jsonpath support multi-names exists filter

alibaba · Jan 16, 2024 · 9ea8c8d · 9ea8c8d
1 parent 5b78609
commit 9ea8c8d
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diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONPathFilter.java b/core/src/main/java/com/alibaba/fastjson2/JSONPathFilter.java
@@ -1,5 +1,6 @@
 package com.alibaba.fastjson2;
 
+import com.alibaba.fastjson2.util.Fnv;
 import com.alibaba.fastjson2.util.IOUtils;
 import com.alibaba.fastjson2.writer.FieldWriter;
 import com.alibaba.fastjson2.writer.ObjectWriter;
@@ -1034,6 +1035,64 @@ public boolean apply(JSONPath.Context context, Object object) {
         }
     }
 
+    static final class NamesExistsFilter
+            extends JSONPathFilter {
+        final String[] names;
+        final long[] nameHashCodes;
+
+        public NamesExistsFilter(List<String> names) {
+            this.names = names.toArray(new String[0]);
+            long[] nameHashCodes = new long[this.names.length];
+            for (int i = 0; i < nameHashCodes.length; i++) {
+                nameHashCodes[i] = Fnv.hashCode64(this.names[i]);
+            }
+            this.nameHashCodes = nameHashCodes;
+        }
+
+        @Override
+        public void eval(JSONPath.Context context) {
+            Object first = context.parent == null
+                    ? context.root
+                    : context.parent.value;
+
+            Object object = first;
+            for (int i = 0; i < names.length; i++) {
+                String name = names[i];
+                if (object instanceof Map) {
+                    Map map = (Map) object;
+                    Object value = map.get(name);
+                    if (i == names.length - 1 || value == null) {
+                        context.value = value != null ? first : null;
+                        return;
+                    }
+                    object = value;
+                }
+            }
+        }
+
+        @Override
+        public void accept(JSONReader jsonReader, JSONPath.Context context) {
+            eval(context);
+        }
+
+        @Override
+        public String toString() {
+            StringBuilder buf = new StringBuilder("exists(");
+            for (int i = 0; i < names.length; i++) {
+                if (i != 0) {
+                    buf.append(", ");
+                }
+            }
+            buf.append(')');
+            return buf.toString();
+        }
+
+        @Override
+        public boolean apply(JSONPath.Context context, Object object) {
+            throw new UnsupportedOperationException();
+        }
+    }
+
     static final class NameIntBetweenSegment
             extends NameFilter {
         private final long begin;

diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONPathParser.java b/core/src/main/java/com/alibaba/fastjson2/JSONPathParser.java
@@ -546,6 +546,24 @@ JSONPathSegment parseFilter() {
                             }
                         }
                         return new JSONPathFilter.NameExistsFilter(fieldName, hashCode);
+                    } else if (jsonReader.ch == '.') {
+                        List<String> names = new ArrayList<>();
+                        names.add(fieldName);
+                        do {
+                            jsonReader.next();
+                            fieldName = jsonReader.readFieldNameUnquote();
+                            names.add(fieldName);
+                        } while (jsonReader.ch == '.');
+
+                        if (jsonReader.nextIfMatch(')')) {
+                            if (parentheses) {
+                                if (!jsonReader.nextIfMatch(')')) {
+                                    throw new JSONException(jsonReader.info("jsonpath syntax error"));
+                                }
+                            }
+                        }
+
+                        return new JSONPathFilter.NamesExistsFilter(names);
                     }
                 }
             }

diff --git a/core/src/test/java/com/alibaba/fastjson2/issues_2100/Issue2190.java b/core/src/test/java/com/alibaba/fastjson2/issues_2100/Issue2190.java
@@ -0,0 +1,21 @@
+package com.alibaba.fastjson2.issues_2100;
+
+import com.alibaba.fastjson2.JSON;
+import com.alibaba.fastjson2.JSONObject;
+import com.alibaba.fastjson2.JSONPath;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+public class Issue2190 {
+    @Test
+    public void test() {
+        String str = "{\"code\":0,\"errMsg\":\"\",\"Data\":{\"is_focus\":1,\"user_info\":{\"userid\":\"13814\",\"nickname\":\"没事改昵称\"}}}";
+        JSONObject jsonObject = JSON.parseObject(str);
+        assertSame(jsonObject, JSONPath.eval(jsonObject, "[?exists(@.Data.user_info.userid)]"));
+        assertNull(JSONPath.eval(jsonObject, "[?exists(@.Data.user_info.userid1)]"));
+        assertNull(JSONPath.eval(jsonObject, "[?exists(@.Data.user_info1.userid)]"));
+        assertNull(JSONPath.eval(jsonObject, "[?exists(@.Data1.user_info.userid)]"));
+    }
+}