代码在修改更新上有一些缺陷，应该先把相应的要修改的部分查询显示显示出来再进行修改。其实完成增删改查的原理与登录注册是一样的。 1.首先建student类。 public class studentmodel {private int id;private string name;private string grade;private str
代码在修改更新上有一些缺陷，应该先把相应的要修改的部分查询显示显示出来再进行修改。其实完成增删改查的原理与登录注册是一样的。
1.首先建student类。public class studentmodel { private int id; private string name; private string grade; private string gender; private int age; private string address; 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 getgrade() { return grade; } public void setgrade(string grade) { this.grade = grade; } public string getgender() { return gender; } public void setgender(string gender) { this.gender = gender; } public int getage() { return age; } public void setage(int age) { this.age = age; } public string getaddress() { return address; } public void setaddress(string address) { this.address = address; }}
2.1)建接口类。
package cn.edu.hpu.service;import cn.edu.hpu.model.studentmodel;public interface student { public boolean addstu(studentmodel studentmodel); public boolean delstu(int id); public boolean updstu(int id,studentmodel studentmodel); public studentmodel selstu(int id);}
2)接口类的实现
package cn.edu.hpu.service;import java.sql.preparedstatement;import java.sql.resultset;import java.sql.sqlexception;import com.mysql.jdbc.connection;import cn.edu.hpu.model.studentmodel;import cn.edu.hpu.util.util;public class studentimpl implements student { @override public boolean addstu(studentmodel studentmodel) { boolean flag=false; string sql=insert into student1(id,name,grade,gender,age,address) value(?,?,?,?,?,?); connection conn=util.getconnection(); preparedstatement pst; try { pst = conn.preparestatement(sql); pst.setint(1, studentmodel.getid()); pst.setstring(2, studentmodel.getname()); pst.setstring(3, studentmodel.getgrade()); pst.setstring(4, studentmodel.getgender()); pst.setint(5, studentmodel.getage()); pst.setstring(6, studentmodel.getaddress()); pst.executeupdate(); flag=true; } catch (sqlexception e) { // todo auto-generated catch block e.printstacktrace(); } return flag; } @override public boolean delstu(int id) { boolean flag=false; string sql=delete from student1 where id=+id; connection conn=util.getconnection(); try { preparedstatement pst=conn.preparestatement(sql); pst.executeupdate(); flag=true; } catch (sqlexception e) { // todo auto-generated catch block e.printstacktrace(); } return flag; } @override public boolean updstu(int id, studentmodel studentmodel) { boolean flag=false; string sql=update student1 set id=?,name=?,grade=?,gender=?,age=?,address=? where id=+id; connection conn=util.getconnection(); preparedstatement pst; try { pst = conn.preparestatement(sql); pst.setint(1, studentmodel.getid()); pst.setstring(2, studentmodel.getname()); pst.setstring(3,studentmodel.getgrade()); pst.setstring(4, studentmodel.getgender()); pst.setint(5, studentmodel.getage()); pst.setstring(6, studentmodel.getaddress()); pst.executeupdate(); flag=true; } catch (sqlexception e) { // todo auto-generated catch block e.printstacktrace(); } return flag; } @override public studentmodel selstu(int id) { studentmodel studentmodel=new studentmodel(); string sql=select * from student1 where id=?; connection conn=util.getconnection(); try { preparedstatement pst=conn.preparestatement(sql); pst.setint(1,id); resultset rs=pst.executequery(); while(rs.next()){ //遍历结果集 studentmodel.setid(rs.getint(id)); studentmodel.setname(rs.getstring(name)); studentmodel.setgrade(rs.getstring(grade)); studentmodel.setgender(rs.getstring(gender)); studentmodel.setage(rs.getint(age)); studentmodel.setaddress(rs.getstring(address)); } } catch (sqlexception e) { // todo auto-generated catch block e.printstacktrace(); } // todo auto-generated method stub return studentmodel; }}
