| career | drupal | java | mac | mysql | perl | scala | uml | unix  

Commons Beanutils example source code file (

This example Commons Beanutils source code file ( is included in the "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Commons Beanutils tags/keywords

abstractarrayconverter, abstractarrayconverter, arraylist, commas, conversionexception, io, needed, no_default, no_default, object, object, streamtokenizer, string, string, stringreader, util

The Commons Beanutils 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
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the License for the specific language governing permissions and
 * limitations under the License.

package org.apache.commons.beanutils.converters;

import java.util.ArrayList;
import java.util.List;
import org.apache.commons.beanutils.ConversionException;
import org.apache.commons.beanutils.Converter;

 * <p>Convenience base class for converters that translate the String
 * representation of an array into a corresponding array of primitives
 * object.  This class encapsulates the functionality required to parse
 * the String into a list of String elements that can later be
 * individually converted to the appropriate primitive type.</p>
 * <p>The input syntax accepted by the parseElements() method
 * is designed to be compatible with the syntax used to initialize arrays
 * in a Java source program, except that only String literal values are
 * supported.  For maximum flexibility, the surrounding '{' and '}'
 * characters are optional, and individual elements may be separated by
 * any combination of whitespace and comma characters.</p>
 * @author Craig R. McClanahan
 * @version $Revision: 690380 $ $Date: 2008-08-29 21:04:38 +0100 (Fri, 29 Aug 2008) $
 * @since 1.4
 * @deprecated Replaced by the new {@link ArrayConverter} implementation

public abstract class AbstractArrayConverter implements Converter {

    // ----------------------------------------------------------- Constructors

     * Create a {@link Converter} that will throw a {@link ConversionException}
     * if a conversion error occurs.
    public AbstractArrayConverter() {

        this.defaultValue = null;
        this.useDefault = false;


     * Create a {@link Converter} that will return the specified default value
     * if a conversion error occurs.
     * @param defaultValue The default value to be returned
     * @since 1.8.0
    public AbstractArrayConverter(Object defaultValue) {

        if (defaultValue == NO_DEFAULT) {
            this.useDefault = false;
        } else {
            this.defaultValue = defaultValue;
            this.useDefault = true;


    // ------------------------------------------------------- Static Variables

     * This is a special reference that can be passed as the "default object"
     * to the constructor to indicate that no default is desired. Note that
     * the value 'null' cannot be used for this purpose, as the caller may
     * want a null to be returned as the default.
     * @since 1.8.0
    public static final Object NO_DEFAULT = new Object();

    // ----------------------------------------------------- Instance Variables

     * <p>Model object for string arrays.

*/ protected static String[] strings = new String[0]; /** * The default value specified to our Constructor, if any. */ protected Object defaultValue = null; /** * Should we return the default value on conversion errors? */ protected boolean useDefault = true; // --------------------------------------------------------- Public Methods /** * Convert the specified input object into an output object of the * specified type. This method must be implemented by a concrete * subclass. * * @param type Data type to which this value should be converted * @param value The input value to be converted * @return The converted value * * @exception ConversionException if conversion cannot be performed * successfully */ public abstract Object convert(Class type, Object value); // ------------------------------------------------------ Protected Methods /** * <p>Parse an incoming String of the form similar to an array initializer * in the Java language into a <code>List individual Strings * for each element, according to the following rules.</p> * <ul> * <li>The string is expected to be a comma-separated list of values. * <li>The string may optionally have matching '{' and '}' delimiters * around the list.</li> * <li>Whitespace before and after each element is stripped. * <li>Elements in the list may be delimited by single or double quotes. * Within a quoted elements, the normal Java escape sequences are valid.</li> * </ul> * * @param svalue String value to be parsed * @return The parsed list of String values * * @exception ConversionException if the syntax of <code>svalue * is not syntactically valid * @exception NullPointerException if <code>svalue * is <code>null */ protected List parseElements(String svalue) { // Validate the passed argument if (svalue == null) { throw new NullPointerException(); } // Trim any matching '{' and '}' delimiters svalue = svalue.trim(); if (svalue.startsWith("{") && svalue.endsWith("}")) { svalue = svalue.substring(1, svalue.length() - 1); } try { // Set up a StreamTokenizer on the characters in this String StreamTokenizer st = new StreamTokenizer(new StringReader(svalue)); st.whitespaceChars(',',','); // Commas are delimiters st.ordinaryChars('0', '9'); // Needed to turn off numeric flag st.ordinaryChars('.', '.'); st.ordinaryChars('-', '-'); st.wordChars('0', '9'); // Needed to make part of tokens st.wordChars('.', '.'); st.wordChars('-', '-'); // Split comma-delimited tokens into a List ArrayList list = new ArrayList(); while (true) { int ttype = st.nextToken(); if ((ttype == StreamTokenizer.TT_WORD) || (ttype > 0)) { list.add(st.sval); } else if (ttype == StreamTokenizer.TT_EOF) { break; } else { throw new ConversionException ("Encountered token of type " + ttype); } } // Return the completed list return (list); } catch (IOException e) { throw new ConversionException(e); } } }

Other Commons Beanutils examples (source code examples)

Here is a short list of links related to this Commons Beanutils source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller


new blog posts


Copyright 1998-2021 Alvin Alexander,
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.