Bulk Inserts with Postgres JDBC COPY

The COPY command is a much faster way to do bulk inserts into a postgres database. The postgres JDBC driver supports this as well.

Here is a simple example of a command line tool to COPY the contents of a text file to a table. Each line becomes a row in the database.

import java.io.FileReader;
import java.sql.Connection;
import java.sql.DriverManager;

import org.postgresql.copy.CopyManager;
import org.postgresql.core.BaseConnection;

public class PgSqlJdbcCopyStreamsExample {

   public static void main(String[] args) throws Exception {

       if(args.length!=4) {
           System.out.println("usage: [url] [user] [password] [file]");
       } else {

           System.err.println("Loading driver");
           Class.forName("org.postgresql.Driver");

           System.err.println("Connecting to " + args[0]);
           Connection con = DriverManager.getConnection(args[0],args[1],args[2]);

           System.err.println("Copying text data rows from stdin");

           CopyManager copyManager = new CopyManager((BaseConnection) con);

           FileReader fileReader = new FileReader(args[3]);
           copyManager.copyIn("COPY t FROM STDIN", fileReader );

           System.err.println("Done.");
       }
   }
}