[AVRO-1716] Java Schema Generated sources, non nullable, default defined fails on setField(null)

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.7.7
• Component/s: java
• Labels: starter
• Assignee: Unassigned
• Reporter: Francois Secherre
• Created: 10/Aug/15 11:20
• Updated: 21/Jul/19 05:17

Description

I define a schema descriptor like:

{
    "namespace": "some.namespace",
    "type": "record",
    "name": "SomeBean",
    "fields": [
        {"name": "someField", "type": "string", "default": ""},
    ]
}

Then I generate some java classes, using org.apache.avro:avro-maven-plugin. In the builder methods I will get the following:

    public some.namespace.SomeBean.Builder setSomeField(java.lang.CharSequence value) {
      validate(fields()[0], value);
      this.someField = value;
      fieldSetFlags()[0] = true;
      return this; 
    }

The Validate methode is like:

    protected void validate(Field field, Object value) {
        if(!isValidValue(field, value)) {
            if(field.defaultValue() == null) {
                throw new AvroRuntimeException("Field " + field + " does not accept null values");
            }
        }
    }

So if I perform SomeBean.setSomeField(null), as the defaultValue is defined, no exception will raise. However, someField will get a null value. That lead to the following type of error:

java.lang.NullPointerException: null of string in field someField of some.namespace.SomeBean	at org.apache.avro.generic.GenericDatumWriter.npe(GenericDatumWriter.java:93)
	at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:87)
	at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:58)
...
Caused by: java.lang.NullPointerException
	at org.apache.avro.io.Encoder.writeString(Encoder.java:121)
	at org.apache.avro.generic.GenericDatumWriter.writeString(GenericDatumWriter.java:213)
	at org.apache.avro.generic.GenericDatumWriter.writeString(GenericDatumWriter.java:208)
	at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:76)
	at org.apache.avro.generic.GenericDatumWriter.writeField(GenericDatumWriter.java:114)
	at org.apache.avro.generic.GenericDatumWriter.writeRecord(GenericDatumWriter.java:104)
	at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:66)
	... 7 more

I believe that in such case we should protect the field from being set to null, and remain at its default value.

Issue Links

• is superceded by: AVRO-2478 RecordBuilderBase.validate doesn't check nullability of composite types