okhttp3简单使用

r囧r小猫 2023-09-30 10:46 21阅读 0赞

#### 文章目录 ####

*   *   *   *  一、简介
             *   *  1、特性
             *  二、导入依赖
             *  三、创建 get 请求
             *  四、创建 post 请求
             *  五、创建异步请求（MultipartBody 表单）
             *  六、FormBody 表单参数
             *  七、OkhttpConfig 配置类
             *  八、OkhttpUtil 工具类
             *  九、小结

##### 一、简介 #####

Square 公司开源的 OkHttp

okhttp 官网 [https://square.github.io/okhttp/][https_square.github.io_okhttp]

*  网络编程（含 UrlConnection 发送 HTTP 请求下载文件）：[https://blog.csdn.net/qq\_41538097/article/details/118722718][https_blog.csdn.net_qq_41538097_article_details_118722718]
 *  Apache HttpComponents 简单使用：[https://blog.csdn.net/qq\_41538097/article/details/123719298][https_blog.csdn.net_qq_41538097_article_details_123719298]
 *  RestTemplate简单使用：[https://blog.csdn.net/qq\_41538097/article/details/123560238][https_blog.csdn.net_qq_41538097_article_details_123560238]
 *  okhttp3简单使用：[https://blog.csdn.net/qq\_41538097/article/details/123677614][https_blog.csdn.net_qq_41538097_article_details_123677614]
 *  HttpURLConnection 简单使用：[https://blog.csdn.net/qq\_41538097/article/details/123697432][https_blog.csdn.net_qq_41538097_article_details_123697432]

###### 1、特性 ######

1）支持HTTP2，对一台机器的所有请求共享同一个socket连接（同域名下所有通信都在单个连接上完成，消除了因多个连接而带来的延时和内存消耗）。

2）内置连接池，支持连接复用，减少请求延迟

3）透明的GZIP压缩减少响应数据的大小

4）通过缓存避免重复请求

5）失败时自动重连，自动重定向

当网络出现问题的时候OkHttp依然坚守自己的职责，它会自动恢复一般的连接问题，如果你的服务有多个IP地址，当第一个IP请求失败时，OkHttp会交替尝试你配置的其他IP，OkHttp使用现代TLS技术(SNI, ALPN)初始化新的连接，当握手失败时会回退到TLS 1.0。

**使用**：OkHttp 是一个适用于 Android、Kotlin 和 Java 应用的 HTTP 和 HTTP/2 客户端，它的请求/响应 API 使用构造器模式 builders 来设计，它支持阻塞式的同步请求和带回调的异步请求。

如果你使用 OkHttpClient，你不用重写你的代码，okhttp-urlconnection 模块实现了 java.net.HttpURLConnection 中的API，okhttp-apache 模块实现了 HttpClient 中的API

<dependency>
        <groupId>com.squareup.okhttp3</groupId>
        <artifactId>okhttp</artifactId>
        <version>4.9.3</version>
    </dependency>

持续更新，和上面的同版本更新

<dependency>
        <groupId>com.squareup.okhttp3</groupId>
        <artifactId>okhttp-urlconnection</artifactId>
        <version>4.9.3</version>
    </dependency>

2016 停止更新

<dependency>
        <groupId>com.squareup.okhttp</groupId>
        <artifactId>okhttp-apache</artifactId>
        <version>2.7.5</version>
    </dependency>

##### 二、导入依赖 #####

<dependency>
                <groupId>com.squareup.okhttp3</groupId>
                <artifactId>okhttp</artifactId>
                <version>4.9.3</version>
            </dependency>

##### 三、创建 get 请求 #####

因为是测试，OkHttpClient 是新建的对象，所以不需要配置类，如果需要 bean 工厂可以添加配置类`步骤七`，工具类`步骤八`

@Test
        public void getUrlParams() throws IOException {
        
            OkHttpClient okHttpClient = new OkHttpClient.Builder().connectTimeout(60, TimeUnit.SECONDS)//设置连接超时时间
                    .readTimeout(60, TimeUnit.SECONDS)//设置读取超时时间
                    .build();
            String url = "http://127.0.0.1:8080/rest/get/url_path_params?name=admin&id=98";
            Request.Builder builder = new Request.Builder();
            Request request = builder.url(url).build();
            Response response = okHttpClient.newCall(request).execute();
            ResponseBody body = response.body();
            System.out.println(body.string());
        }

##### 四、创建 post 请求 #####

post 请求传递 json 数据 `Content-Type:application/json; charset=utf-8`

@PostMapping("/post/params_json_list")
        public JSONObject postParamsJsonList(@RequestBody List<Map<String, Object>> list) {
        
