javaweb build CRUD project

Beginners javaweb build a small project, for me there is a milestone significance to be considered.

The project set up by the servlet + jsp made to achieve a single table crud function, the project is small, but also with the standard three-tier architecture

Package is structured as follows:
Here Insert Picture Description
building a database statement: CREATE TABLEstudent` (

id int(11) NOT NULL,
name varchar(255) NOT NULL,
age int(11) NOT NULL,
sex varchar(255) NOT NULL,
PRIMARY KEY (id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

The INTO the INSERT studentthe VALUES ( '. 1', 'John Doe', '10', 'M');
the INSERT the INTO studentthe VALUES ( '2', 'John Doe', '11', 'M');
the INSERT the INTO studentthe VALUES ( '. 3 '' king five ',' 12 ',' female ');
INSERT INTO studentVALUES (' 4 ',' Zhao six ',' 13 ',' male ');
INSERT INTO studentVALUES (' 5 ',' ... ',' 13 ',' unknown ');'

1. The entity class
Student.java

package com.cm.entity;

public class Student {
	
	private int id;
	private String name;
	private int age;
	private String sex;
	public Student() {
		super();
	}
	public Student(int id, String name, int age, String sex) {
		super();
		this.id = id;
		this.name = name;
		this.age = age;
		this.sex = sex;
	}
	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 int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	
	
}

PageO.java
(Paging used)

package com.cm.entity;

import java.util.List;

public class PageO {
	//当前页
	private int currentPage;
	//当前页码
	private int pageSize;
	//总数据条数
	private int totalCount;
	//总页数
	private int totalPage;
	private List<Student> students;
	public int getCurrentPage() {
		return currentPage;
	}
	public void setCurrentPage(int currentPage) {
		this.currentPage = currentPage;
	}
	public int getPageSize() {
		return pageSize;
	}
	public void setPageSize(int pageSize) {
		this.pageSize = pageSize;
		this.totalPage=this.totalCount%this.pageSize==0?this.totalCount/this.pageSize:this.totalCount/this.pageSize+1;
	}
	public int getTotalCount() {
		return totalCount;
	}
	public void setTotalCount(int totalCount) {
		this.totalCount = totalCount;
	}
	public int getTotalPage() {
		return totalPage;
	}
//	public void setTotalPage(int totalPage) {
//		this.totalPage = totalPage;
//	}
	public List<Student> getStudents() {
		return students;
	}
	public void setStudents(List<Student> students) {
		this.students = students;
	}
	public PageO(int currentPage, int pageSize, int totalCount, int totalPage, List<Student> students) {
		super();
		this.currentPage = currentPage;
		this.pageSize = pageSize;
		this.totalCount = totalCount;
		this.totalPage = totalPage;
		this.students = students;
	}
	public PageO() {
		super();
	}

}

2.jdbc tools
Dbconn.java

package com.cm.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;



public class Dbconn {

	private static final String URL="jdbc:mysql://localhost:3306/smbms?useunicuee=true& characterEncoding=utf8";
	private static final String USERNAME="root";
	private static final String PASSWORD="123456";
	public static Connection connection=null;
	public static PreparedStatement pstm=null;
	public static ResultSet rs=null;
	public static boolean executeUpdate(String sql,Object[] pstms) {
		
		try {
			Class.forName("com.mysql.jdbc.Driver");
			connection=DriverManager.getConnection(URL,USERNAME,PASSWORD);
			pstm=connection.prepareStatement(sql);
			for (int i = 0; i < pstms.length; i++) {
				pstm.setObject(i+1, pstms[i]);
			}
			
			int count=pstm.executeUpdate();
			if(count>0){
				return true;
				}
			else{
				return false;
			}
			
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();	
			return false;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();	
			return false;
		}catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return false;
	}finally{
		try{
		if(rs!=null)rs.close();
		if(pstm!=null)pstm.close();
		if(connection!=null)connection.close();
		}catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}
		
