JDBC - DatabaseMetaData.getTables() null pointer exception - Mailing list pgsql-bugs

Dave Antal (dantal@vigilos.com) reports a bug with a severity of 2
The lower the number the more severe it is.

Short Description
JDBC - DatabaseMetaData.getTables() null pointer exception

Long Description
When you pass the DatabaseMetaData.getTables() method a types array that contains "VIEW" a null pointer exception is
generated.This is in the JDBC driver that is with Postgres 7.1.2.  This is caused by the code not checking for a View
typeon the relkind column returned from the select of pg_class. The code example below contains a version of the method
witha fix in place. 

Sample Code
  /**
   * Get a description of tables available in a catalog.
   *
   * <p>Only table descriptions matching the catalog, schema, table
   * name and type criteria are returned. They are ordered by
   * TABLE_TYPE, TABLE_SCHEM and TABLE_NAME.
   *
   * <p>Each table description has the following columns:
   *
   * <ol>
   * <li><b>TABLE_CAT</b> String => table catalog (may be null)
   * <li><b>TABLE_SCHEM</b> String => table schema (may be null)
   * <li><b>TABLE_NAME</b> String => table name
   * <li><b>TABLE_TYPE</b> String => table type. Typical types are "TABLE",
   * "VIEW", "SYSTEM TABLE", "GLOBAL TEMPORARY", "LOCAL
   * TEMPORARY", "ALIAS", "SYNONYM".
   * <li><b>REMARKS</b> String => explanatory comment on the table
   * </ol>
   *
   * <p>The valid values for the types parameter are:
   * "TABLE", "INDEX", "SEQUENCE", "SYSTEM TABLE" and "SYSTEM INDEX"
   *
   * @param catalog a catalog name; For org.postgresql, this is ignored, and
   * should be set to null
   * @param schemaPattern a schema name pattern; For org.postgresql, this is ignored, and
   * should be set to null
   * @param tableNamePattern a table name pattern. For all tables this should be "%"
   * @param types a list of table types to include; null returns
   * all types
   * @return each row is a table description
   * @exception SQLException if a database-access error occurs.
   */
  public java.sql.ResultSet getTables(String catalog, String schemaPattern, String tableNamePattern, String types[])
throwsSQLException 
  {
    // Handle default value for types
    if(types==null)
      types = defaultTableTypes;

    if(tableNamePattern==null)
      tableNamePattern="%";

    // the field descriptors for the new ResultSet
    Field f[] = new Field[5];
    java.sql.ResultSet r;    // ResultSet for the SQL query that we need to do
    Vector v = new Vector();        // The new ResultSet tuple stuff

    f[0] = new Field(connection, "TABLE_CAT", iVarcharOid, 32);
    f[1] = new Field(connection, "TABLE_SCHEM", iVarcharOid, 32);
    f[2] = new Field(connection, "TABLE_NAME", iVarcharOid, 32);
    f[3] = new Field(connection, "TABLE_TYPE", iVarcharOid, 32);
    f[4] = new Field(connection, "REMARKS", iVarcharOid, 32);

    // Now form the query
    StringBuffer sql = new StringBuffer("select relname,oid,relkind from pg_class where (");
    boolean notFirst=false;
    for(int i=0;i<types.length;i++) {
      for(int j=0;j<getTableTypes.length;j++)
    if(getTableTypes[j][0].equals(types[i])) {
      if(notFirst)
        sql.append(" or ");
      sql.append(getTableTypes[j][1]);
      notFirst=true;
    }
    }

    // Added by Stefan Andreasen <stefan@linux.kapow.dk>
    // Now take the pattern into account
    sql.append(") and relname like '");
    sql.append(tableNamePattern.toLowerCase());
    sql.append("'");

    // Now run the query
    r = connection.ExecSQL(sql.toString());

    byte remarks[];

    while (r.next())
      {
    byte[][] tuple = new byte[5][0];

    // Fetch the description for the table (if any)
    java.sql.ResultSet dr = connection.ExecSQL("select description from pg_description where objoid="+r.getInt(2));
    if(((org.postgresql.ResultSet)dr).getTupleCount()==1) {
      dr.next();
      remarks = dr.getBytes(1);
    } else
      remarks = defaultRemarks;
    dr.close();

    String relKind;
    switch (r.getBytes(3)[0]) {
    case 'r':
        relKind = "TABLE";
        break;
    case 'i':
        relKind = "INDEX";
        break;
    case 'S':
        relKind = "SEQUENCE";
        break;
    case 'v':
        relKind = "VIEW";
        break;
    default:
        relKind = null;
    }

    tuple[0] = null;        // Catalog name
    tuple[1] = null;        // Schema name
    tuple[2] = r.getBytes(1);    // Table name
    tuple[3] = relKind.getBytes();    // Table type
    tuple[4] = remarks;        // Remarks
    v.addElement(tuple);
      }
    r.close();
    return new ResultSet(connection, f, v, "OK", 1);
  }

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