chinabugotech/hutool · error · UnsupportedOperationException

Unsupported target Date type: {}

Error message

Unsupported target Date type: {}

What it means

DateConverter.wrap(DateTime) only returns java.util.Date, DateTime, java.sql.Date, java.sql.Time, java.sql.Timestamp. Any other java.util.Date subclass as targetType throws UnsupportedOperationException.

Source

Thrown at hutool-core/src/main/java/cn/hutool/core/convert/impl/DateConverter.java:114

	private java.util.Date wrap(DateTime date) {
		// 返回指定类型
		if (java.util.Date.class == targetType) {
			return date.toJdkDate();
		}
		if (DateTime.class == targetType) {
			return date;
		}
		if (java.sql.Date.class == targetType) {
			return date.toSqlDate();
		}
		if (java.sql.Time.class == targetType) {
			return new java.sql.Time(date.getTime());
		}
		if (java.sql.Timestamp.class == targetType) {
			return date.toTimestamp();
		}

		throw new UnsupportedOperationException(StrUtil.format("Unsupported target Date type: {}", this.targetType.getName()));
	}

	/**
	 * java.util.Date转为子类型
	 *
	 * @param mills Date
	 * @return 目标类型对象
	 */
	private java.util.Date wrap(long mills) {
		if(GlobalCustomFormat.FORMAT_SECONDS.equals(this.format)){
			// Unix时间戳
			return DateUtil.date(mills * 1000);
		}

		// 返回指定类型
		if (java.util.Date.class == targetType) {
			return new java.util.Date(mills);
		}

View on GitHub (pinned to 8870454b2a)

Solutions

1. Target one of the supported subtypes (typically java.util.Date) and adapt afterwards.
2. Register a custom Converter for your date subtype.
3. Convert to java.util.Date then construct your subtype from getTime().

Example fix

// before
DateConverter c = new DateConverter(MyDate.class);

// after - target base type then adapt
Date base = new DateConverter(Date.class).convert(value, null);
MyDate md = new MyDate(base.getTime());

private static final Set<Class<?>> SUPPORTED = Set.of(
        java.util.Date.class, DateTime.class,
        java.sql.Date.class, java.sql.Time.class, java.sql.Timestamp.class);
if (!SUPPORTED.contains(targetType)) {
    targetType = java.util.Date.class; // fall back to base type
}
new DateConverter(targetType);

try {
    return new DateConverter(targetType).convert(value, null);
} catch (UnsupportedOperationException e) {
    if (e.getMessage().startsWith("Unsupported target Date type")) {
        return new DateConverter(java.util.Date.class).convert(value, null);
    }
    throw e;
}

When it happens

Trigger: Constructing new DateConverter(MyCustomDate.class) where MyCustomDate extends java.util.Date but is not one of the five supported subtypes; converting from a TemporalAccessor/Calendar/DateTime source.

Common situations: Using third-party date types (e.g. Joda DateTime that extends java.util.Date), custom date wrappers.

Related errors

• Can not convert {}:[{}] to {}
• Unsupport Number type: {}
• [{}] is not support to get empty!
• Unsupported object type: {className}
• [type] and [defaultValue] are both null for Converter [{}],

AI-assisted analysis of chinabugotech/hutool@8870454b2a (2026-08-14). Data as JSON: /api/errors/4f284481cbbbac93. Report an issue: GitHub.