| 1 | /* |
| 2 | * Copyright 2002-2008 the original author or authors. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.springframework.batch.item.database; |
| 18 | |
| 19 | import java.util.Map; |
| 20 | import java.util.HashMap; |
| 21 | import java.util.List; |
| 22 | |
| 23 | /** |
| 24 | * Helper methods for SQL statement parameter parsing. |
| 25 | * |
| 26 | * Only intended for internal use. |
| 27 | * |
| 28 | * @author Thomas Risberg |
| 29 | * @author Juergen Hoeller |
| 30 | * @since 2.0 |
| 31 | */ |
| 32 | public class JdbcParameterUtils { |
| 33 | |
| 34 | /** |
| 35 | * Count the occurrences of the character placeholder in an SQL string |
| 36 | * <code>sql</code>. The character placeholder is not counted if it appears |
| 37 | * within a literal, that is, surrounded by single or double quotes. This method will |
| 38 | * count traditional placeholders in the form of a question mark ('?') as well as |
| 39 | * named parameters indicated with a leading ':' or '&'. |
| 40 | * |
| 41 | * The code for this method is taken from an early version of the |
| 42 | * {@link org.springframework.jdbc.core.namedparam.NamedParameterUtils} |
| 43 | * class. That method was later removed after some refactoring, but the code |
| 44 | * is useful here for the Spring Batch project. The code has been altered to better |
| 45 | * suite the batch processing requirements. |
| 46 | * |
| 47 | * @param sql String to search in. Returns 0 if the given String is <code>null</code>. |
| 48 | */ |
| 49 | public static int countParameterPlaceholders(String sql, List<String> namedParameterHolder ) { |
| 50 | if (sql == null) { |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | char[] statement = sql.toCharArray(); |
| 55 | boolean withinQuotes = false; |
| 56 | Map<String, StringBuilder> namedParameters = new HashMap<String, StringBuilder>(); |
| 57 | char currentQuote = '-'; |
| 58 | int parameterCount = 0; |
| 59 | int i = 0; |
| 60 | while (i < statement.length) { |
| 61 | if (withinQuotes) { |
| 62 | if (statement[i] == currentQuote) { |
| 63 | withinQuotes = false; |
| 64 | currentQuote = '-'; |
| 65 | } |
| 66 | } |
| 67 | else { |
| 68 | if (statement[i] == '"' || statement[i] == '\'') { |
| 69 | withinQuotes = true; |
| 70 | currentQuote = statement[i]; |
| 71 | } |
| 72 | else { |
| 73 | if (statement[i] == ':' || statement[i] == '&') { |
| 74 | int j = i + 1; |
| 75 | StringBuilder parameter = new StringBuilder(); |
| 76 | while (j < statement.length && parameterNameContinues(statement, j)) { |
| 77 | parameter.append(statement[j]); |
| 78 | j++; |
| 79 | } |
| 80 | if (j - i > 1) { |
| 81 | if (!namedParameters.containsKey(parameter.toString())) { |
| 82 | parameterCount++; |
| 83 | namedParameters.put(parameter.toString(), parameter); |
| 84 | i = j - 1; |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | else { |
| 89 | if (statement[i] == '?') { |
| 90 | parameterCount++; |
| 91 | } |
| 92 | } |
| 93 | } |
| 94 | } |
| 95 | i++; |
| 96 | } |
| 97 | if (namedParameterHolder != null) { |
| 98 | namedParameterHolder.addAll(namedParameters.keySet()); |
| 99 | } |
| 100 | return parameterCount; |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Determine whether a parameter name continues at the current position, |
| 105 | * that is, does not end delimited by any whitespace character yet. |
| 106 | * @param statement the SQL statement |
| 107 | * @param pos the position within the statement |
| 108 | */ |
| 109 | private static boolean parameterNameContinues(char[] statement, int pos) { |
| 110 | return (statement[pos] != ' ' && statement[pos] != ',' && statement[pos] != ')' && |
| 111 | statement[pos] != '"' && statement[pos] != '\'' && statement[pos] != '|' && |
| 112 | statement[pos] != ';' && statement[pos] != '\n' && statement[pos] != '\r'); |
| 113 | } |
| 114 | |
| 115 | } |