org.simpleframework.xml.load.Persister Maven / Gradle / Ivy
/*
* Persister.java July 2006
*
* Copyright (C) 2006, Niall Gallagher
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
package org.simpleframework.xml.load;
import org.simpleframework.xml.Serializer;
import org.simpleframework.xml.filter.Filter;
import org.simpleframework.xml.filter.PlatformFilter;
import org.simpleframework.xml.stream.InputNode;
import org.simpleframework.xml.stream.NodeBuilder;
import org.simpleframework.xml.stream.OutputNode;
import org.simpleframework.xml.stream.Format;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.InputStream;
import java.io.StringReader;
import java.io.Reader;
import java.io.Writer;
import java.util.HashMap;
import java.util.Map;
import java.io.File;
/**
* The Persister object is used to provide an implementation
* of a serializer. This implements the Serializer interface
* and enables objects to be persisted and loaded from various sources.
* This implementation makes use of Filter objects to
* replace template variables within the source XML document.
*
* Deserialization is performed by passing an XML schema class into one
* of the read methods along with the source of an XML stream.
* The read method then reads the contents of the XML stream and builds
* the object using annotations within the XML schema class.
*
* Serialization is peformed by passing an object and an XML stream into
* one of the write methods. The serialization process will
* use the class of the provided object as the schema class. The object
* is traversed and all fields are marshalled to the result stream.
*
* @author Niall Gallagher
*
* @see org.simpleframework.xml.Serializer
*/
public class Persister implements Serializer {
/**
* This is the strategy object used to load and resolve classes.
*/
private final Strategy strategy;
/**
* This filter is used to replace variables within templates.
*/
private final Filter filter;
/**
* This object is used to format the the generated XML document.
*/
private final Format format;
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use an empty filter.
* This means that template variables will remain unchanged within
* the XML document parsed when an object is deserialized.
*/
public Persister() {
this(new HashMap());
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use a platform filter
* object using the overrides within the provided map. This means
* that template variables will be replaced firstly with mappings
* from within the provided map, followed by system properties.
*
* @param filter this is the map that contains the overrides
*/
public Persister(Map filter) {
this(new PlatformFilter(filter));
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use the provided filter.
* This persister will replace all variables encountered when
* deserializing an object with mappings found in the filter.
*
* @param filter the filter used to replace template variables
*/
public Persister(Filter filter) {
this(new DefaultStrategy(), filter);
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use a strategy object.
* This persister will use the provided Strategy to
* intercept the XML elements in order to read and write persisent
* data, such as the class name or version of the document.
*
* @param strategy this is the strategy used to resolve classes
*/
public Persister(Strategy strategy) {
this(strategy, new HashMap());
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use the provided format
* instructions. The persister uses the Format object
* to structure the generated XML. It determines the indent size
* of the document and whether it should contain a prolog.
*
* @param format this is used to structure the generated XML
*/
public Persister(Format format) {
this(new DefaultStrategy(), format);
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use the provided filter.
* This persister will replace all variables encountered when
* deserializing an object with mappings found in the filter.
*
* @param filter the filter used to replace template variables
* @param format this is used to structure the generated XML
*/
public Persister(Filter filter, Format format) {
this(new DefaultStrategy(), filter, format);
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use a strategy object.
* This persister will use the provided Strategy to
* intercept the XML elements in order to read and write persisent
* data, such as the class name or version of the document.
*
* @param strategy this is the strategy used to resolve classes
* @param format this is used to structure the generated XML
*/
public Persister(Strategy strategy, Format format) {
this(strategy, new HashMap(), format);
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use a platform filter
* object using the overrides within the provided map. This means
* that template variables will be replaced firstly with mappings
* from within the provided map, followed by system properties.
*
* This persister will use the provided Strategy to
* intercept the XML elements in order to read and write persisent
* data, such as the class name or version of the document.
*
* @param strategy this is the strategy used to resolve classes
* @param data this is the map that contains the overrides
*/
public Persister(Strategy strategy, Map data) {
this(strategy, new PlatformFilter(data));
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use the provided filter.
* This persister will replace all variables encountered when
* deserializing an object with mappings found in the filter.
*
* This persister will use the provided Strategy to
* intercept the XML elements in order to read and write persisent
* data, such as the class name or version of the document.
*
* @param strategy this is the strategy used to resolve classes
* @param filter the filter used to replace template variables
*/
public Persister(Strategy strategy, Filter filter) {
this(strategy, filter, new Format());
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use the provided filter.
