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JDBC - 开发实例 - MVC模式

JDBC - 开发实例 - MVC模式

 1. 在web.xml中配置连接数据库的信息

   web.xml:

  <context-param>

    <param-name>server</param-name>  //主机名

    <param-value>localhost</param-value>  

  </context-param>

  <context-param>

    <param-name>db</param-name>  //数据库

    <param-value>test</param-value>  

  </context-param>

  <context-param>

    <param-name>user</param-name>  //用户名

    <param-value>root</param-value>  

  </context-param>

  <context-param>

    <param-name>password</param-name>  //密码

    <param-value>1234</param-value>  

  </context-param>

2. 数据层-创建实体类Student.java

  Student.java:

  package gh.test.entity;

  

  public class Student{

    private int id;

    private String name;

    private int gender;

    private int age;

    private String address;

    private String tel;

    public void setId(int id){    //学号

      this.id = id;

    }

    public int getId(){

      return id;

    }

    public void setName(String name){    //姓名

      this.name = name;

    }

    public String getName(){

      return name;

    }

    public void setGender(int gender){    //性别

      this.gender = gender;

    }

    public int getGender(){

      retuen gender;

    }

    public void setAge(int age){    //年龄

      this.age = age;

    }

    public int getAge(){

      return age;

    }

    public void setAddress(String address){    //地址

      this.address = address;

    }

    public String getAddress(){

      return address;

    }

    public void setTel(String tel){

      return tel;

    }

  }

3. 数据访问层-创建数据库操作类 DB.java & 学生DAO类 StudentDao.java

  DB.java:

  package gh.test.dao;

 

  import java.sql.DriverManager;

  import java.sql.Connection;

  import java.sql.PreparedStatement;

  import java.sql.ResultSet;

  import java.sql.SQLException;

  

  public class DB{

    Connection conn = null;

    PreparedStatement ps = null;

    ResultSet rs = null;

    public Connection getConn

    (String server,String db,String user,String password)throws ClassNotFoundException,InstantiationException,IllegalAccessException,SQLException{  //获取对象

      String driver = "com.mysql.jdbc.Driver";    

      String url = "jdbc:mysql://"+server+":3306/"+db+"?user="+user+"&password="+password+"&characterEncoding=utf-8";

      Class.forName(driver);    //加载驱动

      Connection conn = DriverManager.getConnection(url);    //创建Connection对象

      return conn;

    }

    public ResultSet executeQuery(String sql,String[] params){    //执行查询操作

      try{

          ps = conn.prepareStatement(sql);

          if(params != null){

            for(int i=0;i<params.length;i++){

              ps.setString(i+1,params[i]);

            }

          }

           rs = ps.executeQuery();

      }

      catch(SQLException ex){

        ex.printStackTrace();

      }

      return rs;

    }

    public int executeUpdate(String sql,String[] params){    //执行更新操作

      int n = 0;

      try{

        ps = conn.prepareStatement(sql);

        if(params != null){

          for(int i=0;i<params.length;i++){

            ps.setString(i+1,params[i]);

          }

          n = ps.executeUpdate();

        }

      }catch(SQLException ex){

        ex.printStackTrace();

      }

      return n;

    }

    public void closeAll(){

      if(rs != null){

        try{

          rs.close();

        }catch(SQLException ex){

          ex.printStackTrace();

        }

      }

      if(ps != null){

        try{

          ps.close();

        }catch(SQLException ex){

          ex.printStackTrace();

        }

      }

      if(conn != null){

        try{

          conn.close();

        }catch(SQLException ex){

          ex.printStackTrace();

        }

      }

    }

  }

 

  StudentDao.java:

    package gh.test.dao;

  import gh.test.entity.Student;

  

  public class StudentDao extends DB{

    public int addStudent(Student student){

      String name = student.getName();

      String gender = student.getGender()+"";

      String  age = student.getAge()+"";

      String address = student.getAddress();

      String tel = student.getTel();

      String[] params = new String[]{name,gender,age,address,tel};

      String sql = "insert into studentInfo values(?,?,?,?,?)";

      int result = super.executeUpdate(sql,params);

      return result;

     } 

  }

 

4. 视图显示层&逻辑处理-addStudent.html & AddStudentServlet.java

  addStudent.html:

