Informix JDBC Driver Programmer's Guide Appendix A: Sample Code

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/***************************************************************************
 *
 *  Title:         RSMetaData.java
 *
 *  Description:    Demo a resultsetmetadata operation 
 *		
 *  An example of running the program: 
 *		
 *   java DBMetaData
 *      'jdbc:informix-
sqli://emily:1533:informixserver=emily3;user=rdtest;password=test'
 *		
 *   Expected result:
 * 
 * >>>Simple resultsetmetadata operation test.
 * URL = "jdbc:informix-
sqli://emily:1533/testDB:informixserver=emily3;user=rdtest;password=test"
 * table_cat
 * table_schem
 * table_name
 * column_name
 * data_type
 * type_name
 * column_size
 * buffer_length
 * decimal_digits
 * num_prec_radix
 * nullable
 * remarks
 * column_def
 * sql_data_type
 * sql_datetime_sub
 * char_octet_length
 * ordinal_position
 * testDB
 * 
 * test1
 * c1
 * 4
 * int
 * int
 * 0
 * 0
 * 0
 * 0
 * <null><null><null><null><null><null>testDB
 * 
 * test1
 * c2
 * 8
 * double
 * double
 * 0
 * 0
 * 0
 * 0
 * <null><null><null><null><null><null>testDB
 * 
 * test1
 * c3
 * 1
 * char
 * char
 * 0
 * 0
 * 0
 * 0
 * <null><null><null><null><null><null>testDB
 * 
 * test1
 * c4
 * 12
 * varchar
 * varchar
 * 0
 * 0
 * 0
 * 0
 * <null><null><null><null><null><null>
 * >>>End of Simple resultsetmetadata operation test.
 * 
 ***************************************************************************
 */

 

import java.sql.*;
import java.util.*;
import java.math.BigDecimal ;
import java.io.*;
import java.lang.*;

public class RSMetaData {

    public static void main(String[] args)
    {
        if (args.length == 0)
	    {
	    System.out.println("ERROR: connection URL must be provided in order to run 
the demo!");
	    return;
	    }

        String url = args[0];
        StringTokenizer st = new StringTokenizer(url, ":");
        String token;
        String newUrl = "";

        for (int i = 0; i < 4; ++i)
	    { 
            if (!st.hasMoreTokens())
   	        {
	        System.out.println("ERROR: incorrect URL format!");
	        return;
	        }
            token = st.nextToken();
            if (newUrl != "")
	        newUrl += ":";
            newUrl += token;
            }

        newUrl += "/testDB";

        while (st.hasMoreTokens())
	    { 
            newUrl += ":" + st.nextToken();
            }

	Connection conn = null;
        int 	   rc;
	String     cmd=null;
	Statement  stmt = null;

        String testName = "Simple resultsetmetadata operation";

	System.out.println(">>>" + testName + " test.");
	System.out.println("URL = \"" + newUrl + "\"");

	try 
	    {
	    Class.forName("com.informix.jdbc.IfxDriver");
	    } 
	catch (Exception e)
	    {
	    System.out.println("ERROR: failed to load Informix JDBC driver.");
	    }

	try 
	    {
	    conn = DriverManager.getConnection(newUrl);
	    } 
	catch (SQLException e) 
	    {
	    System.out.println("ERROR: failed to connect!");
	    }
        try 
            {
            Statement  stmt1=conn.createStatement(); 
            stmt1.executeUpdate("drop table test1");
            }
        catch (SQLException e){ }
             

	try
	    {
            ResultSet            rs ;
            DatabaseMetaData     dmd ;

	    stmt = conn.createStatement();
            dmd = conn.getMetaData();
            stmt.executeUpdate (
            "create table test1  (c1 integer, c2 float, c3 char(10), " +
            "c4 varchar(20) ) ") ;
            rs = dmd.getColumns( null, null, "test1" , "%" ) ;
            ResultSetMetaData rsmd = rs.getMetaData(); 
            int ncols = rsmd.getColumnCount(); 
            int i,type; 
            String s = null; 
            for (i = 1; i < ncols ; i++) 
              { 
              System.out.println(rsmd.getColumnLabel(i)); 
              } 
            while (rs.next()) 
                { 
                for (i = 1; i < ncols; i++) 
                    { 
                    type = rsmd.getColumnType(i); 
                    switch (type) 
                       { 
                       case Types.CHAR: 
                       case Types.VARCHAR: 
                       case Types.LONGVARCHAR: 
                           s = rs.getString(i); 
                           break; 
                       case Types.SMALLINT: 
                           short v1 = rs.getShort( i ) ; 
                           if( !rs.wasNull() ) s = "" + v1 ; 
                           break;
                       case Types.FLOAT: 
                           float v2 = rs.getFloat( i ) ; 
                           if( !rs.wasNull() ) s = "" + v2 ; 
                           break;
                       } 
                     if (rs.wasNull() ) 
                         { 
                         System.out.print( "<null>" ) ; 
                         } 
                     else 
                         { 
                         System.out.println( s.trim() ) ; 
                         } 
                      } 
                 } 
         }  
	catch (SQLException e)
	    {
	    System.out.println("ERROR: execution failed - statement: " + cmd);
	    System.out.println("ERROR: " + e.getMessage());
	    }
	System.out.println("\n>>>End of " + testName + " test.");
        try 
            {
            Statement  stmt2 = conn.createStatement() ;
            stmt2.executeUpdate("drop table test1");
            }
        catch (SQLException e){ }
    }

}