Fix escaping issue in filterExpression for RedisVectorStore file name filtering

Signed-off-by: Minu Kim <kmw106933@naver.com>

Author: kmw10693

spring-ai-vector-store/src/main/java/org/springframework/ai/vectorstore/SearchRequest.java

@@ -17,15 +17,14 @@
 package org.springframework.ai.vectorstore;
 
 import java.util.Objects;
+import java.util.Map;
 
 import org.springframework.ai.document.Document;
 import org.springframework.ai.vectorstore.filter.Filter;
 import org.springframework.ai.vectorstore.filter.FilterExpressionBuilder;
 import org.springframework.ai.vectorstore.filter.FilterExpressionTextParser;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
-import java.util.regex.Pattern;
-import java.util.regex.Matcher;
 
 /**
  * Similarity search request. Use the {@link SearchRequest#builder()} to create the
@@ -61,6 +60,8 @@ public class SearchRequest {
 @Nullable
 private Filter.Expression filterExpression;
 
+private static final Map<Character, String> ESCAPE_TEXT = Map.of('\\', "\\\\", '.', "\\.");
+
 /**
  * Copy an existing {@link SearchRequest.Builder} instance.
  * @param originalSearchRequest {@link SearchRequest} instance to copy.
@@ -193,7 +194,6 @@ public Builder similarityThresholdAll() {
 /**
  * Retrieves documents by query embedding similarity and matching the filters.
  * Value of 'null' means that no metadata filters will be applied to the search.
- *
  * For example if the {@link Document#getMetadata()} schema is:
  *
  * <pre>{@code
@@ -290,14 +290,24 @@ public Builder filterExpression(@Nullable String textExpression) {
 }
 
 private String escapeTextExpression(String expression) {
-Pattern pattern = Pattern.compile("'([^']*)'");
-Matcher matcher = pattern.matcher(expression);
-StringBuffer sb = new StringBuffer();
-while (matcher.find()) {
-String content = matcher.group(1).replace("\\", "\\\\").replace(".", "\\.");
-matcher.appendReplacement(sb, "'" + content + "'");
+StringBuilder sb = new StringBuilder(expression.length() + 8);
+boolean inQuote = false;
+
+for (int i = 0; i < expression.length(); i++) {
+char ch = expression.charAt(i);
+
+if (ch == '\'') {
+inQuote = !inQuote;
+sb.append(ch);
+}
+else if (inQuote) {
+sb.append(ESCAPE_TEXT.getOrDefault(ch, String.valueOf(ch)));
+}
+else {
+sb.append(ch);
+}
 }
-matcher.appendTail(sb);
+
 return sb.toString();
 }