biz.c24.io.spring.batch.processor.C24ValidatingItemProcessor.java Source code

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Here is the source code for biz.c24.io.spring.batch.processor.C24ValidatingItemProcessor.java

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/*
 * Copyright 2012 C24 Technologies.
 * 
 * Licensed 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 biz.c24.io.spring.batch.processor;

import java.util.Collection;
import java.util.LinkedList;

import org.springframework.batch.item.ExecutionContext;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.batch.item.ItemStream;
import org.springframework.batch.item.ItemStreamException;

import biz.c24.io.api.data.ComplexDataObject;
import biz.c24.io.api.data.ValidationEvent;
import biz.c24.io.api.data.ValidationException;
import biz.c24.io.api.data.ValidationListener;
import biz.c24.io.api.data.ValidationManager;
import biz.c24.io.spring.batch.C24CompoundValidationException;
import biz.c24.io.spring.batch.reader.C24ValidationException;

/**
 * An ItemProcessor that validates a ComplexDataObject.
 * While no changes are made to the ComplexDataObject, it does allow an ItemProcessorListener to be 
 * wired in to catch any ComplexDataObjects which fail validation.
 * 
 * @author AndrewElmore
 *
 */
public class C24ValidatingItemProcessor implements ItemProcessor<ComplexDataObject, ComplexDataObject>, ItemStream {

    private ThreadLocal<ValidationManager> validators = null;

    /**
     * Whether or not to abort on the first failure
     */
    private boolean failfast = true;

    /*
     * (non-Javadoc)
     * @see org.springframework.batch.item.ItemProcessor#process(java.lang.Object)
     */
    @Override
    public ComplexDataObject process(ComplexDataObject item) throws Exception {
        ValidationManager mgr = validators.get();
        if (mgr == null) {
            mgr = new ValidationManager();
            validators.set(mgr);
        }
        try {
            if (failfast) {
                mgr.validateByException(item);
            } else {
                // Capture all failures
                final Collection<ValidationEvent> events = new LinkedList<ValidationEvent>();

                ValidationListener listener = new ValidationListener() {
                    public void validationPassed(ValidationEvent ve) {
                    }

                    public void validationFailed(ValidationEvent ve) {
                        events.add(ve);
                    }
                };

                mgr.addValidationListener(listener);

                try {
                    if (!mgr.validateByEvents(item)) {
                        if (events.size() == 1) {
                            // Treat it as though we were validating by exception
                            mgr.setEventBased(false);
                            mgr.fireValidationEvent(events.iterator().next());
                        } else {
                            throw new C24CompoundValidationException(item, events);
                        }
                    }
                } finally {
                    mgr.removeValidationListener(listener);
                }
            }
        } catch (ValidationException vEx) {
            throw new C24ValidationException("Failed to validate message: " + vEx.getLocalizedMessage(), item, vEx);
        }
        return item;
    }

    @Override
    public void open(ExecutionContext executionContext) throws ItemStreamException {
        validators = new ThreadLocal<ValidationManager>();

    }

    @Override
    public void update(ExecutionContext executionContext) throws ItemStreamException {

    }

    @Override
    public void close() throws ItemStreamException {
        validators = null;

    }

}