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Tomcat example source code file (JspHelper.java)

This example Tomcat source code file (JspHelper.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Tomcat tags/keywords

dateformat, dateformat, hh:mm:ss, highest_special, highest_special, illegalstateexception, io, ioexception, jsphelper, object, simpledateformat, string, string, stringbuffer, stringbuffer, text, util

The Tomcat JspHelper.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.manager;

import java.io.IOException;
import java.io.Writer;
import java.text.DateFormat;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

import org.apache.catalina.Session;
import org.apache.catalina.manager.util.SessionUtils;


/**
 * Helper JavaBean for JSPs, because JSTL 1.1/EL 2.0 is too dumb to
 * to what I need (call methods with parameters), or I am too dumb to use it correctly. :)
 * @author Cédrik LIME
 */
public class JspHelper {

    private static final String DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
    private static final String DATE_FORMAT = "yyyy-MM-dd";
    private static final String TIME_FORMAT = "HH:mm:ss";

    /**
     * Public constructor, so that this class can be considered a JavaBean
     */
    private JspHelper() {
        super();
    }

    /**
     * Try to get user locale from the session, if possible.
     * IMPLEMENTATION NOTE: this method has explicit support for Tapestry 3 and Struts 1.x
     * @param in_session
     * @return String
     */
    public static String guessDisplayLocaleFromSession(Session in_session) {
        return localeToString(SessionUtils.guessLocaleFromSession(in_session));
    }
    private static String localeToString(Locale locale) {
        if (locale != null) {
            return locale.toString();//locale.getDisplayName();
        } else {
            return "";
        }
    }

    /**
     * Try to get user name from the session, if possible.
     * @param in_session
     * @return String
     */
    public static String guessDisplayUserFromSession(Session in_session) {
        Object user = SessionUtils.guessUserFromSession(in_session);
        return escapeXml(user);
    }


    public static String getDisplayCreationTimeForSession(Session in_session) {
        try {
			DateFormat formatter = new SimpleDateFormat(DATE_TIME_FORMAT);
			return formatter.format(new Date(in_session.getCreationTime()));
        } catch (IllegalStateException ise) {
        	//ignore: invalidated session
        	return "";
		}
    }

    public static String getDisplayLastAccessedTimeForSession(Session in_session) {
        try {
			DateFormat formatter = new SimpleDateFormat(DATE_TIME_FORMAT);
			return formatter.format(new Date(in_session.getLastAccessedTime()));
        } catch (IllegalStateException ise) {
        	//ignore: invalidated session
        	return "";
		}
    }

    public static String getDisplayUsedTimeForSession(Session in_session) {
        return secondsToTimeString(SessionUtils.getUsedTimeForSession(in_session)/1000);
    }

    public static String getDisplayTTLForSession(Session in_session) {
        return secondsToTimeString(SessionUtils.getTTLForSession(in_session)/1000);
    }

    public static String getDisplayInactiveTimeForSession(Session in_session) {
        return secondsToTimeString(SessionUtils.getInactiveTimeForSession(in_session)/1000);
    }

    public static String secondsToTimeString(long in_seconds) {
        StringBuffer buff = new StringBuffer(9);
        long rest = in_seconds;
        long hour = rest / 3600;
        rest = rest % 3600;
        long minute = rest / 60;
        rest = rest % 60;
        long second = rest;
        if (hour < 10) {
            buff.append('0');
        }
        buff.append(hour);
        buff.append(':');
        if (minute < 10) {
            buff.append('0');
        }
        buff.append(minute);
        buff.append(':');
        if (second < 10) {
            buff.append('0');
        }
        buff.append(second);
        return buff.toString();
    }


    /**
    * Following copied from org.apache.taglibs.standard.tag.common.core.OutSupport v1.1.2
    * 
    *  Optimized to create no extra objects and write directly
    *  to the JspWriter using blocks of escaped and unescaped characters
    *
    */
   private static void writeEscapedXml(char[] buffer, int length, Writer w) throws IOException {
       int start = 0;

       for (int i = 0; i < length; i++) {
           char c = buffer[i];
           if (c <= HIGHEST_SPECIAL) {
               char[] escaped = specialCharactersRepresentation[c];
               if (escaped != null) {
                   // add unescaped portion
                   if (start < i) {
                       w.write(buffer,start,i-start);
                   }
                   // add escaped xml
                   w.write(escaped);
                   start = i + 1;
               }
           }
       }
       // add rest of unescaped portion
       if (start < length) {
           w.write(buffer,start,length-start);
       }
   }


    /*
     * Following copied from org.apache.taglibs.standard.tag.common.core.Util v1.1.2
     */

    private static final int HIGHEST_SPECIAL = '>';
    private static char[][] specialCharactersRepresentation = new char[HIGHEST_SPECIAL + 1][];
    static {
        specialCharactersRepresentation['&'] = "&".toCharArray();
        specialCharactersRepresentation['<'] = "<".toCharArray();
        specialCharactersRepresentation['>'] = ">".toCharArray();
        specialCharactersRepresentation['"'] = """.toCharArray();
        specialCharactersRepresentation['\''] = "'".toCharArray();
    }

    public static String escapeXml(Object obj) {
        String value = null;
        try {
            value = (obj == null) ? null : String.valueOf(obj);
        } catch (Exception e) {
            // Ignore
        }
        return escapeXml(value);
    }

    /**
     * Performs the following substring replacements
     * (to facilitate output to XML/HTML pages):
     *
     *    & -> &
     *    < -> <
     *    > -> >
     *    " -> "
     *    ' -> '
     *
     * See also OutSupport.writeEscapedXml().
     */
    public static String escapeXml(String buffer) {
    	if (buffer == null) {
			return "";
		}
        int start = 0;
        int length = buffer.length();
        char[] arrayBuffer = buffer.toCharArray();
        StringBuffer escapedBuffer = null;

        for (int i = 0; i < length; i++) {
            char c = arrayBuffer[i];
            if (c <= HIGHEST_SPECIAL) {
                char[] escaped = specialCharactersRepresentation[c];
                if (escaped != null) {
                    // create StringBuffer to hold escaped xml string
                    if (start == 0) {
                        escapedBuffer = new StringBuffer(length + 5);
                    }
                    // add unescaped portion
                    if (start < i) {
                        escapedBuffer.append(arrayBuffer,start,i-start);
                    }
                    start = i + 1;
                    // add escaped xml
                    escapedBuffer.append(escaped);
                }
            }
        }
        // no xml escaping was necessary
        if (start == 0) {
            return buffer;
        }
        // add rest of unescaped portion
        if (start < length) {
            escapedBuffer.append(arrayBuffer,start,length-start);
        }
        return escapedBuffer.toString();
    }

    public static String formatNumber(long number) {
    	return NumberFormat.getNumberInstance().format(number);
    }
}

Other Tomcat examples (source code examples)

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