BigDecimal in Avro

[Jian Fang]

Hi,

I tried to use Avro 1.6.1 for my existing domain classes with reflection,
but the BigDecimal type caused some trouble for me.

Take the following code as an example,

public class Parent {

    private String name;

    private int age;

    private Date birthday;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
}

public class Child extends Parent {

    private BigDecimal salary;

    public BigDecimal getSalary() {
        return salary;
    }

    public void setSalary(BigDecimal salary) {
        this.salary = salary;
    }
}

I have two classes, the Parent class does not have the BigDecimal type, but
the Child does have.

I created a test case as follows:

public class AvroSchema_UnitTest {

    @Test
    public void testBigDecimal() {
        ReflectData reflectData = ReflectData.AllowNull.get();
        Schema schema = reflectData.getSchema(Parent.class);
        System.out.println("Parent");
        System.out.println(schema.toString());
        schema = reflectData.getSchema(Child.class);
        System.out.println("Parent");
        System.out.println(schema.toString());
    }
}

Run it and here is the following output:

Parent
{"type":"record","name":"Parent","namespace":"com.barnesandnoble.domain","fields":[{"name":"name","type":["null","string"],"default":null},{"name":"age","type":["null","int"],"default":null},{"name":"birthday","type":["null",{"type":"record","name":"Date","namespace":"java.util","fields":[]}],"default":null}]}

org.apache.avro.AvroRuntimeException: java.lang.NoSuchFieldException:
SCHEMA$
    at
org.apache.avro.specific.SpecificData.createSchema(SpecificData.java:193)
    at
org.apache.avro.reflect.ReflectData.createSchema(ReflectData.java:249)
    at
org.apache.avro.reflect.ReflectData.createFieldSchema(ReflectData.java:363)
    at
org.apache.avro.reflect.ReflectData$AllowNull.createFieldSchema(ReflectData.java:68)
    at
org.apache.avro.reflect.ReflectData.createSchema(ReflectData.java:292)
    at
org.apache.avro.specific.SpecificData.getSchema(SpecificData.java:134)
    at
com.barnesandnoble.domain.AvroSchema_UnitTest.testBigDecimal(AvroSchema_UnitTest.java:58)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at
org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at
org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at
org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:76)
    at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
    at
com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:71)
    at
com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:199)
    at
com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:62)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: java.lang.NoSuchFieldException: SCHEMA$
    at java.lang.Class.getDeclaredField(Class.java:1882)
    at
org.apache.avro.specific.SpecificData.createSchema(SpecificData.java:185)
    ... 31 more

As you can see, the Parent class is fine, but the Child class throws an
exception because of the BigDecimal type.

Is this a bug? How to get around this if I am not able to change the
existing domain classes.


Thanks,

John