JSP+Servlet+JavaBean+DAO——学生体质信息管理
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;
}