Java使用OkHttps工具类调用外部接口-白红宇

Java使用OkHttps工具类调用外部接口

阅读量：4580 次

发布时间：2019-06-09

本文共 8999 字，大约阅读时间需要 29 分钟。

前言

现在公司业务已止不是传统的增删改查等简单的业务处理操作，而是对数据各种联调三方接口与其他系统进行交互等，那么就需要我们在后台java中进行外部接口的调用，本文采用OkHttps工具类对接微信接口为大家简单介绍下，java调用外部接口进行数据交互。

第一步新建接口Demo

本文采用Idea作为开发工具

依次按照 file---new---project

紧接着如下

如果这样写就会提示

因为Idea中创建项目-项目名称必须小写

接着继续勾选Jar依赖

Jar依赖选择完成之后，确认项目名称跟所在目录

更具体的步骤请查看公众号之前写的

项目创建好之后，创建两个package，用来存放我们的工具类，与接口

先引入项目所需jar包依赖

buildscript {
      ext {
          springBootVersion = '2.1.2.RELEASE'     }     repositories {
          mavenCentral()     }     dependencies {
          classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")     } } apply plugin: 'java' apply plugin: 'org.springframework.boot' apply plugin: 'io.spring.dependency-management' apply plugin: 'war' group = 'com.ahdd99.example' version = '0.0.1-SNAPSHOT' sourceCompatibility = '1.8' repositories {
      mavenCentral() } dependencies {
      compile 'org.springframework.boot:spring-boot-starter-data-jpa'     compile 'org.springframework.boot:spring-boot-starter-jdbc'     compile 'org.springframework.boot:spring-boot-starter-web'     compile 'mysql:mysql-connector-java'     compile 'org.springframework.boot:spring-boot-starter-test'     compile 'com.squareup.okhttp3:okhttp:3.5.0'     compile group: 'com.google.code.gson', name: 'gson', version: '2.7'     compile 'com.xiaoleilu:hutool-all:3.1.0'     compile 'com.squareup.okhttp3:okhttp:3.5.0'     compileOnly 'org.projectlombok:lombok:1.16.6'     testCompile 'org.springframework.boot:spring-boot-starter-test'     providedRuntime 'org.springframework.boot:spring-boot-starter-tomcat'     providedRuntime 'org.apache.tomcat:tomcat-jasper:8.5.28' }

紧接着，在util包里面引入我们的okhttps工具类

OkHttps工具类中主要封装了get与post请求，这里简单让大家看下，源代码会贴在文章末尾

/**  * OkHttpUtils 工具类  */ @Slf4j public class OkHttpUtils {
    private final static OkHttpClient client = new OkHttpClient().newBuilder()       .writeTimeout(60, TimeUnit.SECONDS)       .readTimeout(60, TimeUnit.SECONDS)       .build();   public static JsonObject doGetRetJson(String url) throws IOException {
      return doGetRetJsonElement(url).getAsJsonObject();   }   public static JsonElement doGetRetJsonElement(String url) throws IOException {
      Request request = new Request.Builder().url(url).build();     return sendSyncRequestRetJsonElement(request);   }   public static JsonObject doPostRetJson(String url, String jsonBody) throws IOException {
      return doPostRetJsonElement(url, jsonBody).getAsJsonObject();   }   public static JsonElement doPostRetJsonElement(String url, String jsonBody) throws IOException {
      RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), jsonBody);     Request request = new Request.Builder().url(url).post(requestBody).build();     return sendSyncRequestRetJsonElement(request);   }   public static String doPostRetJsonString(String url, String jsonBody) throws IOException {
      RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), jsonBody);     Request request = new Request.Builder().url(url).post(requestBody).build();     return sendSyncRequestRetString(request);   }   public static String doPostRetString(String url, String textBody) throws IOException {
      RequestBody requestBody = RequestBody.create(MediaType.parse("application/x-www-form-urlencoded; charset=utf-8"), textBody);     Request request = new Request.Builder().url(url).post(requestBody).build();     return sendSyncRequestRetString(request);   }   public static void doPost(String url, Map
    
      params) throws IOException {
      FormBody.Builder formBuilder = new FormBody.Builder();     for (String key : params.keySet()) {
        formBuilder.add(key, params.get(key));     }     Request request = new Request.Builder().url(url).post(formBuilder.build()).build();     sendSyncRequestRetString(request);   }   public static JsonObject doPostRetJson(String url, Map
     
       params) throws IOException {
      FormBody.Builder formBuilder = new FormBody.Builder();     for (String key : params.keySet()) {
        formBuilder.add(key, params.get(key));     }     Request request = new Request.Builder().url(url).post(formBuilder.build()).build();     return sendSyncRequestRetJson(request);   }   /**    * 支付宝请求返回form    *    * @param url    * @param params    * @return    * @throws IOException   */   public static String doPostResString(String url, Map
      
