| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * https://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.avro.specific; |
| |
| import org.apache.avro.Conversion; |
| import org.apache.avro.Schema; |
| import org.apache.avro.AvroRuntimeException; |
| import org.apache.avro.generic.GenericDatumReader; |
| import org.apache.avro.io.ResolvingDecoder; |
| import org.apache.avro.util.ClassUtils; |
| import java.io.IOException; |
| |
| /** |
| * {@link org.apache.avro.io.DatumReader DatumReader} for generated Java |
| * classes. |
| */ |
| public class SpecificDatumReader<T> extends GenericDatumReader<T> { |
| public SpecificDatumReader() { |
| this(null, null, SpecificData.get()); |
| } |
| |
| /** Construct for reading instances of a class. */ |
| public SpecificDatumReader(Class<T> c) { |
| this(SpecificData.getForClass(c)); |
| setSchema(getSpecificData().getSchema(c)); |
| } |
| |
| /** Construct where the writer's and reader's schemas are the same. */ |
| public SpecificDatumReader(Schema schema) { |
| this(schema, schema, SpecificData.getForSchema(schema)); |
| } |
| |
| /** Construct given writer's and reader's schema. */ |
| public SpecificDatumReader(Schema writer, Schema reader) { |
| this(writer, reader, SpecificData.getForSchema(reader)); |
| } |
| |
| /** |
| * Construct given writer's schema, reader's schema, and a {@link SpecificData}. |
| */ |
| public SpecificDatumReader(Schema writer, Schema reader, SpecificData data) { |
| super(writer, reader, data); |
| } |
| |
| /** Construct given a {@link SpecificData}. */ |
| public SpecificDatumReader(SpecificData data) { |
| super(data); |
| } |
| |
| /** Return the contained {@link SpecificData}. */ |
| public SpecificData getSpecificData() { |
| return (SpecificData) getData(); |
| } |
| |
| @Override |
| public void setSchema(Schema actual) { |
| // if expected is unset and actual is a specific record, |
| // then default expected to schema of currently loaded class |
| if (getExpected() == null && actual != null && actual.getType() == Schema.Type.RECORD) { |
| SpecificData data = getSpecificData(); |
| Class c = data.getClass(actual); |
| if (c != null && SpecificRecord.class.isAssignableFrom(c)) |
| setExpected(data.getSchema(c)); |
| } |
| super.setSchema(actual); |
| } |
| |
| @Override |
| protected Class findStringClass(Schema schema) { |
| Class stringClass = null; |
| switch (schema.getType()) { |
| case STRING: |
| stringClass = getPropAsClass(schema, SpecificData.CLASS_PROP); |
| break; |
| case MAP: |
| stringClass = getPropAsClass(schema, SpecificData.KEY_CLASS_PROP); |
| break; |
| } |
| if (stringClass != null) |
| return stringClass; |
| return super.findStringClass(schema); |
| } |
| |
| private Class getPropAsClass(Schema schema, String prop) { |
| String name = schema.getProp(prop); |
| if (name == null) |
| return null; |
| try { |
| return ClassUtils.forName(getData().getClassLoader(), name); |
| } catch (ClassNotFoundException e) { |
| throw new AvroRuntimeException(e); |
| } |
| } |
| |
| @Override |
| protected Object readRecord(Object old, Schema expected, ResolvingDecoder in) throws IOException { |
| SpecificData data = getSpecificData(); |
| if (data.useCustomCoders()) { |
| old = data.newRecord(old, expected); |
| if (old instanceof SpecificRecordBase) { |
| SpecificRecordBase d = (SpecificRecordBase) old; |
| if (d.hasCustomCoders()) { |
| d.customDecode(in); |
| return d; |
| } |
| } |
| } |
| return super.readRecord(old, expected, in); |
| } |
| |
| @Override |
| protected void readField(Object record, Schema.Field field, Object oldDatum, ResolvingDecoder in, Object state) |
| throws IOException { |
| if (record instanceof SpecificRecordBase) { |
| Conversion<?> conversion = ((SpecificRecordBase) record).getConversion(field.pos()); |
| |
| Object datum; |
| if (conversion != null) { |
| datum = readWithConversion(oldDatum, field.schema(), field.schema().getLogicalType(), conversion, in); |
| } else { |
| datum = readWithoutConversion(oldDatum, field.schema(), in); |
| } |
| |
| getData().setField(record, field.name(), field.pos(), datum); |
| |
| } else { |
| super.readField(record, field, oldDatum, in, state); |
| } |
| } |
| } |