3.建立每个接口方法的servlet。1）添加的servletpackage cn.edu.hpu.servlet;import java.io.ioexception;import javax.servlet.servletexception;import javax.servlet.http.httpservlet;import javax.servlet.http.httpservletrequest;import javax.servlet.http.httpservletresponse;import cn.edu.hpu.model.studentmodel;import cn.edu.hpu.service.student;import cn.edu.hpu.service.studentimpl;public class tianjia extends httpservlet { /** * */ private static final long serialversionuid = 1l; public void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { dopost(request,response); } public void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { request.setcharacterencoding(utf-8); int id = integer.parseint(request.getparameter(id)); string name=request.getparameter(name); string grade=request.getparameter(grade); string gender=request.getparameter(gender); int age=integer.parseint(request.getparameter(age)); string address=request.getparameter(address); studentmodel studentmodel=new studentmodel(); studentmodel.setid(id); studentmodel.setname(name); studentmodel.setgrade(grade); studentmodel.setgender(gender); studentmodel.setage(age); studentmodel.setaddress(address); student stu=new studentimpl(); boolean flag=stu.addstu(studentmodel); if(flag){ studentdaoservlet s=new studentdaoservlet(); s.dopost(request, response); } }}
2）删除的servlet。package cn.edu.hpu.servlet;import java.io.ioexception;import javax.servlet.servletexception;import javax.servlet.http.httpservlet;import javax.servlet.http.httpservletrequest;import javax.servlet.http.httpservletresponse;import cn.edu.hpu.model.studentmodel;import cn.edu.hpu.service.student;import cn.edu.hpu.service.studentimpl;public class shanchu extends httpservlet { /** * */ private static final long serialversionuid = 1l; public void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { dopost(request,response); } public void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { request.setcharacterencoding(utf-8); int id=integer.parseint(request.getparameter(id)); studentmodel studentmodel=new studentmodel(); studentmodel.setid(id); student stu=new studentimpl(); boolean flag=stu.delstu(id); if(flag){ studentdaoservlet s=new studentdaoservlet(); s.dopost(request, response); } }}
3）更新的servlet。package cn.edu.hpu.servlet;import java.io.ioexception;import javax.servlet.servletexception;import javax.servlet.http.httpservlet;import javax.servlet.http.httpservletrequest;import javax.servlet.http.httpservletresponse;import cn.edu.hpu.model.studentmodel;import cn.edu.hpu.service.student;import cn.edu.hpu.service.studentimpl;public class gengxin extends httpservlet { /** * */ private static final long serialversionuid = 1l; public void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { dopost(request,response); } public void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { request.setcharacterencoding(utf-8); int id=integer.parseint(request.getparameter(id)); string name=request.getparameter(name); string grade=request.getparameter(grade); string gender=request.getparameter(gender); int age=integer.parseint(request.getparameter(age)); string address=request.getparameter(address); studentmodel studentmodel=new studentmodel(); studentmodel.setid(id); studentmodel.setname(name); studentmodel.setgrade(grade); studentmodel.setgender(gender); studentmodel.setage(age); studentmodel.setaddress(address); student stu=new studentimpl(); boolean flag=stu.updstu(id, studentmodel); if(flag){ studentdaoservlet s=new studentdaoservlet(); s.dopost(request, response); } }}
4）查询的servlet。以上即完成了增删改查的操作。
4. 建jsp页面。这是登录注册完成后跳转到的页面。有添加，删除，修改，查询的超链接，点击后跳转到相应页面可以进行相应的操作。
可以 my jsp 'success.jsp' starting page 欢迎你！ 欢迎登陆教务处系统
添加
删除
更新
查找
id： name： grade： gender: age: address:
${studentmodel.id } ${studentmodel.name } ${studentmodel.grade } ${studentmodel.gender} ${studentmodel.age} ${studentmodel.address}

至此完成了增删改查的相应操作。