Java 封装OkHttp3工具类，适用于Java后端开发者
说实在话，用过挺多网络请求工具，有过java原生的， HttpClient 3和4，但是个人感觉用了OkHttp3之后，之前的那些完全不想再用了。怎么说呢，代码轻便，使用起来很很很灵活，响应快，比起HttpClient好用许多。当然，这些是我个人观点，不喜勿喷。
准备工作
Maven 项目在pom文件中引入jar包
| <dependency> | |
| <groupId>com.squareup.okhttp</groupId> | |
| <artifactId>okhttp</artifactId> | |
| <version>.10.0</version> | |
| </dependency> | |
| <dependency> | |
| <groupId>com.alibaba</groupId> | |
| <artifactId> fastjson </artifactId> | |
| <version>.2.60</version> | |
| </dependency> |
引入 json 是因为工具类中有些地方用到了，现在通信都流行使用json传输，也少不了要这个jar包
工具类代码
| import com.alibaba.fastjson.JSON; | |
| import okhttp.*; | |
| 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.XCertificate; | |
| 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，并且允许https访问 | |
| */ private OkHttpUtils() { | |
| if (okHttpClient == null) { | |
| synchronized (OkHttpUtils.class) { | |
| if (okHttpClient == null) { | |
| TrustManager[] trustManagers = buildTrustManagers(); | |
| okHttpClient = new OkHttpClient.Builder() | |
| .connectTimeout(, TimeUnit.SECONDS) | |
| .writeTimeout(, TimeUnit.SECONDS) | |
| .readTimeout(, TimeUnit.SECONDS) | |
| .sslSocketFactory(createSSLSocketFactory(trustManagers), (XTrustManager) trustManagers[0]) | |
| .hostnameVerifier((hostName, session) -> true) | |
| .retryOnConnectionFailure(true) | |
| .build(); | |
| addHeader("User-Agent", "Mozilla/.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"); | |
| } | |
| } | |
| } | |
| } | |
| /** | |
| * 用于异步请求时，控制访问线程数，返回结果 | |
| * | |
| * @return | |
| */ private static Semaphore getSemaphoreInstance() { | |
| //只能个线程同时访问 | |
| synchronized (OkHttpUtils.class) { | |
| if (semaphore == null) { | |
| semaphore = new Semaphore(); | |
| } | |
| } | |
| return semaphore; | |
| } | |
| /** | |
| * 创建OkHttpUtils | |
| * | |
| * @return | |
| */ public static OkHttpUtils builder() { | |
| return new OkHttpUtils(); | |
| } | |
| /** | |
| * 添加url | |
| * | |
| * @param url | |
| * @return | |
| */ public OkHttpUtils url(String url) { | |
| this.url = url; | |
| return this; | |
| } | |
| /** | |
| * 添加参数 | |
| * | |
| * @param key 参数名 | |
| * @param value 参数值 | |
| * @return | |
| */ public OkHttpUtils addParam(String key, String value) { | |
| if (paramMap == null) { | |
| paramMap = new LinkedHashMap<>(); | |
| } | |
| paramMap.put(key, value); | |
| return this; | |
| } | |
| /** | |
| * 添加请求头 | |
| * | |
| * @param key 参数名 | |
| * @param value 参数值 | |
| * @return | |
| */ public OkHttpUtils addHeader(String key, String value) { | |
| if (headerMap == null) { | |
| headerMap = new LinkedHashMap<>(); | |
| } | |
| headerMap.put(key, value); | |
| return this; | |
| } | |
| /** | |
| * 初始化get方法 | |
| * | |
| * @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-")). | |
| append("="). | |
| append(URLEncoder.encode(entry.getValue(), "utf-")). | |
| append("&"); | |
| } | |
| } catch (Exception e) { | |
| e.printStackTrace(); | |
| } | |
| urlBuilder.deleteCharAt(urlBuilder.length() - ); | |
| } | |
| request.url(urlBuilder.toString()); | |
| return this; | |
| } | |
| /** | |
| * 初始化post方法 | |
| * | |
