[HADOOP-8104] Inconsistent Jackson versions

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.23.3
• Fix Version/s: 0.23.3, 2.0.2-alpha
• Hadoop Flags: Reviewed
• Assignee: Alejandro Abdelnur
• Reporter: Colin McCabe
• Created: 23/Feb/12 01:11
• Updated: 07/Sep/12 21:01
• Resolved: 28/Feb/12 19:02

Description

This is a maven build issue.

Jersey 1.8 is pulling in version 1.7.1 of Jackson. Meanwhile, we are manually specifying that we want version 1.8 of Jackson in the POM files. This causes a conflict where Jackson produces unexpected results when serializing Map objects.

How to reproduce: try this code:

ObjectMapper mapper = new ObjectMapper();
Map<String, Object> m = new HashMap<String, Object>();
mapper.writeValue(new File("foo"), m);

You will get an exception:

Exception in thread "main" java.lang.NoSuchMethodError: org.codehaus.jackson.type.JavaType.isMapLikeType()Z
at org.codehaus.jackson.map.ser.BasicSerializerFactory.buildContainerSerializer(BasicSerializerFactory.java:396)
at org.codehaus.jackson.map.ser.BeanSerializerFactory.createSerializer(BeanSerializerFactory.java:267)

Basically the inconsistent versions of various Jackson components are causing this NoSuchMethod error.

As far as I know, this only occurs when serializing maps-- that's why it hasn't been found and fixed yet.