crudhelper.java

来自「Java Pattern Oriented Framework (Jt) 是为了」· Java 代码 · 共 558 行

package Jt.wizard.struts;

import java.io.File;
import java.text.DateFormat;
import java.util.Collection;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;

import Jt.JtContext;
import Jt.JtFactory;
import Jt.JtHashTable;
import Jt.JtIterator;
import Jt.JtMessage;
import Jt.JtObject;
import Jt.DAO.JtDAOAdapter;
import Jt.DAO.JtDAOFileAdapter;
import Jt.hibernate.JtHibernateAdapter;
import Jt.wizard.WizardConfig;


import org.apache.struts.action.ActionForm;


/**
 * Implements CRUD (Create, Read, Update and Delete).
 */

public class CRUDHelper extends JtObject {
    private static final long serialVersionUID = 1L;
    /*
    public static final String READ = "READ";
    public static final String DELETE = "DELETE";
    public static final String UPDATE = "UPDATE";
    public static final String CREATE = "CREATE";
    public static final String EXECUTE_QUERY = "EXECUTE_QUERY";
    */
    public static final String JtCLASS_NAME = CRUDHelper.class.getName(); 
    private JtFactory factory = new JtFactory ();
    private transient JtDAOFileAdapter adapter;
    private String key;
    private String classname;
    private Object classInstance;
    private String query;
    private WizardConfig config;
    private String filename;




    public String getKey() {
        return key;
    }



    public void setKey(String key) {
        this.key = key;
    }



    public String getFilename() {
        return filename;
    }



    public void setFilename(String filename) {
        this.filename = filename;
    }



    public String getQuery() {
        return query;
    }



    public void setQuery(String query) {
        this.query = query;
    }



    public String getClassname() {
        return classname;
    }



    public void setClassname(String classname) {
        this.classname = classname;
    }



    private void handleUIError (String error) {
        Collection col;

        if (error == null)
            return;
        col = (Collection) this.getObjErrors();

        if (col == null) {
            col = new LinkedList ();
            setObjErrors (col);
        }
        col.add(error);


    }

    private String concatenatePath (String path, String subpath) {
        char separator = File.separatorChar;
        File file;


        if (path == null)
            return null;
        if (subpath == null)
            return path;

        file = new File (path);


        return (file.getAbsolutePath() + separator + subpath);

    }
    

    private Object readObject (ActionForm form, String content) {
        JtMessage msg = new JtMessage ();
        Object obj;
        ActionForm oform;
        String path;       

        if (form == null)
            return (null); // check

        if (classname == null) {
            handleError ("classname attribute needs to set.");
            return (null);
        }    

        if (classInstance == null) { 
            classInstance = factory.createObject (classname);
            if (classInstance == null) {
                handleError ("unable to create an object of class: " + classname);
                return (null);
            }    

        }
        
        config = (WizardConfig) factory.createObject(WizardConfig.JtCLASS_NAME);
        
        if (config == null) {
            handleError ("Unable to create configuration class");
            return (null);
        }
        
        factory.sendMessage(config, new JtMessage (JtObject.JtINITIALIZE));

        
        if (filename == null) {
            handleError ("Attribute filename needs to be set.");
            return (null);           
        }

        adapter = (JtDAOFileAdapter) factory.createObject (JtDAOFileAdapter.JtCLASS_NAME);
        
        path = config.getWorkingDirectory();
        
        adapter.setPath(concatenatePath (path, filename));


        msg.setMsgId (JtDAOAdapter.JtREAD);
        //msg.setMsgContent(classInstance);


        obj = factory.sendMessage (adapter, msg);

        // Propagate the exception

        if (adapter.getObjException() != null) {
            this.setObjException(adapter.getObjException());
            //factory.sendMessage (adapter, new JtMessage (JtObject.JtREMOVE));
            return (null);
        }

        if (obj == null)
            handleUIError ("Unable to find item.");

        factory.sendMessage (adapter, new JtMessage (JtObject.JtREMOVE));

        if (obj == null)
            return (null);

        oform = (ActionForm) factory.createObject(form.getClass().getName());
        copyToForm (obj, oform);


        return (oform);        
    }

    private JtHashTable getAttributes (Object obj) {
        JtMessage msg = new JtMessage (JtFactory.JtGET_ATTRIBUTES);

        if (obj == null)
            return (null);
        msg.setMsgContent(obj);

        return ((JtHashTable) factory.processMessage(msg));