	}	
	
	}
	
	public static ResultSet qusery(String sql,Object[] pstms){
		
		try {
			Class.forName("com.mysql.jdbc.Driver");
			connection=DriverManager.getConnection(URL,USERNAME,PASSWORD);
			pstm=connection.prepareStatement(sql);
			if(pstms!=null){
			for (int i = 0; i < pstms.length; i++) {
				pstm.setObject(i+1, pstms[i]);
			}
			}
			rs=pstm.executeQuery();	
			return rs;
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
	}
	
		
	}
	
	public static int getTotalCount(String sql) {
		int count=-1;
		
			try {
				rs = qusery(sql, null);
				if (rs.next()) {
				count=rs.getInt(1);
				}
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}finally{
				try{
					if(rs!=null)rs.close();
					if(pstm!=null)pstm.close();
					if(connection!=null)connection.close();
					}catch (Exception e) {
						// TODO: handle exception
						e.printStackTrace();
					}
					
				}
			return count;	
			
		
	}
}

3.dao layer
StudentDao.java

package com.cm.dao;

import java.util.List;
import com.cm.entity.Student;


public interface StudentDao {
	public Student quseryOne(int id);
	public boolean isExist(int id);
	public boolean add(Student student);
	public boolean delete(int id);
	public List<Student> qusery();
	public boolean updata(Student student);
	public int getTotalCount();
	public List<Student> queryByPage(int currentPage,int pageSize);
}

StudentDaoImpl.java

package com.cm.dao.Impl;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.cm.dao.StudentDao;
import com.cm.entity.Student;
import com.cm.util.Dbconn;

public class StudentDaoImpl implements StudentDao {

	public boolean isExist(int id) {
		return quseryOne(id) == null ? false : true;

	}

	public boolean add(Student student) {
		String sql = "insert into student values(?,?,?,?)";
		Object[] pstms = { student.getId(), student.getName(), student.getAge(), student.getSex() };
		return Dbconn.executeUpdate(sql, pstms);
	}

	public boolean delete(int id) {
		String sql = "delete from student where id=?";
		Object[] pstms = { id };
		return Dbconn.executeUpdate(sql, pstms);

	}

	public boolean updata(Student student) {
		String sql = "UPDATE student SET name=?,age=?,sex=? WHERE id=?";
		Object[] pstms = { student.getName(), student.getAge(), student.getSex(), student.getId() };
		return Dbconn.executeUpdate(sql, pstms);
	}

	public Student quseryOne(int id) {
		Student student = new Student();
		student = null;
		ResultSet rs = null;
		try {
			String sql = "select * from student where id=?";
			Object[] pstms = { id };
			rs = Dbconn.qusery(sql, pstms);
			if (rs.next()) {
				String name = rs.getString("name");
				int age = rs.getInt("age");
				String sex = rs.getString("sex");
				student = new Student(id, name, age, sex);
			}
			return student;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		} finally {
			try{
				if(rs!=null)rs.close();
				if(Dbconn.pstm!=null)Dbconn.pstm.close();
				if(Dbconn.connection!=null)Dbconn.connection.close();
				}catch (Exception e) {
					// TODO: handle exception
					e.printStackTrace();
				}
				}

	}

	public List<Student> qusery(){
		List<Student> students=new ArrayList<Student>();
		ResultSet rs=null;
		
			String sql="select * from student";
			rs=Dbconn.qusery(sql, null);
			
				try {
					while(rs.next()) {
					Student student=new Student();
					student.setId( rs.getInt("id"));
					student.setName(rs.getString("name"));
					student.setAge(rs.getInt("age"));
					student.setSex(rs.getString("sex"));
					students.add(student);	
					}
					return students;
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
					return null;
				}finally {
		try{
		if(rs!=null)rs.close();
		if(Dbconn.pstm!=null)Dbconn.pstm.close();
		if(Dbconn.connection!=null)Dbconn.connection.close();
		}catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}
		}
	}
	public int getTotalCount() {
		String sql="select count(1) from student";
		return Dbconn.getTotalCount(sql);
	}

