Commons Math example source code file (MathException.java)

This example Commons Math source code file (MathException.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 - Commons Math tags/keywords

exception, io, locale, mathexception, mathexception, messageformat, missingresourceexception, object, object, override, override, printwriter, resourcebundle, string, string, text, util

The Commons Math MathException.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.commons.math;

import java.io.PrintStream;
import java.io.PrintWriter;
import java.text.MessageFormat;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;


/**
* Base class for commons-math checked exceptions.
* <p>
* Supports nesting, emulating JDK 1.4 behavior if necessary.</p>
* <p>
* Adapted from <a href="http://commons.apache.org/collections/api-release/org/apache/commons/collections/FunctorException.html"/>.

*
* @version $Revision: 822850 $ $Date: 2009-10-07 14:56:42 -0400 (Wed, 07 Oct 2009) $
*/
public class MathException extends Exception {

    /** Serializable version identifier. */
    private static final long serialVersionUID = -9004610152740737812L;

    /**
     * Pattern used to build the message.
     */
    private final String pattern;

    /**
     * Arguments used to build the message.
     */
    private final Object[] arguments;

    /**
     * Constructs a new <code>MathException with no
     * detail message.
     */
    public MathException() {
        this.pattern   = null;
        this.arguments = new Object[0];
    }

    /**
     * Constructs a new <code>MathException with specified
     * formatted detail message.
     * Message formatting is delegated to {@link java.text.MessageFormat}.
     * @param pattern format specifier
     * @param arguments format arguments
     */
    public MathException(String pattern, Object ... arguments) {
      this.pattern   = pattern;
      this.arguments = (arguments == null) ? new Object[0] : arguments.clone();
    }

    /**
     * Constructs a new <code>MathException with specified
     * nested <code>Throwable root cause.
     *
     * @param rootCause  the exception or error that caused this exception
     *                   to be thrown.
     */
    public MathException(Throwable rootCause) {
        super(rootCause);
        this.pattern   = getMessage();
        this.arguments = new Object[0];
    }

    /**
     * Constructs a new <code>MathException with specified
     * formatted detail message and nested <code>Throwable root cause.
     * Message formatting is delegated to {@link java.text.MessageFormat}.
     * @param rootCause the exception or error that caused this exception
     * to be thrown.
     * @param pattern format specifier
     * @param arguments format arguments
     * @since 1.2
     */
    public MathException(Throwable rootCause, String pattern, Object ... arguments) {
      super(rootCause);
      this.pattern   = pattern;
      this.arguments = (arguments == null) ? new Object[0] : arguments.clone();
    }

    /**
     * Translate a string to a given locale.
     * @param s string to translate
     * @param locale locale into which to translate the string
     * @return translated string or original string
     * for unsupported locales or unknown strings
     */
    private static String translate(String s, Locale locale) {
        try {
            ResourceBundle bundle =
                    ResourceBundle.getBundle("org.apache.commons.math.MessagesResources", locale);
            if (bundle.getLocale().getLanguage().equals(locale.getLanguage())) {
                // the value of the resource is the translated string
                return bundle.getString(s);
            }

        } catch (MissingResourceException mre) {
            // do nothing here
        }

        // the locale is not supported or the resource is unknown
        // don't translate and fall back to using the string as is
        return s;

    }

    /** Gets the pattern used to build the message of this throwable.
     *
     * @return the pattern used to build the message of this throwable
     * @since 1.2
     */
    public String getPattern() {
        return pattern;
    }

    /** Gets the arguments used to build the message of this throwable.
     *
     * @return the arguments used to build the message of this throwable
     * @since 1.2
     */
    public Object[] getArguments() {
        return arguments.clone();
    }

    /** Gets the message in a specified locale.
     *
     * @param locale Locale in which the message should be translated
     *
     * @return localized message
     * @since 1.2
     */
    public String getMessage(final Locale locale) {
        return (pattern == null) ? "" : new MessageFormat(translate(pattern, locale), locale).format(arguments);
    }

    /** {@inheritDoc} */
    @Override
    public String getMessage() {
        return getMessage(Locale.US);
    }

    /** {@inheritDoc} */
    @Override
    public String getLocalizedMessage() {
        return getMessage(Locale.getDefault());
    }

    /**
     * Prints the stack trace of this exception to the standard error stream.
     */
    @Override
    public void printStackTrace() {
        printStackTrace(System.err);
    }

    /**
     * Prints the stack trace of this exception to the specified stream.
     *
     * @param out  the <code>PrintStream to use for output
     */
    @Override
    public void printStackTrace(PrintStream out) {
        synchronized (out) {
            PrintWriter pw = new PrintWriter(out, false);
            printStackTrace(pw);
            // Flush the PrintWriter before it's GC'ed.
            pw.flush();
        }
    }

}