001package votorola.g.sql; // Copyright 2008, Michael Allan. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Votorola Software"), to deal in the Votorola Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Votorola Software, and to permit persons to whom the Votorola Software is furnished to do so, subject to the following conditions: The preceding copyright notice and this permission notice shall be included in all copies or substantial portions of the Votorola Software. THE VOTOROLA SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE VOTOROLA SOFTWARE OR THE USE OR OTHER DEALINGS IN THE VOTOROLA SOFTWARE. 002 003import votorola.g.lang.*; 004 005 006/** Array utilities. Alternatives to PreparedStatement.setArray(). To use setArray(), 007 * one must implement a compatible java.sql.Array instance, and this requires 008 * documentation or support from the JDBC driver that appears to be missing for 009 * PostgreSQL. Hence these alternative utilities for converting between arrays (which we 010 * cannot store) and strings (which we can). 011 */ 012public @ThreadSafe final class ArrayX 013{ 014 015 016 private ArrayX() {} 017 018 019 020 /** Returns the space-delimited concatenation of the specified int array. 021 * 022 * @return space-delimited concatenation of intArray; 023 * or null, if the intArray is empty 024 * 025 * @see #stringToInts(String) 026 */ 027 public static String intsToString( final int[] intArray ) 028 { 029 if( intArray.length == 0 ) return null; 030 031 final StringBuilder b = new StringBuilder( /*initial capacity, guess*/100 ); 032 for( int i = 0;; ) 033 { 034 b.append( intArray[i] ); 035 ++i; 036 if( i < intArray.length ) b.append( ' ' ); 037 else break; 038 } 039 return b.toString(); 040 } 041 042 043 /** Splits the space-delimited string (s) of integers into an array. 044 * 045 * @param s space-delimited string of integers, 046 * which may be empty or null (in which cases, an empty array is returned) 047 * 048 * @see #intsToString(int[]) 049 */ 050 public static int[] stringToInts( final String s ) 051 { 052 if( s == null ) return new int[0]; 053 054 final String[] stringArray = s.split( " " ); 055 final int[] intArray = new int[stringArray.length]; 056 for( int i = intArray.length - 1; i >= 0; --i ) 057 { 058 intArray[i] = Integer.parseInt( stringArray[i] ); 059 } 060 return intArray; 061 } 062 063 064 065 /** Returns the space-delimited concatenation of the specified string array. 066 * 067 * @return space-delimited concatenation of stringArray; 068 * or null, if the stringArray is empty 069 * 070 * @see #stringToStrings(String) 071 */ 072 public static String stringsToString( final String[] stringArray ) 073 { 074 if( stringArray.length == 0 ) return null; 075 076 final StringBuilder b = new StringBuilder( /*initial capacity, guess*/100 ); 077 for( int i = 0;; ) 078 { 079 b.append( stringArray[i] ); 080 ++i; 081 if( i < stringArray.length ) b.append( ' ' ); 082 else break; 083 } 084 return b.toString(); 085 } 086 087 088 /** Splits the space-delimited string (s) of strings into an array. 089 * 090 * @param s space-delimited string of strings, which may be empty or null 091 * (in which cases, an empty array is returned) 092 * 093 * @see #stringsToString(String[]) 094 */ 095 public static String[] stringToStrings( final String s ) 096 { 097 if( s == null ) return new String[0]; 098 099 return s.split( " " ); 100 } 101 102 103 104}