	@Override
	public List<Student> queryByPage(int currentPage,int pageSize) {
		List<Student> students=new ArrayList<Student>();
		ResultSet rs=null;
		String sql="select * from student limit ? ,?";
		int i=(currentPage-1)*pageSize;
		Object[] pstms={i,pageSize};
			rs=Dbconn.qusery(sql, pstms);
			
				try {
					while(rs.next()) {
					Student student=new Student();
					student.setId( rs.getInt("id"));
					student.setName(rs.getString("name"));
					student.setAge(rs.getInt("age"));
					student.setSex(rs.getString("sex"));
					students.add(student);	
					}
					return students;
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
					return null;
				}finally {
		try{
		if(rs!=null)rs.close();
		if(Dbconn.pstm!=null)Dbconn.pstm.close();
		if(Dbconn.connection!=null)Dbconn.connection.close();
		}catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}
		}
	}

}

4.service layer
StudentService.java

package com.cm.service;


import java.util.List;
import com.cm.entity.Student;

public interface StudentService {
	public boolean add(Student student);
	public List<Student> qusery();
	public boolean delete(int id);
	public Student quseryOne(int id);
	public boolean updata(Student student);
	public List<Student> queryByPage(int currentPage,int pageSize);
	public int getTotalCount();

}

StudentServiceImpl.java

package com.cm.service.Impl;

import java.util.List;

import com.cm.dao.StudentDao;
import com.cm.dao.Impl.StudentDaoImpl;
import com.cm.entity.Student;
import com.cm.service.StudentService;


public class StudentServiceImpl implements StudentService {
	StudentDao studentDao=new StudentDaoImpl();
	public boolean add(Student student){
		if (!studentDao.isExist(student.getId())) {
			studentDao.add(student);
			return true;
		}else{
			System.out.println("此人已存在！");
			return false;
		}
		
	}
	public List<Student> qusery() {
		return studentDao.qusery();
	}
	public boolean delete(int id) {
		return studentDao.delete(id);
	}
	public Student quseryOne(int id) {
		return studentDao.quseryOne(id);
		}
	public boolean updata(Student student){
		return studentDao.updata(student);
	}
	public List<Student> queryByPage(int currentPage,int pageSize){
		return studentDao.queryByPage(currentPage, pageSize);
	}
	public int getTotalCount(){
		return studentDao.getTotalCount();
	}

}

The layers view
the servlet
AddStudentServlet.java

package com.cm.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.cm.entity.Student;
import com.cm.service.StudentService;
import com.cm.service.Impl.StudentServiceImpl;



public class AddStudentServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
		throws ServletException, IOException {
	request.setCharacterEncoding("UTF-8");
	int id = Integer.parseInt(request.getParameter("id"));
	String name = request.getParameter("name");
	System.out.println(name);
	int age = Integer.parseInt(request.getParameter("age"));
	String sex=request.getParameter("sex");
	Student student=new Student(id,name,age,sex);
	StudentService studentService=new StudentServiceImpl();
	boolean result=studentService.add(student);
	response.setContentType("text/html;charset=UTF-8");
	response.setCharacterEncoding("utf-8");
	PrintWriter out = response.getWriter();
	if(result==true){
		out.print("增加成功");
	}else {
		out.print("增加失败");
	}
}
@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}
}

DeleteStudentServlet.java

package com.cm.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.cm.service.StudentService;
import com.cm.service.Impl.StudentServiceImpl;



public class DeleteStudentServlet extends HttpServlet {


	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		int id = Integer.parseInt(request.getParameter("id"));
		StudentService studentService=new StudentServiceImpl();
		boolean result=studentService.delete(id);
		response.setContentType("text/html;charset=UTF-8");
		response.setCharacterEncoding("utf-8");
		PrintWriter out = response.getWriter();
		if(result==true){
			out.print("删除成功");
		}else {
			out.print("删除失败");
		}
	}

