apache/flink · error · UTFDataFormatException

malformed input: partial character at end

Error message

malformed input: partial character at end

What it means

Error "malformed input: partial character at end" thrown in apache/flink.

Source

Thrown at flink-core/src/main/java/org/apache/flink/types/Record.java:1495

                switch (c >> 4) {
                    case 0:
                    case 1:
                    case 2:
                    case 3:
                    case 4:
                    case 5:
                    case 6:
                    case 7:
                        /* 0xxxxxxx */
                        count++;
                        chararr[chararr_count++] = (char) c;
                        break;
                    case 12:
                    case 13:
                        /* 110x xxxx 10xx xxxx */
                        count += 2;
                        if (count > utflen) {
                            throw new UTFDataFormatException(
                                    "malformed input: partial character at end");
                        }
                        char2 = (int) bytearr[count - 1];
                        if ((char2 & 0xC0) != 0x80) {
                            throw new UTFDataFormatException(
                                    "malformed input around byte " + count);
                        }
                        chararr[chararr_count++] = (char) (((c & 0x1F) << 6) | (char2 & 0x3F));
                        break;
                    case 14:
                        /* 1110 xxxx 10xx xxxx 10xx xxxx */
                        count += 3;
                        if (count > utflen) {
                            throw new UTFDataFormatException(
                                    "malformed input: partial character at end");
                        }
                        char2 = (int) bytearr[count - 2];
                        char3 = (int) bytearr[count - 1];

View on GitHub (pinned to 2f3c205e92)

Solutions

1. Address the cause reported by the error message: malformed input: partial character at end
2. Verify the inputs, configuration values, and classpath/dependency setup related to this operation, then retry.

Example fix

Correct the condition described ("malformed input: partial character at end") and rerun the job or command.

When it happens

Trigger: Triggered at runtime when the operation fails because: malformed input: partial character at end.

Common situations: Commonly caused by misconfiguration, missing dependencies or files, unsupported types or operations, or invalid user input leading to: malformed input: partial character at end.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/08e8244d9e0ae968. Report an issue: GitHub.