* This persister will replace all variables encountered when
* deserializing an object with mappings found in the filter.
*
* This persister will use the provided Strategy to
* intercept the XML elements in order to read and write persisent
* data, such as the class name or version of the document.
*
* @param strategy this is the strategy used to resolve classes
* @param data the filter data used to replace template variables
* @param format this is used to format the generated XML document
*/
public Persister(Strategy strategy, Map data, Format format) {
this(strategy, new PlatformFilter(data), format);
}
/**
* Constructor for the Persister object. This is used
* to create a serializer object that will use the provided filter.
* This persister will replace all variables encountered when
* deserializing an object with mappings found in the filter.
*
* This persister will use the provided Strategy to
* intercept the XML elements in order to read and write persisent
* data, such as the class name or version of the document.
*
* @param strategy this is the strategy used to resolve classes
* @param filter the filter used to replace template variables
* @param format this is used to format the generated XML document
*/
public Persister(Strategy strategy, Filter filter, Format format) {
this.strategy = strategy;
this.filter = filter;
this.format = format;
}
/**
* This read method will read the contents of the XML
* document from the provided source and convert it into an object
* of the specified type. If the XML source cannot be deserialized
* or there is a problem building the object graph an exception
* is thrown. The instance deserialized is returned.
*
* @param type this is the class type to be deserialized from XML
* @param source this provides the source of the XML document
*
* @return the object deserialized from the XML document
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(Class type, String source) throws Exception {
return (T)read(type, new StringReader(source));
}
/**
* This read method will read the contents of the XML
* document from the provided source and convert it into an object
* of the specified type. If the XML source cannot be deserialized
* or there is a problem building the object graph an exception
* is thrown. The instance deserialized is returned.
*
* @param type this is the class type to be deserialized from XML
* @param source this provides the source of the XML document
*
* @return the object deserialized from the XML document
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(Class type, File source) throws Exception {
InputStream file = new FileInputStream(source);
try {
return (T)read(type, file);
} finally {
file.close();
}
}
/**
* This read method will read the contents of the XML
* document from the provided source and convert it into an object
* of the specified type. If the XML source cannot be deserialized
* or there is a problem building the object graph an exception
* is thrown. The instance deserialized is returned.
*
* @param type this is the class type to be deserialized from XML
* @param source this provides the source of the XML document
*
* @return the object deserialized from the XML document
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(Class type, InputStream source) throws Exception {
return (T)read(type, source, "utf-8");
}
/**
* This read method will read the contents of the XML
* document from the provided source and convert it into an object
* of the specified type. If the XML source cannot be deserialized
* or there is a problem building the object graph an exception
* is thrown. The instance deserialized is returned.
*
* @param type this is the class type to be deserialized from XML
* @param source this provides the source of the XML document
* @param charset this is the character set to read the XML with
*
* @return the object deserialized from the XML document
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(Class type, InputStream source, String charset) throws Exception {
return (T)read(type, new InputStreamReader(source, charset));
}
/**
* This read method will read the contents of the XML
* document from the provided source and convert it into an object
* of the specified type. If the XML source cannot be deserialized
* or there is a problem building the object graph an exception
* is thrown. The instance deserialized is returned.
*
* @param type this is the class type to be deserialized from XML
* @param source this provides the source of the XML document
*
* @return the object deserialized from the XML document
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(Class type, Reader source) throws Exception {
return (T)read(type, NodeBuilder.read(source));
}
/**
* This read method will read the contents of the XML
* document from the provided source and convert it into an object
* of the specified type. If the XML source cannot be deserialized
* or there is a problem building the object graph an exception
* is thrown. The instance deserialized is returned.
*
* @param type this is the class type to be deserialized from XML
* @param source this provides the source of the XML document
*
* @return the object deserialized from the XML document
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(Class type, InputNode source) throws Exception {
return (T)read(type, source, filter);
}
/**
* This read method will read the contents of the XML
* document provided and convert it to an object of the specified
* type. If the XML document cannot be deserialized or there is a
* problem building the object graph an exception is thrown. The
* object graph deserialized is returned.
*
* @param type this is the XML schema class to be deserialized
* @param node the document the object is deserialized from
* @param filter this is the filter used by the templating engine
*
* @return the object deserialized from the XML document given
*
* @throws Exception if the object cannot be fully deserialized
*/
private T read(Class type, InputNode node, Filter filter) throws Exception {
return (T)read(type, node, new Source(strategy, filter));
}
/**
* This read method will read the contents of the XML
* document provided and convert it to an object of the specified
* type. If the XML document cannot be deserialized or there is a
* problem building the object graph an exception is thrown. The
* object graph deserialized is returned.
