Fix HashMapper issue flattening java.math types.

We now make sure to include types from the java.math namespace.

Closes: #2365

Author: christophstrobl

src/main/java/org/springframework/data/redis/hash/Jackson2HashMapper.java

@@ -34,7 +34,9 @@
 import org.springframework.data.mapping.MappingException;
 import org.springframework.data.util.DirectFieldAccessFallbackBeanWrapper;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.NumberUtils;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
@@ -153,6 +155,8 @@
  */
 public class Jackson2HashMapper implements HashMapper<Object, String, Object>, HashObjectReader<String, Object> {
 
+	private static final boolean SOURCE_VERSION_PRESENT = ClassUtils.isPresent("javax.lang.model.SourceVersion", Jackson2HashMapper.class.getClassLoader());
+
 	private final HashMapperModule HASH_MAPPER_MODULE = new HashMapperModule();
 
 	private final ObjectMapper typingMapper;
@@ -287,8 +291,7 @@ public <R> R fromHash(Class<R> type, Map<String, Object> hash) {
 
 			if (flatten) {
 
-				return typingMapper.reader().forType(type)
-						.readValue(untypedMapper.writeValueAsBytes(doUnflatten(hash)));
+				return typingMapper.reader().forType(type).readValue(untypedMapper.writeValueAsBytes(doUnflatten(hash)));
 			}
 
 			return typingMapper.treeToValue(untypedMapper.valueToTree(hash), type);
@@ -394,10 +397,42 @@ private void flattenElement(String propertyPrefix, Object source, Map<String, Ob
 				if (cur.isArray()) {
 					this.flattenCollection(propertyPrefix, cur.elements(), resultMap);
 				} else {
+					if (nodes.hasNext() && mightBeJavaType(cur)) {
+
+						JsonNode next = nodes.next();
+
+						if (next.isArray()) {
+							this.flattenCollection(propertyPrefix, next.elements(), resultMap);
+						}
+
+						if (cur.asText().equals("java.util.Date")) {
+							resultMap.put(propertyPrefix, next.asText());
+							break;
+						}
+						if (next.isNumber()) {
+							resultMap.put(propertyPrefix, next.numberValue());
+							break;
+						}
+						if (next.isTextual()) {
+
+							resultMap.put(propertyPrefix, next.textValue());
+							break;
+						}
+						if (next.isBoolean()) {
+
+							resultMap.put(propertyPrefix, next.booleanValue());
+							break;
+						}
+						if (next.isBinary()) {
+
+							try {
+								resultMap.put(propertyPrefix, next.binaryValue());
+							} catch (IOException e) {
+								throw new IllegalStateException(String.format("Cannot read binary value of '%s'", propertyPrefix), e);
+							}
+							break;
+						}
 
-					if (cur.asText().equals("java.util.Date")) {
-						resultMap.put(propertyPrefix, nodes.next().asText());
-						break;
 					}
 				}
 			}
@@ -409,6 +444,27 @@ private void flattenElement(String propertyPrefix, Object source, Map<String, Ob
 		}
 	}
 
+	private boolean mightBeJavaType(JsonNode node) {
+
+		String textValue = node.asText();
+		if (!SOURCE_VERSION_PRESENT) {
+
+			if (ObjectUtils.nullSafeEquals(textValue, "java.util.Date")) {
+				return true;
+			}
+			if (ObjectUtils.nullSafeEquals(textValue, "java.math.BigInteger")) {
+				return true;
+			}
+			if (ObjectUtils.nullSafeEquals(textValue, "java.math.BigDecimal")) {
+				return true;
+			}
+
+			return false;
+		}
+		return javax.lang.model.SourceVersion.isName(textValue);
+
+	}
+
 	private void flattenCollection(String propertyPrefix, Iterator<JsonNode> list, Map<String, Object> resultMap) {
 
 		int counter = 0;

src/test/java/org/springframework/data/redis/mapping/Jackson2HashMapperUnitTests.java

@@ -19,6 +19,8 @@
 
 import lombok.Data;
 
+import java.math.BigDecimal;
+import java.math.BigInteger;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.util.ArrayList;
@@ -199,6 +201,24 @@ void mapFinalClass() {
 		assertBackAndForwardMapping(source);
 	}
 
+	@Test // GH-2365
+	void bigIntegerShouldBeTreatedCorrectly() {
+
+		WithBigWhatever source = new WithBigWhatever();
+		source.bigI = BigInteger.TEN;
+
+		assertBackAndForwardMapping(source);
+	}
+
+	@Test // GH-2365
+	void bigDecimalShouldBeTreatedCorrectly() {
+
+		WithBigWhatever source = new WithBigWhatever();
+		source.bigD = BigDecimal.ONE;
+
+		assertBackAndForwardMapping(source);
+	}
+
 	@Data
 	public static class WithList {
 		List<String> strings;
@@ -223,6 +243,12 @@ private static class WithDates {
 		private LocalDateTime localDateTime;
 	}
 
+	@Data
+	private static class WithBigWhatever {
+		private BigDecimal bigD;
+		private BigInteger bigI;
+	}
+
 	@Data
 	public static final class MeFinal {
 		private String value;