CustomDateEditor.java

package message.mvc.editor;

import org.springframework.util.StringUtils;

import java.beans.PropertyEditorSupport;
import java.text.DateFormat;
import java.text.ParseException;
import java.util.Date;

/**
 * override spring CustomDateEditor, modify dateFormat type
 * {@linkplain org.springframework.beans.propertyeditors.CustomDateEditor Spring-CustomDateEditor}
 *
 * @author sunhao(sunhao.java@gmail.com)
 * @version V1.0, 12-7-1 上午12:01
 * @see java.util.Date
 * @see java.text.DateFormat
 * @see org.springframework.validation.DataBinder#registerCustomEditor
 */
public class CustomDateEditor extends PropertyEditorSupport {

	private final DateFormat dateFormat;

	private final boolean allowEmpty;

	private final int exactDateLength;


	/**
	 * Create a new CustomDateEditor instance, using the given DateFormat
	 * for parsing and rendering.
	 * <p>The "allowEmpty" parameter states if an empty String should
	 * be allowed for parsing, i.e. get interpreted as null value.
	 * Otherwise, an IllegalArgumentException gets thrown in that case.
	 * @param dateFormat DateFormat to use for parsing and rendering
	 * @param allowEmpty if empty strings should be allowed
	 */
	public CustomDateEditor(DateFormat dateFormat, boolean allowEmpty) {
		this.dateFormat = dateFormat;
		this.allowEmpty = allowEmpty;
		this.exactDateLength = -1;
	}

	/**
	 * Create a new CustomDateEditor instance, using the given DateFormat
	 * for parsing and rendering.
	 * <p>The "allowEmpty" parameter states if an empty String should
	 * be allowed for parsing, i.e. get interpreted as null value.
	 * Otherwise, an IllegalArgumentException gets thrown in that case.
	 * <p>The "exactDateLength" parameter states that IllegalArgumentException gets
	 * thrown if the String does not exactly match the length specified. This is useful
	 * because SimpleDateFormat does not enforce strict parsing of the year part,
	 * not even with <code>setLenient(false)</code>. Without an "exactDateLength"
	 * specified, the "01/01/05" would get parsed to "01/01/0005".
	 * @param dateFormat DateFormat to use for parsing and rendering
	 * @param allowEmpty if empty strings should be allowed
	 * @param exactDateLength the exact expected length of the date String
	 */
	public CustomDateEditor(DateFormat dateFormat, boolean allowEmpty, int exactDateLength) {
		this.dateFormat = dateFormat;
		this.allowEmpty = allowEmpty;
		this.exactDateLength = exactDateLength;
	}


	/**
	 * Parse the Date from the given text, using the specified DateFormat.
	 */
	@Override
	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 && this.exactDateLength >= 0 && text.length() != this.exactDateLength) {
			throw new IllegalArgumentException(
					"Could not parse date: it is not exactly" + this.exactDateLength + "characters long");
		}
		else {
			try {
				setValue(this.dateFormat.parse(text));
			}
			catch (ParseException ex) {
				throw new IllegalArgumentException("Could not parse date: " + ex.getMessage(), ex);
			}
		}
	}

	/**
	 * Format the Date as String, using the specified DateFormat.
	 */
	@Override
	public String getAsText() {
		Date value = (Date) getValue();
		return (value != null ? this.dateFormat.format(value) : "");
	}

}