JSP+Servlet+JavaBean+DAO------学生体质信息管理

Posted 2020-10-13 ing

1.描述学生信息的数据类：Student

package exam1;

public class Student {
    private int id;
    private String name;
    private String sex;
    private int age;
    private float weight;
    private float hight;
    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 getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public float getWeight() {
        return weight;
    }
    public void setWeight(float weight) {
        this.weight = weight;
    }
    public float getHight() {
        return hight;
    }
    public void setHight(float hight) {
        this.hight = hight;
    }
    
}

2.数据库连接和关闭的工具：JavaBean

package exam1;
import java.sql.*;

public class DbConnect {
    private static String driverName="com.mysql.jdbc.Driver";
    private static String userName="root";
    private static String userPwd="123456";
    private static String dbName="student";
    static Connection getDBconnection(){
        String url1="jdbc:mysql://localhost:3306/"+dbName;
        String url2="?user="+userName+"&password="+userPwd;
        String url3="&useUnicode=true&characterEncoding=UTF-8";
        String url=url1+url2+url3;
        try{
            Class.forName(driverName);
            Connection con=DriverManager.getConnection(url);
            return con;
        }catch(Exception e){
            e.printStackTrace();
        }
        return null;
    }
    public static void closeDB(Connection con,PreparedStatement pstmt,ResultSet rs){
        try{
            if(rs!=null)rs.close();
            if(pstmt!=null)pstmt.close();
            if(con!=null)con.close();
        }catch(SQLException e){
            e.printStackTrace();
        }
    }
}

3.实现数据库访问和业务逻辑的结合体ＤＡＯ

package exam1;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public  class StudentDAO implements IStudentDAO {
    protected static final String FIELDS_INSERT="id,name,sex,age,weight,hight";
    protected static String INSERT_SQL="insert into stu_info("+FIELDS_INSERT+")"+"values(?,?,?,?,?,?)";
    protected static String SELECT_SQL="select"+FIELDS_INSERT+"from stu_info where id=?";
    protected static String UPDATE_SQL="update stu_info set"+"id=?,name=?,sex=?,age=?,weight=?,hight=? where id=?";
    protected static String DELETE_SQL="delete from stu_info where id=?";
    
     public Student create(Student stu)throws Exception{
         Connection con=null;
         PreparedStatement preStmt=null;
         ResultSet rs=null;
         try{
             con=DbConnect.getDBconnection();
             preStmt=con.prepareStatement(INSERT_SQL);
             preStmt.setInt(1, stu.getId());
             preStmt.setString(2, stu.getName());
             preStmt.setString(3, stu.getSex());
             preStmt.setInt(4, stu.getAge());
             preStmt.setFloat(5, stu.getWeight());
             preStmt.setFloat(6, stu.getHight());
             preStmt.executeUpdate();
         }catch(Exception e){
         }finally{
             DbConnect.closeDB(con, preStmt, rs);
         }
         return stu;
     }


    @Override
    public void remove(Student stu) throws Exception {
        // TODO Auto-generated method stub
        
    }

    @Override
    public Student find(Student stu) throws Exception {
     Connection con=null;
        PreparedStatement preStmt=null;
        ResultSet rs=null;
        Student stu2=null;
        try{
            con=DbConnect.getDBconnection();
            preStmt=con.prepareStatement(SELECT_SQL);
            preStmt.setInt(1, stu.getId());
            rs=preStmt.executeQuery();
            if(rs.next()){
                stu2=new Student();
                stu2.setId(rs.getInt(1));
                stu2.setName(rs.getString(2));
               stu2.setSex(rs.getString(3));
               stu2.setAge(rs.getInt(4));
               stu2.setWeight(rs.getFloat(5));
               stu2.setHight(rs.getFloat(6));
            }
        }catch(Exception e){
        }finally{
            DbConnect.closeDB(con, preStmt, rs);
        }
        return stu2;
    }

    @Override
    public List<Student> findAll() throws Exception {
        Connection con=null;
            PreparedStatement prepStmt=null;
            ResultSet rs=null;
            List<Student> student=new ArrayList<Student>();
            con=DbConnect.getDBconnection();
            prepStmt=con.prepareStatement("select * from stu_info");
           while(rs.next()){
                    Student stu2=new Student();
                    stu2.setId(rs.getInt(1));
                    stu2.setName(rs.getString(2));
                   stu2.setSex(rs.getString(3));
                   stu2.setAge(rs.getInt(4));
                   stu2.setWeight(rs.getFloat(5));
                   stu2.setHight(rs.getFloat(6));
                   student.add(stu2);
                }
                DbConnect.closeDB(con, prepStmt, rs);
            return student;
    }

    @Override
    public void update(Student stu) throws Exception {
        Connection con=null;
        PreparedStatement preStmt=null;
        ResultSet rs=null;
        try{
            con=DbConnect.getDBconnection();
            preStmt=con.prepareStatement(UPDATE_SQL);
            preStmt.setInt(1, stu.getId());
            preStmt.setString(2, stu.getName());
            preStmt.setString(3, stu.getSex());
            preStmt.setInt(4, stu.getAge());
            preStmt.setFloat(5, stu.getWeight());
            preStmt.setFloat(6, stu.getHight());
            int rowCount=preStmt.executeUpdate();
            if(rowCount==0){
                throw new Exception("Update Error:Student Id:"+stu.getId());
            }
        }catch(Exception e){
        }finally{
            DbConnect.closeDB(con, preStmt, rs);
        }
        
    }
}

４.实现业务逻辑处理的接口

package exam1;
import java.util.List;

public interface IStudentDAO {
    public abstract Student create(Student stu)throws Exception;
    public abstract void remove(Student stu)throws Exception;
    public abstract Student find(Student stu)throws Exception;
    public abstract List<Student>findAll()throws Exception;
    public abstract void update(Student stu)throws Exception;

}