Flexjson has been good to me, but every once in a while it jumps up and surprises me. Here’s an example.
AbstractFoo.java
abstract class AbstractFoo {
private Float a = 1.1f;
private Float b = 2.2f;
private Float c = 3.3f;
public Float getA() {
return a;
}
public Float getB() {
return b;
}
public Float getC() {
return c;
}
}
Foo.java
import flexjson.JSONSerializer;
public final class Foo extends AbstractFoo {
public static void main(final String[] args) {
final Foo myFoo = new Foo();
final JSONSerializer serializer = new JSONSerializer();
System.out.println(serializer.serialize(myFoo));
}
}
Can you guess what you’re going to get when you compile this and run java Foo? If you guessed:
{"a":1.1,"b":2.2,"c":3.3,"class":"Foo"}
you were wrong. You really get:
Exception in thread "main" flexjson.JSONException: Error trying to serialize path: [ a ]
at flexjson.JSONSerializer$ObjectVisitor.bean(JSONSerializer.java:603)
at flexjson.JSONSerializer$ObjectVisitor.json(JSONSerializer.java:471)
at flexjson.JSONSerializer$ObjectVisitor.visit(JSONSerializer.java:435)
at flexjson.JSONSerializer.serialize(JSONSerializer.java:222)
at Foo.main(Foo.java:7)
Caused by: java.lang.IllegalAccessException: Class flexjson.JSONSerializer$ObjectVisitor can not access a member of class AbstractFoo with modifiers "public"
at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:65)
at java.lang.reflect.Method.invoke(Method.java:578)
at flexjson.JSONSerializer$ObjectVisitor.bean(JSONSerializer.java:579)
... 4 more
It appears that Flexjson’s serialization algorithm can’t handle a
package- visible, abstract
super class. Changing it to public
fixes
the problem and you can continue on your merry way.
Back to flipping out…