网页设计-用户注册&登录

package com.entity; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class Person { private String username; private String name; private String age; private String telenumber; public String getUsername() { return username; } public String getName() { return name; } public String getAge() { return age; } public String getTele() { return telenumber; } public Person(String username,String name,String age,String telenumber) { this.username=username; this.name=name; this.age=age; this.telenumber=telenumber; } public void person_Increase(Connection con) throws SQLException { Statement sta; sta=con.createStatement(); String sql; if(age.equals("")) { if(telenumber.equals("")) { sql="insert into person (username,name) values('"+username+"','"+name+"')"; } else {sql="insert into person (username,name,teleno) values('"+username+"','"+name+"','"+telenumber+"')";} } else{ if(telenumber.equals("")) { sql="insert into person (username,name,age) values('"+username+"','"+name+"','"+age+"')"; } else {sql="insert into person values('"+username+"','"+name+"','"+age+"','"+telenumber+"')";} } sta.executeUpdate(sql); } public static void delete_person(Connection con,String username) throws SQLException { Statement sta,state; sta=con.createStatement(); String sql="select * from person"; ResultSet rs=sta.executeQuery(sql); while(rs.next()){ if(rs.getString(1).equals(username)) { state=con.createStatement(); String sql1="delete from person where username='"+username+"'"; //SQL语句 state.executeUpdate(sql1); } } rs.close(); } public String Person_insert(Connection con) throws SQLException { String operate="更新"; Statement sta,state; sta=con.createStatement(); String sql="select * from person"; ResultSet rs=sta.executeQuery(sql); int flag=0; while(rs.next()){ if(rs.getString(1).equals(username)) { if(name.equals("")) name=rs.getString(2); if(age.equals("")&&(rs.getString(3)!=null)) age=rs.getString(3); if(telenumber.equals("")&&(rs.getString(4)!=null)) telenumber=rs.getString(4); state=con.createStatement(); String sql1; if(age.equals("")) { if(telenumber.equals("")) { sql1="update person set name='"+name+"' where username='"+username+"'"; }else { sql1="update person set name='"+name+"',teleno='"+telenumber+"' where username='"+username+"'"; } }else { if(telenumber.equals("")) { sql1="update person set name='"+name+"',age='"+age+"' where username='"+username+"'"; }else { sql1="update person set name='"+name+"',age='"+age+"',teleno='"+telenumber+"' where username='"+username+"'"; } } state.executeUpdate(sql1); //将sql语句上传至数据库执行 flag=1; } } if(flag==0) { sql="select * from users"; rs=sta.executeQuery(sql); boolean flag1=false; while(rs.next()){ if(rs.getString(1).equals(username)) { flag1=true; break; } } if(!flag1){ User usr = new User(username,"888888"); usr.users_Increase(con); } Person person=new Person(username,name,age,telenumber); person.person_Increase(con); operate="插入"; } rs.close(); return operate; } }