SpringBoot 集成 okhttp3

前言

为什么要用 okhttp3 ？

因为：OkHttpClient 绝对线程安全，而且 JVM 全局共享一个 OkHttpClient ，性能更好～

SpringBoot 集成 okhttp3

Maven 导入 jar 包，具体版本根据自己需求来，在此只是举例：

<dependency>
  <groupId>com.squareup.okhttp3</groupId>
  <artifactId>okhttp</artifactId>
  <version>4.0.0-RC1</version>
</dependency>

配置代码如下：

import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.concurrent.TimeUnit;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import okhttp3.ConnectionPool;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class OkHttp3Configuration {

  @Bean
  public OkHttpClient okHttpClient() {
    return new OkHttpClient.Builder()
        .readTimeout(60, TimeUnit.SECONDS)
        .connectTimeout(60, TimeUnit.SECONDS)
        .writeTimeout(120, TimeUnit.SECONDS)
        .connectionPool(new ConnectionPool(200, 5, TimeUnit.MINUTES))
        .retryOnConnectionFailure(false)
        .sslSocketFactory(sslSocketFactory(), x509TrustManager())
        .addInterceptor(chain -> {
          Request originalRequest = chain.request();
          Request requestWithUserAgent = originalRequest.newBuilder()
              .header("test", "test")
              .build();
          return chain.proceed(requestWithUserAgent);
        }).build();
  }

  @Bean
  public X509TrustManager x509TrustManager() {
    return new X509TrustManager() {
      @Override
      public void checkClientTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
      }

      @Override
      public void checkServerTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
      }

      @Override
      public X509Certificate[] getAcceptedIssuers() {
        return new X509Certificate[0];
      }
    };
  }

  @Bean
  public SSLSocketFactory sslSocketFactory() {
    try {
      //信任任何链接
      SSLContext sslContext = SSLContext.getInstance("TLS");
      sslContext.init(null, new TrustManager[]{x509TrustManager()}, new SecureRandom());
      return sslContext.getSocketFactory();
    } catch (NoSuchAlgorithmException e) {
      e.printStackTrace();
    } catch (KeyManagementException e) {
      e.printStackTrace();
    }
    return null;
  }

}

常规操作

Get
Post
Put
Delete

Request request = new Request.Builder().url(url).get().build();
Request request = new Request.Builder().url(url).method("GET", null).build();
Request request = new Request.Builder().url(url).post().build();
Request request = new Request.Builder().url(url).put().build();
Request request = new Request.Builder().url(url).delete().build();

Map<String, String> headerMap = Maps.newHashMap();
headerMap.put("Content-Type","application/json");
Headers header = Headers.of(headerMap);
Request request = new Request.Builder().headers(header).url(url).get().build();

FormBody

RequestBody formBody = new FormBody.Builder()
        .add("test1", "1")
        .add("test2", "2")
        .build();
Request request = new Request.Builder().url(url).post(formBody).build();

发送 JSON 数据

RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), jsonParams);
Request request = new Request.Builder().url(url).post(requestBody).build();

发送 XML 数据

RequestBody requestBody = RequestBody.create(MediaType.parse("application/xml; charset=utf-8"), xml);
Request request = new Request.Builder().url(url).post(requestBody).build();

同步请求

Request request = new Request.Builder().url("http://www.baidu.com").get().build();
try (Response response = client.newCall(request).execute()) {
  log.info("{}", response.body().string());
}

异步请求

Request request = new Request.Builder().url("http://blog.sonicshield.cn").get().build();
Call call = okHttpClient.newCall(request);
call.enqueue(new Callback() {
  @Override
  public void onFailure(Call call, IOException e) {
    log.info("{}", e.getMessage());
  }
  
  @Override
  public void onResponse(Call call, Response response) throws IOException {
    if (response.isSuccessful()) {
      log.info("{}", response.body().string());
    }
  }
});

扩展阅读

Call

Call 是一个接口，定义了各种 Http 连接请求的方法

public interface Call extends Cloneable {
  Request request();

  Response execute() throws IOException;

  void enqueue(Callback var1);

  void cancel();

  boolean isExecuted();

  boolean isCanceled();

  Call clone();

  public interface Factory {
    Call newCall(Request var1);
  }
}

通过 request() 方法获取自己的请求体，调用 enqueue 发起异步请求，调用 execute 发起同步请求。

RealCall

RealCall 则是 Call 的实现类，其中实现了 execute 和 enqueue 等方法。而在 RealCall 的 execute 和 enqueue 方法中都调用到了 dispatcher.enqueue / execute

