Introduction to Java Basics to Practical Applications: High-Performance Practical Skills

Java is known for its high performance. The execution speed can be significantly improved by using the following techniques: Select efficient data structures (such as HashMap) Optimize memory management (use object pool) Make full use of multi-threads (Thread and ExecutorService) Optimization algorithms (such as Use quick sort) to reduce I/O operations (load data in batches)

Java Basics to Practical Applications: High-Performance Practical Skills

Preface

Java is known for its high performance, and the correct use of techniques can significantly increase the speed of code execution. This article will introduce some high-performance techniques and demonstrate them through practical cases.

1. Use efficient data structures

Choosing the right data structure is critical to code performance. For example, for frequent lookup operations, use a HashMap over an ArrayList.

2. Optimize memory management

Improper memory management can cause applications to slow down. Using an object pool can reduce the number of objects created and destroyed, thereby improving performance.

3. Make full use of multi-threading

Multiple threads can execute tasks in parallel, thus improving overall performance. Java provides several multi-threading mechanisms such as Thread and ExecutorService.

4. Optimization algorithm

The choice of algorithm can greatly affect code performance. For large data sets, it is more efficient to use a sorting algorithm such as quick sort instead of bubble sort.

5. Reduce I/O operations

I/O operations are often time-consuming. Reduce the number of these operations as much as possible, such as loading data into memory in batches instead of reading them one by one.

Practical case

Scenario: Large data set sorting

There are 1 million integers that need to be sorted. Using bubble sort will be very time consuming. We can use the quick sort algorithm:

// 输入：未排序整数数组
int[] nums = {5, 3, 1, 2, 4};

// 调用快速排序
Arrays.sort(nums);

// 输出：排序后数组
for (int num : nums) {
  System.out.println(num);
}

Using the quick sort algorithm, the sorting time complexity is O(n log n), which is much faster than the O(n²) of bubble sort.

Conclusion

By applying these high-performance tips, you can increase the speed at which your Java code executes, thereby enhancing the overall performance of your application.

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