            JSONObject jsonObject = JSON.parseObject("{\"message\":\"SUCCESS\",\"code\":200,\"type\":\"okhttp3\"}");
            jsonObject.put("body", list);
            return jsonObject;
        }

RequestBody 封装 body 参数

@Test
        public void postParamsJson() throws IOException {
        
            OkHttpClient build = new OkHttpClient.Builder()
                    .connectTimeout(60, TimeUnit.SECONDS)
                    .readTimeout(60, TimeUnit.SECONDS).build();
            String json = "{\"name\": \"admin\",\"id\": 10}";
            String url = "http://127.0.0.1:8080/okhttp3/post/params_json";
            RequestBody requestBody = RequestBody.create(json, MediaType.parse("application/json; charset=utf-8"));
            Request request = new Request.Builder().post(requestBody).url(url).build();
            Response execute = build.newCall(request).execute();
            ResponseBody responseBody = execute.body();
            assert responseBody != null;
            log.info(responseBody.string());
        }

##### 五、创建异步请求（MultipartBody 表单） #####

form 表单上传表单（含文件）`Content-Type:multipart/form-data;`

@PostMapping("/post/params_from_async")
        public JSONObject postParamsFromAsync(@RequestParam("file") MultipartFile file, HttpServletRequest request) throws InterruptedException, IOException, ServletException {
        
            TimeUnit.SECONDS.sleep(30);
            JSONObject jsonObject;
            TreeMap<String, Object> treeMap = new TreeMap<>();
            Collection<Part> parts = request.getParts();
            parts.forEach((part) -> {
        
                if (part.getContentType() == null) {
        
                    treeMap.put(part.getName(), request.getParameter(part.getName()));
                }
            });
            String s = UUID.randomUUID().toString().replace("-", "").substring(0, 5) + Objects.requireNonNull(file.getOriginalFilename()).substring(file.getOriginalFilename().indexOf("."));
            try {
        
                file.transferTo(new File("I:\\spring\\spring-boot-aop-test\\file\\" + s));
                jsonObject = JSON.parseObject("{\"message\":\"文件下载成功\",\"code\":200,\"type\":\"okhttp3\"}");
                jsonObject.put("body", treeMap);
            } catch (IOException e) {
        
                e.printStackTrace();
                jsonObject = JSON.parseObject("{\"message\":\"文件下载失败\",\"code\":201,\"type\":\"okhttp3\"}");
            }
            return jsonObject;
        }

测试方法

@Test
        public void postParamsFromAsync() throws IOException {
        
            String url = "http://127.0.0.1:8080/okhttp3/post/params_from_async";
    
            File file = new File("C:\\Users\\Administrator\\Pictures\\图标\\influxdb-studio.png");
            RequestBody multipartBody = MultipartBody.create(file, MediaType.parse("image/png"));
    
            MultipartBody body = new MultipartBody.Builder()
                    .addFormDataPart("file", "influxdb.png", multipartBody)
                    .addFormDataPart("age", "18")
                    .build();
            Request request = new Request.Builder()
                    .post(body)
                    .url(url)
                    .addHeader("Connection", "keep-alive")
                    .build();
            okHttpClient.newCall(request).enqueue(new Callback() {
        
                @Override
                public void onFailure(@NotNull Call call, @NotNull IOException e) {
        
                    log.error("okhttp", "onFailure: " + e.getMessage());
                }
    
                @Override
                public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
        
                    log.info("okhttp", "onResponse: " + response.body().string());
                }
            });
        }

##### 六、FormBody 表单参数 #####

form 表单上传表单 `Content-Type:application/x-www-form-urlencoded`

@PostMapping("/post/params_from")
        public JSONObject postParamsFrom(HttpServletRequest request) throws InterruptedException, IOException, ServletException {
        
            JSONObject jsonObject;
            Map<String, Object> treeMap = new TreeMap<>();
            Map<String, String[]> parameterMap = request.getParameterMap();
            parameterMap.forEach((key, value) -> {
        
                if (value.length == 1) {
        
                    treeMap.put(key, value[0]);
                } else {
        
                    treeMap.put(key, value);
                }
            });
            jsonObject = JSON.parseObject("{\"message\":\"表单读取成功\",\"code\":200,\"type\":\"okhttp3\"}");
            if (treeMap.keySet().size() > 0) {
        
                jsonObject.put("body", treeMap);
            }
            return jsonObject;
        }

测试方法

@Autowired
        OkHttpClient okHttpClient;
        @Test
        public void postParamsFrom() throws IOException {
        
