新手求教JSP怎么使用javabean
我有个B.JSP文件接受A.JSP文件传递来的值，想用javabean判断是否和数据库里有重复，java文件已经试过没问题（我具体在JAVA文件里赋值测试没问题）。但是在JSP里无论接受什么值都说已经重复。怎么办？
JSP:
<%String username= "1223 ";%> //假设1223是传递来的值
<jsp:useBean id= "ID " class= "count.Username " scope= "page "/>
<%String end = ID.namecheck();%>
<%=end%>
JAVA:
public String namecheck(){
Connection conn = null;
Statement stmt=null;
ResultSet rs = null;
String username=null;
String end = "you can use the username! ";
try{
Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver ");
conn = DriverManager.getConnection( "jdbc:odbc:register ");
stmt = conn.createStatement();
String sql = "select * from register where username= ' "+username+ " ' ";
rs = stmt.executeQuery(sql);
while(rs.next()){
String username2 = rs.getString( "username ");
if(username==username2 || username2.equals(username)){
end = "username is being! ";
}
}
}
catch(SQLException ex){
System.out.println( "database.executeQuery: "+ex.getMessage());
}
catch(java.lang.ClassNotFoundException e){
//打印错误信息
System.out.print( "mydb(): "+e.getMessage());
}
System.out.print(end);
return end;
}
[解决办法]
if(rs.next())
{
end = "username is being! ";
}
else
{
.....................加入你要自己代码
}
username==username2 这个比较就是错的