    }


    private void copyFormAttributes (ActionForm form, Object obj) {
        JtHashTable attributes;
        JtIterator iterator;
        String attribute;
        Object value;

        if (obj == null || form == null)
            return;
        attributes = getAttributes (obj);

        if (attributes == null)
            return;
        iterator = (JtIterator) attributes.processMessage(new JtMessage (JtHashTable.JtGET_KEYS));

        if (iterator == null)
            return;

        for (;;) {
            attribute = (String) iterator.processMessage(new JtMessage (JtIterator.JtNEXT));
            if (attribute == null)
                break;
            value = factory.getValue(form,attribute);
            factory.setValue (obj, attribute, value);

        }

    }

    private String DateToString (Date date) {
        String sdate;
        DateFormat df = DateFormat.getDateInstance(DateFormat.SHORT);

        if (date == null)
            return null;
        try {

            sdate = df.format (date);

        } catch (Exception e) {
            handleException (e);
            return null;
        }

        return (sdate);

    }

    private void copyToForm (Object obj, ActionForm form) {
        JtHashTable attributes;
        JtIterator iterator;
        String attribute;
        Object value;

        if (obj == null || form == null)
            return;
        attributes = getAttributes (obj);

        if (attributes == null)
            return;
        iterator = (JtIterator) attributes.processMessage(new JtMessage (JtHashTable.JtGET_KEYS));

        if (iterator == null)
            return;

        for (;;) {
            attribute = (String) iterator.processMessage(new JtMessage (JtIterator.JtNEXT));
            if (attribute == null)
                break;
            value = factory.getValue(obj,attribute);
            if (value instanceof Date)
                factory.setValue (form, attribute, DateToString ((Date) value));
            else
                factory.setValue (form, attribute, value);

        }

    }

    private void deleteObject (ActionForm form) {
        JtMessage msg = new JtMessage ();

        //JtHashTable attributes;
        //Member member = new Member ();


        if (form == null)
            return; // check

        adapter = (JtDAOFileAdapter) factory.createObject (JtHibernateAdapter.JtCLASS_NAME);


        classInstance = factory.createObject (classname);
        if (classInstance == null) {
            handleError ("unable to create an object of class: " + classname);
            return;
        }    


        copyFormAttributes (form, classInstance);

        msg = new JtMessage (JtDAOAdapter.JtDELETE);   
        msg.setMsgContent(classInstance);


        factory.sendMessage (adapter, msg);

        // Propagate the exception

        if (adapter.getObjException() != null) {
            this.setObjException(adapter.getObjException());
        }  

        factory.sendMessage (adapter, new JtMessage (JtObject.JtREMOVE));

    }

    private void updateObject (ActionForm form) {
        JtMessage msg = new JtMessage ();
        String path;

        //Member member = new Member ();


        if (form == null)
            return; // check

        //adapter = (JtDAOFileAdapter) factory.createObject (JtHibernateAdapter.JtCLASS_NAME);
        
        adapter = (JtDAOFileAdapter) factory.createObject (JtDAOFileAdapter.JtCLASS_NAME);
        
        config = (WizardConfig) factory.createObject(WizardConfig.JtCLASS_NAME);
        
        if (config == null) {
            handleError ("Unable to create configuration class");
            return;
        }
        
        factory.sendMessage(config, new JtMessage (JtObject.JtINITIALIZE));

        
        if (filename == null) {
            handleError ("Attribute filename needs to be set.");
            return;           
        }
        
        path = config.getWorkingDirectory();
        
        adapter.setPath(concatenatePath (path, filename));

        classInstance = factory.createObject (classname);
        if (classInstance == null) {
            handleError ("unable to create an object of class: " + classname);
            return;
        }          

        copyFormAttributes (form, classInstance);

        msg = new JtMessage (JtDAOAdapter.JtUPDATE);   
        msg.setMsgContent(classInstance);


        factory.sendMessage (adapter, msg);

