Sebastian J. created AVRO-2438:
----------------------------------
Summary: SpecificData.deepCopy() cannot be used with URI fields
Key: AVRO-2438
URL: https://issues.apache.org/jira/browse/AVRO-2438
Project: Apache Avro
Issue Type: Bug
Components: java
Affects Versions: 1.8.2
Reporter: Sebastian J.
Having a schema fragment like this:
{code:java}
{
"name": "ownerId",
"type": [
"null",
{
"type": "string",
"java-class": "java.net.URI"
}
],
"default": null
}{code}
can be perfectly deserialized in a generated POJO with
{code:java}
@org.apache.avro.specific.AvroGenerated
public class MyAvroDataObject extends
org.apache.avro.specific.SpecificRecordBase implements
org.apache.avro.specific.SpecificRecord {
...
@Deprecated public java.net.URI ownerId;{code}
as
{{GenericDatumReader.readString(Object, Schema, Decoder)}} uses via the
{{stringClassCache}} with
{code:java}
{"type":"string","java-class":"java.net.URI"}=class java.net.URI{code}
The {{URI}} class itself to rehydrate the value via {{newInstanceFromString}}.
On the other hand, {{deepCopy}} only considers the schema-type of the field and
turns in {{org.apache.avro.generic.GenericData.deepCopy(Schema, T)}}
the {{URI}} value into an {{org.apache.avro.util.Utf8}} via the {{String}} case
which then causes a {{ClassCastException}}:
{noformat}
java.lang.ClassCastException: org.apache.avro.util.Utf8 cannot be cast to
java.net.URI
at com.example.MyAvroDataObject.put(MyAvroDataObject.java:104)
at org.apache.avro.generic.GenericData.setField(GenericData.java:660)
at org.apache.avro.generic.GenericData.setField(GenericData.java:677)
at org.apache.avro.generic.GenericData.deepCopy(GenericData.java:1082)
at org.apache.avro.generic.GenericData.deepCopy(GenericData.java:1102)
at
org.apache.avro.generic.GenericData.deepCopy(GenericData.java:1080){noformat}
The following dirty hack seems to avoid the issue - but is not in sync with the
{{stringClassCache}} which should be consulted, too:
{code:java}
case STRING:
// Strings are immutable
if (value instanceof String) {
return (T)value;
}
// Dirty Harry 9 3/4 start
// URIs are immutable and are probably modeled as an URI itself
// TODO: Check with stringClassCache & the schema
else if (value instanceof URI) {
return (T)value;
}
// Dirt Harry 9 3/4 end
// Some CharSequence subclasses are mutable, so we still need to make
// a copy
else if (value instanceof Utf8) {
// Utf8 copy constructor is more efficient than converting
// to string and then back to Utf8
return (T)new Utf8((Utf8)value);
}
return (T)new Utf8(value.toString());
{code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
