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Generic serializer / marshaller / unserializer / unmarshaller class to convert objects into strings and vice versa. Uses the JAXB lib. Personally used this class for converting messages received/sent to a queue (JMS).
/*
* Copyright (c) 2013, Arno Moonen <info@arnom.nl>
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package amnl.util;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import javax.xml.bind.annotation.XmlAnyElement;
/**
* Generic collection wrapper class.
*
* Makes it easier to (un)marshall a collectiono of a single type.
*
* @author Arno Moonen <info@arnom.nl>
*/
public class JAXBCollection<T>
{
@XmlAnyElement (lax = true)
private List<T> items;
public JAXBCollection(Collection<T> contents)
{
if (contents instanceof List)
{
items = (List<T>) contents;
}
else
{
items = new ArrayList<T>(contents);
}
}
public JAXBCollection()
{
this(new ArrayList<T>());
}
public List<T> getItems()
{
return items;
}
}
/*
* Copyright (c) 2013, Arno Moonen <info@arnom.nl>
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package amnl.util;
import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.namespace.QName;
import javax.xml.transform.Source;
import javax.xml.transform.stream.StreamSource;
/**
* Generic serializer (marshaller/unmarshaller) class that uses JAXB.
*
* @author Arno Moonen <info@arnom.nl>
*/
public class Serializer
{
/**
* Convert a string to an object of a given class.
*
* @param cl Type of object
* @param s Input string
* @return Object of the given type
* @throws JAXBException
*/
public static <T> T unmarshal(Class<T> cl, String s) throws JAXBException
{
return unmarshal(cl, new StringReader(s));
}
/**
* Convert the contents of a file to an object of a given class.
*
* @param cl Type of object
* @param f File to be read
* @return Object of the given type
* @throws JAXBException
*/
public static <T> T unmarshal(Class<T> cl, File f) throws JAXBException
{
return unmarshal(cl, new StreamSource(f));
}
/**
* Convert the contents of a Reader to an object of a given class.
*
* @param cl Type of object
* @param r Reader to be read
* @return Object of the given type
* @throws JAXBException
*/
public static <T> T unmarshal(Class<T> cl, Reader r) throws JAXBException
{
return unmarshal(cl, new StreamSource(r));
}
/**
* Convert the contents of an InputStream to an object of a given
* class.
*
* @param cl Type of object
* @param s InputStream to be read
* @return Object of the given type
* @throws JAXBException
*/
public static <T> T unmarshal(Class<T> cl, InputStream s) throws JAXBException
{
return unmarshal(cl, new StreamSource(s));
}
/**
* Convert the contents of a Source to an object of a given class.
*
* @param cl Type of object
* @param s Source to be used
* @return Object of the given type
* @throws JAXBException
*/
public static <T> T unmarshal(Class<T> cl, Source s) throws JAXBException
{
JAXBContext ctx = JAXBContext.newInstance(cl);
Unmarshaller u = ctx.createUnmarshaller();
return u.unmarshal(s, cl).getValue();
}
/**
* Converts the contents of the string to a List with objects of
* the given class.
*
* @param cl Type to be used
* @param s Input string
* @return List with objects of the given type
* @throws JAXBException
*/
public static <T> List<T> unmarshalCollection(Class<T> cl, String s) throws JAXBException
{
return unmarshalCollection(cl, new StringReader(s));
}
/**
* Converts the contents of the Reader to a List with objects of
* the given class.
*
* @param cl Type to be used
* @param r Input
* @return List with objects of the given type
* @throws JAXBException
*/
public static <T> List<T> unmarshalCollection(Class<T> cl, Reader r) throws JAXBException
{
return unmarshalCollection(cl, new StreamSource(r));
}
/**
* Converts the contents of the InputStream to a List with objects
* of the given class.
*
* @param cl Type to be used
* @param s Input
* @return List with objects of the given type
* @throws JAXBException
*/
public static <T> List<T> unmarshalCollection(Class<T> cl, InputStream s) throws JAXBException
{
return unmarshalCollection(cl, new StreamSource(s));
}
/**
* Converts the contents of the Source to a List with objects of
* the given class.
*
* @param cl Type to be used
* @param s Input
* @return List with objects of the given type
* @throws JAXBException
*/
public static <T> List<T> unmarshalCollection(Class<T> cl, Source s) throws JAXBException
{
JAXBContext ctx = JAXBContext.newInstance(JAXBCollection.class, cl);
Unmarshaller u = ctx.createUnmarshaller();
JAXBCollection<T> collection = u.unmarshal(s, JAXBCollection.class).getValue();
return collection.getItems();
}
/**
* Convert an object to a string.
