StudentDao：
java
package dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import util.JdbcUtil;
import entity.Student;
public class StudentDao {
//�����ݿ�������û���¼�ķ���add()
public void add(Student student) throws Exception{
Connection conn = null;
PreparedStatement ps = null;
try {
conn = JdbcUtil.getConnection();
String sql = "insert into student2 values (null,?,?,?,?) ";
ps = conn.prepareStatement(sql);
ps.setString(1, student.getSno());
ps.setString(2,student.getSname());
ps.setString(3,student.getSex());
ps.setString(4,student.getPhoto());
ps.executeUpdate();
}finally {JdbcUtil.free(null,ps, conn);}
}
//�����ݿ��û���¼�ķ���update()
public void update(Student student) throws Exception{
Connection conn = null;
PreparedStatement ps = null;
try {
conn = JdbcUtil.getConnection();
String sql = "update student2 set sno=?,sname=?,sex=?,photo=? where id=? ";
ps = conn.prepareStatement(sql);
ps.setString(1,student.getSno());
ps.setString(2,student.getSname());
ps.setString(3, student.getSex());
ps.setString(4, student.getPhoto());
ps.setInt(5, student.getId());
ps.executeUpdate();
}finally {JdbcUtil.free(null,ps, conn);}
}
//ɾ�����ݿ��û���¼�ķ���delete()
public void delete(int id) throws Exception{
Connection conn = null;
PreparedStatement ps = null;
try {
conn = JdbcUtil.getConnection();
String sql = "delete from student2 where id=?";
ps = conn.prepareStatement(sql);
ps.setInt(1,id);
ps.executeUpdate();
}finally {JdbcUtil.free( null,ps, conn);}
}
//����id��ѯ�û��ķ���findStudentById()
public Student findStudentById(int id) throws Exception{
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
Student student=null;
try {
conn = JdbcUtil.getConnection();
String sql = "select * from student2 where id=? ";
ps = conn.prepareStatement(sql);
ps.setInt(1, id);
rs=ps.executeQuery();
if(rs.next()){
student=new Student();
student.setId(rs.getInt(1));
student.setSno(rs.getString(2));
student.setSname(rs.getString(3));
student.setSex(rs.getString(4));
}
}finally {JdbcUtil.free(rs, ps, conn);}
return student;
}
//��ѯȫ���û��ķ���QueryAll()
public List<Student> query() throws Exception{
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
List<Student> studentList=new ArrayList<Student>();
try {
conn = JdbcUtil.getConnection();
String sql = "select * from student2 ";
ps=conn.prepareStatement(sql);
rs=ps.executeQuery();
while(rs.next()){
Student student=new Student();
student.setId(rs.getInt(1));
student.setSno(rs.getString(2));
student.setSname(rs.getString(3));
student.setSex(rs.getString(4));
student.setPhoto(rs.getString(5));
studentList.add(student);
}
}finally {JdbcUtil.free(rs, ps, conn);}
return studentList;
}
}Servlet：
java
package servlet;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.oreilly.servlet.MultipartRequest;
import com.oreilly.servlet.multipart.DefaultFileRenamePolicy;
import com.oreilly.servlet.multipart.FileRenamePolicy;
import dao.StudentDao;
import entity.Student;
/**
* Servlet implementation class StudentServlet
*/
@WebServlet("/admin/studentServlet")
public class StudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
StudentDao studentDao = new StudentDao();
/**
* @see HttpServlet#HttpServlet()
*/
public StudentServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
this.doPost(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding("UTF-8");
String op = request.getParameter("op");
if ("add".equals(op)) {
this.add(request, response);
} else if ("update".equals(op)) {
this.update(request, response);
} else if ("delete".equals(op)) {
this.delete(request, response);
} else if ("query".equals(op)) {
this.query(request, response);
}
}
private void add(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
String saveDirectory =this.getServletContext().getRealPath("/photo");
int maxPostSize =3 * 1024 * 1024 ;
String info="";
FileRenamePolicy policy =(FileRenamePolicy)new DefaultFileRenamePolicy();
MultipartRequest multi = new MultipartRequest(request, saveDirectory, maxPostSize,"utf-8",policy);
String photo=multi.getFilesystemName("photo");
if(photo==null){
photo="";
}
StudentDao studentDao = new StudentDao();
try {
Student student = new Student();
student.setSno(multi.getParameter("sno"));
student.setSname(multi.getParameter("sname"));
student.setSex(multi.getParameter("sex"));
student.setPhoto(photo);
studentDao.add(student);
info="添加成功";
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
info="添加失败";
}
request.setAttribute("info",info);
request.getRequestDispatcher("/admin/student/add.jsp").forward(request, response);
}
private void update(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
String saveDirectory =this.getServletContext().getRealPath("/photo");
int maxPostSize =3 * 1024 * 1024 ; //���ϴ���С���ƣ�3M
FileRenamePolicy policy =(FileRenamePolicy)new DefaultFileRenamePolicy();
MultipartRequest multi = new MultipartRequest(request, saveDirectory, maxPostSize,"utf-8",policy);
String photo=multi.getFilesystemName("photo");
String oldphoto=multi.getParameter("oldphoto");
if(photo==null){
photo=oldphoto;
}
else{
if(!"".equals(oldphoto))
new File(saveDirectory+"/"+oldphoto).delete();
}
StudentDao studentDao = new StudentDao();
try {
Student student = new Student();
student.setId(Integer.parseInt(multi.getParameter("id")));
student.setSno(multi.getParameter("sno"));
student.setSname(multi.getParameter("sname"));
student.setSex(multi.getParameter("sex"));
student.setPhoto(photo);
studentDao.update(student);
response.sendRedirect("/zdwxz/admin/studentServlet?op=query");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
out.print("<script>alert('更新失败')</script>");
}
}
private void delete(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
try {
studentDao.delete(Integer.parseInt(request.getParameter("id")));
String photo=request.getParameter("photo");
String appPath=this.getServletContext().getRealPath("/photo");
if(!"".equals(photo))
new File(appPath+"/"+photo).delete();
response.sendRedirect("/zdwxz/admin/studentServlet?op=query");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private void query(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
try {
List<Student> studentList=studentDao.query();
request.setAttribute("studentList",studentList );
request.getRequestDispatcher("/admin/student/query.jsp").forward(request, response);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
