
public boolean updStu(int id, Studentmodel studentmodel) {
boolean flag=false;
String sql="update student1 set id=?,name=?,grade=?,gender=?,age=?,address=? where id="+id;
Connection conn=Util.getConnection();
PreparedStatement pst;
try {
pst = conn.prepareStatement(sql);
pst.setInt(1, studentmodel.getId());
pst.setString(2, studentmodel.getName());
pst.setString(3,studentmodel.getGrade());
pst.setString(4, studentmodel.getGender());
pst.setInt(5, studentmodel.getAge());
pst.setString(6, studentmodel.getAddress());
pst.executeUpdate();
flag=true;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return flag;
}
@Override
public Studentmodel selStu(int id) {
Studentmodel studentmodel=new Studentmodel();
String sql="select * from student1 where id=?";
Connection conn=Util.getConnection();
try {
PreparedStatement pst=conn.prepareStatement(sql);
pst.setInt(1,id);
ResultSet rs=pst.executeQuery();
while(rs.next()){
//遍历结果集
studentmodel.setId(rs.getInt("id"));
studentmodel.setName(rs.getString("name"));
studentmodel.setGrade(rs.getString("grade"));
studentmodel.setGender(rs.getString("gender"));
studentmodel.setAge(rs.getInt("age"));
studentmodel.setAddress(rs.getString("address"));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// TODO Auto-generated method stub
return studentmodel;
}
}
package cn.edu.hpu.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.edu.hpu.model.Studentmodel;
import cn.edu.hpu.service.Student;
import cn.edu.hpu.service.StudentImpl;
public class tianjia extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
int Id = Integer.parseInt(request.getParameter("id"));
String Name=request.getParameter("name");
String Grade=request.getParameter("grade");
String Gender=request.getParameter("gender");
int Age=Integer.parseInt(request.getParameter("age"));
String Address=request.getParameter("address");
Studentmodel studentmodel=new Studentmodel();
studentmodel.setId(Id);
studentmodel.setName(Name);
studentmodel.setGrade(Grade);
studentmodel.setGender(Gender);
studentmodel.setAge(Age);
studentmodel.setAddress(Address);
Student stu=new StudentImpl();
boolean flag=stu.addStu(studentmodel);
if(flag){
StudentDaoServlet s=new StudentDaoServlet();
s.doPost(request, response);
}
}
}
package cn.edu.hpu.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.edu.hpu.model.Studentmodel;
import cn.edu.hpu.service.Student;
import cn.edu.hpu.service.StudentImpl;
public class shanchu extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
int Id=Integer.parseInt(request.getParameter("id"));
Studentmodel studentmodel=new Studentmodel();
studentmodel.setId(Id);
Student stu=new StudentImpl();
boolean flag=stu.delStu(Id);
if(flag){
StudentDaoServlet s=new StudentDaoServlet();
s.doPost(request, response);
}
}
}
package cn.edu.hpu.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.edu.hpu.model.Studentmodel;
import cn.edu.hpu.service.Student;
import cn.edu.hpu.service.StudentImpl;
public class gengxin extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
int Id=Integer.parseInt(request.getParameter("id"));
String Name=request.getParameter("name");
String Grade=request.getParameter("grade");
String Gender=request.getParameter("gender");
int Age=Integer.parseInt(request.getParameter("age"));
String Address=request.getParameter("address");
Studentmodel studentmodel=new Studentmodel();
studentmodel.setId(Id);
studentmodel.setName(Name);
studentmodel.setGrade(Grade);
studentmodel.setGender(Gender);
studentmodel.setAge(Age);
studentmodel.setAddress(Address);
Student stu=new StudentImpl();
boolean flag=stu.updStu(Id, studentmodel);
if(flag){
StudentDaoServlet s=new StudentDaoServlet();
s.doPost(request, response);
}
}
}
