Support reading of double[]

jr-objects/src/main/java/com/fasterxml/jackson/jr/ob/impl/SimpleValueReader.java

@@ -6,9 +6,8 @@
 import java.net.URL;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.UUID;
+import java.util.*;
+import java.util.stream.DoubleStream;
 import java.util.stream.IntStream;
 import java.util.stream.LongStream;
 
@@ -30,6 +29,9 @@ public class SimpleValueReader extends ValueReader
     private final static int[] NO_INTS = new int[0];
     private final static long[] NO_LONGS = new long[0];
 
+    // @since 2.21
+    private final static double[] NO_DOUBLES = new double[0];    
+
     protected final int _typeId;
 
     public SimpleValueReader(Class<?> raw, int typeId) {
@@ -119,9 +121,11 @@ public Object read(JSONReader reader, JsonParser p) throws IOException
         case SER_BOOLEAN_ARRAY:
         case SER_SHORT_ARRAY:
         case SER_FLOAT_ARRAY:
-        case SER_DOUBLE_ARRAY:
             throw JSONObjectException.from(p,
                 "Deserialization of `"+_valueTypeDesc()+"` not yet supported");
+        case SER_DOUBLE_ARRAY:
+            return _readDoubleArray(p);
+
         case SER_TREE_NODE:
             return reader.readTree();
 
@@ -390,4 +394,36 @@ protected long _fetchLong(JsonParser p) throws IOException
         throw JSONObjectException.from(p, "Can not get long numeric value from JSON (to construct "
                 +_valueTypeDesc()+") from "+_tokenDesc(p, t));
     }
+
+    protected double[] _readDoubleArray(JsonParser p) throws IOException {
+        if (JsonToken.START_ARRAY.equals(p.currentToken())) {
+            p.nextToken();
+        }
+
+        final DoubleStream.Builder builder = DoubleStream.builder();
+        int t = p.currentTokenId();
+
+        if (t == JsonTokenId.ID_END_ARRAY) {
+            return NO_DOUBLES;
+        }
+
+        main_loop:
+        while (true) {
+            switch (t) {
+            case JsonTokenId.ID_NUMBER_FLOAT:
+            case JsonTokenId.ID_NUMBER_INT:
+            case JsonTokenId.ID_NULL:
+                builder.add(p.getValueAsDouble());
+                break;
+            case JsonTokenId.ID_END_ARRAY:
+                break main_loop;
+            default:
+                throw new JSONObjectException("Failed to bind `double` element of `double[]` from value: "+
+                        _tokenDesc(p));
+            }
+            p.nextToken();
+            t = p.currentTokenId();
+        }
+        return builder.build().toArray();
+    }
 }

jr-objects/src/main/java/com/fasterxml/jackson/jr/ob/impl/ValueLocatorBase.java

@@ -64,7 +64,7 @@ public abstract class ValueLocatorBase
     public final static int SER_FLOAT_ARRAY = 8; // since 2.20
     public final static int SER_DOUBLE_ARRAY = 9; // since 2.20
     public final static int SER_BOOLEAN_ARRAY = 10;
-    
+
     /**
      * An implementation of {@link com.fasterxml.jackson.core.TreeNode}
      */

jr-objects/src/test/java/com/fasterxml/jackson/jr/ob/PrimitiveArrayTest.java

@@ -141,40 +141,47 @@ public void testFloatArrayWrite() throws Exception {
 
     @Test
     public void testDoubleArrayRead() throws Exception {
-        //assertArrayEquals(DOUBLE_ARRAY, JSON.std.beanFrom(double[].class, DOUBLE_ARRAY_JSON),
-        //        0.00001);
-
-        try {
-            JSON.std.beanFrom(double[].class, DOUBLE_ARRAY_JSON);
-            fail("Should not pass");
-        } catch (JSONObjectException e) {
-            verifyException(e, "Deserialization of `double[]` not yet supported");
-        }
+        assertArrayEquals(DOUBLE_ARRAY, JSON.std.beanFrom(double[].class, DOUBLE_ARRAY_JSON),
+                0.00001);
     }
 
     @Test
     public void testDoubleArrayWrite() throws Exception {
         assertEquals(DOUBLE_ARRAY_JSON, JSON.std.asString(DOUBLE_ARRAY));
     }
 
-    // Test empty arrays
-    // Not yet implemented in Jackson-jr
+    // Test empty arrays, success cases
     @Test
     public void testEmptyArrays() throws Exception {
         assertArrayEquals(new char[0], JSON.std.beanFrom(char[].class, "\"\""));
         assertArrayEquals(new int[0], JSON.std.beanFrom(int[].class, "[]"));
         assertArrayEquals(new long[0], JSON.std.beanFrom(long[].class, "[]"));
+        assertArrayEquals(new double[0], JSON.std.beanFrom(double[].class, "[]"), 0.0);
     }
 
-    // Not yet implemented in Jackson-jr
+    // Empty arrays: Not yet implemented in Jackson-jr
     @JacksonTestFailureExpected
     @Test
-    public void testEmptyArraysFailing() throws Exception {
+    public void testEmptyArraysFailingBooleanArray() throws Exception {
         assertArrayEquals(new boolean[0], JSON.std.beanFrom(boolean[].class, "[]"));
+    }
+
+    @JacksonTestFailureExpected
+    @Test
+    public void testEmptyArraysFailingByteArray() throws Exception {
         assertArrayEquals(new byte[0], JSON.std.beanFrom(byte[].class, "[]"));
+    }
+
+    @JacksonTestFailureExpected
+    @Test
+    public void testEmptyArraysFailingShortArray() throws Exception {
         assertArrayEquals(new short[0], JSON.std.beanFrom(short[].class, "[]"));
+    }
+
+    @JacksonTestFailureExpected
+    @Test
+    public void testEmptyArraysFailingFloatArray() throws Exception {
         assertArrayEquals(new float[0], JSON.std.beanFrom(float[].class, "[]"), 0.0f);
-        assertArrayEquals(new double[0], JSON.std.beanFrom(double[].class, "[]"), 0.0);
     }
 
     // Not yet fully implemented in Jackson-jr

release-notes/VERSION-2.x

@@ -13,7 +13,7 @@ Modules:
 
 2.21.0 (not yet released)
 
-No changes since 2.20
+#208: Support reading of `double[]`
 
 2.20.0 (28-Aug-2025)