support JSONSchema from value

Author: wenshao

core/src/main/java/com/alibaba/fastjson2/schema/JSONSchema.java

@@ -16,6 +16,7 @@
 import java.net.URL;
 import java.net.URLDecoder;
 import java.util.Collection;
+import java.util.Iterator;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -173,7 +174,36 @@ public static JSONSchema of(java.lang.reflect.Type type) {
         return of(type, null);
     }
 
-    public static JSONSchema of(java.lang.reflect.Type type, JSONSchema root) {
+    public static JSONSchema ofValue(Object value) {
+        return ofValue(value, null);
+    }
+
+    static JSONSchema ofValue(Object value, JSONSchema root) {
+        if (value == null) {
+            return null;
+        }
+
+        if (value instanceof Map) {
+            JSONObject object = JSONObject.of("type", "object");
+            ObjectSchema schema = new ObjectSchema(object, root);
+
+            Map map = (Map) value;
+            for (Iterator it = map.entrySet().iterator(); it.hasNext();) {
+                Map.Entry entry = (Map.Entry) it.next();
+                Object entryKey = entry.getKey();
+                if (entryKey instanceof String) {
+                    JSONSchema valueSchema = ofValue(entry.getValue(), root == null ? schema : root);
+                    schema.properties.put((String) entryKey, valueSchema);
+                }
+            }
+
+            return schema;
+        }
+
+        return of(value.getClass(), root);
+    }
+
+    static JSONSchema of(java.lang.reflect.Type type, JSONSchema root) {
         if (type instanceof ParameterizedType) {
             ParameterizedType paramType = (ParameterizedType) type;
 

core/src/test/java/com/alibaba/fastjson2/schema/FromClass.java

@@ -8,8 +8,7 @@
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
-import java.util.Collection;
-import java.util.Map;
+import java.util.*;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
@@ -28,6 +27,10 @@ public void test() {
         );
         JSONSchema pased = JSONSchema.of(JSON.parseObject(string));
         assertTrue(Differ.diff(schema, pased));
+
+        Bean bean = new Bean();
+        JSONSchema valueSchema = JSONSchema.ofValue(bean);
+        assertTrue(Differ.diff(schema, valueSchema));
     }
 
     public static class Bean {
@@ -87,4 +90,18 @@ public void testEishay() {
         JSONSchema pased = JSONSchema.of(JSON.parseObject(string));
         assertTrue(Differ.diff(schema, pased));
     }
+
+    @Test
+    public void fromValueMap() {
+        Map map = new HashMap();
+        map.put("id", 123);
+        assertEquals("{\"type\":\"object\",\"properties\":{\"id\":{\"type\":\"integer\"}}}", JSONSchema.ofValue(map).toString());
+    }
+
+    @Test
+    public void fromValueList() {
+        List list = new ArrayList();
+        list.add("xxx");
+        assertEquals("{\"type\":\"array\"}", JSONSchema.ofValue(list).toString());
+    }
 }