org.apache.commons.beanutils.converters.AbstractArrayConverter Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* 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.beanutils.converters;
import java.io.IOException;
import java.io.StreamTokenizer;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.beanutils.ConversionException;
import org.apache.commons.beanutils.Converter;
/**
* 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.
*
* 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.
*
* @version $Id$
* @since 1.4
* @deprecated Replaced by the new {@link ArrayConverter} implementation
*/
@Deprecated
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(final 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
/**
* 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
*
* @throws ConversionException if conversion cannot be performed
* successfully
*/
public abstract Object convert(Class type, Object value);
// ------------------------------------------------------ Protected Methods
/**
* Parse an incoming String of the form similar to an array initializer
* in the Java language into a List individual Strings
* for each element, according to the following rules.
*
* - The string is expected to be a comma-separated list of values.
* - The string may optionally have matching '{' and '}' delimiters
* around the list.
* - Whitespace before and after each element is stripped.
* - Elements in the list may be delimited by single or double quotes.
* Within a quoted elements, the normal Java escape sequences are valid.
*
*
* @param svalue String value to be parsed
* @return The parsed list of String values
*
* @throws ConversionException if the syntax of svalue
* is not syntactically valid
* @throws NullPointerException if svalue
* is 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
final 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
final ArrayList list = new ArrayList();
while (true) {
final 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 (final IOException e) {
throw new ConversionException(e);
}
}
}