*
* @param type this is the XML schema class to be deserialized
* @param source the contextual object used for derserialization
*
* @return the object deserialized from the XML document given
*
* @throws Exception if the object cannot be fully deserialized
*/
private T read(Class type, InputNode node, Source source) throws Exception {
return (T)new Traverser(source).read(node, type);
}
/**
* This read method will read the contents of the XML
* document from the provided source and populate the object with
* the values deserialized. This is used as a means of injecting an
* object with values deserialized from an XML document. If the
* XML source cannot be deserialized or there is a problem building
* the object graph an exception is thrown.
*
* @param value this is the object to deserialize the XML in to
* @param source this provides the source of the XML document
*
* @return the same instance provided is returned when finished
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(T value, String source) throws Exception{
return (T)read(value, new StringReader(source));
}
/**
* This read method will read the contents of the XML
* document from the provided source and populate the object with
* the values deserialized. This is used as a means of injecting an
* object with values deserialized from an XML document. If the
* XML source cannot be deserialized or there is a problem building
* the object graph an exception is thrown.
*
* @param value this is the object to deserialize the XML in to
* @param source this provides the source of the XML document
*
* @return the same instance provided is returned when finished
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(T value, File source) throws Exception{
InputStream file = new FileInputStream(source);
try {
return (T)read(value, file);
}finally {
file.close();
}
}
/**
* This read method will read the contents of the XML
* document from the provided source and populate the object with
* the values deserialized. This is used as a means of injecting an
* object with values deserialized from an XML document. If the
* XML source cannot be deserialized or there is a problem building
* the object graph an exception is thrown.
*
* @param value this is the object to deserialize the XML in to
* @param source this provides the source of the XML document
*
* @return the same instance provided is returned when finished
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(T value, InputStream source) throws Exception{
return (T)read(value, source, "utf-8");
}
/**
* This read method will read the contents of the XML
* document from the provided source and populate the object with
* the values deserialized. This is used as a means of injecting an
* object with values deserialized from an XML document. If the
* XML source cannot be deserialized or there is a problem building
* the object graph an exception is thrown.
*
* @param value this is the object to deserialize the XML in to
* @param source this provides the source of the XML document
* @param charset this is the character set to read the XML with
*
* @return the same instance provided is returned when finished
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(T value, InputStream source, String charset) throws Exception{
return (T)read(value, new InputStreamReader(source, charset));
}
/**
* This read method will read the contents of the XML
* document from the provided source and populate the object with
* the values deserialized. This is used as a means of injecting an
* object with values deserialized from an XML document. If the
* XML source cannot be deserialized or there is a problem building
* the object graph an exception is thrown.
*
* @param value this is the object to deserialize the XML in to
* @param source this provides the source of the XML document
*
* @return the same instance provided is returned when finished
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(T value, Reader source) throws Exception{
return (T)read(value, NodeBuilder.read(source));
}
/**
* This read method will read the contents of the XML
* document from the provided source and populate the object with
* the values deserialized. This is used as a means of injecting an
* object with values deserialized from an XML document. If the
* XML source cannot be deserialized or there is a problem building
* the object graph an exception is thrown.
*
* @param value this is the object to deserialize the XML in to
* @param source this provides the source of the XML document
*
* @return the same instance provided is returned when finished
*
* @throws Exception if the object cannot be fully deserialized
*/
public T read(T value, InputNode source) throws Exception {
return (T)read(value, source, filter);
}
/**
* This read method will read the contents of the XML
* document from the provided source and populate the object with
* the values deserialized. This is used as a means of injecting an
* object with values deserialized from an XML document. If the
* XML source cannot be deserialized or there is a problem building
* the object graph an exception is thrown.
*
* @param value this is the object to deserialize the XML in to
* @param node this provides the source of the XML document
* @param filter this is the filter used by the templating engine
*
* @return the same instance provided is returned when finished
*
* @throws Exception if the object cannot be fully deserialized
*/
private T read(T value, InputNode node, Filter filter) throws Exception {
return (T)read(value, node, new Source(strategy, filter));
}
/**
* This read method will read the contents of the XML
* document from the provided source and populate the object with
* the values deserialized. This is used as a means of injecting an
* object with values deserialized from an XML document. If the
* XML source cannot be deserialized or there is a problem building
* the object graph an exception is thrown.
