Mastering OKHttpUtil: Simplify Java HTTP Requests with Ready‑to‑Use Code

OKHttpUtil Features

Automatically determines HTTP or HTTPS based on the URL.

Cookies are recorded by default, enabling simulated login sessions.

Automatically handles 304 redirects and retries.

Supports proxy configuration.

Supports referer configuration.

Supports User-Agent configuration.

Automatically decompresses GZIP responses.

Supports Spring Boot configuration files.

Provides a minimalistic wrapper for easy invocation.

OKHttpUtil Usage

Maven Dependency

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

Latest version can be found at: https://search.maven.org/artifact/io.github.admin4j/http

GET Request

The simplest GET request uses the HttpUtil class:

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

POST Request

A one‑line POST request with JSON body:

Response post = HttpUtil.post(
    "https://oapi.dingtalk.com/robot/send?access_token=YOUR_TOKEN",
    "{\"msgtype\": \"text\",\"text\": {\"content\":\"【Feedback】Sample message\"}}");
System.out.println("post = " + post);

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 Response Helper

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

File 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", "YOUR_TOKEN");
Response response = HttpUtil.upload("https://upload.qiniup.com/", formParams);
System.out.println(response);

File Download

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

Chained Requests with HttpRequest

# GET example
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);

# POST form example
Response response = HttpRequest.get("http://192.168.1.13:9100/auth/login")
    .queryMap("q", "admin4j")
    .header(HttpHeaderKey.USER_AGENT, "admin4j")
    .form("username", "admin")
    .form("password", "admin123")
    .execute();
System.out.println("response = " + response);

Using OKHttpUtil in Spring Boot

Maven Dependency

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

Spring Boot allows personalized OKHttp configuration via a configuration class:

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;

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

Quickly Wrapping External APIs

Example: wrapping eBay APIs with a custom client.

public class EbayClient extends ApiJsonClient {
    public EbayClient(Long storeId) {
        // TODO fetch store configuration
        basePath = "https://api.ebay.com";
        defaultHeaderMap.put("Authorization", "Bearer " + config.get("accessToken"));
        defaultHeaderMap.put("X-EBAY-C-MARKETPLACE-ID", config.get("marketplaceId"));
    }
}

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);
    }
}

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

Similarly, an EbayOrderClient can be created to fetch order lists using appropriate query parameters.