didi/DoKit · error · IllegalArgumentException

input must be shorter than or equal to the number of spaces:

Error message

input must be shorter than or equal to the number of spaces: " + size

What it means

Thrown by DoKit's StringUtil.padLeft(input, size) when the input string is longer than the target padded length. padLeft prepends spaces until the string reaches exactly `size` characters; if the input already exceeds that length there is no valid way to pad it, so the method rejects the call with IllegalArgumentException.

Source

Thrown at Android/dokit/src/main/java/com/didichuxing/doraemonkit/kit/loginfo/util/StringUtil.java:23

import java.util.ArrayList;
import java.util.List;

/**
 * @author nolan
 */
public class StringUtil {

    /**
     * Pad the specified number of spaces to the input string to make it that length
     *
     * @param input
     * @param size
     * @return
     */
    public static String padLeft(String input, int size) {

        if (input.length() > size) {
            throw new IllegalArgumentException("input must be shorter than or equal to the number of spaces: " + size);
        }

        StringBuilder sb = new StringBuilder();
        for (int i = input.length(); i < size; i++) {
            sb.append(" ");
        }
        return sb.append(input).toString();
    }

    /**
     * same as the String.split(), except it doesn't use regexes, so it's faster.
     *
     * @param str       - the string to split up
     * @param delimiter the delimiter
     * @return the split string
     */
    public static String[] split(String str, String delimiter) {
        List<String> result = new ArrayList<>();

View on GitHub (pinned to 626827cddb)

Solutions

1. Truncate or verify the input before calling: if (input.length() > size) input = input.substring(0, size);
2. Reconsider whether a hard fail is desired — for display purposes a truncate-and-warn policy is usually friendlier than an exception
3. Pass a size that is always >= the maximum possible input length

Example fix

// before
String s = StringUtil.padLeft(longUrl, 8); // throws if longUrl > 8 chars

// after
String s = longUrl.length() > 8 ? longUrl.substring(0, 8) : StringUtil.padLeft(longUrl, 8);

if (input != null && input.length() <= size) { String s = StringUtil.padLeft(input, size); } else { /* truncate or reject */ }

When it happens

Trigger: Calling StringUtil.padLeft("hello", 3) or any variant where input.length() > size, e.g. while formatting log/network trace columns in the loginfo kit with a string longer than the configured column width.

Common situations: Fixed-width formatting of dynamic content (URLs, headers, tag strings) where the developer assumed the input would fit; column width configured smaller than the longest expected value.

Related errors

• maxStoredHeapDumps must be at least 1
• precision shouldn't be less than zero!
• byteSize shouldn't be less than zero!
• invalid shadow size
• Expected alternating header names and values

AI-assisted analysis of didi/DoKit@626827cddb (2026-08-14). Data as JSON: /api/errors/5de2eb8db8b22c8b. Report an issue: GitHub.