https://github.com/spring-projects/spring-framework: Spring Beans (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2018 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
 *
 *      https://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 java.text.NumberFormat;

import org.springframework.lang.Nullable;
import org.springframework.util.NumberUtils;
import org.springframework.util.StringUtils;


Property editor for any Number subclass such as Short, Integer, Long, BigInteger, Float, Double, BigDecimal. Can use a given NumberFormat for (locale-specific) parsing and rendering, or alternatively the default decode / valueOf / toString methods. 
This is not meant to be used as system PropertyEditor but rather
as locale-specific number editor within custom controller code,
parsing user-entered number strings into Number properties of beans
and rendering them in the UI form.

In web MVC code, this editor will typically be registered with binder.registerCustomEditor calls. 
Author:Juergen Hoeller
See Also:
Since:06.06.2003
/**
 * Property editor for any Number subclass such as Short, Integer, Long,
 * BigInteger, Float, Double, BigDecimal. Can use a given NumberFormat for
 * (locale-specific) parsing and rendering, or alternatively the default
 * {@code decode} / {@code valueOf} / {@code toString} methods.
 *
 * <p>This is not meant to be used as system PropertyEditor but rather
 * as locale-specific number editor within custom controller code,
 * parsing user-entered number strings into Number properties of beans
 * and rendering them in the UI form.
 *
 * <p>In web MVC code, this editor will typically be registered with
 * {@code binder.registerCustomEditor} calls.
 *
 * @author Juergen Hoeller
 * @since 06.06.2003
 * @see Number
 * @see java.text.NumberFormat
 * @see org.springframework.validation.DataBinder#registerCustomEditor
 */
public class CustomNumberEditor extends PropertyEditorSupport {

	private final Class<? extends Number> numberClass;

	@Nullable
	private final NumberFormat numberFormat;

	private final boolean allowEmpty;


	
Create a new CustomNumberEditor instance, using the default valueOf methods for parsing and toString methods for rendering. 
The "allowEmpty" parameter states if an empty String should be allowed for parsing, i.e. get interpreted as null value. Else, an IllegalArgumentException gets thrown in that case. 
Params:
  • numberClass – the Number subclass to generate
  • allowEmpty – if empty strings should be allowed
Throws:
See Also:
/**
	 * Create a new CustomNumberEditor instance, using the default
	 * {@code valueOf} methods for parsing and {@code toString}
	 * methods for rendering.
	 * <p>The "allowEmpty" parameter states if an empty String should
	 * be allowed for parsing, i.e. get interpreted as {@code null} value.
	 * Else, an IllegalArgumentException gets thrown in that case.
	 * @param numberClass the Number subclass to generate
	 * @param allowEmpty if empty strings should be allowed
	 * @throws IllegalArgumentException if an invalid numberClass has been specified
	 * @see org.springframework.util.NumberUtils#parseNumber(String, Class)
	 * @see Integer#valueOf
	 * @see Integer#toString
	 */
	public CustomNumberEditor(Class<? extends Number> numberClass, boolean allowEmpty) throws IllegalArgumentException {
		this(numberClass, null, allowEmpty);
	}

	
Create a new CustomNumberEditor instance, using the given NumberFormat
for parsing and rendering.

The allowEmpty parameter states if an empty String should be allowed for parsing, i.e. get interpreted as null value. Else, an IllegalArgumentException gets thrown in that case. 
Params:
  • numberClass – the Number subclass to generate
  • numberFormat – the NumberFormat to use for parsing and rendering
  • allowEmpty – if empty strings should be allowed
Throws:
See Also:
/**
	 * Create a new CustomNumberEditor instance, using the given NumberFormat
	 * for parsing and rendering.
	 * <p>The allowEmpty parameter states if an empty String should
	 * be allowed for parsing, i.e. get interpreted as {@code null} value.
	 * Else, an IllegalArgumentException gets thrown in that case.
	 * @param numberClass the Number subclass to generate
	 * @param numberFormat the NumberFormat to use for parsing and rendering
	 * @param allowEmpty if empty strings should be allowed
	 * @throws IllegalArgumentException if an invalid numberClass has been specified
	 * @see org.springframework.util.NumberUtils#parseNumber(String, Class, java.text.NumberFormat)
	 * @see java.text.NumberFormat#parse
	 * @see java.text.NumberFormat#format
	 */
	public CustomNumberEditor(Class<? extends Number> numberClass,
			@Nullable NumberFormat numberFormat, boolean allowEmpty) throws IllegalArgumentException {

		if (!Number.class.isAssignableFrom(numberClass)) {
			throw new IllegalArgumentException("Property class must be a subclass of Number");
		}
		this.numberClass = numberClass;
		this.numberFormat = numberFormat;
		this.allowEmpty = allowEmpty;
	}


	
Parse the Number from the given text, using the specified NumberFormat.

/**
	 * Parse the Number from the given text, using the specified NumberFormat.
	 */
	@Override
	public void setAsText(String text) throws IllegalArgumentException {
		if (this.allowEmpty && !StringUtils.hasText(text)) {
			// Treat empty String as null value.
			setValue(null);
		}
		else if (this.numberFormat != null) {
			// Use given NumberFormat for parsing text.
			setValue(NumberUtils.parseNumber(text, this.numberClass, this.numberFormat));
		}
		else {
			// Use default valueOf methods for parsing text.
			setValue(NumberUtils.parseNumber(text, this.numberClass));
		}
	}

	
Coerce a Number value into the required target class, if necessary.

/**
	 * Coerce a Number value into the required target class, if necessary.
	 */
	@Override
	public void setValue(@Nullable Object value) {
		if (value instanceof Number) {
			super.setValue(NumberUtils.convertNumberToTargetClass((Number) value, this.numberClass));
		}
		else {
			super.setValue(value);
		}
	}

	
Format the Number as String, using the specified NumberFormat.

/**
	 * Format the Number as String, using the specified NumberFormat.
	 */
	@Override
	public String getAsText() {
		Object value = getValue();
		if (value == null) {
			return "";
		}
		if (this.numberFormat != null) {
			// Use NumberFormat for rendering value.
			return this.numberFormat.format(value);
		}
		else {
			// Use toString method for rendering value.
			return value.toString();
		}
	}

}