        // Propagate the exception

        if (adapter.getObjException() != null) {
            this.setObjException(adapter.getObjException());
        } 

        factory.sendMessage (adapter, new JtMessage (JtObject.JtREMOVE));

    }

    private void createObject (ActionForm form) {
        JtMessage msg = new JtMessage ();

        //Member member = new Member ();


        if (form == null)
            return; // check

        adapter = (JtDAOFileAdapter) factory.createObject (JtHibernateAdapter.JtCLASS_NAME);


        classInstance = factory.createObject (classname);
        if (classInstance == null) {
            handleError ("unable to create an object of class: " + classname);
            return;
        }    


        copyFormAttributes (form, classInstance);

        msg = new JtMessage (JtDAOAdapter.JtCREATE);   
        msg.setMsgContent(classInstance);


        factory.sendMessage (adapter, msg);

        // Propagate the exception

        if (adapter.getObjException() != null) {
            this.setObjException(adapter.getObjException());
        }     

        factory.sendMessage (adapter, new JtMessage (JtObject.JtREMOVE));

    }   

    private List executeQuery () {
        JtMessage msg = new JtMessage ();
        List result;

        adapter = (JtDAOFileAdapter) factory.createObject (JtHibernateAdapter.JtCLASS_NAME);

        msg.setMsgId (JtHibernateAdapter.JtEXECUTE_QUERY);

        if (query == null || query.equals("")) {
            handleError ("query attribute needs to be set.");   
            return (null);
        }    
        //msg.setMsgContent("select * from roster");
        msg.setMsgContent(query);


        classInstance = factory.createObject (classname);
        if (classInstance == null) {
            handleError ("unable to create an object of class: " + classname);
            return (null);
        }           
        msg.setMsgData(classInstance);


        result = (List) factory.sendMessage (adapter, msg);

        // Propagate the exception

        if (adapter.getObjException() != null) {
            this.setObjException(adapter.getObjException());
            result = null;
        }

        factory.sendMessage (adapter, new JtMessage (JtObject.JtREMOVE));
        return (result);
    }

    /**
     * Process object messages.
     * <ul>
     * <li> JtACTIVATE
     * </ul>
     * @param message message
     */

    public Object processMessage (Object message) {
        Object data;
        String content;
        JtContext context;
        ActionForm form = null;

        JtMessage e = (JtMessage) message;

        if (e == null ||  (e.getMsgId() == null))
            return (null);

        factory.setStopClass(JtObject.class);

        /*
        if (e.getMsgId().equals(JtObject.JtACTIVATE)) {

            // pass the form information   
            data = e.getMsgData ();
            return ( getActionMappings ());
        }
         */   
        
        context = (JtContext) e.getMsgContext();
        if (context != null)
            form = (ActionForm) context.getActionForm();  


        if (e.getMsgId().equals(JtDAOAdapter.JtREAD)) {

            content = (String) e.getMsgContent ();
            //data = e.getMsgData ();

            return (readObject ((ActionForm) form, content));

        }

        if (e.getMsgId().equals(JtDAOAdapter.JtDELETE)) {

            //data = e.getMsgData ();
            
            deleteObject ((ActionForm) form);
            return (null);
        }


        if (e.getMsgId().equals(JtDAOAdapter.JtUPDATE)) {

            //data = e.getMsgData ();
            updateObject ((ActionForm) form);
            return (null);
        }

        if (e.getMsgId().equals(JtDAOAdapter.JtCREATE)) {

            //data = e.getMsgData ();
            createObject ((ActionForm) form);
            return (null); // check
        }



        return (super.processMessage(message));

    }
    /**
     * Demonstrates the messages processed by this class.
     */
/*
    public static void main(String[] args) {

        JtObject factory = new JtFactory ();
        CRUDHelper crud;
        JtMessage msg;
        //List list;
        Object obj;
        MemberForm form = new MemberForm ();


        msg = new JtMessage (JtDAOAdapter.JtCREATE);


    }
*/
}