okhttp的使用介紹

轉載請以鏈接形式標明出處：
本文出自:103style的博客

---

目錄

• 簡介
• 分支介紹
• 使用示例
• 混淆配置

---

簡介

• github地址
• 官方介紹

okhttp 的優勢：

• 採用連接池技術減少
• 默認使用 GZIP 數據壓縮格式，降低傳輸內容的大小
• 採用緩存避免重複的網絡請求
• 支持 SPDY、HTTP/2.0，對於同一主機的請求可共享同一 socket 連接
• 若 SPDY 或 HTTP/2.0 不可用，還會採用連接池提高連接效率
• 網絡出現問題、會自動重連（嘗試連接同一主機的多個ip地址）
• 使用 okio 庫簡化數據的訪問和存儲

---

分支介紹

目前 okhttp 主要有三個分支：

• 4.2.0：要求 Android 5.0+ (API level 21+) and on Java 8+。
  • 源碼是用kotlin寫的。
  • 支持 TLS 1.3。

  implementation("com.squareup.okhttp3:okhttp:4.2.0")
  

• 3.14.2：要求 Android 5.0+ (API level 21+) and on Java 8+。
  • 功能同 4.2.0 版本，區別是源碼是用java寫的。

  implementation("com.squareup.okhttp3:okhttp:3.14.2")
  

• 3.12.0：Android 2.3+ (API level 9+) and Java 7+.
  • 源碼是用java寫的。
  • 不支持 TLS 1.2 ，計劃在 2020年12月31日 前提供關鍵修復。

  implementation("com.squareup.okhttp3:okhttp:3.12.0")
  

---

使用示例

初始化 OkHttpClient 和 ThreadPoolExecutor：

private OkHttpClient client = new OkHttpClient.Builder()
        .build();

private ThreadPoolExecutor service = new ThreadPoolExecutor(0, Integer.MAX_VALUE,
        60L, TimeUnit.SECONDS,
        new SynchronousQueue<>(),
        r -> {
            Thread thread = new Thread(r);
            thread.setName(MainActivity.this.getPackageName());
            return thread;
        });

• 同步請求示例：

  private void runSync() {
      service.execute(() -> {
          try {
              Request request = new Request.Builder()
                      .url("https://publicobject.com/helloworld.txt")
                      .build();
  
              try (Response response = client.newCall(request).execute()) {
                  if (response.body() == null) {
                      return;
                  }
                  InputStream is = response.body().source().inputStream();
                  int r;
                  while ((r = is.read()) != -1) {
                      System.out.print((char) r);
                  }
                  System.out.println();
              }
          } catch (IOException e) {
              e.printStackTrace();
          }
      });
  }
  

• 異步請求示例：

  private void runAsync() {
      Request request = new Request.Builder()
              .url("https://publicobject.com/helloworld.txt")
              .build();
  
      client.newCall(request).enqueue(new Callback() {
          @Override
          public void onFailure(Call call, IOException e) {
              System.out.println(e.getMessage());
          }
  
          @Override
          public void onResponse(Call call, Response response) throws IOException {
              if (response.body() == null) {
                  System.out.println("response.body() is null");
                  return;
              }
              InputStream is = response.body().source().inputStream();
              int r;
              while ((r = is.read()) != -1) {
                  System.out.print((char) r);
              }
              System.out.println();
          }
      });
  }
  

• post請求示例：

  private void post(String url, String json) throws Exception {
      MediaType JSON = MediaType.get("application/json; charset=utf-8");
  
      RequestBody body = RequestBody.create(JSON, json);
      Request request = new Request.Builder()
              .url(url)
              .post(body)
              .build();
      Response response = client.newCall(request).execute();
      if (response.body() != null) {
          System.out.println(response.body().string());
      }
  }
  

• 取消請求示例：

  ScheduledThreadPoolExecutor service = new ScheduledThreadPoolExecutor(1,
          r -> {
              Thread thread = new Thread(r);
              thread.setName(MainActivity.this.getPackageName());
              return thread;
          });
  
  public void run() {
      Request request = new Request.Builder()
              .url("http://httpbin.org/delay/2")
              .build();
  
      final long startNanos = System.nanoTime();
      final Call call = client.newCall(request);
  
      // Schedule a job to cancel the call in 1 second.
      service.schedule(() -> {
          System.out.printf("%.2f Canceling call.%n", (System.nanoTime() - startNanos) / 1e9f);
          call.cancel();
          System.out.printf("%.2f Canceled call.%n", (System.nanoTime() - startNanos) / 1e9f);
      }, 1, TimeUnit.SECONDS);
  
      System.out.printf("%.2f Executing call.%n", (System.nanoTime() - startNanos) / 1e9f);
      service.execute(() -> {
          try (Response response = call.execute()) {
              System.out.printf("%.2f Call was expected to fail, but completed: %s%n",
                      (System.nanoTime() - startNanos) / 1e9f, response);
          } catch (IOException e) {
              System.out.printf("%.2f Call failed as expected: %s%n",
                      (System.nanoTime() - startNanos) / 1e9f, e);
          }
      });
  
  }
  

• 其他使用方式

  • 修改Headers
  • 上傳文件
  • 設置響應緩存
  • 更多使用方式

---

混淆配置

# JSR 305 annotations are for embedding nullability information.
-dontwarn javax.annotation.**

# A resource is loaded with a relative path so the package of this class must be preserved.
-keepnames class okhttp3.internal.publicsuffix.PublicSuffixDatabase

# Animal Sniffer compileOnly dependency to ensure APIs are compatible with older versions of Java.
# okio
-dontwarn org.codehaus.mojo.animal_sniffer.*

# OkHttp platform used only on JVM and when Conscrypt dependency is available.
-dontwarn okhttp3.internal.platform.ConscryptPlatform

---

以上