웹 사이트 액세스 속도를 높이기 위해 Java 코드를 최적화하는 방법은 무엇입니까?

List<String> list = new ArrayList<>();
list.add("item1");
list.add("item2");
list.add("item3");

// 使用ArrayList的get方法获取元素
String item = list.get(1);

Map<String, Integer> map = new HashMap<>();
map.put("key1", 1);
map.put("key2", 2);
map.put("key3", 3);

// 使用HashMap的get方法获取键值对
int value = map.get("key2");

// 使用Ehcache进行缓存
CacheManager cacheManager = CacheManagerBuilder.newCacheManagerBuilder().build();
cacheManager.init();

Cache<String, List<String>> cache = cacheManager.createCache("myCache",
        CacheConfigurationBuilder.newCacheConfigurationBuilder(String.class, List.class, ResourcePoolsBuilder.heap(10)));

// 向缓存中存入数据
List<String> data = getDataFromDatabase();
cache.put("data", data);

// 从缓存中读取数据
List<String> cachedData = cache.get("data");

// 使用StringBuilder而不是String拼接字符串
StringBuilder sb = new StringBuilder();
sb.append("Hello");
sb.append("World");

String result = sb.toString();

// 使用对象池重复利用对象
ObjectPool<StringBuilder> pool = new GenericObjectPool<>(new StringBuilderFactory());
StringBuilder sb = pool.borrowObject();
sb.append("Hello");
sb.append("World");
String result = sb.toString();
pool.returnObject(sb);

ExecutorService executorService = Executors.newFixedThreadPool(10);
List<Future<String>> futures = new ArrayList<>();

for (int i = 0; i < 10; i++) {
    Callable<String> task = new MyTask();
    Future<String> future = executorService.submit(task);
    futures.add(future);
}

// 获取线程执行结果
for (Future<String> future : futures) {
    String result = future.get();
    System.out.println(result);
}

// 关闭线程池
executorService.shutdown();

// 使用快速排序对数组进行排序
int[] array = {6, 2, 8, 1, 4, 9};
Arrays.sort(array);

// 使用BufferedReader读取大文件
try(BufferedReader reader = new BufferedReader(new FileReader("largefile.txt"))) {
    String line;
    while ((line = reader.readLine()) != null) {
        // 处理每一行数据
    }
} catch (IOException e) {
    e.printStackTrace();
}