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TSL2 Framework Descriptor (currency-handling, generic formatter, descriptors for beans, collections, actions and values)

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/*
 * File: $HeadURL$
 * Id  : $Id$
 * 
 * created by: Thomas Schneider
 * created on: Dec 20, 2012
 * 
 * Copyright: (c) Thomas Schneider 2012, all rights reserved
 */
package de.tsl2.nano.bean;

import java.io.File;
import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

import org.apache.commons.logging.Log;
import org.simpleframework.xml.Attribute;
import org.simpleframework.xml.Default;
import org.simpleframework.xml.DefaultType;
import org.simpleframework.xml.ElementMap;

import de.tsl2.nano.bean.def.BeanDefinition;
import de.tsl2.nano.collection.CollectionUtil;
import de.tsl2.nano.core.ENV;
import de.tsl2.nano.core.IPredicate;
import de.tsl2.nano.core.ITransformer;
import de.tsl2.nano.core.cls.AReference;
import de.tsl2.nano.core.cls.BeanClass;
import de.tsl2.nano.core.log.LogFactory;
import de.tsl2.nano.core.serialize.XmlUtil;
import de.tsl2.nano.core.util.FileUtil;
import de.tsl2.nano.core.util.StringUtil;

/**
 * persistable context. avoids serializing entities (mostly having a tree of dependencies) directly - using
 * {@link BReference} to reference entities through their ids.
 * 
 * @author Thomas Schneider
 * @version $Revision$
 */
@SuppressWarnings({ "unchecked", "rawtypes" })
@Default(value = DefaultType.FIELD, required = false)
public class Context implements Serializable, Map {

    /** serialVersionUID */
    private static final long serialVersionUID = -5738577461481485970L;

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

    @Attribute
    String name;

    @ElementMap(entry = "property", key = "name", attribute = true, inline = true, required = false, keyType = String.class, valueType = Object.class)
    private TreeMap properties;

    /** if true, this context will be persisted on any change. */
    transient boolean autopersist = false;

    /**
     * creates a new instance from file or through constructor
     * 
     * @param name context name, used as filename on persisting to file system
     * @param autoPersist whether to persist this context on each change. if name is null, no persisting will be done.
     * @return new context instance
     */
    public static Context create(String name, boolean autoPersist) {
        Context context = null;
        if (name == null) {
            context = new Context();
            autoPersist = false;
        } else {
            String fname = getFileName(name);
            File file = new File(fname);
            if (file.exists()) {
                LOG.debug("loading Context for '" + name + "'");
                context = XmlUtil.loadXml(file.getPath(), Context.class);
            } else {
                LOG.debug("creating new Context for '" + name + "' (file: " + fname + ")");
                context = new Context(name);
            }
        }
        context.init(autoPersist);
        return context;
    }

    /**
     * init
     * 
     * @param context
     * @param autoPersist
     */
    protected void init(boolean autoPersist) {
        if (properties == null)
            properties = new TreeMap();
        this.autopersist = autoPersist;
    }

    protected Context() {
        this(null);
    }

    protected Context(String name) {
        this.name = name;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int size() {
        return properties.size();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean isEmpty() {
        return properties.isEmpty();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean containsKey(Object key) {
        return properties.containsKey(key);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean containsValue(Object value) {
        return properties.containsValue(value);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Object get(Object key) {
        return properties.get(key);
    }

    public Object add(Object obj) {
        String k = BeanClass.getDefiningClass(obj.getClass()).getName();//String.valueOf(obj.hashCode());
        put(k, obj);
        return k;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Object put(Object key, Object value) {
        Object result = properties.put(key, reference(value));
        if (autopersist) {
            save();
        }
        return result;
    }

    protected Object reference(Object value) {
        return value != null && BeanContainer.instance().isPersistable(BeanClass.getDefiningClass(value.getClass()))
            ? new BReference(value) : value;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Object remove(Object key) {
        Object result = properties.remove(key);
        if (autopersist) {
            save();
        }
        return result;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void putAll(Map m) {
        properties.putAll(m);
        if (autopersist) {
            save();
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Set keySet() {
        return properties.keySet();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Collection values() {
        return properties.values();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Set entrySet() {
        return properties.entrySet();
    }

    /**
     * resets the current environment to be empty
     */
    public void clear() {
        properties.clear();
        if (autopersist) {
            save();
        }
    }

    /**
     * if no value was found for given key, the defaultValue will be put to the map and returned
     * 
     * @param key
     * @param defaultValue
     * @return map value or defaultValue
     */
    public  T get(String key, T defaultValue) {
        T value = (T) materialize(properties.get(key));
        if (value == null && defaultValue != null) {
            value = defaultValue;
            put(key, value);
        }
        return value;
    }

    protected Object materialize(Object obj) {
        return obj instanceof AReference ? ((AReference) obj).resolve() : obj;
    }

    /**
     * filters only values of valueType to be returned in a filtered iterator. if there are persistable entities, they
     * are wrapped into {@link BReference} - so, these references can be collected giving a valueType =
     * BReference.class.
     * 
     * @param valueType any type to be collected from current context.
     * @return filtered map values
     */
    public  Iterator get(final Class valueType) {
        return CollectionUtil.getTransforming(properties.values(), new ITransformer() {
            @Override
            public T transform(Object toTransform) {
                if (toTransform instanceof BReference) {
                    return (T) (BeanDefinition.class.isAssignableFrom(valueType)
                            ? ((BReference) toTransform).bean() : ((BReference) toTransform).resolve());
                } else {
                    return (T) toTransform;
                }
            }
        }, new IPredicate() {
            @Override
            public boolean eval(Object arg0) {
                if (BeanDefinition.class.isAssignableFrom(valueType) && (arg0 instanceof BReference))
                    return ((BReference) arg0).resolve() != null;
                return arg0 != null && (valueType.isAssignableFrom(arg0.getClass()) || (arg0 instanceof AReference
                    && valueType.isAssignableFrom(((AReference) arg0).resolve().getClass())));
            }
        }).iterator();
    }

    /**
     * isPersisted
     * 
     * @return true, if this context was created on file system
     */
    public boolean isPersisted() {
        return new File(getFileName(getName())).exists();
    }

    /**
     * persists the current context
     */
    public void save() {
        if (!properties.isEmpty())
            XmlUtil.saveXml(getFileName(getName()), this);
    }

    public String getName() {
        if (name == null)
            name = FileUtil.getUniqueFileName("context");
        return name;
    }

    public static String getFileName(String name) {
        return ENV.getTempPathRel() + "context-" + name + ".xml";
    }

    String toStringEntries() {
        StringBuilder str = new StringBuilder();
        String ks;
        for (Object k : properties.keySet()) {
            ks = StringUtil.substring((String) k, ".", null, true);
            str.append(StringUtil.fixString(ENV.translate(ks, true), 32, ' ', true) + " : " + properties.get(k) + "\n");
        }
        return str.toString();
    }

    @Override
    public String toString() {
        return getName() + " (items: " + StringUtil.toFormattedString(toStringEntries(), 20) + ")";
    }
}




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