Optimize the collection operation in the Java class library with the Fastutil framework
Optimize the collection operation in the Java class library with the Fastutil framework
Summary:
In most Java applications, collection operations are very common and frequent operations.However, the set class (such as ArrayList and HashMap) provided in the Java standard library may become a performance bottleneck in some cases.To solve this problem, we can use the Fastutil framework to optimize the performance of the collection operation.This article will introduce the Fastutil framework and provide some example code to demonstrate how to use the framework to improve the performance of the Java collection operation.
1. Fastutil framework
FastUTIL is an open source Java class library, which aims to provide high -performance collection classes. It expands the set class in the Java standard library and optimizes performance.The design and implementation of the FastUTIL collection class considers memory use efficiency and operating efficiency, and provides some additional functions.
2. The advantage of the FastUtil collection class
Compared with the set class in the Java standard library, the FastUtil set class has the following advantages:
-The higher performance: The Fastutil set class is optimized in terms of memory use and operating efficiency, and it can provide faster access and operation speed in most cases.
-Lonal memory occupation: Fastutil collection class usually occupies less memory than the collection classes in the Java standard library.
-In support more original types: FastUSTIL collection class provides a collection implementation support for the original type (int, long, etc.), which can reduce the overhead caused by automatic boxing operations.
-Super with more functions: Fastutil collection classes support some additional functions, such as fast iteration, sorting and search.
3. Example of the use of Fastutil framework
Below we will demonstrate how to use the Fastutil framework to optimize the performance of the Java collection operation.
Example 1: Use Fastutil's IntarrayList class to replace the ArrayList class
By using FastUtil's IntarrayList class, we can avoid boxing operations and reduce memory consumption.
import it.unimi.dsi.fastutil.ints.IntArrayList;
public class FastutilExample {
public static void main(String[] args) {
IntArrayList list = new IntArrayList();
// Add elements
list.add(1);
list.add(2);
list.add(3);
// Traversing elements
for (int i : list) {
System.out.println(i);
}
}
}
Example 2: Use Fastutil's int2InTopenhashMap class to replace the HashMap class
By using FastUtil's IntopopenhashMap class, we can avoid boxing operations and improve the performance of HashMap.
import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
public class FastutilExample {
public static void main(String[] args) {
Int2IntOpenHashMap map = new Int2IntOpenHashMap();
// Add key value pair
map.put(1, 10);
map.put(2, 20);
map.put(3, 30);
// Get the value
int value = map.get(2);
System.out.println(value);
}
}
4. Summary
By using the Fastutil framework, we can optimize the performance of the collection operation in the Java class library.It provides high -performance and memory efficiency collection classes and supports more functions.When performing large -scale set operations, considering using the FastUtil framework can improve the performance and efficiency of the program.
