关于java:Java封装OkHttp3工具类

Java 封装 OkHttp3 工具类，实用于 Java 后端开发者

说实在话，用过挺多网络申请工具，有过 java 原生的，HttpClient3 和 4，然而个人感觉用了 OkHttp3 之后，之前的那些齐全不想再用了。怎么说呢，代码轻便，应用起来很很很灵便，响应快，比起 HttpClient 好用许多。当然，这些是我个人观点，不喜勿喷。

筹备工作

Maven 我的项目在 pom 文件中引入 jar 包

<dependency>
    <groupId>com.squareup.okhttp3</groupId>
    <artifactId>okhttp</artifactId>
    <version>3.10.0</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.60</version>
</dependency>

引入 json 是因为工具类中有些中央用到了，当初通信都风行应用 json 传输，也少不了要这个 jar 包

工具类代码

import com.alibaba.fastjson.JSON;
import okhttp3.*;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.io.IOException;
import java.net.URLEncoder;
import java.security.SecureRandom;
import java.security.cert.X509Certificate;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;

public class OkHttpUtils {
    private static volatile OkHttpClient okHttpClient = null;
    private static volatile Semaphore semaphore = null;
    private Map<String, String> headerMap;
    private Map<String, String> paramMap;
    private String url;
    private Request.Builder request;

    /**
     * 初始化 okHttpClient，并且容许 https 拜访
     */
    private OkHttpUtils() {if (okHttpClient == null) {synchronized (OkHttpUtils.class) {if (okHttpClient == null) {TrustManager[] trustManagers = buildTrustManagers();
                    okHttpClient = new OkHttpClient.Builder()
                            .connectTimeout(15, TimeUnit.SECONDS)
                            .writeTimeout(20, TimeUnit.SECONDS)
                            .readTimeout(20, TimeUnit.SECONDS)
                            .sslSocketFactory(createSSLSocketFactory(trustManagers), (X509TrustManager) trustManagers[0])
                            .hostnameVerifier((hostName, session) -> true)
                            .retryOnConnectionFailure(true)
                            .build();
                    addHeader("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36");
                }
            }
        }
    }

    /**
     * 用于异步申请时，管制拜访线程数，返回后果
     *
     * @return
     */
    private static Semaphore getSemaphoreInstance() {
        // 只能 1 个线程同时拜访
        synchronized (OkHttpUtils.class) {if (semaphore == null) {semaphore = new Semaphore(0);
            }
        }
        return semaphore;
    }

    /**
     * 创立 OkHttpUtils
     *
     * @return
     */
    public static OkHttpUtils builder() {return new OkHttpUtils();
    }

    /**
     * 增加 url
     *
     * @param url
     * @return
     */
    public OkHttpUtils url(String url) {
        this.url = url;
        return this;
    }

    /**
     * 增加参数
     * 
     * @param key   参数名
     * @param value 参数值
     * @return
     */
    public OkHttpUtils addParam(String key, String value) {if (paramMap == null) {paramMap = new LinkedHashMap<>(16);
        }
        paramMap.put(key, value);
        return this;
    }

    /**
     * 增加申请头
     *
     * @param key   参数名
     * @param value 参数值
     * @return
     */
    public OkHttpUtils addHeader(String key, String value) {if (headerMap == null) {headerMap = new LinkedHashMap<>(16);
        }
        headerMap.put(key, value);
        return this;
    }

    /**
     * 初始化 get 办法
     *
     * @return
     */
    public OkHttpUtils get() {request = new Request.Builder().get();
        StringBuilder urlBuilder = new StringBuilder(url);
        if (paramMap != null) {urlBuilder.append("?");
            try {for (Map.Entry<String, String> entry : paramMap.entrySet()) {urlBuilder.append(URLEncoder.encode(entry.getKey(), "utf-8")).
                            append("=").
                            append(URLEncoder.encode(entry.getValue(), "utf-8")).
                            append("&");
                }
            } catch (Exception e) {e.printStackTrace();
            }
            urlBuilder.deleteCharAt(urlBuilder.length() - 1);
        }
        request.url(urlBuilder.toString());
        return this;
    }

    /**
     * 初始化 post 办法
     *
     * @param isJsonPost true 等于 json 的形式提交数据，相似 postman 里 post 办法的 raw
     *                   false 等于一般的表单提交
     * @return
     */
    public OkHttpUtils post(boolean isJsonPost) {
        RequestBody requestBody;
        if (isJsonPost) {
            String json = "";
            if (paramMap != null) {json = JSON.toJSONString(paramMap);
            } 
            requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), json);
        } else {FormBody.Builder formBody = new FormBody.Builder();
            if (paramMap != null) {paramMap.forEach(formBody::add);
            }
            requestBody = formBody.build();}
        request = new Request.Builder().post(requestBody).url(url);
        return this;
    }