*
* @param obj Object that needs to be serialized / marshalled.
* @return String representation of obj
* @throws JAXBException
*/
public static <T> String marshal(T obj) throws JAXBException
{
StringWriter sw = new StringWriter();
marshal(obj, sw);
return sw.toString();
}
/**
* Convert an object to a string and send it to a Writer.
*
* @param obj Object that needs to be serialized / marshalled
* @param wr Writer used for outputting the marshalled object
* @throws JAXBException
*/
public static <T> void marshal(T obj, Writer wr) throws JAXBException
{
JAXBContext ctx = JAXBContext.newInstance(obj.getClass());
Marshaller m = ctx.createMarshaller();
m.marshal(obj, wr);
}
/**
* Convert an object to a string and save it to a File.
*
* @param obj Object that needs to be serialized / marshalled
* @param f Save file
* @throws JAXBException
*/
public static <T> void marshal(T obj, File f) throws JAXBException
{
JAXBContext ctx = JAXBContext.newInstance(obj.getClass());
Marshaller m = ctx.createMarshaller();
m.marshal(obj, f);
}
/**
* Convert an object to a string and send it to an OutputStream.
*
* @param obj Object that needs to be serialized / marshalled
* @param s Stream used for output
* @throws JAXBException
*/
public static <T> void marshal(T obj, OutputStream s) throws JAXBException
{
JAXBContext ctx = JAXBContext.newInstance(obj.getClass());
Marshaller m = ctx.createMarshaller();
m.marshal(obj, s);
}
/**
* Convert a collection to a string.
*
* @param rootName Name of the XML root element
* @param c Collection that needs to be marshalled
* @return String representation of the collection
* @throws JAXBException
*/
public static <T> String marshal(String rootName, Collection<T> c) throws JAXBException
{
StringWriter sw = new StringWriter();
marshal(rootName, c, sw);
return sw.toString();
}
/**
* Convert a collection to a string and sends it to the Writer.
*
* @param rootName Name of the XML root element
* @param c Collection that needs to be marshalled
* @param w Output
* @throws JAXBException
*/
public static <T> void marshal(String rootName, Collection<T> c, Writer w) throws JAXBException
{
// Create context with generic type
JAXBContext ctx = JAXBContext.newInstance(findTypes(c));
Marshaller m = ctx.createMarshaller();
// Create wrapper collection
JAXBElement element = createCollectionElement(rootName, c);
m.marshal(element, w);
}
/**
* Convert a collection to a string and stores it in a File.
*
* @param rootName Name of the XML root element
* @param c Collection that needs to be marshalled
* @param f Output file
* @throws JAXBException
*/
public static <T> void marshal(String rootName, Collection<T> c, File f) throws JAXBException
{
// Create context with generic type
JAXBContext ctx = JAXBContext.newInstance(findTypes(c));
Marshaller m = ctx.createMarshaller();
// Create wrapper collection
JAXBElement element = createCollectionElement(rootName, c);
m.marshal(element, f);
}
/**
* Convert a collection to a string and sends it to the
* OutputStream.
*
* @param rootName Name of the XML root element
* @param c Collection that needs to be marshalled
* @param s Output
* @throws JAXBException
*/
public static <T> void marshal(String rootName, Collection<T> c, OutputStream s) throws JAXBException
{
// Create context with generic type
JAXBContext ctx = JAXBContext.newInstance(findTypes(c));
Marshaller m = ctx.createMarshaller();
// Create wrapper collection
JAXBElement element = createCollectionElement(rootName, c);
m.marshal(element, s);
}
/**
* Discovers all the classes in the given Collection. These need
* to be in the JAXBContext if you want to marshal those objects.
* Unfortunatly there's no way of getting the generic type at
* runtime.
*
* @param c Collection that needs to be scanned
* @return Classes found in the collection, including
* JAXBCollection.
*/
protected static <T> Class[] findTypes(Collection<T> c)
{
Set<Class> types = new HashSet<Class>();
types.add(JAXBCollection.class);
for (T o : c)
{
if (o != null)
{
types.add(o.getClass());
}
}
return types.toArray(new Class[0]);
}
/**
* Create a JAXBElement containing a JAXBCollection. Needed for
* marshalling a generic collection without a seperate wrapper
* class.
*
* @param rootName Name of the XML root element
* @param c
* @return JAXBElement containing the given Collection, wrapped in
* a JAXBCollection.
*/
protected static <T> JAXBElement createCollectionElement(String rootName, Collection<T> c)
{
JAXBCollection collection = new JAXBCollection(c);
return new JAXBElement<JAXBCollection>(new QName(rootName), JAXBCollection.class, collection);
}
}
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