Javaweb——一个简单的学生管理系统

先来看效果：

1.展示和添加页面

2.登录

这是我学习javaEE时用原生技术写的一个简单的增、删、改、查的demo，如有错误请大家指正！

需要用到的jar包：

这里红框框住的是自己做的原生的BaseDao的jar包，下一篇文章会详细说明。

数据操作：

就是对数据的一系类操作：前端页面获取数据，后台处理数据，到数据库查询，返回数据给前端页面。

下面上代码：

前端代码：

index.jsp

	
			

		

			学生信息管理(添加学生)
		
		

			
编号
			
姓名
			
年龄
			
性别
			
专业
			
成绩
			
操作
		
		

				
${student.id }
				
${student.name }
				
${student.age }
				
${student.sex }
				
${student.major }
				
${student.grade }
				
删除   修改
			
		
	
	

		
			
				上一页
			
			
				上一页
			
		
		
			${i }
		
		
			
				下一页
			
			
				下一页
			
		
		一共${page.pageTotal }页 ${page.recordsNum }条信息
	

listStudent.jsp

	
			

		

			学生信息管理(添加学生)
		
		

			
编号
			
姓名
			
年龄
			
性别
			
专业
			
成绩
			
操作
		
		

				
${student.id }
				
${student.name }
				
${student.age }
				
${student.sex }
				
${student.major }
				
${student.grade }
				
删除   修改
			
		
	
	

		
			
				上一页
			
			
				上一页
			
		
		
			${i }
		
		
			
				下一页
			
			
				下一页
			
		
		一共${page.pageTotal }页 ${page.recordsNum }条信息
	

addStudent.jsp

	
添加学生信息
	

		姓名: 年龄:
		性别: 专业:
		成绩: 
	

后台代码：

Student.java

public class Student {
	@Id
	private Integer id;
	private String name;
	private Integer age;
	private String sex;
	private String major;
	private String grade;
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Integer getAge() {
		return age;
	}
	public void setAge(Integer age) {
		this.age = age;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	public String getMajor() {
		return major;
	}
	public void setMajor(String major) {
		this.major = major;
	}
	public String getGrade() {
		return grade;
	}
	public void setGrade(String grade) {
		this.grade = grade;
	}
	
	public Student() {
	}
	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + ", age=" + age + ", sex=" + sex + ", major=" + major
				+ ", grade=" + grade + "]";
	}
	
}

IStudentDao.java

public interface IStudentDao extends IBaseDao {
	int getRecordsNum();
}

StudentDaoImpl.java

public class StudentDaoImpl extends BaseDaoImpl implements IStudentDao{

	public StudentDaoImpl() {
		super(Student.class);
	}

	@Override
	public int getRecordsNum() {
		Connection con=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		int recordsNum=0;
		try {
			con=JDBCUtil.intstance.getConn();
			String sql="select count(*) count from student";
			ps=con.prepareStatement(sql);
			rs=ps.executeQuery();
			while(rs.next()){
				recordsNum=rs.getInt("count");
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			try {
				JDBCUtil.intstance.close(con, ps, null);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return recordsNum;
	}
	public List findByPageNum(Page page){
		int begin=(page.getPageNum()-1)*page.getPageSize();
		List sudentList=new ArrayList();
		Connection con=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		try {
			con=JDBCUtil.intstance.getConn();
			String sql="select * from student limit ?,?";
			ps=con.prepareStatement(sql);
			ps.setInt(1, begin);
			ps.setInt(2, page.getPageSize());
			rs=ps.executeQuery();
			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"));
				student.setMajor(rs.getString("major"));
				student.setGrade(rs.getString("grade"));
				sudentList.add(student);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			try {
				JDBCUtil.intstance.close(con, ps, rs);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return sudentList;
	}
}

ControllerServlet.java

@WebServlet("*.do")
public class ControllerServlet extends HttpServlet {

	
	private static final long serialVersionUID = 1L;
	private StudentDaoImpl sd = new StudentDaoImpl();

	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		String url=request.getRequestURI();
		String action=request.getRequestURI().substring(url.lastIndexOf('/')+1, url.lastIndexOf('.'));
		if("list".equals(action)){
			Page page=new Page();
			String pageNum=request.getParameter("pageNum");
			if(pageNum==null){
				page.setPageNum(1);
			}else{
				page.setPageNum(Integer.parseInt(pageNum));
			}	
			List listStudent=sd.findByPageNum(page);
			request.setAttribute("listStudent", listStudent);
			request.setAttribute("page", page);
			request.getRequestDispatcher("listStudent.jsp").forward(request, response);
		}
		else if("add".equals(action)){
			Student student = new Student();
			student.setName(request.getParameter("name"));
			student.setAge(Integer.parseInt(request.getParameter("age")));
			student.setSex(request.getParameter("sex"));
			student.setMajor(request.getParameter("major"));
			student.setGrade(request.getParameter("grade"));
			sd.add(student);
			response.sendRedirect("list.do");
		}else if("delete".equals(action)){
			int id=Integer.parseInt(request.getParameter("id"));
			sd.delect(id);
			response.sendRedirect("list.do");
		}else if("load".equals(action)){
			Student student = sd.queryOne(Integer.parseInt(request.getParameter("id")));
			request.setAttribute("student",student);
			request.getRequestDispatcher("studentInfo.jsp").forward(request, response);
		}else if("update".equals(action)){
			Student student = new Student();
			student.setId(Integer.parseInt(request.getParameter("id")));
			student.setName(request.getParameter("name"));
			student.setAge(Integer.parseInt(request.getParameter("age")));
			student.setSex(request.getParameter("sex"));
			student.setMajor(request.getParameter("major"));
			student.setGrade(request.getParameter("grade"));
			sd.updata(student);
			response.sendRedirect("list.do");
		}
	}
}

以上就是关键代码。