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SDB is a persistence layer for use with Apache Jena that uses an SQL database to store triples/quads.
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.sdb.sql;
import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
/** SQL Utilities */
public class RS
{
// Three pass is a bit excessive but its clear and pass 2 is cheap.
// 1 - col to strings.
// 2 - string to widths
// 3 - output
static String lead = "| " ;
static String sep = " | " ;
static String trail = "| " ;
public static void close(ResultSetJDBC rs)
{
if ( rs != null )
rs.close();
}
public static void close(Statement s )
{
try { if ( s != null ) s.close() ; } catch (SQLException ex) {}
}
// public static void close(ResultSet rs)
// {
// try {
// Statement s = rs.getStatement() ;
// if ( s != null )
// s.close() ;
// else
// rs.close() ;
// } catch (SQLException ex)
// {
// LoggerFactory.getLogger(RS.class).warn("Problems closing result set : "+ex.getMessage()) ;
// }
//
// }
public static void consume(ResultSet resultSet) throws SQLException
{
while ( resultSet.next() )
{
}
resultSet.close() ;
}
public static void printResultSet(ResultSet resultSet) throws SQLException
{ printResultSet(System.out, resultSet) ; }
public static void printResultSet(PrintStream out, ResultSet resultSet) throws SQLException
{
ResultSetMetaData rsmd = resultSet.getMetaData();
List> rows = pass0(resultSet) ;
int[] colWidths = pass1(rsmd, rows) ;
fmtRow(out, rsmd, "+-", "---", '-', "-+", colWidths) ;
out.print("| ") ;
for ( int i = 1; i <= rsmd.getColumnCount() ; i++)
{
if ( i != 1 )
out.print(" | ") ;
fmt(out, rsmd.getColumnLabel(i), colWidths[i]) ;
}
out.print(" |") ;
out.println() ;
fmtRow(out, rsmd, "| ", " | ", '=', " |", colWidths) ;
for ( List x : rows )
{
out.print("| ") ;
for ( int i = 1; i <= rsmd.getColumnCount() ; i++)
{
if ( i != 1 )
out.print(sep) ;
String s = x.get(i) ;
fmt(out, s, colWidths[i]) ;
}
out.print(" |") ;
out.println() ;
}
fmtRow(out, rsmd, "+-", "---", '-', "-+", colWidths) ;
}
static void fmtRow(PrintStream out, ResultSetMetaData rsmd, String lead, String sep, char pad, String trail, int []colWidths)
throws SQLException
{
out.print(lead) ;
for ( int i = 1; i <= rsmd.getColumnCount() ; i++)
{
if ( i != 1 )
out.print(sep) ;
fmt(out, "", colWidths[i], pad) ;
}
out.print(trail) ;
out.println() ;
}
// Column => String.
static List> pass0(ResultSet resultSet) throws SQLException
{
ResultSetMetaData rsmd = resultSet.getMetaData();
int N = rsmd.getColumnCount() ;
List> x = new ArrayList>() ;
while ( resultSet.next() )
{
List z = new ArrayList() ;
z.add("NULL") ;
x.add(z) ;
for ( int i = 1; i <= N ; i++)
{
String s = colAsString(resultSet, i) ;
z.add(s) ;
}
}
return x ;
}
// Strings to widths.
static int[] pass1(ResultSetMetaData rsmd, List> rows) throws SQLException
{
// zero is blank.
int col[] = new int[rsmd.getColumnCount()+1] ;
col[0] = -1 ;
for ( int i = 1; i <= rsmd.getColumnCount() ; i++)
{
int w = rsmd.getColumnLabel(i).length() ;
col[i] = w ;
}
for ( List x : rows )
{
int i = 0 ;
for ( String z : x )
{
if ( z == null )
continue ;
if ( z.length() > col[i] )
col[i] = z.length() ;
i++ ;
}
}
return col ;
}
// Make an interface sometime
static String colAsString(ResultSet resultSet, int i) throws SQLException
{
ResultSetMetaData rsmd = resultSet.getMetaData();
String str = null ;
switch (rsmd.getColumnType(i))
{
case Types.VARCHAR:
case Types.LONGVARCHAR:
case Types.CHAR:
str = "\""+resultSet.getString(i)+"\"" ;
break ;
case Types.INTEGER:
//case Types.BIGINT:
str = Integer.toString(resultSet.getInt(i)) ;
break ;
case Types.DOUBLE:
str = Double.toString(resultSet.getDouble(i)) ;
break ;
case Types.FLOAT:
str = Float.toString(resultSet.getFloat(i)) ;
break ;
case Types.BLOB:
byte[] b2 = resultSet.getBytes(1) ;
try { str = new String(b2, 0, b2.length, "UTF-8") ; }
catch (UnsupportedEncodingException ex) { ex.printStackTrace(); }
break ;
default:
str = resultSet.getString(i) ;
}
if ( resultSet.wasNull() )
str = "" ;
return str ;
}
// static void fmt(String s, int w, char pad)
// { fmt(System.out, s, w, pad) ; }
//
//
// static void fmt(String s, int w)
// { fmt(System.out, s, w, ' ' ) ; }
static void fmt(PrintStream out, String s, int w)
{ fmt(out, s, w, ' ' ) ; }
static void fmt(PrintStream out, String s, int w, char pad)
{
if ( s == null )
s = "NULL" ;
for ( int i = 0 ; i < (w-s.length()) ; i++ )
out.print(pad) ;
out.print(s) ;
}
}