writetag.java

这是一个轻便的j2ee的web应用框架,是一个在多个项目中运用的实际框架,采用struts,hebinate,xml等技术,有丰富的tag,role,navigation,session,dictio

/*
 * $Header: /sfroot/cvs/esimple/src/core/com/esimple/framework/web/taglib/bean/WriteTag.java,v 1.1.1.1 2004/09/08 06:38:15 lava Exp $
 * $Revision: 1.1.1.1 $
 * $Date: 2004/09/08 06:38:15 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Struts", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */


package com.esimple.framework.web.taglib.bean;


import java.util.Locale;
import java.text.SimpleDateFormat;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.Format;

import java.text.DecimalFormat;
import java.text.NumberFormat;
import javax.servlet.jsp.JspException;

import javax.servlet.jsp.tagext.TagSupport;

import org.apache.struts.util.MessageResources;
import org.apache.struts.util.RequestUtils;
import org.apache.struts.util.ResponseUtils;


/**
 * Tag that retrieves the specified property of the specified bean, converts
 * it to a String representation (if necessary), and writes it to the current
 * output stream, optionally filtering characters that are sensitive in HTML.
 *
 * @author Craig R. McClanahan
 * @version $Revision: 1.1.1.1 $ $Date: 2004/09/08 06:38:15 $
 */

public class WriteTag extends TagSupport {

    /**
     * The key to search default format string for 
     * java.sql.Timestamp in resources.
     */    
    public static final String SQL_TIMESTAMP_FORMAT_KEY = 
      "org.apache.struts.taglib.bean.format.sql.timestamp";

    /**
     * The key to search default format string for 
     * java.sql.Date in resources.
     */
    public static final String SQL_DATE_FORMAT_KEY = 
      "org.apache.struts.taglib.bean.format.sql.date";

    /**
     * The key to search default format string for 
     * java.sql.Time in resources.
     */
    public static final String SQL_TIME_FORMAT_KEY = 
      "org.apache.struts.taglib.bean.format.sql.time";

    /**
     * The key to search default format string for 
     * java.util.Date in resources.
     */
    public static final String DATE_FORMAT_KEY = 
      "org.apache.struts.taglib.bean.format.date";

    /**
     * The key to search default format string for int
     * (byte, short, etc.) in resources.
     */
    public static final String INT_FORMAT_KEY = 
      "org.apache.struts.taglib.bean.format.int";

    /**
     * The key to search default format string for float
     * (double, BigDecimal) in resources.
     */
    public static final String FLOAT_FORMAT_KEY = 
      "org.apache.struts.taglib.bean.format.float";

    /**
     * The message resources for this package.
     */
    protected static MessageResources messages =
        MessageResources.getMessageResources
        ("org.apache.struts.taglib.bean.LocalStrings");

    // ------------------------------------------------------------- Properties


    /**
     * Filter the rendered output for characters that are sensitive in HTML?
     */
    protected boolean filter = true;

    public boolean getFilter() {
        return (this.filter);
    }

    public void setFilter(boolean filter) {
        this.filter = filter;
    }


    /**
     * Should we ignore missing beans and simply output nothing?
     */
    protected boolean ignore = false;

    public boolean getIgnore() {
        return (this.ignore);
    }

    public void setIgnore(boolean ignore) {
        this.ignore = ignore;
    }



    /**
     * Name of the bean that contains the data we will be rendering.
     */
    protected String name = "baseForm";//modify by steven

    public String getName() {
        return (this.name);
    }

    public void setName(String name) {
        this.name = name;
    }


    /**
     * Name of the property to be accessed on the specified bean.
     */
    protected String property = null;

    public String getProperty() {
        return (this.property);
    }

    public void setProperty(String property) {
        this.property = property;
    }


    /**
     * The scope to be searched to retrieve the specified bean.
     */
    protected String scope = null;

    public String getScope() {
        return (this.scope);
    }

    public void setScope(String scope) {
        this.scope = scope;
    }

    /**
     * The format string to be used as format to convert 
     * value to String.
     */
    protected String formatStr = null;

    public String getFormat() {
        return (this.formatStr);
    }

    public void setFormat(String formatStr) {
        this.formatStr = formatStr;
    }

    /**
     * The key to search format string in applciation resources
     */
    protected String formatKey = null;

    public String getFormatKey() {
        return (this.formatKey);
    }

    public void setFormatKey(String formatKey) {
        this.formatKey = formatKey;
    }

    /**
     * The session scope key under which our Locale is stored.
     */
    protected String localeKey = null;

    public String getLocale() {
        return (this.localeKey);
    }

    public void setLocale(String localeKey) {
        this.localeKey = localeKey;
    }

    /**
     * The servlet context attribute key for our resources.
     */
    protected String bundle = null;

    public String getBundle() {
        return (this.bundle);
    }

    public void setBundle(String bundle) {
        this.bundle = bundle;
    }

    // --------------------------------------------------------- Public Methods


    /**
     * Process the start tag.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {

