hibernate/hibernate-orm · error · IllegalArgumentException

Cannot parse given string into array of Booleans. First and

Error message

Cannot parse given string into array of Booleans. First and last character must be { and }

What it means

BooleanPrimitiveArrayJavaType.fromString parses a boolean[] from an array literal in the PostgreSQL output format, e.g. '{true,false}'. If the first character is not '{' or the last is not '}', it throws IllegalArgumentException instead of attempting to parse a plain list.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/type/descriptor/java/BooleanPrimitiveArrayJavaType.java:84

		sb.append( value[0] );
		for ( int i = 1; i < value.length; i++ ) {
			sb.append( value[i] );
			sb.append( ',' );
		}
		sb.append( '}' );
		return sb.toString();
	}

	@Override
	public boolean[] fromString(CharSequence charSequence) {
		if ( charSequence == null ) {
			return null;
		}
		final List<Boolean> list = new ArrayList<>();
		final char lastChar = charSequence.charAt( charSequence.length() - 1 );
		final char firstChar = charSequence.charAt( 0 );
		if ( firstChar != '{' || lastChar != '}' ) {
			throw new IllegalArgumentException( "Cannot parse given string into array of Booleans. First and last character must be { and }" );
		}
		final int len = charSequence.length();
		int elementStart = 1;
		for ( int i = elementStart; i < len; i ++ ) {
			final char c = charSequence.charAt( i );
			if ( c == ',' ) {
				list.add( Boolean.parseBoolean( charSequence.subSequence( elementStart, i ).toString() ) );
				elementStart = i + 1;
			}
		}
		final boolean[] result = new boolean[list.size()];
		for ( int i = 0; i < result.length; i ++ ) {
			result[ i ] = list.get( i );
		}
		return result;
	}

	@Override

View on GitHub (pinned to fad1729dce)

Solutions

1. Store values in '{...}' array-literal form (the exact inverse of toString()).
2. Map boolean[] with a real SQL array type: @JdbcTypeCode(SqlTypes.BOOLEAN_ARRAY) on a supporting database.
3. Transform legacy rows before reading: wrap the value in braces.

Example fix

// before
UPDATE flags SET vals = 'true,false'; -- row read later throws IllegalArgumentException

// after
UPDATE flags SET vals = '{true,false}';

// mapping alternative
@JdbcTypeCode(SqlTypes.BOOLEAN_ARRAY)
private boolean[] vals;

static boolean isArrayLiteral(CharSequence s) {
    return s != null && s.length() >= 2 && s.charAt(0) == '{' && s.charAt(s.length() - 1) == '}';
}
// before assignment: if (!isArrayLiteral(value)) value = '{' + value + '}';

When it happens

Trigger: Reading a boolean[] attribute from a String-typed column whose content is a plain comma list like 'true,false'; native queries returning array text without braces; a boolean[] field mapped with @JdbcTypeCode(SqlTypes.VARCHAR) or read from a cache value not produced by toString().

Common situations: Hand-written column values or seed data; ETL inserting list strings; mapping boolean[] against an incompatible JdbcType after a mapping refactor.

Related errors

• Unexpected PostgreSQL lock_timeout format: {}
• Could not find root
• Cannot parse given string into array of strings. First and l
• Cannot parse given string into array of strings. Outside of
• The string is not a valid string representation of a binary

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/cbec2edacbe14604. Report an issue: GitHub.