/*
* Carrot2 project.
*
* Copyright (C) 2002-2014, Dawid Weiss, Stanisław Osiński.
* All rights reserved.
*
* Refer to the full license file "carrot2.LICENSE"
* in the root folder of the repository checkout or at:
* http://www.carrot2.org/carrot2.LICENSE
*/
package org.carrot2.workbench.core.helpers;
import java.beans.Introspector;
import java.io.*;
import org.apache.commons.lang.StringUtils;
import org.carrot2.util.ExceptionUtils;
import org.carrot2.workbench.core.WorkbenchCorePlugin;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.ui.IMemento;
import org.eclipse.ui.XMLMemento;
import org.simpleframework.xml.Root;
import org.simpleframework.xml.core.Persister;
/**
* Utilities for storing and reading preferences ({@link IMemento},
* {@link IPreferenceStore}) using <code>org.simpleframework.xml</code> library.
*/
public final class SimpleXmlMemento
{
/**
* Creates an {@link XMLMemento} from Simple XML-annotated bean.
*/
static IMemento toMemento(Object benchmarkSettings) throws IOException
{
try
{
final StringWriter w = new StringWriter();
new Persister().write(benchmarkSettings, w);
XMLMemento memento = XMLMemento
.createReadRoot(new StringReader(w.toString()));
return memento;
}
catch (Exception e)
{
throw ExceptionUtils.wrapAs(IOException.class, e);
}
}
/**
* Reads an object from a {@link IMemento}. The memento's type (root) must equal the
* bean's {@link Root} annotation name attribute.
*/
static <T> T fromMemento(Class<T> clazz, IMemento memento) throws IOException
{
try
{
final StringWriter sw = new StringWriter();
final XMLMemento m = XMLMemento.createWriteRoot(memento.getType());
m.putMemento(memento);
m.save(sw);
return new Persister().read(clazz, new StringReader(sw.toString()));
}
catch (Exception e)
{
throw ExceptionUtils.wrapAs(IOException.class, e);
}
}
/**
* A shortcut for:
*
* <pre>
* fromMemento(clazz, memento.getChild(childName))
* </pre>
*
* verifying precondition that only one child of a given name exists.
*/
static <T> T fromMemento(Class<T> clazz, IMemento memento, String childName)
throws IOException
{
final IMemento [] children = memento.getChildren(childName);
if (children.length != 1)
{
throw new IOException("Expected a single node named '" + childName
+ "' under memento '" + memento.getType() + "'.");
}
return fromMemento(clazz, children[0]);
}
/**
* Convert any {@link IMemento} to a string.
*/
public static String toString(IMemento memento)
{
if (!(memento instanceof XMLMemento))
{
XMLMemento m = XMLMemento.createWriteRoot(memento.getType());
m.putMemento(memento);
memento = m;
}
try
{
final StringWriter w = new StringWriter();
((XMLMemento) memento).save(w);
return w.toString();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
/**
* Convert any <code>org.simpleframework.xml</code>-enabled object to an XML string.
*/
public static String toString(Object object) throws IOException
{
checkObject(object);
try
{
final StringWriter w = new StringWriter();
new Persister().write(object, w);
return w.toString();
}
catch (Exception e)
{
throw ExceptionUtils.wrapAs(IOException.class, e);
}
}
/**
* Convert an XML string to <code>org.simpleframework.xml</code>-enabled object.
*/
public static <T> T fromString(Class<T> clazz, String xml) throws IOException
{
try
{
final StringReader r = new StringReader(xml);
return new Persister().read(clazz, r);
}
catch (Exception e)
{
throw ExceptionUtils.wrapAs(IOException.class, e);
}
}
/**
* Add a child node to a given memento, named after the object's {@link Root}
* annotation.
*/
public static void addChild(IMemento memento, Object object) throws IOException
{
checkObject(object);
final IMemento child = toMemento(object);
memento.createChild(child.getType()).putMemento(child);
}
/**
* Returns an object deserialized from a child node of a given memento.
*/
public static <T> T getChild(Class<T> clazz, IMemento memento) throws IOException
{
Root root = clazz.getAnnotation(Root.class);
if (root == null)
{
throw new IllegalArgumentException("Missing @Root annotation on: "
+ clazz.getName());
}
String childName = root.name();
if (StringUtils.isEmpty(childName))
{
childName = getClassName(clazz);
}
IMemento [] children = memento.getChildren(childName);
if (children.length == 0)
{
return null;
}
if (children.length != 1)
{
throw new IOException("More than one child named '" + childName + "':"
+ children.length);
}
return fromMemento(clazz, children[0]);
}
/**
* Save an object to global plugin's preference store.
*/
public static void toPreferenceStore(String globalPreferenceKey, Object object)
{
final IPreferenceStore prefStore =
WorkbenchCorePlugin.getDefault().getPreferenceStore();
try
{
prefStore.setValue(globalPreferenceKey, toString(object));
}
catch (IOException e)
{
Utils.logError(e, false);
}
}
/**
* Read an object from the global plugin's preference store. May return
* <code>null</code> if an error occurred.
*/
public static <T> T fromPreferenceStore(Class<T> clazz, String globalPreferenceKey)
{
final IPreferenceStore prefStore =
WorkbenchCorePlugin.getDefault().getPreferenceStore();
final String xml = prefStore.getString(globalPreferenceKey);
if (!StringUtils.isEmpty(xml))
{
try
{
return fromString(clazz, xml);
}
catch (IOException e)
{
Utils.logError(e, false);
}
}
return null;
}
/**
* Check if the target contains simple XML's annotation.
*/
private static void checkObject(Object object)
{
Root root = object.getClass().getAnnotation(Root.class);
if (root == null)
{
throw new IllegalArgumentException("Missing @Root annotation on: "
+ object.getClass());
}
}
/**
* Mimics SimpleXML's naming for classes without {@link Root#name()}.
*/
private static String getClassName(Class<?> type)
{
if (type.isArray()) type = type.getComponentType();
final String name = type.getSimpleName();
if (type.isPrimitive()) return name;
else return Introspector.decapitalize(name);
}
}