One‑Line HTTP Requests with OKHttpUtil: A Minimal Java Wrapper

OKHttpUtil Overview

OKHttpUtil is a thin wrapper around Square's OkHttp library that simplifies HTTP requests for Java, Kotlin, Android, and server‑side use.

Features

Automatically selects HTTP or HTTPS based on the URL.

Cookies are recorded by default, enabling session‑preserving calls such as login.

Automatically handles 304 redirects and retries.

Supports proxy configuration.

Supports referer configuration.

Supports User‑Agent configuration.

Detects and decompresses Gzip responses.

Integrates with Spring Boot configuration files.

Provides a minimal API for one‑line calls.

Maven Dependency

<dependency>
    <groupId>io.github.admin4j</groupId>
    <artifactId>http</artifactId>
    <version>0.4.0</version>
</dependency>

Basic GET and POST

GET example:

Response response = HttpUtil.get("https://github.com/search", Pair.of("q", "okhttp"));
System.out.println("response = " + response);

POST JSON example:

Response post = HttpUtil.post("https://oapi.dingtalk.com/robot/send?access_token=...", {"msgtype": "text", "text": {"content": "[Feedback] I am unique"}});
System.out.println("post = " + post);

Form POST example:

Map<String, Object> formParams = new HashMap<>(16);
formParams.put("username", "admin");
formParams.put("password", "admin123");
Response response = HttpUtil.postForm("http://192.168.1.13:9100/auth/login", formParams);
System.out.println("response = " + response);

JSON Helper

When the response is JSON, HttpJsonUtil can directly return a JSONObject:

JSONObject object = HttpJsonUtil.get("https://github.com/search", Pair.of("q", "http"), Pair.of("username", "agonie201218"));
System.out.println("object = " + object);

File Upload / Download

Upload:

File file = new File("C:\\Users\\andanyang\\Downloads\\Sql.txt");
Map<String, Object> formParams = new HashMap<>();
formParams.put("key", "test");
formParams.put("file", file);
formParams.put("token", "...");
Response response = HttpUtil.upload("https://upload.qiniup.com/", formParams);
System.out.println(response);

Download:

HttpUtil.down("https://gitee.com/admin4j/common-http", "path/");

Fluent HttpRequest

Response response = HttpRequest.get("https://search.gitee.com/?skin=rec&type=repository")
    .queryMap("q", "admin4j")
    .header(HttpHeaderKey.USER_AGENT, "admin4j")
    .execute();
System.out.println("response = " + response);

Spring Boot Integration

Maven starter dependency:

<dependency>
    <groupId>io.github.admin4j</groupId>
    <artifactId>common-http-starter</artifactId>
    <version>0.4.0</version>
</dependency>

Configuration class example (log level, timeouts, connection pool, proxy, cookie handling):

public class HttpConfig {
    private HttpLoggingInterceptor.Level loggLevel = HttpLoggingInterceptor.Level.BODY;
    private long readTimeout = 30;
    private long connectTimeout = 30;
    private boolean followRedirects = false;
    private int maxIdleConnections = 5;
    private long keepAliveDuration = 5;
    private String userAgent = "OKHTTP";
    private boolean cookie = false;
    private ProxyConfig proxy;
    // getters/setters omitted
}

public static class ProxyConfig {
    private Proxy.Type type = Proxy.Type.HTTP;
    private String host;
    private Integer port = 80;
    private String userName;
    private String password;
}

Wrapping External APIs – eBay Example

Base client sets common headers and base URL:

public class EbayClient extends ApiJsonClient {
    public EbayClient(Long storeId) {
        Map<String, String> config = new HashMap<>();
        basePath = "https://api.ebay.com";
        defaultHeaderMap.put("Authorization", "Bearer " + config.get("accessToken"));
        defaultHeaderMap.put("X-EBAY-C-MARKETPLACE-ID", config.get("marketplaceId"));
    }
}

Inventory client adds a method to fetch items:

public class EbayInventoryClient extends EbayClient {
    public EbayInventoryClient(Long storeId) { super(storeId); }
    public JSONObject inventoryItem(Integer limit, Integer offset) throws IOException {
        Map<String, Object> queryMap = new HashMap<>(2);
        queryMap.put("limit", limit);
        queryMap.put("offset", offset);
        return get("/sell/inventory/v1/inventory_item", queryMap);
    }
}

Order client builds a filter string and query map:

public class EbayOrderClient extends EbayClient {
    public EbayOrderClient(Long storeId) { super(storeId); }
    public JSONObject orders(String beginTime, String endTime, int limit, int offset) {
        String filter = MessageFormat.format("lastmodifieddate:[{0}..{1}]", beginTime, endTime);
        Map<String, Object> queryMap = new HashMap<>(8);
        queryMap.put("filter", filter);
        queryMap.put("limit", limit);
        queryMap.put("offset", offset);
        return get("/sell/inventory/v1/inventory_item", queryMap);
    }
}

Usage example:

EbayInventoryClient ebayInventoryClient = new EbayInventoryClient(1L);
JSONObject jsonObject = ebayInventoryClient.inventoryItem(0, 10);

Source Code

Repository: https://github.com/admin4j/common-http