*
* @param value this is the object to deserialize the XML in to
* @param node this provides the source of the XML document
* @param source the contextual object used for deserialization
*
* @return the same instance provided is returned when finished
*
* @throws Exception if the object cannot be fully deserialized
*/
private T read(T value, InputNode node, Source source) throws Exception {
return (T)new Traverser(source).read(node, value);
}
/**
* This write method will traverse the provided object
* checking for field annotations in order to compose the XML data.
* This uses the getClass method on the object to
* determine the class file that will be used to compose the schema.
* If there is no Root annotation for the class then
* this will throw an exception. The root annotation is the only
* annotation required for an object to be serialized.
*
* @param source this is the object that is to be serialized
* @param root this is where the serialized XML is written to
*
* @throws Exception if the schema for the object is not valid
*/
public void write(Object source, OutputNode root) throws Exception {
write(source, root, filter);
}
/**
* This write method will traverse the provided object
* checking for field annotations in order to compose the XML data.
* This uses the getClass method on the object to
* determine the class file that will be used to compose the schema.
* If there is no Root annotation for the class then
* this will throw an exception. The root annotation is the only
* annotation required for an object to be serialized.
*
* @param source this is the object that is to be serialized
* @param root this is where the serialized XML is written to
* @param filter this is the filter object used for templating
*
* @throws Exception if the schema for the object is not valid
*/
private void write(Object source, OutputNode root, Filter filter) throws Exception {
write(source, root, new Source(strategy, filter));
}
/**
* This write method will traverse the provided object
* checking for field annotations in order to compose the XML data.
* This uses the getClass method on the object to
* determine the class file that will be used to compose the schema.
* If there is no Root annotation for the class then
* this will throw an exception. The root annotation is the only
* annotation required for an object to be serialized.
*
* @param source this is the object that is to be serialized
* @param root this is a contextual object used for serialization
*
* @throws Exception if the schema for the object is not valid
*/
private void write(Object source, OutputNode node, Source root) throws Exception {
new Traverser(root).write(node, source);
}
/**
* This write method will traverse the provided object
* checking for field annotations in order to compose the XML data.
* This uses the getClass method on the object to
* determine the class file that will be used to compose the schema.
* If there is no Root annotation for the class then
* this will throw an exception. The root annotation is the only
* annotation required for an object to be serialized.
*
* @param source this is the object that is to be serialized
* @param out this is where the serialized XML is written to
*
* @throws Exception if the schema for the object is not valid
*/
public void write(Object source, File out) throws Exception {
OutputStream file = new FileOutputStream(out);
try {
write(source, file);
}finally {
file.close();
}
}
/**
* This write method will traverse the provided object
* checking for field annotations in order to compose the XML data.
* This uses the getClass method on the object to
* determine the class file that will be used to compose the schema.
* If there is no Root annotation for the class then
* this will throw an exception. The root annotation is the only
* annotation required for an object to be serialized.
*
* @param source this is the object that is to be serialized
* @param out this is where the serialized XML is written to
*
* @throws Exception if the schema for the object is not valid
*/
public void write(Object source, OutputStream out) throws Exception {
write(source, out, "utf-8");
}
/**
* This write method will traverse the provided object
* checking for field annotations in order to compose the XML data.
* This uses the getClass method on the object to
* determine the class file that will be used to compose the schema.
* If there is no Root annotation for the class then
* this will throw an exception. The root annotation is the only
* annotation required for an object to be serialized.
*
* @param source this is the object that is to be serialized
* @param out this is where the serialized XML is written to
* @param charset this is the character encoding to be used
*
* @throws Exception if the schema for the object is not valid
*/
public void write(Object source, OutputStream out, String charset) throws Exception {
write(source, new OutputStreamWriter(out, charset));
}
/**
* This write method will traverse the provided object
* checking for field annotations in order to compose the XML data.
* This uses the getClass method on the object to
* determine the class file that will be used to compose the schema.
* If there is no Root annotation for the class then
* this will throw an exception. The root annotation is the only
* annotation required for an object to be serialized.
*
* @param source this is the object that is to be serialized
* @param out this is where the serialized XML is written to
*
* @throws Exception if the schema for the object is not valid
*/
public void write(Object source, Writer out) throws Exception {
write(source, NodeBuilder.write(out, format));
}
}