org.springframework.batch.item.database.JdbcParameterUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2008 the original author or authors.
*
* Licensed 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
*
* https://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.springframework.batch.item.database;
import java.util.Map;
import java.util.HashMap;
import java.util.List;
/**
* Helper methods for SQL statement parameter parsing.
*
* Only intended for internal use.
*
* @author Thomas Risberg
* @author Juergen Hoeller
* @since 2.0
*/
public class JdbcParameterUtils {
/**
* Count the occurrences of the character placeholder in an SQL string
* sql. The character placeholder is not counted if it appears
* within a literal, that is, surrounded by single or double quotes. This method will
* count traditional placeholders in the form of a question mark ('?') as well as
* named parameters indicated with a leading ':' or '&'.
*
* The code for this method is taken from an early version of the
* {@link org.springframework.jdbc.core.namedparam.NamedParameterUtils}
* class. That method was later removed after some refactoring, but the code
* is useful here for the Spring Batch project. The code has been altered to better
* suite the batch processing requirements.
*
* @param sql String to search in. Returns 0 if the given String is null.
* @param namedParameterHolder holder for the named parameters
* @return the number of named parameter placeholders
*/
public static int countParameterPlaceholders(String sql, List namedParameterHolder ) {
if (sql == null) {
return 0;
}
char[] statement = sql.toCharArray();
boolean withinQuotes = false;
Map namedParameters = new HashMap();
char currentQuote = '-';
int parameterCount = 0;
int i = 0;
while (i < statement.length) {
if (withinQuotes) {
if (statement[i] == currentQuote) {
withinQuotes = false;
currentQuote = '-';
}
}
else {
if (statement[i] == '"' || statement[i] == '\'') {
withinQuotes = true;
currentQuote = statement[i];
}
else {
if (statement[i] == ':' || statement[i] == '&') {
int j = i + 1;
StringBuilder parameter = new StringBuilder();
while (j < statement.length && parameterNameContinues(statement, j)) {
parameter.append(statement[j]);
j++;
}
if (j - i > 1) {
if (!namedParameters.containsKey(parameter.toString())) {
parameterCount++;
namedParameters.put(parameter.toString(), parameter);
i = j - 1;
}
}
}
else {
if (statement[i] == '?') {
parameterCount++;
}
}
}
}
i++;
}
if (namedParameterHolder != null) {
namedParameterHolder.addAll(namedParameters.keySet());
}
return parameterCount;
}
/**
* Determine whether a parameter name continues at the current position,
* that is, does not end delimited by any whitespace character yet.
* @param statement the SQL statement
* @param pos the position within the statement
*/
private static boolean parameterNameContinues(char[] statement, int pos) {
return (statement[pos] != ' ' && statement[pos] != ',' && statement[pos] != ')' &&
statement[pos] != '"' && statement[pos] != '\'' && statement[pos] != '|' &&
statement[pos] != ';' && statement[pos] != '\n' && statement[pos] != '\r');
}
}