From: thhal at mailblocks.com (Thomas Hallgren)
Date: Mon, 28 Mar 2005 23:01:21 +0200
Subject: [Pljava-dev] java.lang.SecurityException
In-Reply-To: <11C803742910E84E9CDBFD344773B814759F87@srqech02.teltronics.com>
References: <11C803742910E84E9CDBFD344773B814759F87@srqech02.teltronics.com>
Message-ID: <424870A1.6020503@mailblocks.com>

Joves Luo wrote:

> Here is my code that calls the Driver.  The host, database, username, 
> and password all come from another constants file included in the 
> PGtoXML package.  I guess there is something wrong with the way I use 
> the JDBC driver.  I tried removing the import java.sql.* line to stop 
> it from looking for the JDBC jar files.  But now everything is broken 
> without it.  Do I need to rewrite all my code to use the pljava JDBC 
> driver?  Also why is it that this works 100% on a windows system, ( I 
> can even access the Linux database with the windows postgresql 
> function)?  Thank you for your help, I would have gotten nowhere 
> without it.
>
>  
>
Only one method needs to be rewritten AFAICS, and that's the 
constructor. Try this:

public OWDBConnection() throws SQLException{
    db = DriverManager.getConnection("jdbc:default:connection");
}

That should do it. You will still use JDBC (that's just the interfaces) 
but now you'll use the PL/Java jdbc implementation. The connection used 
by PL/Java is implicit since it reflects the session of the caller of 
the function, hence there's need to "login".

If you got your code working on a windows system you probably have an 
older version of PL/Java then yor setup must be slightly different 
there. PL/Java somehow finds the jar file of the client driver. Perhaps 
you had that jar file in your classpath in combination with a sligthly 
older version of PL/Java where security was not as tight as it is now? 
Eihter that, or you loaded the actual PostgreSQL client driver .jar file 
into the database using sqlj.install_jar. As I explained earlier, such a 
setup might seem to work although what really happens is that your 
function will behave like a client for yet another backend. I have a 
hard time thinking of a case when that would be desirable.

Regards,
Thomas Hallgren

>  
>
> package PGtoXML;
>
>  
>
> import java.sql.*;
>
>  
>
> public class OWDBConnection { 
>
>   private Connection db;
>
>   public OWDBConnection() throws ClassNotFoundException, SQLException{
>
>             Class.forName("org.postgresql.Driver");
>
>             db = DriverManager.getConnection("jdbc:postgresql:" +
>
>                                                                                                 
> Constants.host +
>
>                                                                                                 
> Constants.database,
>
>                                                                                                 
> Constants.username,
>
>                                                                                                 
> Constants.password);
>
>   }
>
>  
>
>  
>
>   public ResultSet getTableNames() throws SQLException{
>
>             Statement sql = db.createStatement();
>
>             ResultSet results = sql.executeQuery
>
>                         ("select viewname from pg_views where 
> schemaname = 'public' and viewname like 'xml_%'");
>
>             return results;
>
>   }
>
>  
>
>  
>
>   public ResultSet getTableColNames (String name) throws SQLException{
>
>             Statement sql = db.createStatement();
>
>             ResultSet results = sql.executeQuery
>
>                                                                         
> ("select column_name from information_schema.columns where table_name 
> = '"
>
>                                                  + name + "' order by 
> ordinal_position");
>
>             return results;   
>
>   }
>
>  
>
>  
>
>   public ResultSet getTableData (String name) throws SQLException{
>
>             Statement sql = db.createStatement();
>
>             ResultSet results = sql.executeQuery("select * from " + name);
>
>             return results;
>
>   }
>
>  
>
>  
>
>   public static void main (String args[]) {
>
>     try{
>
>             OWDBConnection demo = new OWDBConnection();
>
>             System.out.println("\n");
>
>             ResultSet tableNames = demo.getTableNames();
>
>             ResultSet tableData;
>
>        
>
>             while (tableNames.next()) {
>
>             System.out.println(tableNames.getString(1));
>
>             tableData = demo.getTableData(tableNames.getString(1));    
>        
>
>             for (int i=1; i<=tableData.getMetaData().getColumnCount(); 
> i++){   
>
>                         System.out.print("\t\t\t" + 
> tableData.getMetaData().getColumnName(i));
>
>             }
>
>             while (tableData.next()){
>
>                         System.out.println();
>
>                         for (int i=1; 
> i<=tableData.getMetaData().getColumnCount(); i++){
>
>                                     System.out.print("\t\t\t" + 
> tableData.getString(i));
>
>                         }
>
>             }
>
>             System.out.println("\n");
>
>         }
>
>     }
>
>     catch (Exception ex) {
>
>         System.out.println("***Exception:\n"+ex);
>
>         ex.printStackTrace();
>
>     }
>
>  
>
>   }
>
> }
>
>------------------------------------------------------------------------
>
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>  
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