Understanding the ClassCastException in (String[])List.toArray()
The code snippet you provided raises a ClassCastException when attempting to cast an ArrayList of Strings to a String array. This occurs because the toArray() method in Java returns an Object[] array, which is not compatible with a String[] array.
To overcome this issue, you need to specify the type of array you want to create when using toArray(). The correct method to use in this case is toArray(new String[v2.size()]). This method allocates a String[] array of the appropriate size and assigns the elements from the ArrayList to it.
For example:
<code class="java">final String[] v1 = i18nCategory.translation.get(id); final ArrayList<String> v2 = new ArrayList<>(Arrays.asList(v1)); String[] v3 = (String[])v2.toArray(new String[v2.size()]);</code>
In this updated code, we explicitly specify that we want a String array to be created, ensuring that the casting operation succeeds without any ClassCastException.
The above is the detailed content of Here are a few English question-based titles that fit your provided text: * Why Does `List.toArray()` Throw a `ClassCastException` When Casting to `String[]`? * How to Safely Convert an `ArrayList`. For more information, please follow other related articles on the PHP Chinese website!