Migration to Spring Boot 2 and using Spring Batch 4

Question

I am migrating Spring Boot from 1.4.2 to 2.0.0, which also includes migrating Spring batch from 3.0.7 to 4.0.0 and it looks like batch process is no longer working when i tr

Answer 1

In the solution by @anotherdave and @michael-minella, you could also replace the plain XStreamExecutionContextStringSerializer with an instance of the following class. It accepts both formats when deserializing and serializes to the new format.

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Map;
import com.fasterxml.jackson.core.JsonProcessingException;
import org.springframework.batch.core.repository.ExecutionContextSerializer;
import org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer;
import org.springframework.batch.core.repository.dao.XStreamExecutionContextStringSerializer;


/**
 * Enables Spring Batch 4 to read both ExecutionContext entries written by ealier versions and the Spring 5 format. Entries are
 * written in Spring 5 format.
 */
@SuppressWarnings("deprecation")
class XStreamOrJackson2ExecutionContextSerializer implements ExecutionContextSerializer {
    private final XStreamExecutionContextStringSerializer xStream = new XStreamExecutionContextStringSerializer();
    private final Jackson2ExecutionContextStringSerializer jackson = new Jackson2ExecutionContextStringSerializer();

    public XStreamOrJackson2ExecutionContextSerializer() throws Exception {
        xStream.afterPropertiesSet();
    }

    // The caller closes the stream; and the decoration by ensureMarkSupported does not need any cleanup.
    @SuppressWarnings("resource")
    @Override
    public Map deserialize(InputStream inputStream) throws IOException {
        InputStream repeatableInputStream = ensureMarkSupported(inputStream);
        repeatableInputStream.mark(Integer.MAX_VALUE);

        try {
            return jackson.deserialize(repeatableInputStream);
        } catch (JsonProcessingException e) {
            repeatableInputStream.reset();
            return xStream.deserialize(repeatableInputStream);
        }
    }

    private static InputStream ensureMarkSupported(InputStream in) {
        return in.markSupported() ? in : new BufferedInputStream(in);
    }

    @Override
    public void serialize(Map object, OutputStream outputStream) throws IOException {
        jackson.serialize(object, outputStream);
    }
}