    /**
     * 同步申请
     *
     * @return
     */
    public String sync() {setHeader(request);
        try {Response response = okHttpClient.newCall(request.build()).execute();
            assert response.body() != null;
            return response.body().string();
        } catch (IOException e) {e.printStackTrace();
            return "申请失败：" + e.getMessage();}
    }

    /**
     * 异步申请，有返回值
     */
    public String async() {StringBuilder buffer = new StringBuilder("");
        setHeader(request);
        okHttpClient.newCall(request.build()).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {buffer.append("申请出错：").append(e.getMessage());
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {assert response.body() != null;
                buffer.append(response.body().string());
                getSemaphoreInstance().release();
            }
        });
        try {getSemaphoreInstance().acquire();} catch (InterruptedException e) {e.printStackTrace();
        }
        return buffer.toString();}

    /**
     * 异步申请，带有接口回调
     *
     * @param callBack
     */
    public void async(ICallBack callBack) {setHeader(request);
        okHttpClient.newCall(request.build()).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {callBack.onFailure(call, e.getMessage());
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {assert response.body() != null;
                callBack.onSuccessful(call, response.body().string());
            }
        });
    }

    /**
     * 为 request 增加申请头
     *
     * @param request
     */
    private void setHeader(Request.Builder request) {if (headerMap != null) {
            try {for (Map.Entry<String, String> entry : headerMap.entrySet()) {request.addHeader(entry.getKey(), entry.getValue());
                }
            } catch (Exception e) {e.printStackTrace();
            }
        }
    }


    /**
     * 生成安全套接字工厂，用于 https 申请的证书跳过
     *
     * @return
     */
    private static SSLSocketFactory createSSLSocketFactory(TrustManager[] trustAllCerts) {
        SSLSocketFactory ssfFactory = null;
        try {SSLContext sc = SSLContext.getInstance("SSL");
            sc.init(null, trustAllCerts, new SecureRandom());
            ssfFactory = sc.getSocketFactory();} catch (Exception e) {e.printStackTrace();
        }
        return ssfFactory;
    }

    private static TrustManager[] buildTrustManagers() {return new TrustManager[]{new X509TrustManager() {
                    @Override
                    public void checkClientTrusted(X509Certificate[] chain, String authType) { }

                    @Override
                    public void checkServerTrusted(X509Certificate[] chain, String authType) { }

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

    /**
     * 自定义一个接口回调
     */
    public interface ICallBack {void onSuccessful(Call call, String data);

        void onFailure(Call call, String errorMsg);

    }
}

应用教程

public static void main(String[] args) {
    // get 申请，办法程序依照这种形式，切记抉择 post/get 肯定要放在倒数第二，同步或者异步倒数第一，才会正确执行
    OkHttpUtils.builder().url("申请地址，http/https 都能够")
            // 有参数的话增加参数，可多个
            .addParam("参数名", "参数值")
            .addParam("参数名", "参数值")
            // 也能够增加多个
            .addHeader("Content-Type", "application/json; charset=utf-8")
            .get()
            // 可抉择是同步申请还是异步申请
            //.async();
            .sync();

    // post 申请，分为两种，一种是一般表单提交，一种是 json 提交
    OkHttpUtils.builder().url("申请地址，http/https 都能够")
            // 有参数的话增加参数，可多个
            .addParam("参数名", "参数值")
            .addParam("参数名", "参数值")
            // 也能够增加多个
            .addHeader("Content-Type", "application/json; charset=utf-8")
            // 如果是 true 的话，会相似于 postman 中 post 提交形式的 raw，用 json 的形式提交，不是表单
            // 如果是 false 的话传统的表单提交
            .post(true)
            .sync();
    
    // 抉择异步有两个办法，一个是带回调接口，一个是间接返回后果
    OkHttpUtils.builder().url("")
            .post(false)
            .async();

    OkHttpUtils.builder().url("").post(false).async(new OkHttpUtils.ICallBack() {
        @Override
        public void onSuccessful(Call call, String data) {// 申请胜利后的解决}

        @Override
        public void onFailure(Call call, String errorMsg) {// 申请失败后的解决}
    });
}

结语

封装的明明白白，应用的简简单单，简略的几下就能做申请，用建造者模式是真的难受

作者：如漩涡
起源：https://blog.csdn.net/m0_3770…