stackOverflow on serialize org.apache.commons.lang3.tuple.Pair

[ChinaXing]

ObjectMapper objectMapper = new ObjectMapper();
        try {
            JsonGenerator generator = objectMapper.getFactory().createGenerator(System.out);
            Pair<Integer, String> a = Pair.of(10, "100");
            objectMapper.writer().writeValue(generator, a);
        } catch (Exception e) {
            e.printStackTrace();
        }

will produce stack overflow:

java.lang.StackOverflowError
    at com.fasterxml.jackson.databind.type.ClassKey.equals(ClassKey.java:78)
    at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:940)
    at com.fasterxml.jackson.databind.util.LRUMap.get(LRUMap.java:68)
    at com.fasterxml.jackson.databind.type.TypeFactory._fromClass(TypeFactory.java:870)
    at com.fasterxml.jackson.databind.type.TypeFactory._constructType(TypeFactory.java:480)
    at com.fasterxml.jackson.databind.type.TypeBindings._resolveBindings(TypeBindings.java:314)
    at com.fasterxml.jackson.databind.type.TypeBindings._resolve(TypeBindings.java:212)
    at com.fasterxml.jackson.databind.type.TypeBindings.findType(TypeBindings.java:126)
    at com.fasterxml.jackson.databind.type.TypeFactory._fromVariable(TypeFactory.java:1068)
    at com.fasterxml.jackson.databind.type.TypeFactory._constructType(TypeFactory.java:493)
....
    at com.fasterxml.jackson.databind.type.TypeFactory.findTypeParameters(TypeFactory.java:397)
    at com.fasterxml.jackson.databind.type.TypeFactory.findTypeParameters(TypeFactory.java:373)
    at com.fasterxml.jackson.databind.type.TypeFactory._fromParamType(TypeFactory.java:1032)
    at com.fasterxml.jackson.databind.type.TypeFactory._constructType(TypeFactory.java:484)
    at com.fasterxml.jackson.databind.type.TypeBindings._resolveBindings(TypeBindings.java:267)
    at com.fasterxml.jackson.databind.type.TypeBindings._resolveBindings(TypeBindings.java:328)
    at com.fasterxml.jackson.databind.type.TypeBindings._resolve(TypeBindings.java:212)
    at com.fasterxml.jackson.databind.type.TypeBindings.findType(TypeBindings.java:126)
    at com.fasterxml.jackson.databind.type.TypeFactory._fromVariable(TypeFactory.java:1068)
    at com.fasterxml.jackson.databind.type.TypeFactory._constructType(TypeFactory.java:493)
    at com.fasterxml.jackson.databind.type.TypeFactory.findTypeParameters(TypeFactory.java:397)
    at com.fasterxml.jackson.databind.type.TypeFactory.findTypeParameters(TypeFactory.java:373)
    at com.fasterxml.jackson.databind.type.TypeFactory._fromParamType(TypeFactory.java:1032)
    at com.fasterxml.jackson.databind.type.TypeFactory._constructType(TypeFactory.java:484)

[cowtowncoder]

Which version of Jackson?

[ChinaXing]

com.fasterxml.jackson.core jackson-core 2.6.2 com.fasterxml.jackson.core jackson-databind 2.6.2

[ChinaXing]

It because of

public abstract class Pair<L, R> implements Map.Entry<L, R>, Comparable<Pair<L, R>>, Serializable {

which has a circle reference of parameter type : the interface Comparable's parameter type reference the Pair<L,R>, which is the type to serialize.

so, I think any classes with such circle reference parameter type situation, will produce such exception and can not be serialized.

It should be fix.

[cowtowncoder]

@ChinaXing Jackson 2.7 has a completely rewritten type resolution system, and I was asking because problems previous versions had can not be fixed for those versions in patches.
There were a few known issues and this could be one of those.

I would suggest you to see whether things work with 2.7.3; I would expect that to handle recursion better.

[ChinaXing]

I choose Gson instead.