db4o を使ってみる。


GPLライセンスのdb4oを使ってみた。
これはすばらしい。

/*
 * プロジェクト:com.keystonebrand.squid
 *
 * db4o を使ってみたサンプル。
 *
 * あれこれテストしているので、美しくない。
 *
 * author : Keystone kanagawa
 */

package com.keystonebrand.squid.model;

import java.util.Vector;
import com.keystonebrand.squid.lib.KsIcallBackBasic;
import com.db4o.*;


/**
 *
 * @author kanagawa
 */
public class KsDb4o implements KsIdbAccess {
    private String dbpath = null;
    private static ObjectContainer objectContainer = null;

    public KsDb4o() {
        this.dbpath = com.keystonebrand.squid.property.KsInformation.dbpath;
    }

    public KsDb4o(String aDbPath) {
        if (aDbPath != null)
        {
            com.keystonebrand.squid.property.KsInformation.dbpath = aDbPath;
            this.dbpath = com.keystonebrand.squid.property.KsInformation.dbpath;
        }
    }

    public void exec(com.keystonebrand.squid.lib.KsIblockBack aBlockBack)
    {
        try
        {
            KsDb4o.openObjectContainer(this.dbpath);
            aBlockBack.exec(this);
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.getMessage());
        }
        finally
        {
            KsDb4o.closeObjectContainer();
        }

    }

    public <T> void regist(T aObject) {
        try
        {
            if (aObject == null)
            {
                throw new Exception("引数がnullだ");
            }
            this.getOC().store(aObject);
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.getMessage());
        }
        finally
        {
        }
    }

    public <T> Vector<T> gets(String aClassName) {
        java.util.Vector<T> wReturn = null;
        try
        {
            Class wClass = Class.forName(aClassName);
            ObjectSet wResults = this.getOC().queryByExample(wClass);
            if (wResults != null && wResults.size() > 0)
            {
                wReturn = new java.util.Vector<T>();
            }
            while(wResults.hasNext()) {
                wReturn.addElement((T)wResults.next());
            }
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.getMessage());
        }
        finally
        {
        }
        return wReturn;
    }
    public <T1, T2> Vector<T1> gets(T2 aClass) {
        java.util.Vector<T1> wReturn = null;
        try
        {
            ObjectSet wResults = this.getOC().queryByExample(aClass.getClass());
            if (wResults.size() > 0)
            {
                wReturn = new java.util.Vector<T1>();
            }

            while(wResults.hasNext()) {
                wReturn.addElement((T1)wResults.next());
            }
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.getMessage());
        }
        finally
        {
        }
        return wReturn;
    }
    public <T1, T2> Vector<T1> queryByExample(T2 Object) {
        java.util.Vector<T1> wReturn = null;
        try
        {
            ObjectSet wResults = this.getOC().queryByExample(Object);
            if (wResults.size() > 0)
            {
                wReturn = new java.util.Vector<T1>();
            }

            while(wResults.hasNext()) {
                wReturn.addElement((T1)wResults.next());
            }
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.getMessage());
        }
        finally
        {
        }
        return wReturn;
    }
    public <Tvalue, TgetValue>
    	void find_each(String aClassName,
					   String aVarName,
					   TgetValue aValue,
					   com.keystonebrand.squid.lib.KsIcallBackBasic<Tvalue> aCallBack) {
        try
        {
            com.db4o.query.Query wQuery=this.getOC().query();
            Class wClass = Class.forName(aClassName);
            wQuery.constrain(wClass);
            if (aValue != null)
            {
                wQuery.descend(aVarName).constrain(aValue).like();
            }
            ObjectSet wObjectSet = wQuery.execute();
            if (wObjectSet != null)
            {
                Tvalue wValue = null;
                while(wObjectSet.hasNext()) {
                    wValue = (Tvalue)wObjectSet.next();
                    aCallBack.exec(wValue);
                }
            }
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.toString());
        }
        finally
        {
        }
    }
    public <Treturn, TgetValue> Treturn find_first(String aClassName,
                                                  String aVarName,
                                                  TgetValue aValue) {
        Treturn wReturn = null;
        try
        {
            com.db4o.query.Query wQuery=this.getOC().query();
            Class wClass = Class.forName(aClassName);
            wQuery.constrain(wClass);
            if (aValue != null)
            {
                wQuery.descend(aVarName).constrain(aValue).like();
            }
            ObjectSet wObjectSet = wQuery.execute();
            if (wObjectSet != null && wObjectSet.size() > 0)
            {
                Object wObject = wObjectSet.get(0);
                if (wObject != null)
                {
                    wReturn = (Treturn)wObject;
                }
            }
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.toString());
        }
        finally
        {
        }
        return wReturn;
    }
    public <T> T match(String aClassName, String aVarName, String aValue) {
        T wReturn = null;
        try
        {
            com.db4o.query.Query wQuery=this.getOC().query();
            Class wClass = Class.forName(aClassName);
            wQuery.constrain(wClass);
            if (aValue != null)
            {
                wQuery.descend(aVarName).constrain(aValue);
            }
            ObjectSet wObjectSet = wQuery.execute();
            if (wObjectSet != null)
            {
                while(wObjectSet.hasNext()) {
                    wReturn = (T)wObjectSet.next();
                    break;
                }
            }
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.toString());
        }
        return wReturn;
    }

    public ObjectContainer getOC()
    {
        try
        {
            if (KsDb4o.objectContainer == null)
            {
                KsDb4o.openObjectContainer(this.dbpath);
            }
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.getMessage());
        }

        return KsDb4o.objectContainer;
    }
    public static ObjectContainer openObjectContainer(String aDbPath)
    {
        try
        {
            if (KsDb4o.objectContainer == null)
            {
                KsDb4o.objectContainer = Db4o.openFile(aDbPath);
            }
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.getMessage());
        }

        return KsDb4o.objectContainer;
    }

    public static void closeObjectContainer()
    {
        try
        {
            if (KsDb4o.objectContainer != null)
            {
                KsDb4o.objectContainer.close();
                KsDb4o.objectContainer = null;
            }
        }
        catch(Exception e)
        {
            com.keystonebrand.squid.property.KsInformation.getLogger().warning(e.getMessage());
        }
    }

}
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