java 中 Date 类型快判断日期是否合法.

// 如果日期不合法，则抛异常
try {
	String date_str = "5555-22-33";

	SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd");
	format.setLenient(false);
	Date date = format.parse(date_str);

} catch (Exception ex){
	ex.printStackTrace();
	System.out.println("日期不合法");
}

JDK 中的注释说明：

/**
     * Specify whether or not date/time parsing is to be lenient.  With
     * lenient parsing, the parser may use heuristics to interpret inputs that
     * do not precisely match this object's format.  With strict parsing,
     * inputs must match this object's format.
     *
     * <p>This method is equivalent to the following call.
     * <blockquote><pre>
     *  getCalendar().setLenient(lenient)
     * </pre></blockquote>
     *
     * <p>This leniency value is overwritten by a call to {@link
     * #setCalendar(java.util.Calendar) setCalendar()}.
     *
     * @param lenient when {@code true}, parsing is lenient
     * @see java.util.Calendar#setLenient(boolean)
     */
    public void setLenient(boolean lenient)
    {
        calendar.setLenient(lenient);
    }