Example Java POJO based Beam Coder

SomePojo.java

/*
 * 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
 *
 *     http://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 example;

public class SomePojo {
    private final String aString;
    private final Integer anInteger;

    private final Double aDouble;

    public SomePojo(String aString, Integer anInteger, Double aDouble) {
        this.aString = aString;
        this.anInteger = anInteger;
        this.aDouble = aDouble;
    }

    public String getAString() {
        return aString;
    }

    public Integer getAnInteger() {
        return anInteger;
    }

    public Double getADouble() {
        return aDouble;
    }
}

SomePojoCoder.java

/*
 * 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
 *
 *     http://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 example;

import org.apache.beam.sdk.coders.CoderException;
import org.apache.beam.sdk.coders.CustomCoder;
import org.apache.beam.sdk.coders.DoubleCoder;
import org.apache.beam.sdk.coders.StringUtf8Coder;
import org.apache.beam.sdk.coders.VarIntCoder;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class SomePojoCoder extends CustomCoder<SomePojo> {

    private static final StringUtf8Coder STRING_UTF_8_CODER = StringUtf8Coder.of();
    private static final VarIntCoder VAR_INT_CODER = VarIntCoder.of();

    private static final DoubleCoder DOUBLE_CODER = DoubleCoder.of();

    @Override
    public void encode(SomePojo value, OutputStream outStream) throws CoderException, IOException {
        STRING_UTF_8_CODER.encode(value.getAString(), outStream);
        VAR_INT_CODER.encode(value.getAnInteger(), outStream);
        DOUBLE_CODER.encode(value.getADouble(), outStream);
    }

    @Override
    public SomePojo decode(InputStream inStream) throws CoderException, IOException {
        String aString = STRING_UTF_8_CODER.decode(inStream);
        Integer anInteger = VAR_INT_CODER.decode(inStream);
        Double aDouble = DOUBLE_CODER.decode(inStream);
        return new SomePojo(aString, anInteger, aDouble);
    }
}