org.alloy.metal.xml.merge.MergeXmlConfigResource.java Source code

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Here is the source code for org.alloy.metal.xml.merge.MergeXmlConfigResource.java

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/*
* #%L
* BroadleafCommerce Common Libraries
* %%
* Copyright (C) 2009 - 2013 Broadleaf Commerce
* %%
* 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.
* #L%
*/

package org.alloy.metal.xml.merge;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.List;

import org.alloy.metal.resource.ResourceInputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.FatalBeanException;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.Resource;

import com.google.common.collect.Iterables;

/**
*
* @author jfischer
*
*/
public class MergeXmlConfigResource {

    private static final Log LOG = LogFactory.getLog(MergeXmlConfigResource.class);

    private ApplicationContext applicationContext;
    private String defaultHandlerConfiguration;

    public MergeXmlConfigResource(String defaultHandlerConfiguration, ApplicationContext applicationContext) {
        this.applicationContext = applicationContext;
        this.defaultHandlerConfiguration = defaultHandlerConfiguration;
    }

    public Resource getMergedConfigResource(List<ResourceInputStream> sources) throws BeansException {
        Resource configResource = null;
        ResourceInputStream merged = null;
        try {
            merged = merge(sources);

            // read the final stream into a byte array
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            boolean eof = false;
            while (!eof) {
                int temp = merged.read();
                if (temp == -1) {
                    eof = true;
                } else {
                    baos.write(temp);
                }
            }
            configResource = new ByteArrayResource(baos.toByteArray());

            if (LOG.isDebugEnabled()) {
                LOG.debug("Merged config: \n" + serialize(configResource));
            }
        } catch (MergeException e) {
            throw new FatalBeanException("Unable to merge source and patch locations", e);
        } catch (MergeManagerSetupException e) {
            throw new FatalBeanException("Unable to merge source and patch locations", e);
        } catch (IOException e) {
            throw new FatalBeanException("Unable to merge source and patch locations", e);
        } finally {
            if (merged != null) {
                try {
                    merged.close();
                } catch (Throwable e) {
                    LOG.error("Unable to merge source and patch locations", e);
                }
            }
        }

        return configResource;
    }

    protected ResourceInputStream merge(List<ResourceInputStream> sources)
            throws MergeException, MergeManagerSetupException {
        if (sources.size() <= 1) {
            return Iterables.getFirst(sources, null);
        }

        ResourceInputStream response = null;
        ResourceInputStream[] pair = new ResourceInputStream[2];
        pair[0] = sources.get(0);
        for (int j = 1; j < sources.size(); j++) {
            pair[1] = sources.get(j);
            response = mergeItems(pair[0], pair[1]);
            try {
                pair[0].close();
            } catch (Throwable e) {
                LOG.error("Unable to merge source and patch locations", e);
            }
            try {
                pair[1].close();
            } catch (Throwable e) {
                LOG.error("Unable to merge source and patch locations", e);
            }
            pair[0] = response;
        }

        return response;
    }

    protected ResourceInputStream mergeItems(ResourceInputStream sourceLocationFirst,
            ResourceInputStream sourceLocationSecond) throws MergeException, MergeManagerSetupException {
        ResourceInputStream response = new MergeContext(defaultHandlerConfiguration, applicationContext)
                .merge(sourceLocationFirst, sourceLocationSecond);

        return response;
    }

    public String serialize(Resource resource) {
        String response = "";
        try {
            response = serialize(resource.getInputStream());
        } catch (IOException e) {
            LOG.error("Unable to merge source and patch locations", e);
        }

        return response;
    }

    public String serialize(InputStream in) {
        InputStreamReader reader = null;
        int temp;
        StringBuilder item = new StringBuilder();
        boolean eof = false;
        try {
            reader = new InputStreamReader(in);
            while (!eof) {
                temp = reader.read();
                if (temp == -1) {
                    eof = true;
                } else {
                    item.append((char) temp);
                }
            }
        } catch (IOException e) {
            LOG.error("Unable to merge source and patch locations", e);
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (Throwable e) {
                    LOG.error("Unable to merge source and patch locations", e);
                }
            }
        }

        return item.toString();
    }

    protected byte[] buildArrayFromStream(InputStream source) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        boolean eof = false;
        try {
            while (!eof) {
                int temp = source.read();
                if (temp == -1) {
                    eof = true;
                } else {
                    baos.write(temp);
                }
            }
        } finally {
            try {
                source.close();
            } catch (Throwable e) {
                LOG.error("Unable to merge source and patch locations", e);
            }
        }

        return baos.toByteArray();
    }
}