            String url = "http://127.0.0.1:8080/okhttp3/post/params_from";
            LinkedHashMap<String, String> linkedHashMap = new LinkedHashMap<>();
            linkedHashMap.put("password", "123456");
            linkedHashMap.put("address", "西安");
            FormBody.Builder builder = new FormBody.Builder();
            builder.add("name", "admin");
            linkedHashMap.forEach((key, value) -> {
        
                builder.add(key, value);
            });
            RequestBody formBody = builder.build();
    
            Request request = new Request.Builder()
                    .post(formBody)
                    .url(url)
                    .addHeader("Connection", "keep-alive")
                    .build();
            Response response = okHttpClient.newCall(request).execute();
            log.info(response.body().string());
        }

##### 七、OkhttpConfig 配置类 #####

详细配置参考 [https://www.freesion.com/article/3815946206/][https_www.freesion.com_article_3815946206]

@Configuration
    @Slf4j
    public class OkHttpConfig {
        
    
        @Bean
        public OkHttpClient okHttpClient() throws NoSuchAlgorithmException, KeyStoreException {
        
            // 详细配置可参考 https://www.freesion.com/article/3815946206/
            return new OkHttpClient.Builder()
                    .connectTimeout(60, TimeUnit.SECONDS)      //设置连接超时
                    .readTimeout(60, TimeUnit.SECONDS)         //设置读超时
                    .writeTimeout(60, TimeUnit.SECONDS)        //设置写超时
                    .retryOnConnectionFailure(true)                     //是否自动重连
                    // 设置https配置，此处忽略了所有证书
                    .sslSocketFactory(sslSocketFactory(), new EasyX509TrustManager(null))
                    // 验证服务器的证书域名。在https握手期间，如果 URL 的主机名和服务器的标识主机名不匹配，则验证机制可以回调此接口的实现程序来确定是否应该允许此连接
                    .hostnameVerifier(new HostnameVerifier() {
        
                        @Override
                        public boolean verify(String hostname, SSLSession session) {
        
                            return true;
                        }
                    })
                    // 拦截器日志记录
                    .addInterceptor((Interceptor.Chain chain) -> {
        
                        Request request = chain.request();
                        log.info("intercept 接口地址:" + request.url()
                                + "\r\n接口参数）:" + request.body().toString());
                        return chain.proceed(chain.request());
                    })
                    // 添加证书，一般不要设置
                    .certificatePinner(new CertificatePinner.Builder()
                            .add("test1.com", "sha1/sdfsdsdsdsdsdsdsdsdsdsdds=")
                            .add("test2.com", "sha1/sdsdsdsdsdsdsdsdsdssdssds=")
                            .build())
                    //.connectionSpecs(...) // 设置连接的规格、TLS版本和密码套件等，最好不要去设置
                    //.socketFactory(new SocketFactory() {...}) // 使用定制的用于http请求的套接字
    /*                .authenticator(new Authenticator() { // 添加授权证书
                        @Override
                        public Request authenticate(Route route, Response response) throws IOException {
                        }
                    }) */
                    .cache(new Cache(new File("cache.tmp"), 10 * 1024 * 1024)) // 10M缓存
                    // 定义连接池，最多有五个空闲连接，每个空闲连接最多保持6分钟
                    .connectionPool(new ConnectionPool(5, 6, TimeUnit.MINUTES))
                    // 指定分发器，即异步执行http请求时的线程池，http响应的回调也是在此线程池的线程中执行
                    // .dispatcher(new Dispatcher(new ThreadPoolExecutor(...)))
                    .followRedirects(true)       // 允许http重定向
                    .followSslRedirects(false)   // 截断https的重定向
                    .pingInterval(30, TimeUnit.SECONDS) // 设置ping检测网络连通性的间隔。默认为0
                    //.proxy(...) // 设置单个代理
                    //.proxyAuthenticator(...)  // 设置代理验证
                    //.proxySelector(...) // 为不同的链接设置不同的代理
                    .build();
    
        }
    
        public class EasyX509TrustManager implements X509TrustManager {
        
    
            private X509TrustManager standardTrustManager = null;
    
            /**
             * Constructor for EasyX509TrustManager.
             */
            public EasyX509TrustManager(KeyStore keystore) throws NoSuchAlgorithmException,
                    KeyStoreException {
        
                super();
                TrustManagerFactory factory = TrustManagerFactory.getInstance(TrustManagerFactory
                        .getDefaultAlgorithm());
                factory.init(keystore);
                TrustManager[] trustmanagers = factory.getTrustManagers();
                if (trustmanagers.length == 0) {
        
                    throw new NoSuchAlgorithmException("no trust manager found");
                }
                this.standardTrustManager = (X509TrustManager) trustmanagers[0];
            }
    
