java runtime_error ai_generated true

java.lang.NegativeArraySizeException

ID: java/negative-array-size

Also available as: JSON · Markdown · 中文
87%Fix Rate
81%Confidence
1Evidence
2024-06-12First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
Java 8 active — — —
Java 11 active — — —
Java 17 active — — —
Java 21 active — — —

Root Cause

Thrown when an array is created with a negative size, usually due to an integer overflow or a bug in array size calculation.

generic

中文

当使用负数大小创建数组时抛出，通常是由于整数溢出或数组大小计算错误。

Official Documentation

https://docs.oracle.com/javase/8/docs/api/java/lang/NegativeArraySizeException.html

Workarounds

  1. 95% success Validate the array size before creation: `if (size < 0) throw new IllegalArgumentException("Size must be non-negative: " + size);`. 
    Validate the array size before creation: `if (size < 0) throw new IllegalArgumentException("Size must be non-negative: " + size);`.
  2. 90% success Use long arithmetic for size calculation to prevent integer overflow: `long safeSize = (long) a * b; if (safeSize > Integer.MAX_VALUE) throw new IllegalArgumentException("Size too large");`. 
    Use long arithmetic for size calculation to prevent integer overflow: `long safeSize = (long) a * b; if (safeSize > Integer.MAX_VALUE) throw new IllegalArgumentException("Size too large");`.
  3. 85% success Add a guard clause: `int size = computeSize(); if (size < 0) { size = 0; }` to handle edge cases gracefully. 
    Add a guard clause: `int size = computeSize(); if (size < 0) { size = 0; }` to handle edge cases gracefully.

中文步骤

  1. Validate the array size before creation: `if (size < 0) throw new IllegalArgumentException("Size must be non-negative: " + size);`.
  2. Use long arithmetic for size calculation to prevent integer overflow: `long safeSize = (long) a * b; if (safeSize > Integer.MAX_VALUE) throw new IllegalArgumentException("Size too large");`.
  3. Add a guard clause: `int size = computeSize(); if (size < 0) { size = 0; }` to handle edge cases gracefully.

Dead Ends

Common approaches that don't work:

  1. 95% fail

    The root cause (negative size) is not fixed; retrying will throw the same exception.

  2. 70% fail

    This masks the underlying bug and may lead to incorrect program behavior or data loss.

  3. 80% fail

    If the size is Integer.MIN_VALUE, Math.abs() returns a negative value due to overflow, still causing the exception.