Java EE (Java Enterprise Edition) General Discussion

Dear all,

In my project i used like this for inserting data,

step 1 : getting max id from the table

step 2 : using that max id inserting the data

public datacall{
AccessObj accesdataobj = new AccessObj();
public int access(String s,String s2,String s3)
{
int i=0;
try
{

// insert data in first table....
long loginid = accesdataobj.fmaxId("select max(userloginid) from login_tb");
String s31 = "insert into login_tb values(" loginid "," + s1 + ",'"+s2+"','" + s2 + "',null)
i =accesdataobj.insertUpdateDeleteRecord(s31);

//insert data in second table
long userlogid = accesdataobj.fmaxId("select max(userlogid) from userlog_tb");
String s31 = "insert into userlog_tb values(" +userlogid + "," + loginid+ ",'"+s2+"','" + s2 + "',null)
i =accesdataobj.insertUpdateDeleteRecord(s31);


}catch(Exception e){}
return i;
}
}

AccessObj.class


public long fmaxId(String s)
throws SQLException
{
long l = 0L;
Object obj = null;
try
{
createNewConnection();
stmt = super.cnewcon.createStatement();
ResultSet resultset = stmt.executeQuery(s);
if(resultset.next())
l = resultset.getLong(1);
l++;
}
catch(Exception exception)
{
System.out.println("SQL Exception ::" + exception.getMessage());
}
finally
{
try
{
closeConnection()
}
catch(Exception _ex) { }
}
return l;
}

public int insertUpdateDeleteRecord(String s)
throws SQLException
{
int i = 0;
try
{
createNewConnection();
stmt = super.cnewcon.createStatement();
i = stmt.executeUpdate(s);
}
catch(SQLException sqlexception)
{
System.out.println("Insert Update =" + sqlexception.getMessage());
}
finally
{
try
{
closeConnection();
}
catch(Exception _ex) { }
}
return i;
}



My question is ,

1. My idea for inserting data is correct?.

2. same time two users are inserting data in same time, that time i getting Primary key conflict error is coming in second table.

I need help in this.. inserting primary key, is there any procedure is there.