Using Stream Builder to deserialization of int[] (#125)

Author: Shounaks

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

@@ -1,28 +1,33 @@
 package com.fasterxml.jackson.jr.ob.impl;
 
-import static com.fasterxml.jackson.jr.ob.impl.ValueWriterLocator.*;
-
 import java.io.File;
 import java.io.IOException;
 import java.net.URI;
 import java.net.URL;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.*;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.UUID;
+import java.util.stream.IntStream;
 
 import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonToken;
 import com.fasterxml.jackson.core.JsonTokenId;
 import com.fasterxml.jackson.jr.ob.JSONObjectException;
 import com.fasterxml.jackson.jr.ob.api.ValueReader;
 
+import static com.fasterxml.jackson.jr.ob.impl.ValueWriterLocator.*;
+
 /**
  * Default {@link ValueReader} used for simple scalar types and related,
  * not including POJO-, {@link java.util.Map} and {@link java.util.Collection}
  * types.
  */
 public class SimpleValueReader extends ValueReader
 {
+    private final static int[] NO_INTS = new int[0];
+
     protected final int _typeId;
 
     public SimpleValueReader(Class<?> raw, int typeId) {
@@ -290,10 +295,37 @@ protected Path _readPath(JsonParser p) throws IOException {
         }
     }
 
-    protected int[] _readIntArray(JsonParser p) throws IOException
-    {
-        // !!! TODO
-        throw new JSONObjectException("Reading of int[] not yet implemented");
+    protected int[] _readIntArray(JsonParser p) throws IOException {
+        if (JsonToken.START_ARRAY.equals(p.currentToken())) {
+            p.nextToken();
+        }
+
+        final IntStream.Builder builder = IntStream.builder();
+        int t = p.currentTokenId();
+
+        // Tiny optimization
+        if (t == JsonTokenId.ID_END_ARRAY) {
+            return NO_INTS;
+        }
+        
+        main_loop:
+        while (true) {
+            switch (t) {
+            case JsonTokenId.ID_NUMBER_FLOAT:
+            case JsonTokenId.ID_NUMBER_INT:
+            case JsonTokenId.ID_NULL:
+                builder.add(p.getValueAsInt());
+                break;
+            case JsonTokenId.ID_END_ARRAY:
+                break main_loop;
+            default:
+                throw new JSONObjectException("Failed to bind `int` element if `int[]` from value: "+
+                        _tokenDesc(p));
+            }
+            p.nextToken();
+            t = p.currentTokenId();
+        }
+        return builder.build().toArray();
     }
 
     protected long _fetchLong(JsonParser p) throws IOException

jr-objects/src/test/java/com/fasterxml/jackson/jr/failing/ReadIntArray7Test.java

@@ -0,0 +1,33 @@
+package com.fasterxml.jackson.jr.ob;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class ReadIntArray7Test extends TestBase {
+    public void testReadIntArray() throws Exception {
+        final int[] input = new int[]{1, 2, 3, 25, 999};
+        String json = JSON.std.asString(input);
+        int[] result = JSON.std.beanFrom(int[].class, json);
+        assertArrayEquals(input, result);
+    }
+
+    public void testReadIntArray2() throws Exception {
+        final int[][] input = new int[][]{{1, 2, 3, 25, 999},{456,678,789},{1},{},{1000,2000,3000}};
+        String json = JSON.std.asString(input);
+        int[][] result = JSON.std.beanFrom(int[][].class, json);
+        assertArrayEquals(input, result);
+    }
+
+    public void testReadIntArray3() throws Exception {
+        final int[][][] input = new int[][][]{{{1, 2, 3, 25, 999},{6,7,3}},{{456}, {678, 789}},{},{{},{23}},{{}}};
+        String json = JSON.std.asString(input);
+        int[][][] result = JSON.std.beanFrom(int[][][].class, json);
+        assertArrayEquals(input, result);
+    }
+
+    public void testReadIntArrayWhenEmpty() throws Exception {
+        final int[][][] input = new int[][][]{};
+        String json = JSON.std.asString(input);
+        int[][][] result = JSON.std.beanFrom(int[][][].class, json);
+        assertArrayEquals(input, result);
+    }
+}

jr-objects/src/test/java/com/fasterxml/jackson/jr/ob/ReadIntArray7Test.java

@@ -343,16 +343,6 @@ public void testTreeNodeCreationWithoutCodec() throws Exception {
         }
     }
 
-    // not yet supported (but probably should)
-    public void testIntArray() throws Exception {
-        try {
-            JSON.std.beanFrom(IntArrayWrapper.class, "{\"value\":[ 3 ]}");
-            fail("Should not pass");
-        } catch (JSONObjectException e) {
-            verifyException(e, "not yet implemented");
-        }
-    }
-
     public void testInvalidSource() throws Exception {
         try {
             JSON.std.beanFrom(Object.class, Long.valueOf(67));

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

@@ -1,7 +1,5 @@
 package com.fasterxml.jackson.jr.ob;
 
-import com.fasterxml.jackson.jr.ob.JSON;
-
 // for [jackson-jr#25], allowing single-int constructors
 public class ReadWithCtors25Test extends TestBase
 {

jr-objects/src/test/java/com/fasterxml/jackson/jr/ob/ReadWithCtors25Test.java

@@ -48,6 +48,8 @@ Julian Honnen (@jhonnen)
 
 @Shounaks
 
+* Contributed #7: Support deserialization of int[]
+ (2.17.0)
 * Contributed PoC of #25: Add support single-int Constructors
  (2.17.0)
 * Contributed fix for #93: Skip serialization of `groovy.lang.MetaClass` values

release-notes/CREDITS-2.x

@@ -11,6 +11,11 @@ Modules:
 === Releases ===
 ------------------------------------------------------------------------
 
+Not yet released
+
+#7: Support deserialization of `int[]`
+ (contributed by @Shounaks) 
+
 2.17.0-rc1 (26-Feb-2024)
 
 #25: Add support single-int Constructors