  <html>

    <head>

      <meta http-equiv="Content-Type" content="text/html;charset=utf-8">

      <title>添加学生信息</title>

    </head>

    <body>

      <form name="form1" action="AddStudentServlet" method="post">

        <table>

          <tr>

            <th colspan="2">学生信息</th>

          </tr>

          <tr>

            <td>姓名:</td>

            <td><input type="text" name="name"/></td>

          </tr>

          <tr>

            <td>性别:</td>

            <td>

              <input type="radio" name="gender" value="http://www.mamicode.com/0" check="checked"/>男&nbsp;&nbsp;

              <input type="radio" name="gender" value="http://www.mamicode.com/1"/>女

            </td>

          </tr>

          <tr>

            <td>年龄:</td>

            <td>

              <select name="age">

                <option value="http://www.mamicode.com/18" select="selected">18</option>

                <option value="http://www.mamicode.com/19">19</option>

                <option value="http://www.mamicode.com/20">20</option>

                <option value="http://www.mamicode.com/21">21</option>

                <option value="http://www.mamicode.com/22">22</option>

              </select>

            </td>

          </tr>

          <tr>

            <td>地址:</td>

            <td><input type="text" name="address"/></td>

          </tr>

          <tr>

            <td>电话:</td>

            <td><input type="text" name="tel"/></td>

          </tr>

          <tr>

            <td colspan="2" align="center">

              <input type="submit" name="tj" value="http://www.mamicode.com/提交" onclick="check();"/>&nbsp;&nbsp;

              <input type="reset" name="cz" value="http://www.mamicode.com/重置"/>

            </td>

          </tr>

        </table>

      </form>

      <script language="javascript">

        function check(){

          if(document.form1.name.value =http://www.mamicode.com/=""){

            alert("请输入姓名!");

            document.form1.name.focus();      

            return false;

          }

          if(document.form1.age.value =http://www.mamicode.com/=""){

            alert("请输入年龄!");

            document.form1.age.focus();      

            return false;

          }

          if(document.form1.address.value =http://www.mamicode.com/=""){

            alert("请输入地址!");

            document.form1.address.focus();      

            return false;

          }

          if(document.form1.tel.value =http://www.mamicode.com/=""){

            alert("请输入电话号码!");

            document.form1.tel.focus();      

            return false;

          }

          return true;

        }

      </script>

    </body>

  </html>

 

 

  AddStudentServlet.java:

   package gh.test.servlet;

  import java.io.IOException;

  import java.io.PrintWriter;

  import java.sql.SQLException;

  import javax.servlet.ServletContent;

  import javax.servlet.ServletException;

  import javax.servlet.http.HttpServlet;

  import javax.servlet.http.HttpServletRequest;

  import javax.servlet.http.HttpServletResponse;

 

  import gh.test.entity.Student;

  import gh.test.dao.StudentDao;

  public class AddStudentServlet extends HttpServlet{

    private static final long serialVersionUID = 1L;

    public AddStudentServlet(){

      super();

    }

    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");

      response.setContentType("text/html;charset=utf-8");

      PrintWriter out = response.getWriter();

      String name = request.getParameter("name");

      int gender = Integer.parseInt(request.getParameter("gender"));

      int age = Integer.parseInt(request.getParameter("age"));

      String address = request.getParameter("address");

      String tel = request.getParameter("tel");

      Student student = new Student();

      student.setName(name);

      student.setGender(gender);

      student.setAge(age);

      student.setAddress(address);

      student.setTel(tel);

      ServletContext ctx = this.getServletContext();

      String server = ctx.getInitParameter("server");

      String db = ctx.getInitParameter("db");

      String user = ctx.getInitParameter("user");

        String password = ctx.getInitParameter("password");

      StudentDao studentDao = new StudentDao();

      try{

        studentDao.getConn(server,db,user,password);

        if(studentDao.addStudent(student) == 1){

          out.print("添加新同学信息成功!<br>");

        }

        else{

          out.print("添加失败!<br>");

        }

        out.print("<a href=http://www.mamicode.com/‘addStudent.html‘>返回");

      }catch(ClassNotFoundException ex){

        ex.printStackTrace();

      }catch(Exception ex){

        ex.printStackTrace();

      }

    } 

  }


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JDBC - 开发实例 - MVC模式