	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

QueryStudentByPage.java

package com.cm.servlet;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.cm.entity.PageO;
import com.cm.entity.Student;
import com.cm.service.StudentService;
import com.cm.service.Impl.StudentServiceImpl;


public class QueryStudentByPage extends HttpServlet {       
  
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
	PageO pageo=new PageO();
	StudentService studentService=new StudentServiceImpl();
	int totalCount = studentService.getTotalCount();
	pageo.setTotalCount(totalCount);
	pageo.setPageSize(3);
	int currentPage;
	
	if (request.getParameter("currentPage")==null) {
		currentPage=1;
	}else {
		currentPage=Integer.parseInt(request.getParameter("currentPage"));
	}
	pageo.setCurrentPage(currentPage);
	List<Student> students=studentService.queryByPage(pageo.getCurrentPage(), pageo.getPageSize());
	pageo.setStudents(students);
	request.setAttribute("pageo", pageo);
	request.getRequestDispatcher("/paging.jsp").forward(request, response);
	}
	


	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
	
		doGet(request, response);
	}

}

ShowAllStudentServlet.java

package com.cm.servlet;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.cm.entity.Student;
import com.cm.service.StudentService;
import com.cm.service.Impl.StudentServiceImpl;

public class ShowAllStudentServlet extends HttpServlet {


	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		StudentService studentService=new StudentServiceImpl();
		List<Student> students=studentService.qusery();
		request.setAttribute("students", students);
		request.getRequestDispatcher("/list.jsp").forward(request, response);
	
	}

	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}



}

ShowOneStudentSevlet.java

package com.cm.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.cm.entity.Student;
import com.cm.service.StudentService;
import com.cm.service.Impl.StudentServiceImpl;

public class ShowOneStudentSevlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		int id = Integer.parseInt(request.getParameter("id"));
		StudentService studentService=new StudentServiceImpl();
		Student student=new Student();
		student = studentService.quseryOne(id);
		request.setAttribute("student",student);
		request.getRequestDispatcher("/showone.jsp").forward(request, response);
	}

	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

	doGet(request, response);
	}

}

UpdataStudentServlet.java

package com.cm.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.cm.entity.Student;
import com.cm.service.StudentService;
import com.cm.service.Impl.StudentServiceImpl;


public class UpdataStudentServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("UTF-8");
		int id = Integer.parseInt(request.getParameter("id"));
		String name = request.getParameter("name");
		int age = Integer.parseInt(request.getParameter("age"));
		String sex=request.getParameter("sex");
		Student student=new Student(id,name,age,sex);
		StudentService studentService=new StudentServiceImpl();
		boolean result=studentService.updata(student);
		response.setContentType("text/html;charset=UTF-8");
		response.setCharacterEncoding("utf-8");
		PrintWriter out = response.getWriter();
		if(result==true){
			out.print("修改成功");
		}else {
			out.print("修改失败");
		}
		
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

jsp
add.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%
    request.setCharacterEncoding("UTF-8");
	%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
  <body>
    <form action="AddStudentServlet" method="post" >
    学号<input type="text" name="id"><br/>
    姓名<input type="text" name="name"><br/>
    年龄<input type="text" name="age"><br/>
    性别<input type="text" name="sex"><br/>
    <input type="submit" value="提交" />
    </form>
  </body>
</html>

list.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@page import="com.cm.entity.Student,com.cm.servlet.ShowAllStudentServlet,java.util.*"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
   <a  href="add.jsp">新增</a>
   <form action="ShowOneStudentSevlet" method="post">
   <table border="2" align="center">
   <tr><td>学号</td><td>姓名</td><td>年龄</td><td>性别</td></tr>
   <%
   List<Student> students=(List)request.getAttribute("students");
   for(int i=0;i<students.size();i++){
	   Student student = students.get(i);
   %>
   <tr>
   <td> <input type="submit" value="<%=student.getId()%>" name="id"/> </td>
   <td><%=student.getName()%></td>
   <td><%=student.getAge()%></td>
   <td><%=student.getSex() %></td>
   <td></td>
   </tr>
   
