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The Spring Batch Infrastructure is a set of
low-level components, interfaces and tools for batch processing
applications and optimisations
/*
* Copyright 2002-2021 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
* @author Marten Deinum
* @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;
}
boolean withinQuotes = false;
Map namedParameters = new HashMap<>();
char currentQuote = '-';
int parameterCount = 0;
int i = 0;
while (i < sql.length()) {
if (withinQuotes) {
if (sql.charAt(i) == currentQuote) {
withinQuotes = false;
currentQuote = '-';
}
}
else {
if (sql.charAt(i) == '"' || sql.charAt(i) == '\'') {
withinQuotes = true;
currentQuote = sql.charAt(i);
}
else {
if (sql.charAt(i) == ':' || sql.charAt(i) == '&') {
int j = i + 1;
StringBuilder parameter = new StringBuilder();
while (j < sql.length() && parameterNameContinues(sql, j)) {
parameter.append(sql.charAt(j));
j++;
}
if (j - i > 1) {
if (!namedParameters.containsKey(parameter.toString())) {
parameterCount++;
namedParameters.put(parameter.toString(), parameter);
i = j - 1;
}
}
}
else {
if (sql.charAt(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(String statement, int pos) {
char character = statement.charAt(pos);
return (character != ' ' && character != ',' && character != ')' && character != '"' && character != '\''
&& character != '|' && character != ';' && character != '\n' && character != '\r');
}
}