How to use

field

method

in

org.apache.beam.sdk.transforms.reflect.DoFnSignature$FieldAccessDeclaration

checkArgument(
  fieldAccessDeclaration != null, "No FieldAccessDeclaration  defined with id", id);
checkArgument(fieldAccessDeclaration.field().getType().equals(FieldAccessDescriptor.class));
try {
 fieldAccessDescriptor = (FieldAccessDescriptor) fieldAccessDeclaration.field().get(fn);
} catch (IllegalAccessException e) {
 throw new RuntimeException(e);

@Test
public void testFieldAccess() throws IllegalAccessException {
 FieldAccessDescriptor descriptor = FieldAccessDescriptor.withFieldNames("foo", "bar");
 DoFn<String, String> doFn =
   new DoFn<String, String>() {
    @FieldAccess("foo")
    final FieldAccessDescriptor fieldAccess = descriptor;
    @ProcessElement
    public void process(@FieldAccess("foo") Row row) {}
   };
 DoFnSignature sig = DoFnSignatures.getSignature(doFn.getClass());
 assertThat(sig.fieldAccessDeclarations().get("foo"), notNullValue());
 Field field = sig.fieldAccessDeclarations().get("foo").field();
 assertThat(field.getName(), equalTo("fieldAccess"));
 assertThat(field.get(doFn), equalTo(descriptor));
 assertThat(sig.processElement().getRowParameter(), notNullValue());
}

checkArgument(
  fieldAccessDeclaration != null, "No FieldAccessDeclaration defined with id", id);
checkArgument(fieldAccessDeclaration.field().getType().equals(FieldAccessDescriptor.class));
try {
 fieldAccessDescriptor = (FieldAccessDescriptor) fieldAccessDeclaration.field().get(fn);
} catch (IllegalAccessException e) {
 throw new RuntimeException(e);