            /**
             * @see X509TrustManager#checkClientTrusted(X509Certificate[],
             * String authType)
             */
            public void checkClientTrusted(X509Certificate[] certificates, String authType)
                    throws CertificateException {
        
                standardTrustManager.checkClientTrusted(certificates, authType);
            }
    
            /**
             * @see X509TrustManager#checkServerTrusted(X509Certificate[],
             * String authType)
             */
            public void checkServerTrusted(X509Certificate[] certificates, String authType)
                    throws CertificateException {
        
                if ((certificates != null) && (certificates.length == 1)) {
        
                    certificates[0].checkValidity();
                } else {
        
                    standardTrustManager.checkServerTrusted(certificates, authType);
                }
            }
    
            /**
             * @see X509TrustManager#getAcceptedIssuers()
             */
            public X509Certificate[] getAcceptedIssuers() {
        
                return this.standardTrustManager.getAcceptedIssuers();
            }
        }
    
        public SSLSocketFactory sslSocketFactory() {
        
            try {
        
                //信任任何链接
                SSLContext sslContext = SSLContext.getInstance("TLS");
                sslContext.init(null, new TrustManager[]{
        new EasyX509TrustManager(null)}, new SecureRandom());
                return sslContext.getSocketFactory();
            } catch (NoSuchAlgorithmException e) {
        
                e.printStackTrace();
            } catch (KeyManagementException e) {
        
                e.printStackTrace();
            } catch (KeyStoreException e) {
        
                e.printStackTrace();
            }
            return null;
        }
    }

##### 八、OkhttpUtil 工具类 #####

@Slf4j
    @Component
    public class OkHttpUtil{
        
    
        private static OkHttpClient  okHttpClient;
    
        @Autowired
        public OkHttpUtil(OkHttpClient  okHttpClient) {
        
            OkHttpUtil.okHttpClient= okHttpClient;
        }
    
        /**
         * get
         * @param url     请求的url
         * @param queries 请求的参数，在浏览器？后面的数据，没有可以传null
         */
        public static  String get(String url, Map<String, String> queries) {
        
            String responseBody = "";
            StringBuffer sb = new StringBuffer(url);
            if (queries != null && queries.keySet().size() > 0) {
        
                boolean firstFlag = true;
                Iterator iterator = queries.entrySet().iterator();
                while (iterator.hasNext()) {
        
                    Map.Entry entry = (Map.Entry<String, String>) iterator.next();
                    if (firstFlag) {
        
                        sb.append("?" + entry.getKey() + "=" + entry.getValue());
                        firstFlag = false;
                    } else {
        
                        sb.append("&" + entry.getKey() + "=" + entry.getValue());
                    }
                }
            }
            Request request = new Request.Builder()
                    .url(sb.toString())
                    .build();
            Response response = null;
            try {
        
                response = okHttpClient.newCall(request).execute();
                int status = response.code();
                if (response.isSuccessful()) {
        
                    return response.body().string();
                }
            } catch (Exception e) {
        
                log.error("okhttp3 put error >> ", e);
            } finally {
        
                if (response != null) {
        
                    response.close();
                }
            }
            return responseBody;
        }
    
        /**
         * post
         *
         * @param url    请求的url
         * @param params post form 提交的参数
         * @return
         */
        public static String post(String url, Map<String, String> params) {
        
            String responseBody = "";
            FormBody.Builder builder = new FormBody.Builder();
            //添加参数
            if (params != null && params.keySet().size() > 0) {
        
                for (String key : params.keySet()) {
        
                    builder.add(key, params.get(key));
                }
            }
            Request request = new Request.Builder()
                    .url(url)
                    .post(builder.build())
                    .build();
            Response response = null;
            try {
        
                response = okHttpClient.newCall(request).execute();
                int status = response.code();
                if (response.isSuccessful()) {
        
                    return response.body().string();
                }
            } catch (Exception e) {
        
                log.error("okhttp3 post error >> ", e);
            } finally {
        
                if (response != null) {
        
                    response.close();
                }
            }
            return responseBody;
        }
    
        /**
         * get
         * @param url     请求的url
         * @param queries 请求的参数，在浏览器？后面的数据，没有可以传null
         * @return
         */
        public static String getForHeader(String url, Map<String, String> queries) {
        
            String responseBody = "";
            StringBuffer sb = new StringBuffer(url);
            if (queries != null && queries.keySet().size() > 0) {
        
                boolean firstFlag = true;
                Iterator iterator = queries.entrySet().iterator();
                while (iterator.hasNext()) {
        