| * @param isJsonPost true等于json的方式提交数据，类似postman里post方法的raw | |
| * false等于普通的表单提交 | |
| * @return | |
| */ public OkHttpUtils post(boolean isJsonPost) { | |
| RequestBody requestBody; | |
| if (isJsonPost) { | |
| String json = ""; | |
| if (paramMap != null) { | |
| json = JSON.toJSONString(paramMap); | |
| } | |
| request Body = 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; | |
| } | |
| /** | |
| * 同步请求 | |
| * | |
| * @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 "请求失败：" + e.getMessage(); | |
| } | |
| } | |
| /** | |
| * 异步请求，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("请求出错：").append(e.getMessage()); | |
| } | |
| 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(); | |
| } | |
| /** | |
| * 异步请求，带有接口回调 | |
| * | |
| * @param callBack | |
| */ public void async(ICallBack callBack) { | |
| setHeader(request); | |
| okHttpClient.newCall(request.build()).enqueue(new Callback() { | |
| public void onFailure(Call call, IOException e) { | |
| callBack.onFailure(call, e.getMessage()); | |
| } | |
| public void onResponse(Call call, Response response) throws IOException { | |
| assert response.body() != null; | |
| callBack.onSuccessful(call, response.body().string()); | |
| } | |
| }); | |
| } | |
| /** | |
| * 为request添加请求头 | |
| * | |
| * @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请求的证书跳过 | |
| * | |
| * @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 XTrustManager() { | |
| public void checkClientTrusted(XCertificate[] chain, String authType) { | |
| } | |
| public void checkServerTrusted(XCertificate[] chain, String authType) { | |
| } | |
| public XCertificate[] getAcceptedIssuers() { | |
| return new XCertificate[]{}; | |
| } | |
| } | |
| }; | |
| } | |
| /** | |
| * 自定义一个接口回调 | |
| */ public interface ICallBack { | |
| void onSuccessful(Call call, String data); | |
| void onFailure(Call call, String errorMsg); | |
| } | |
| } |
使用教程
| public static void main(String[] args) { | |
| // get请求，方法顺序按照这种方式，切记选择post/get一定要放在倒数第二，同步或者异步倒数第一，才会正确执行 | |
| OkHttpUtils.builder().url("请求地址，http/https都可以") | |
| // 有参数的话添加参数，可多个 | |
| .addParam("参数名", "参数值") | |
| .addParam("参数名", "参数值") | |
| // 也可以添加多个 | |
| .addHeader("Content-Type", "application/json; charset=utf-") | |
| .get() | |
| // 可选择是同步请求还是异步请求 | |
| //.async(); | |
| .sync(); | |
| // post请求，分为两种，一种是普通表单提交，一种是json提交 | |
| OkHttpUtils.builder().url("请求地址，http/https都可以") | |
| // 有参数的话添加参数，可多个 | |
| .addParam("参数名", "参数值") | |
| .addParam("参数名", "参数值") | |
| // 也可以添加多个 | |
| .addHeader("Content-Type", "application/json; charset=utf-") | |
| // 如果是true的话，会类似于postman中post提交方式的raw，用json的方式提交，不是表单 | |
| // 如果是 false 的话传统的表单提交 | |
| .post(true) | |
| .sync(); | |
| // 选择异步有两个方法，一个是带回调接口，一个是直接返回结果 | |
| OkHttpUtils.builder().url("") | |
| .post(false) | |
| .async(); | |
| OkHttpUtils.builder().url("").post(false).async(new OkHttpUtils.ICallBack() { | |
| public void onSuccessful(Call call, String data) { | |
| // 请求成功后的处理 | |
| } | |
| public void onFailure(Call call, String errorMsg) { | |
| // 请求失败后的处理 | |
| } | |
| }); | |
| } |
结语
封装的明明白白，使用的简简单单，简单的几下就能做请求，用建造者模式是真的舒服