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Java 1.8+ Library with XML handling routines
/*
* Copyright (C) 2014-2023 Philip Helger (www.helger.com)
* philip[at]helger[dot]com
*
* 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 com.helger.xml.microdom.util;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Map;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.WillClose;
import javax.annotation.concurrent.Immutable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.helger.commons.ValueEnforcer;
import com.helger.commons.annotation.PresentForCodeCoverage;
import com.helger.commons.annotation.ReturnsMutableCopy;
import com.helger.commons.collection.impl.CommonsHashMap;
import com.helger.commons.collection.impl.ICommonsMap;
import com.helger.commons.io.EAppend;
import com.helger.commons.io.IHasInputStream;
import com.helger.commons.io.IHasOutputStream;
import com.helger.commons.io.stream.StreamHelper;
import com.helger.commons.state.ESuccess;
import com.helger.xml.microdom.IMicroDocument;
import com.helger.xml.microdom.IMicroElement;
import com.helger.xml.microdom.MicroDocument;
import com.helger.xml.microdom.serialize.MicroReader;
import com.helger.xml.microdom.serialize.MicroWriter;
import com.helger.xml.serialize.write.XMLWriterSettings;
/**
* Simple class that reads a generic String-to-String mapping from a classpath
* resource into a {@link Map}.
* The XML file needs to look as follows:
*
*
* <mapping>
* <map key="..." value="..."/>
* <map key="..." value="..."/>
* ...
* </mapping>
*
*
* @author Philip
*/
@Immutable
public final class XMLMapHandler
{
/** Root element name */
public static final String ELEMENT_MAPPING = "mapping";
/** Element name for a single mapping */
public static final String ELEMENT_MAP = "map";
/** Attribute name for key of a single mapping */
public static final String ATTR_KEY = "key";
/** Attribute name for value of a single mapping */
public static final String ATTR_VALUE = "value";
private static final Logger LOGGER = LoggerFactory.getLogger (XMLMapHandler.class);
@PresentForCodeCoverage
private static final XMLMapHandler INSTANCE = new XMLMapHandler ();
private XMLMapHandler ()
{}
@Nullable
@ReturnsMutableCopy
public static ICommonsMap readMap (@Nonnull final IHasInputStream aISP)
{
ValueEnforcer.notNull (aISP, "InputStreamProvider");
return readMap (aISP.getInputStream ());
}
@Nonnull
public static ESuccess readMap (@Nonnull final IHasInputStream aISP, @Nonnull final Map aTargetMap)
{
ValueEnforcer.notNull (aISP, "InputStreamProvider");
return readMap (aISP.getInputStream (), aTargetMap);
}
/**
* Read a mapping from the passed input stream.
*
* @param aIS
* The input stream to read from. May not be null.
* @return null if reading the map failed
*/
@Nullable
@ReturnsMutableCopy
public static ICommonsMap readMap (@Nonnull @WillClose final InputStream aIS)
{
final ICommonsMap ret = new CommonsHashMap <> ();
if (readMap (aIS, ret).isFailure ())
return null;
return ret;
}
/**
* Read a mapping from the passed input stream.
*
* @param aIS
* The input stream to read from. May not be null.
* @param aTargetMap
* The target map to be filled.
* @return {@link ESuccess#SUCCESS} if the stream could be opened, if it could
* be read as XML and if the root element was correct.
* {@link ESuccess#FAILURE} otherwise.
*/
@Nonnull
public static ESuccess readMap (@Nonnull @WillClose final InputStream aIS,
@Nonnull final Map aTargetMap)
{
ValueEnforcer.notNull (aIS, "InputStream");
ValueEnforcer.notNull (aTargetMap, "TargetMap");
try (final InputStream aCloseMe = aIS)
{
// open file
final IMicroDocument aDoc = MicroReader.readMicroXML (aIS);
if (aDoc != null)
{
readMap (aDoc.getDocumentElement (), aTargetMap);
return ESuccess.SUCCESS;
}
}
catch (final Exception ex)
{
LOGGER.warn ("Failed to read mapping resource '" + aIS + "'", ex);
}
return ESuccess.FAILURE;
}
@Nonnull
public static ESuccess readMap (@Nonnull final IMicroElement aParentElement,
@Nonnull final Map aTargetMap)
{
ValueEnforcer.notNull (aParentElement, "ParentElement");
ValueEnforcer.notNull (aTargetMap, "TargetMap");
try
{
// and insert all elements
for (final IMicroElement eMap : aParentElement.getAllChildElements (ELEMENT_MAP))
{
final String sName = eMap.getAttributeValue (ATTR_KEY);
if (sName == null)
LOGGER.warn ("Ignoring mapping element because key is null");
else
{
final String sValue = eMap.getAttributeValue (ATTR_VALUE);
if (sValue == null)
LOGGER.warn ("Ignoring mapping element because value is null");
else
{
if (aTargetMap.containsKey (sName))
LOGGER.warn ("Key '" + sName + "' is already contained - overwriting!");
aTargetMap.put (sName, sValue);
}
}
}
return ESuccess.SUCCESS;
}
catch (final Exception ex)
{
LOGGER.warn ("Failed to read mapping document", ex);
}
return ESuccess.FAILURE;
}
@Nonnull
public static IMicroDocument createMapDocument (@Nonnull final Map aMap)
{
ValueEnforcer.notNull (aMap, "Map");
final IMicroDocument aDoc = new MicroDocument ();
final IMicroElement eRoot = aDoc.appendElement (ELEMENT_MAPPING);
for (final Map.Entry aEntry : aMap.entrySet ())
{
final IMicroElement eMap = eRoot.appendElement (ELEMENT_MAP);
eMap.setAttribute (ATTR_KEY, aEntry.getKey ());
eMap.setAttribute (ATTR_VALUE, aEntry.getValue ());
}
return aDoc;
}
@Nonnull
public static ESuccess writeMap (@Nonnull final Map aMap, @Nonnull final IHasOutputStream aOSP)
{
ValueEnforcer.notNull (aOSP, "OutputStreamProvider");
return writeMap (aMap, aOSP.getOutputStream (EAppend.DEFAULT));
}
/**
* Write the passed map to the passed output stream using the predefined XML
* layout.
*
* @param aMap
* The map to be written. May not be null.
* @param aOS
* The output stream to write to. The stream is closed independent of
* success or failure. May not be null.
* @return {@link ESuccess#SUCCESS} when everything went well,
* {@link ESuccess#FAILURE} otherwise.
*/
@Nonnull
public static ESuccess writeMap (@Nonnull final Map aMap, @Nonnull @WillClose final OutputStream aOS)
{
ValueEnforcer.notNull (aMap, "Map");
ValueEnforcer.notNull (aOS, "OutputStream");
try
{
final IMicroDocument aDoc = createMapDocument (aMap);
return MicroWriter.writeToStream (aDoc, aOS, XMLWriterSettings.DEFAULT_XML_SETTINGS);
}
finally
{
StreamHelper.close (aOS);
}
}
}