Fix IndexOutOfBoundsException with quoted parameters in JulParameterizedArguments

Escape special characters (backslashes and double quotes) in the format
string before passing it to JavaTemplate. Without escaping, format strings
containing quotes like "Log message \"{0}\"" resulted in invalid Java syntax
during template application.

Fixes #273

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: timtebeek

src/main/java/org/openrewrite/java/logging/slf4j/JulParameterizedArguments.java

@@ -65,6 +65,15 @@ public static boolean isStringLiteral(Expression expression) {
             return expression instanceof J.Literal && TypeUtils.isString(((J.Literal) expression).getType());
         }
 
+        /**
+         * Escapes special characters in a string so it can be safely used as content
+         * inside a Java string literal in a JavaTemplate.
+         */
+        private static String escapeForJavaStringLiteral(String s) {
+            // Order matters: escape backslashes first to avoid double-escaping
+            return s.replace("\\", "\\\\").replace("\"", "\\\"");
+        }
+
         private static @Nullable String getMethodIdentifier(Expression levelArgument) {
             String levelSimpleName = levelArgument instanceof J.FieldAccess ?
                     (((J.FieldAccess) levelArgument).getName().getSimpleName()) :
@@ -124,12 +133,13 @@ public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, Execu
                             .withType(((JavaType.Array) requireNonNull(newArray.getType())).withElemType(JavaType.ShallowClass.build("java.lang.Object")));
                 }
 
+                String slf4jFormatString = escapeForJavaStringLiteral(originalFormatString.replaceAll("\\{\\d*}", "{}"));
                 J.MethodInvocation updatedMi = JavaTemplate.builder(newName + "(\"#{}\",#{anyArray(Object)})")
                         .build()
                         .apply(
                                 getCursor(),
                                 method.getCoordinates().replaceMethod(),
-                                originalFormatString.replaceAll("\\{\\d*}", "{}"),
+                                slf4jFormatString,
                                 updatedStringFormatArgument
                         );
 

src/test/java/org/openrewrite/java/logging/slf4j/JulParameterizedArgumentsTest.java

@@ -16,6 +16,7 @@
 package org.openrewrite.java.logging.slf4j;
 
 import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.openrewrite.DocumentExample;
 import org.openrewrite.Issue;
@@ -295,4 +296,65 @@ void method(Logger logger, Level level, String param1) {
           )
         );
     }
+
+    @Nested
+    @Issue("https://github.com/openrewrite/rewrite-logging-frameworks/issues/273")
+    class EscapedCharactersInFormatString {
+
+        @Test
+        void quotedParameters() {
+            rewriteRun(
+              // language=java
+              java(
+                """
+                  import java.util.logging.Level;
+                  import java.util.logging.Logger;
+
+                  class Test {
+                      void method(Logger logger, String param1) {
+                          logger.log(Level.SEVERE, "Log message with quoted parameter \\"{0}\\"", param1);
+                      }
+                  }
+                  """,
+                """
+                  import org.slf4j.Logger;
+
+                  class Test {
+                      void method(Logger logger, String param1) {
+                          logger.error("Log message with quoted parameter \\"{}\\"", param1);
+                      }
+                  }
+                  """
+              )
+            );
+        }
+
+        @Test
+        void backslashInFormatString() {
+            rewriteRun(
+              // language=java
+              java(
+                """
+                  import java.util.logging.Level;
+                  import java.util.logging.Logger;
+
+                  class Test {
+                      void method(Logger logger, String param1) {
+                          logger.log(Level.INFO, "Path: C:\\\\Users\\\\{0}", param1);
+                      }
+                  }
+                  """,
+                """
+                  import org.slf4j.Logger;
+
+                  class Test {
+                      void method(Logger logger, String param1) {
+                          logger.info("Path: C:\\\\Users\\\\{}", param1);
+                      }
+                  }
+                  """
+              )
+            );
+        }
+    }
 }