texttag.java

webwork source

/*
 * WebWork, Web Application Framework
 *
 * Distributable under Apache license.
 * See terms of license at opensource.org
 */
package webwork.view.taglib;

import javax.servlet.jsp.JspException;
import java.lang.ref.SoftReference;
import java.text.DateFormat;
import java.text.Format;
import java.text.MessageFormat;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.Locale;
import java.util.WeakHashMap;

/**
 * Access a i18n-ized message. The message must be in a resource bundle
 * with the same name as the action that it is associated with. In practice
 * this means that you should create a properties file in the same package
 * as your Java class with the same name as your class, but with .properties
 * extension.
 *
 * See examples for further info on how to use.
 *
 * If the named message is not found, then the body of the tag will be used as default message.
 * If no body is used, then the name of the message will be used.
 *
 * @author Rickard 謆erg ([e-mail])
 * @version $Revision: 1.9 $
 */
public class TextTag
      extends WebWorkBodyTagSupport
      implements ParamTag.UnnamedParametric {
   // Attributes ----------------------------------------------------
   protected String nameAttr;
   protected String value0Attr;
   protected String value1Attr;
   protected String value2Attr;
   protected String value3Attr;

   private ArrayList values;
   private WeakHashMap fmtCache = new WeakHashMap();

   // Public --------------------------------------------------------
   public void setName(String aName) {
      nameAttr = aName;
   }

   public void setValue0(String aName) {
      value0Attr = aName;
   }

   public void setValue1(String aName) {
      value1Attr = aName;
   }

   public void setValue2(String aName) {
      value2Attr = aName;
   }

   public void setValue3(String aName) {
      value3Attr = aName;
   }

   public void addParameter(String aName, Object aValue) {
      addParameter(aValue);
   }

   public void addParameter(Object aValue) {
      if (aValue == null)
         return;
      if (values == null)
         values = new ArrayList();
      values.add(aValue);
   }

   // BodyTag implementation ----------------------------------------
   public int doEndTag() throws JspException {
      // Get message
      String msg;
      try {
         msg = findString("text(" + nameAttr + ")");
         if (msg==null) {
            if (bodyContent != null && bodyContent.getString().trim().length() > 0) {
               // Show tag body
               msg = bodyContent.getString().trim();
            } else {
               // Show message name
               msg = findString(nameAttr);
            }
         }
      } catch (Exception e) {
         if (bodyContent != null && bodyContent.getString().trim().length() > 0) {
            // Show tag body
            msg = bodyContent.getString().trim();
         } else {
            // Show message name
            msg = findString(nameAttr);
         }
      }

      // Add tag attribute values
      // These can be used to parameterize the i18n-ized message
      if (value0Attr != null)
         addParameter(findValue(value0Attr));
      if (value1Attr != null)
         addParameter(findValue(value1Attr));
      if (value2Attr != null)
         addParameter(findValue(value2Attr));
      if (value3Attr != null)
         addParameter(findValue(value3Attr));

      try {
         if (values != null) {
            // Try to do something interesting
            // Use MessageFormat with parameters
            // Check cache first for previously used MessageFormats
            MessageFormat fmt = null;
            SoftReference ref = (SoftReference) fmtCache.get(msg);
            if (ref != null)
               fmt = (MessageFormat) ref.get();
            if (fmt == null) {
               //call ActionSupport's getLocale() first in
               //case there are overrides
               Locale wwLocale = (Locale) findValue("locale");
               if (wwLocale == null) {
                  wwLocale = pageContext.getRequest().getLocale();
               }

               if (wwLocale.equals(Locale.getDefault())) {
                  fmt = new MessageFormat(msg);
               } else {
                  // Use chosen locale
                  fmt = new MessageFormat("");
                  fmt.setLocale(wwLocale);
                  fmt.applyPattern(msg);
               }

               fmtCache.put(msg, new SoftReference(fmt));
            }

            // This isn't fool-proof, but it's better than nothing
            // The idea is to try and convert strings into the
            // types of objects that the formatters expects
            // i.e. Numbers and Dates
            Format[] formats = fmt.getFormats();
            for (int i = 0; i < formats.length; i++) {
               Format format = formats[i];
               if (format != null) {
                  if (format instanceof DateFormat) {
                     if (values.size() > i) {
                        Object value = values.get(i);
                        if (value instanceof String) {
                           DateFormat dateFmt = (DateFormat) format;
                           value = dateFmt.parse((String) value);
                           values.set(i, value);
                        }
                     }
                  }
                  else if (format instanceof NumberFormat) {
                     if (values.size() > i) {
                        Object value = values.get(i);
                        if (value instanceof String) {
                           NumberFormat numberFmt = (NumberFormat) format;
                           value = numberFmt.parse((String) value);
                           values.set(i, value);
                        }
                     }
                  }
               }
            }

            String result = fmt.format(values.toArray());
            pageContext.getOut().write(result);

            values = null;
         } else {
            // Print out string
            pageContext.getOut().write(msg);
         }
      } catch (Exception e) {
         e.printStackTrace();
         throw new JspException(toString(e));
      }

      return EVAL_PAGE;
   }
}