commonmbean.java

Some common function write by java

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package com.s7turn.common;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.faces.context.FacesContext;
import javax.faces.model.SelectItem;

/**
 *
 * @author Long
 */
public abstract class CommonMBean<T> {
    
    
    protected T instance;
    
    public CommonMBean()
    {
        instance = createInstance();
    }
    
    protected String getIdKey()
    {
        return "id";
    }
    
    protected String getIdProperty()
    {
        return "Id";
                
    }
    
    protected String getFoundAction()
    {
        return "found";
    }
    
    protected String getSaveAction()
    {
        return "saved";
    }
    
    protected String getRemoveAction()
    {
        return "removed";
    }    
    public abstract CommonService<T> getService();
    
    public String findById()
    {
        Long id = Long.parseLong( getParameter(getIdKey()) );
        instance = getService().findById(id);
        return getFoundAction();
    }
    
    public String save()
    {
        getService().save(getInstance());
        return getSaveAction();
    }
    
    public String remove()
    {
        T t = getInstance(); 
        Long id = Long.parseLong(getParameter(getIdKey()));
        setBeanProperty(t, getIdProperty(), id );
        getService().remove(t);
        return getRemoveAction();
    }
    
    public List getAllItems()
    {
        return getService().getAllItems();
    }
    
    protected abstract T createInstance();
    
    public String getParameter( String param )
    {
        FacesContext fctx = FacesContext.getCurrentInstance();
        String tempId = fctx.getExternalContext().getRequestParameterMap().get( param );
        return tempId;
    }
    
    public Long getLongParameter(String param, long defaultValue)
    {
        try{
            return Long.parseLong(getParameter(param));
        }catch(Exception e)
        {
        }
        return new Long(defaultValue);
    }
    
    
    public T getInstance()
    {
        return instance;
    }
    
    public void setInstance(T t)
    {
        instance = t;
    }
    
    protected void setBeanProperty( Object bean, String prop, Object objvalue )
    {
        try {
            Method method = bean.getClass().getMethod("set" + prop);
            method.invoke(bean, new Object[]{objvalue});
        } catch (IllegalAccessException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IllegalArgumentException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InvocationTargetException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        } catch (NoSuchMethodException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        } catch (SecurityException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    
    protected Object getProperty( Object bean, String prop, Object defaultValue )
    {
        try {
            Method method = bean.getClass().getMethod("get" + prop, new Class[0]);
            Object obv = method.invoke(bean, new Object[0]);
            return obv;
        } catch (IllegalAccessException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IllegalArgumentException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InvocationTargetException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        } catch (NoSuchMethodException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        } catch (SecurityException ex) {
            Logger.getLogger(CommonMBean.class.getName()).log(Level.SEVERE, null, ex);
        }
        return defaultValue;
    }
    
    protected SelectItem[] toSelectItems(List list, String propValue, String propLabel, String propDisabled)
    {
        int allSize = list == null ? 0 : list.size();
        SelectItem[] items = new SelectItem[ allSize ];
        int i = 0;
        for( Object obj : list )
        {
            Object objKey = getProperty( obj, propValue, null );
            if( objKey != null )
            {
                Object objDesc = getProperty( obj, propLabel, null );
                items[i] = new SelectItem();
                items[i].setLabel(objDesc.toString());
                items[i].setValue( objKey );
                if( propDisabled != null )
                {
                    Boolean disb = (Boolean) getProperty( obj, propDisabled, new Boolean(false) );
                    items[i].setDisabled(disb.booleanValue());
                }
                i ++;
            }
        }
        return items;
    }
}