HTTP client lifetime (ARCH4083)

Key java.performance.http-client-lifetime · Severity error · Category performance

Creating a new HttpClient per call rebuilds the connection pool and accumulates sockets in TIME_WAIT. The client should be a shared singleton.

Incorrect

public String fetch(String url) throws Exception {
    HttpClient client = HttpClient.newHttpClient();
    return client.send(request(url), ofString()).body();
}

Correct

private static final HttpClient CLIENT = HttpClient.newHttpClient();

public String fetch(String url) throws Exception {
    return CLIENT.send(request(url), ofString()).body();
}

Fix

Hold a single HttpClient instance in a shared field and reuse it across all requests.