fix jsonpath 1.x compatible, for issue #2542

fastjson1-compatible/src/main/java/com/alibaba/fastjson/JSONPath.java

@@ -50,6 +50,9 @@ public static <T> T read(String json, String path, Type clazz) {
     }
 
     public static Object eval(Object rootObject, String path) {
+        if (rootObject instanceof String) {
+            return com.alibaba.fastjson2.JSONPath.eval((String) rootObject, path);
+        }
         com.alibaba.fastjson2.JSONPath jsonPath = com.alibaba.fastjson2.JSONPath.of(path);
         return jsonPath.eval(rootObject);
     }

fastjson1-compatible/src/test/java/com/alibaba/fastjson/v2issues/Issue2542.java

@@ -0,0 +1,20 @@
+package com.alibaba.fastjson.v2issues;
+
+import com.alibaba.fastjson2.JSONPath;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue2542 {
+    @Test
+    public void test() {
+        String temp = "{\n" +
+                "  \"code\": \"1003\", \n" +
+                "  \"data\": [1, 2], \n" +
+                "}\n";
+        assertEquals(
+                JSONPath.eval(temp, "$.data"),
+                com.alibaba.fastjson.JSONPath.eval(temp, "$.data")
+        );
+    }
+}