Java Program to Convert Integer List to Integer Array
There are many ways to convert integer List to ArrayList where in this article we will be discussing out 2 approaches as below:
- Using concept od streams in Java8
- Using Apache Commons Lang
- Using Guava Library
Method 1: Using concept od streams in Java8
So, first, we will get to know about how to convert integer list to array list using java 8. In java 8 there is a stream provided for converting a list of integer to an integer array.
- Convert List<Integer> to Stream<Integer> using List.stream() —> Here List is calling stream() method.
- Now we convert Stream<Integer> to int.
Method 2: Using Apache Commons Lang
Apache Commons Lang’s ArrayUtils class provides toPrimitive() method that can convert an Integer array to primitive ints. We need to convert a list of integers to an Integer array first. We can use List.toArray() for easy conversion.
- Use toPrimtive() method of Apache Common Lang’s
- Use List.toArray() method
Method 3: Using Guava Library
Guava library is an open-source decentralized software development model which is a set of common libraries of java providing utility methods for collections, caching, primitives support, concurrency, string processing, and validations. Here we will be glancing at string processing in the guava library by converting integer list to integer array. It is depicted in below example as follows:
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