                    Map.Entry entry = (Map.Entry<String, String>) iterator.next();
                    if (firstFlag) {
        
                        sb.append("?" + entry.getKey() + "=" + entry.getValue());
                        firstFlag = false;
                    } else {
        
                        sb.append("&" + entry.getKey() + "=" + entry.getValue());
                    }
                }
            }
            Request request = new Request.Builder()
                    .addHeader("key", "value")
                    .url(sb.toString())
                    .build();
            Response response = null;
            try {
        
                response = okHttpClient.newCall(request).execute();
                int status = response.code();
                if (response.isSuccessful()) {
        
                    return response.body().string();
                }
            } catch (Exception e) {
        
                log.error("okhttp3 put error >> ", e);
            } finally {
        
                if (response != null) {
        
                    response.close();
                }
            }
            return responseBody;
        }
    
        /**
         * Post请求发送JSON数据....{"name":"zhangsan","pwd":"123456"}
         * 参数一：请求Url
         * 参数二：请求的JSON
         * 参数三：请求回调
         */
        public static String postJsonParams(String url, String jsonParams) {
        
            String responseBody = "";
            RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), jsonParams);
            Request request = new Request.Builder()
                    .url(url)
                    .post(requestBody)
                    .build();
            Response response = null;
            try {
        
                response = okHttpClient.newCall(request).execute();
                int status = response.code();
                if (response.isSuccessful()) {
        
                    return response.body().string();
                }
            } catch (Exception e) {
        
                log.error("okhttp3 post error >> ", e);
            } finally {
        
                if (response != null) {
        
                    response.close();
                }
            }
            return responseBody;
        }
    
        /**
         * Post请求发送xml数据....
         * 参数一：请求Url
         * 参数二：请求的xmlString
         * 参数三：请求回调
         */
        public static String postXmlParams(String url, String xml) {
        
            String responseBody = "";
            RequestBody requestBody = RequestBody.create(MediaType.parse("application/xml; charset=utf-8"), xml);
            Request request = new Request.Builder()
                    .url(url)
                    .post(requestBody)
                    .build();
            Response response = null;
            try {
        
                response = okHttpClient.newCall(request).execute();
                int status = response.code();
                if (response.isSuccessful()) {
        
                    return response.body().string();
                }
            } catch (Exception e) {
        
                log.error("okhttp3 post error >> "+ e);
            } finally {
        
                if (response != null) {
        
                    response.close();
                }
            }
            return responseBody;
        }
    }

##### 九、小结 #####

okhttp 创建 request 请求常见的 body 类型

*  RequestBody 适合传一个参数，如：json （2 和 3 示例）
 *  FormBody 表单参数（仅支持文本） （示例 6）
 *  MultipartBody 表单（支持文本 和 文件）（示例 4）

创建 okhttp 请求，主要生成 request（包含 method、url、body、header），最后通过 OkHttpClient 执行同步（execute）异步（enqueue）方法

Request request = new Request.Builder()
                    .post(formBody)
                    .url(url)
                    .addHeader("Connection", "keep-alive")
                    .build();
            Response response = okHttpClient.newCall(request).execute();

1、OkHttp3使用起来简单，但是实际上其原理代码十分复杂，这也使得OkHttp3功能很强大，包括缓存、gzip、长连接、重定向等。

2、OkHttp3原理复杂，但是它的主要功能就是网络访问，网络访问就是要完成读写功能，于是我们只需要好好把握HttpEngine中的sendRequest作用和readResponse作用即可，即sendRequest完成初始化，并通过Socket方式建立同服务器的网络连接，而readResponse通过Socket完成读写功能。

3、OkHttp3依赖于Okio,主要体现在网络访问数据放在okio.Buffer中，通过okio.Okio write方法写服务器数据，通过okio.Okio read方法读取服务器返回数据。

[https_square.github.io_okhttp]: https://square.github.io/okhttp/
[https_blog.csdn.net_qq_41538097_article_details_118722718]: https://blog.csdn.net/qq_41538097/article/details/118722718
[https_blog.csdn.net_qq_41538097_article_details_123719298]: https://blog.csdn.net/qq_41538097/article/details/123719298
[https_blog.csdn.net_qq_41538097_article_details_123560238]: https://blog.csdn.net/qq_41538097/article/details/123560238
[https_blog.csdn.net_qq_41538097_article_details_123677614]: https://blog.csdn.net/qq_41538097/article/details/123677614
[https_blog.csdn.net_qq_41538097_article_details_123697432]: https://blog.csdn.net/qq_41538097/article/details/123697432
[https_www.freesion.com_article_3815946206]: https://www.freesion.com/article/3815946206/