improved jsonpath, for issue #2401

alibaba · Apr 6, 2024 · 7493a2f · 7493a2f
1 parent c7aa978
commit 7493a2f
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diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONPathFunction.java b/core/src/main/java/com/alibaba/fastjson2/JSONPathFunction.java
@@ -583,4 +583,33 @@ protected boolean eq(Object item) {
             return value.equals(item.toString());
         }
     }
+
+    static final class IndexValue
+            implements Function {
+        final int index;
+
+        public IndexValue(int index) {
+            this.index = index;
+        }
+
+        @Override
+        public Object apply(Object o) {
+            if (o == null) {
+                return null;
+            }
+
+            if (o instanceof List) {
+                return ((List) o).get(index);
+            }
+
+            if (o.getClass().isArray()) {
+                int len = Array.getLength(o);
+                for (int i = 0; i < len; i++) {
+                    return Array.get(o, i);
+                }
+            }
+
+            return null;
+        }
+    }
 }
diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONPathParser.java b/core/src/main/java/com/alibaba/fastjson2/JSONPathParser.java
@@ -707,6 +707,15 @@ JSONPathSegment parseFilter() {
             }
         }
 
+        if (function == null && jsonReader.ch == '[') {
+            jsonReader.next();
+            int index = jsonReader.readInt32Value();
+            function = new JSONPathFunction.IndexValue(index);
+            if (!jsonReader.nextIfMatch(']')) {
+                throw new JSONException("syntax error, [" + index);
+            }
+        }
+
         if (operator == null) {
             operator = JSONPath.parseOperator(jsonReader);
         }

diff --git a/core/src/test/java/com/alibaba/fastjson2/issues_2400/Issue2401.java b/core/src/test/java/com/alibaba/fastjson2/issues_2400/Issue2401.java
@@ -0,0 +1,33 @@
+package com.alibaba.fastjson2.issues_2400;
+
+import com.alibaba.fastjson2.JSON;
+import com.alibaba.fastjson2.JSONPath;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue2401 {
+    @Test
+    public void test() {
+        String str = "{\n" +
+                "\t\"objects\": [\n" +
+                "\t\t{\n" +
+                "\t\t\t\"objclass\": \"GamePropertySheet\",\n" +
+                "\t\t\t\"aliases\": [\n" +
+                "\t\t\t\t\"DefaultGameProps\"\n" +
+                "\t\t\t],\n" +
+                "\t\t\t\"objdata\": {\n" +
+                "\t\t\t\t\"Plants\": [\n" +
+                "\t\t\t\t\t\"plant1\",\n" +
+                "\t\t\t\t\t\"plant2\"\n" +
+                "\t\t\t\t]\n" +
+                "\t\t\t}\n" +
+                "\t\t}\n" +
+                "\t]\n" +
+                "}";
+
+        String path = "$.objects[?(@.aliases[0] == 'DefaultGameProps')].objdata";
+        Object result = JSONPath.eval(str, path);
+        assertEquals("[{\"Plants\":[\"plant1\",\"plant2\"]}]", JSON.toJSONString(result));
+    }
+}