        // Look up the requested bean (if necessary)
        if (ignore) {
            if (RequestUtils.lookup(pageContext, name, scope) == null)
                return (SKIP_BODY);  // Nothing to output
        }

        // Look up the requested property value
        Object value =
            RequestUtils.lookup(pageContext, name, property, scope);
        if (value == null)
            return (SKIP_BODY);  // Nothing to output

        // Convert value to the String with some formatting
        String output = formatValue( value );

        // Print this property value to our output writer, suitably filtered
        if (filter)
            ResponseUtils.write(pageContext, ResponseUtils.filter(output));
        else
            ResponseUtils.write(pageContext, output);

        // Continue processing this page
        return (SKIP_BODY);

    }

    /**
     * Retrieve format string from message bundle and return null if
     * message not found or message string.
     * 
     * @param formatKey value to use as key to search message in bundle
     * @exception JspException if a JSP exception has occurred
     */
    protected String retrieveFormatString( String formatKey ) throws JspException {
        String result = RequestUtils.message( pageContext, this.bundle, 
                                this.localeKey, formatKey );
        if( ( result!=null ) &&
              !( result.startsWith( "???" ) &&
                 result.endsWith( "???" ) ) )
                return result;
        else
                return null;
    }

    /**
     * Format value according to specified format string (as tag attribute or
     * as string from message resources) or to current user locale.
     * 
     * @param valueToFormat value to process and convert to String
     * @exception JspException if a JSP exception has occurred
     */
    protected String formatValue(Object valueToFormat) throws JspException {
        Format format = null;
        Object value = valueToFormat;
        Locale locale =
            RequestUtils.retrieveUserLocale( pageContext, this.localeKey );
        boolean formatStrFromResources = false;
        String formatString = formatStr;

        // Return String object as is.
        if ( value instanceof java.lang.String ) {
                return (String)value;
        } else {

            // Try to retrieve format string from resources by the key from formatKey.
            if( ( formatString==null ) && ( formatKey!=null ) ) {
                    formatString = retrieveFormatString( this.formatKey );
                    if( formatString!=null )
                            formatStrFromResources = true;
            }

            // Prepare format object for numeric values.
            if ( value instanceof Number ) {

                if( formatString==null ) {
                        if( ( value instanceof Byte )    ||
                            ( value instanceof Short )   ||
                            ( value instanceof Integer ) ||
                            ( value instanceof Long )    ||
                            ( value instanceof BigInteger ) )
                                formatString = retrieveFormatString( INT_FORMAT_KEY );
                        else if( ( value instanceof Float ) ||
                                 ( value instanceof Double ) ||
                                 ( value instanceof BigDecimal ) )
                                formatString = retrieveFormatString( FLOAT_FORMAT_KEY );
                        if( formatString!=null ) 
                                formatStrFromResources = true;
                }

                if( formatString!=null ) {
                        try {
                                format = NumberFormat.getNumberInstance( locale );
                                if( formatStrFromResources ) 
                                        ( ( DecimalFormat ) format ).applyLocalizedPattern( formatString );
                                else
                                        ( ( DecimalFormat ) format ).applyPattern( formatString );                                        
                        } catch( IllegalArgumentException _e ) {
                                JspException e = new JspException(messages.getMessage("write.format", formatString));
                                RequestUtils.saveException(pageContext, e);
                                throw e;
                        }
                }

            } else if (  value instanceof java.util.Date ) {

                if( formatString==null ) {

                        if (  value instanceof java.sql.Timestamp ) {
                                formatString = retrieveFormatString( SQL_TIMESTAMP_FORMAT_KEY );
                        } else if (  value instanceof java.sql.Date ) {
                                formatString = retrieveFormatString( SQL_DATE_FORMAT_KEY );
                        } else if (  value instanceof java.sql.Time ) {
                                formatString = retrieveFormatString( SQL_TIME_FORMAT_KEY );
                        } else if (  value instanceof java.util.Date ) {
                                formatString = retrieveFormatString( DATE_FORMAT_KEY );
                        }

                        if( formatString!=null ) 
                                formatStrFromResources = true;

                }
                
                if( formatString!=null ) {
                        if( formatStrFromResources ) {
                                format = new SimpleDateFormat( formatString, locale );
                        } else {
                                format = new SimpleDateFormat( formatString );
                        }
                }

            } 
        }

        if( format!=null )
                return format.format( value );
        else
                return value.toString();

    }

    /**
     * Release all allocated resources.
     */
    public void release() {

        super.release();
        filter = true;
        ignore = false;
        name = null;
        property = null;
        scope = null;
        formatStr = null;
        formatKey = null;
        localeKey = null;
        bundle = null;

    }


}