同步方法 RealCall.execute

  public Response execute() throws IOException {
    synchronized(this) {
      if (this.executed) {
        throw new IllegalStateException("Already Executed");
      }

      this.executed = true;
    }

    this.captureCallStackTrace();

    Response var2;
    try {
      this.client.dispatcher().executed(this);
      Response result = this.getResponseWithInterceptorChain();
      if (result == null) {
        throw new IOException("Canceled");
      }

      var2 = result;
    } finally {
      this.client.dispatcher().finished(this);
    }

    return var2;
  }

检查这个 call 是否已经被执行了，每个 call 只能被执行一次
实际执行代码 client.dispatcher().executed(this)，dispatcher（调度器，里面包含了线程池和三个队列（readyAsyncCalls：保存等待执行的异步请求）
调用 getResponseWithInterceptorChain() 函数获取 HTTP 返回结果，从函数名可以看出，这一步还会进行一系列 “拦截” 操作，可以配置拦截器
最后还要通知 dispatcher 已经执行完毕

实际真正发出网络请求，解析返回结果的是 getResponseWithInterceptorChain

异步方法 RealCall.enqueue

  public void enqueue(Callback responseCallback) {
    synchronized(this) {
      if (this.executed) {
        throw new IllegalStateException("Already Executed");
      }

      this.executed = true;
    }

    this.captureCallStackTrace();
    this.client.dispatcher().enqueue(new RealCall.AsyncCall(responseCallback));
  }

查看代码 this.client.dispatcher().enqueue(new RealCall.AsyncCall(responseCallback)); 实际是通过 AsyncCall 来实现异步

  final class AsyncCall extends NamedRunnable {
    private final Callback responseCallback;

    AsyncCall(Callback responseCallback) {
      super("OkHttp %s", new Object[]{RealCall.this.redactedUrl()});
      this.responseCallback = responseCallback;
    }

    String host() {
      return RealCall.this.originalRequest.url().host();
    }

    Request request() {
      return RealCall.this.originalRequest;
    }

    RealCall get() {
      return RealCall.this;
    }

    protected void execute() {
      boolean signalledCallback = false;

      try {
        Response response = RealCall.this.getResponseWithInterceptorChain();
        if (RealCall.this.retryAndFollowUpInterceptor.isCanceled()) {
          signalledCallback = true;
          this.responseCallback.onFailure(RealCall.this, new IOException("Canceled"));
        } else {
          signalledCallback = true;
          this.responseCallback.onResponse(RealCall.this, response);
        }
      } catch (IOException var6) {
        if (signalledCallback) {
          Platform.get().log(4, "Callback failure for " + RealCall.this.toLoggableString(), var6);
        } else {
          this.responseCallback.onFailure(RealCall.this, var6);
        }
      } finally {
        RealCall.this.client.dispatcher().finished(this);
      }

    }
  }

AsyncCall 继承于 NamedRunnable ，而 NamaedRunnable 则实现了 Runnable 方法
AsyncCall 在线程池中，执行 run 方法 -> execute 方法
NamedRunnable 提供了一个抽象方法 execute，需要 AsyncCall 实现，并会放在 run 方法中执行

getResponseWithInterceptorChain

  Response getResponseWithInterceptorChain() throws IOException {
    List<Interceptor> interceptors = new ArrayList();
    interceptors.addAll(this.client.interceptors());
    // add 重定向拦截器
    interceptors.add(this.retryAndFollowUpInterceptor);
    // add 桥接拦截器
    interceptors.add(new BridgeInterceptor(this.client.cookieJar()));
    // add 缓存拦截器
    interceptors.add(new CacheInterceptor(this.client.internalCache()));
    // add 链接拦截器
    interceptors.add(new ConnectInterceptor(this.client));
    if (!this.forWebSocket) {
      interceptors.addAll(this.client.networkInterceptors());
    }
    // add 读写拦截器(请求服务器拦截器)
    interceptors.add(new CallServerInterceptor(this.forWebSocket));
    Chain chain = new RealInterceptorChain(interceptors, (StreamAllocation)null, (HttpCodec)null, (RealConnection)null, 0, this.originalRequest);
    // 执行链表拦截
    return chain.proceed(this.originalRequest);
  }

代码中添加了各种 interceptor ，并赋给了 RealInterceptorChain (拦截器链表)
拦截器链表最终执行 RealInterceptorChain.proceed() 方法，去做一系列的网络拦截操作，最终获取到网络数据

最后修改于 2019-06-12

前言

SpringBoot 集成 okhttp3

常规操作

自定义 Header

FormBody

发送 JSON 数据

发送 XML 数据

同步请求

异步请求

扩展阅读

Call

RealCall

getResponseWithInterceptorChain