org.springframework.beans.propertyeditors.CharacterEditor Maven / Gradle / Ivy
/*
* Copyright 2002-2006 the original author or authors.
*
* Licensed 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.springframework.beans.propertyeditors;
import java.beans.PropertyEditorSupport;
import org.springframework.util.StringUtils;
/**
* Editor for a {@link java.lang.Character}, to populate a property
* of type Character or char from a String value.
*
* Note that the JDK does not contain a default
* {@link java.beans.PropertyEditor property editor} for char!
* {@link org.springframework.beans.BeanWrapperImpl} will register this
* editor by default.
*
*
Also supports conversion from a Unicode character sequence; e.g.
* u0041 ('A').
*
* @author Juergen Hoeller
* @author Rob Harrop
* @author Rick Evans
* @since 1.2
* @see java.lang.Character
* @see org.springframework.beans.BeanWrapperImpl
*/
public class CharacterEditor extends PropertyEditorSupport {
/**
* The prefix that identifies a string as being a Unicode character sequence.
*/
private static final String UNICODE_PREFIX = "\\u";
/**
* The length of a Unicode character sequence.
*/
private static final int UNICODE_LENGTH = 6;
private final boolean allowEmpty;
/**
* Create a new CharacterEditor instance.
*
The "allowEmpty" parameter controls whether an empty String is
* to be allowed in parsing, i.e. be interpreted as the null
* value when {@link #setAsText(String) text is being converted}. If
* false, an {@link IllegalArgumentException} will be thrown
* at that time.
* @param allowEmpty if empty strings are to be allowed
*/
public CharacterEditor(boolean allowEmpty) {
this.allowEmpty = allowEmpty;
}
public void setAsText(String text) throws IllegalArgumentException {
if (this.allowEmpty && !StringUtils.hasText(text)) {
// Treat empty String as null value.
setValue(null);
}
else if (text == null) {
throw new IllegalArgumentException("null String cannot be converted to char type");
}
else if (isUnicodeCharacterSequence(text)) {
setAsUnicode(text);
}
else if (text.length() != 1) {
throw new IllegalArgumentException("String [" + text + "] with length " +
text.length() + " cannot be converted to char type");
}
else {
setValue(new Character(text.charAt(0)));
}
}
public String getAsText() {
Object value = getValue();
return (value != null ? value.toString() : "");
}
private void setAsUnicode(String text) {
int code = Integer.parseInt(text.substring(UNICODE_PREFIX.length()), 16);
setValue(new Character((char) code));
}
private static boolean isUnicodeCharacterSequence(String sequence) {
return sequence.startsWith(UNICODE_PREFIX)
&& sequence.length() == UNICODE_LENGTH;
}
}