JavaWeb实现学生信息管理系统（3）

本⽂接着，继续为⼤家分享了JavaWeb实现学⽣信息管理系统，供⼤家参考，具体内容如下今⽇任务：实现学⽣管理系统的删除、更新、修改和模糊查询功能！

⼀、删除学⽣信息

点击超链接，弹出⼀个询问是否删除的对话框，如果点击了确定，删除此学⽣的信息。1. 超链接执⾏⼀个js⽅法

删除

在doDelete()⽅法⾥判断点击的选项，然后跳转到DeleteServlet。

2. DeleteServlet收到了请求，然后去调⽤service，service去调⽤dao。DeleteServlet.java

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try {

//1.接受id

int sid = Integer.parseInt(request.getParameter(\"sid\"));

//2.执⾏删除

StudentService service = new StudentServiceImpl(); service.delete(sid);

//3.跳转到列表页

request.getRequestDispatcher(\"StudentListServlet\").forward(request,response); } catch (SQLException e) { e.printStackTrace(); } }

StudentDao.java & StudentService.java

/**

* 根据id删除学⽣ * @param sid

* @throws SQLException */

void delete(int sid) throws SQLException;

StudentDaoImpl.java & StudentServiceImpl.java

public class StudentDaoImpl implements StudentDao {

@Override

public void delete(int sid) throws SQLException {

QueryRunner runner = new QueryRunner(JDBCUtil02.getDataSource()); String sql = \"delete from stu where sid=?\"; runner.update(sql,sid); }}

public class StudentServiceImpl implements StudentService{ @Override

public void delete(int sid) throws SQLException { StudentDao dao = new StudentDaoImpl(); dao.delete(sid); } }

3. 删除结果如下：删除id = 3的学⽣的信息

⼆、更新（修改）学⽣信息

1. 点击列表上的更新，跳转到EditServlet上

更新

2. 在EditServlet⾥⾯，根据id查询这个学⽣的所有信息

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try {

//1.接受id

int sid = Integer.parseInt(request.getParameter(\"sid\"));

//2.查询学⽣数据

StudentService service = new StudentServiceImpl(); Student stu = service.findStudentById(sid);

//3.显⽰数据 //存数据

request.setAttribute(\"stu\ //跳转

request.getRequestDispatcher(\"edit.jsp\").forward(request, response); } catch (SQLException e) { e.printStackTrace(); } }

3. 跳转到更新页⾯edit.jsp，在edit.jsp上显⽰数据

原来的学⽣信息如图所⽰，我们修改编号为2的学⽣的电话为11111。点击更新，跳转到该学⽣的修改页⾯，如下：

修改页⾯代码如下：

更新学⽣页⾯

修改该学⽣的电话为11111,如下：

4. 修改完数据，提交数据到UpdateServlet

【备：代码与AddServlet代码相似，唯⼀的不同点就是：提交上来的数据是没有带id的，我们需要⼿动创建⼀个隐藏的输⼊框，在这⾥⾯给定id的值，以便提交表单时，带上id。

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

request.setCharacterEncoding(\"utf-8\"); try {

//1.获取客户端提交上来的数据

int sid = Integer.parseInt(request.getParameter(\"sid\")); System.out.println(sid);

String sname = request.getParameter(\"sname\"); System.out.println(sname);

String gender = request.getParameter(\"gender\"); String phone = request.getParameter(\"phone\");

String birthday = request.getParameter(\"birthday\"); //传过来是1989-10-18 String info = request.getParameter(\"info\");

//String hobby = request.getParameter(\"hobby\"); String [] h = request.getParameterValues(\"hobby\"); //[篮球，⾜球，写字]-----篮球，⾜球，写字 String hobby = Arrays.toString(h);

hobby = hobby.substring(1,hobby.length()-1);

//String-------Date

Date date = new SimpleDateFormat(\"yyyy-MM-dd\").parse(birthday);

Student student = new Student(sid,sname,gender,phone,hobby,info,date);

//2.更新数据库数据

StudentService service = new StudentServiceImpl(); service.update(student);

//3.跳转界⾯

request.getRequestDispatcher(\"StudentListServlet\").forward(request, response); } catch (Exception e) { e.printStackTrace(); } }

5. 获取数据，调⽤service，调⽤daoStudentDao.java & StudentService.java

/**

* 更新学⽣信息

* @param student 需要更新的学⽣数据 * @throws SQLException */

void update(Student student) throws SQLException;

StudentDaoImpl.java

public class StudentDaoImpl implements StudentDao { @Override

public void update(Student student) throws SQLException {

QueryRunner runner = new QueryRunner(JDBCUtil02.getDataSource());

String sql = \"update stu set sname=? , gender=? , phone=? , birthday=? , hobby=? , info=? where sid=?\"; runner.update(sql, student.getSname(), student.getGender(), student.getPhone(), student.getBirthday(), student.getHobby(), student.getInfo(), student.getSid() ); }}

StudentServiceImpl.java

public class StudentServiceImpl implements StudentService{ @Override

public void update(Student student) throws SQLException {

StudentDao dao = new StudentDaoImpl(); dao.update(student); } }

6. 更新（修改）学⽣信息结果如下：

三、模糊查询

1. 在list.jsp加⼊进⾏查询的⽂本框

实现效果如下图所⽰：

2. 在SearchServlet⾥⾯，查询符合查询条件的学⽣信息代码实现如下：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

request.setCharacterEncoding(\"utf-8\"); try {

//1.取到了要查询的关键数据：姓名，性别

String sname = request.getParameter(\"sname\"); String sgender = request.getParameter(\"sgender\");

//2.查询

StudentService service = new StudentServiceImpl();

List list = service.searchStudent(sname, sgender);

request.setAttribute(\"list\

//3.跳转界⾯--列表界⾯

request.getRequestDispatcher(\"list.jsp\").forward(request, response); } catch (SQLException e) { e.printStackTrace(); } }

例如：查询所有性别为男的学⽣信息；

查询结果如下：

3. 获取数据，调⽤service，调⽤daoStudentDao.java & StudentService.java

/**

* 模糊查询，根据姓名或者根据性别，或者两者兼有 * @param sname * @param sgender

* @return List * @throws SQLException */

List searchStudent(String sname,String sgender) throws SQLException;

StudentDaoImpl.java【这是⼀个需要注意的部分】

@Override

public List searchStudent(String sname, String sgender) throws SQLException { QueryRunner runner = new QueryRunner(JDBCUtil02.getDataSource()); /**

* 如果只有姓名 select * from stu where sname like?; * 如果只有性别 select * from stu where gender=?

* 如果两个都有 select * from stu where sname like? and gender=? * 如果两个都没有就查询所有 */

String sql = \"select * from stu where 1=1 \"; List list = new ArrayList();

//判断是否有姓名，如果有，就组拼到sql语句⾥ if(!TestUtils.isEmpty(sname)) { sql = sql + \"and sname like ?\"; list.add(\"%\"+sname+\"%\"); }

//判断是否有性别，如果有，就组拼到sql语句⾥ if(!TestUtils.isEmpty(sgender)) { sql = sql + \"and gender = ?\"; list.add(sgender); }

return runner.query(sql, new BeanListHandler(Student.class),list.toArray()); }

StudentServiceImol…java

@Override

public List searchStudent(String sname, String sgender) throws SQLException { StudentDao dao = new StudentDaoImpl(); return dao.searchStudent(sname, sgender); }

以上就是本⽂的全部内容，希望对⼤家的学习有所帮助，也希望⼤家多多⽀持。