A Minimalist HTTP Client: One‑Line Requests with OKHttpUtil

OKHttpUtil is a thin wrapper around Square's OkHttp that provides a lightweight, single‑line API for HTTP communication in Java.

Features

Automatically selects HTTP or HTTPS based on the URL.

Cookie handling is enabled by default, allowing session simulation after a login request.

Detects 304 redirects and follows them automatically.

Supports proxy configuration.

Customizable Referer and User‑Agent headers.

Automatically decompresses Gzip‑encoded responses.

Provides a Spring Boot starter for configuration via properties.

Minimal and intuitive API surface.

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

Basic Usage

GET Request

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

POST Request

# JSON body
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 body
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 and 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", "WXyUseb-...");
Response response = HttpUtil.upload("https://upload.qiniup.com/", formParams);
System.out.println(response);

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

Chainable Requests with HttpRequest

# GET with query and header
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 with chain
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);

Spring Boot Integration

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

Configuration properties are bound to a HttpConfig class, for example:

public class HttpConfig {
    /** Log level */
    private HttpLoggingInterceptor.Level loggLevel = HttpLoggingInterceptor.Level.BODY;
    /** Read timeout (seconds) */
    private long readTimeout = 30;
    /** Connect timeout (seconds) */
    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;
    }
}

Rapid External API Wrappers

OKHttpUtil can be used to build thin client wrappers for third‑party services. The following example shows a base EbayClient that configures common headers and a concrete EbayInventoryClient that implements an inventoryItem method.

public class EbayClient extends ApiJsonClient {
    public EbayClient(Long storeId) {
        // TODO fetch store configuration
        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"));
    }
}

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 client = new EbayInventoryClient(1L);
JSONObject json = client.inventoryItem(0, 10);

A similar EbayOrderClient can be created for order‑related endpoints.

Source Code

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