   <% }%>
   </table>
   </form>
</body>
</html>

paging.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@page import="com.cm.entity.Student,com.cm.servlet.ShowAllStudentServlet,java.util.*"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
   <a  href="add.jsp">新增</a>
   <form action="ShowOneStudentSevlet" method="post">
   <table border="2" align="center">
   <tr><td>学号</td><td>姓名</td><td>年龄</td><td>性别</td></tr>
   <%
   List<Student> students=(List)request.getAttribute("students");
   for(int i=0;i<students.size();i++){
	   Student student = students.get(i);
   %>
   <tr>
   <td> <input type="submit" value="<%=student.getId()%>" name="id"/> </td>
   <td><%=student.getName()%></td>
   <td><%=student.getAge()%></td>
   <td><%=student.getSex() %></td>
   <td></td>
   </tr>
   
   <% }%>
   </table>
   </form>
</body>
</html>

showone.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%request.setCharacterEncoding("UTF-8");%>
<%@page import="com.cm.entity.Student"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

   <form action="UpdataStudentServlet" method="post">
   <table border="2" align="center">
   <tr><td>学号</td><td>姓名</td><td>年龄</td><td>性别</td><td>操作</td></tr>
   <%
   Student student=(Student)request.getAttribute("student");
   
   %>
   <tr>
   <td><input type="text" value="<%=student.getId()%>" name="id"/></td>
   <td><input type="text" value="<%=student.getName()%>" name="name"/></td>
   <td><input type="text" value="<%=student.getAge()%>" name="age"/></td>
   <td><input type="text" value="<%=student.getSex()%>" name="sex"/></td>
   <td><a href="DeleteStudentServlet?id=<%=student.getId()%>">删除</a></td>
   <td> <input type="submit" value="修改"/></td>
   </tr>
   </table>
   </form>
</body>
</html>

Finally, there is a web.xml file

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  <welcome-file-list>
    <welcome-file>QueryStudentByPage</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>AddStudentServlet</servlet-name>
    <servlet-class>com.cm.servlet.AddStudentServlet</servlet-class>
  </servlet>
  <servlet>
    <servlet-name>ShouAllStudent</servlet-name>
    <servlet-class>com.cm.servlet.ShouAllStudent</servlet-class>
  </servlet>
  <servlet>
    <servlet-name>DeleteStudentServlet</servlet-name>
    <servlet-class>com.cm.servlet.DeleteStudentServlet</servlet-class>
  </servlet>
  <servlet>
    <servlet-name>ShowOneStudentSevlet</servlet-name>
    <servlet-class>com.cm.servlet.ShowOneStudentSevlet</servlet-class>
  </servlet>
  <servlet>
    <servlet-name>UpdataStudentServlet</servlet-name>
    <servlet-class>com.cm.servlet.UpdataStudentServlet</servlet-class>
  </servlet>
  <servlet>
    <servlet-name>QueryStudentByPage</servlet-name>
    <servlet-class>com.cm.servlet.QueryStudentByPage</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>AddStudentServlet</servlet-name>
    <url-pattern>/AddStudentServlet</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>ShouAllStudent</servlet-name>
    <url-pattern>/ShouAllStudent</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>DeleteStudentServlet</servlet-name>
    <url-pattern>/DeleteStudentServlet</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>ShowOneStudentSevlet</servlet-name>
    <url-pattern>/ShowOneStudentSevlet</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>UpdataStudentServlet</servlet-name>
    <url-pattern>/UpdataStudentServlet</url-pattern>
  </servlet-mapping> <servlet-mapping>
    <servlet-name>QueryStudentByPage</servlet-name>
    <url-pattern>/QueryStudentByPage</url-pattern>
  </servlet-mapping>
</web-app>

Operating results as follows:
Here Insert Picture Description
Click the button to enter the operation page id:

This is done Beginners first successful small projects, a large amount of code, but not many realize the function, there are many places are not perfect, now less willing to continue to improve it, but that is able to run the project, be reserved for a memorial.

javaweb build CRUD project

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