        params) throws IOException {
      FormBody.Builder formBuilder = new FormBody.Builder();     for (String key : params.keySet()) {
        formBuilder.add(key, params.get(key));     }     Request request = new Request.Builder().url(url).post(formBuilder.build()).build();     return sendSyncRequestRetString(request);   }   public static JsonObject doPostRetJsonForUploadFile(String url, Map
       
         params) throws IOException {
      MultipartBody.Builder formBuilder = new MultipartBody.Builder();     formBuilder.setType(MultipartBody.FORM);     params.forEach((key, value) -> {
        if (value instanceof File) {
          File file = (File) value;         formBuilder.addFormDataPart(key, file.getName(), RequestBody.create(MediaType.parse("application/pdf; charset=utf-8"), file));       } else {
          formBuilder.addFormDataPart(key, value.toString());       }     });     Request request = new Request.Builder().url(url).post(formBuilder.build()).build();     return sendSyncRequestRetJson(request);   }   private static JsonObject sendSyncRequestRetJson(Request request) throws IOException {
      return sendSyncRequestRetJsonElement(request).getAsJsonObject();   }   private static JsonElement sendSyncRequestRetJsonElement(Request request) throws IOException {
      return JsonUtils.toJsonElement(sendSyncRequestRetString(request));   }   private static String sendSyncRequestRetString(Request request) throws IOException {
      Response response = client.newCall(request).execute();     if (!response.isSuccessful()) {
        throw new IOException("请求出错，出错信息：" + response.message());     }     String retString = response.body().string();     if (StrUtil.isEmpty(retString)) {
        return "";     }     return retString;   } }

kHttps工具类引入完成之后，引入JsonUtils工具类，这个主要是帮助我们吧参数封给JSON，免去我们在每个接口中再进行单独封装

/**  * 参数转json工具类  */ public class JsonUtils {
    private static final JsonParser JSON_PARSER = new JsonParser();   public static String toJson(Object object) {
      Gson gson = new GsonBuilder().create();     return gson.toJson(object);   }   public static JsonObject toJsonObject(String json) {
      return JSON_PARSER.parse(json).getAsJsonObject();   }   public static JsonArray jsonObjectToJsonArray(JsonObject jsonObject) {
      JsonArray jsonArray = new JsonArray();     jsonArray.add(jsonObject);     return jsonArray;   }   public static JsonElement toJsonElement(String json) {
      return JSON_PARSER.parse(json);   } }

工具类都引入完毕之后，就是我们的重头戏了

接口开发第一步，抽离接口Api工具类

将所有的接口路径抽离为工具类，并且定义为常量，方便后期维护

/**  * 接口api路径  * @author gyk  * @date 2019-03-27 11:27  */ public class WxPortApi {
      /**      * 接口请求路径      */     public final static  String WX_API = "https://api.weixin.qq.com";     /**      * 学习栈appID      */     public final  static  String WX_APP_ID = "";     /**      * 学习栈AppSecret      */     public final  static  String AppSecret = "";     /**      * 获取access_token接口      */     public final static  String ACCESS_TOKEN = "/cgi-bin/token"; }

下来就是接口调用

创建package service

编写接口service层业务处理

/**  * 获取公众号的access_token  * @param appId --- 微信appId  * @param secret  --- 微信秘钥  * @return  */ public JsonObject getAccessTocken(String appId, String secret){
      JsonObject resultJson = new JsonObject();     Map
    
      params = new HashMap<>(3);     //赋值接口需传递参数     //获取access_token填写client_credential     params.put("grant_type", "client_credential");     // 第三方用户唯一凭证     params.put("appid", appId);     // 第三方用户唯一凭证密钥，即appSecret     params.put("secret", secret);     try {
          //调用okHttps工具类进行接口调用         return OkHttpUtils.doPostRetJson(WxPortApi.WX_API + WxPortApi.ACCESS_TOKEN, params);     } catch (IOException e) {
          //赋值失败结果         resultJson.addProperty("result","-1");         resultJson.addProperty("msg",msg +"获取access_token失败");         return resultJson;     } }

然后编写单元测试

/**  * 测试获取公众号的access_token  */ @Test public void getAccessTocken() {
      WxPortService wxPortService = new WxPortService();     JsonObject jsonObject =  wxPortService.getAccessTocken(WxPortApi.WX_APP_ID, WxPortApi.AppSecret);     //获取错误码     String error_code = String.valueOf(jsonObject.get("errcode"));     //如果errcode 为空，那么证明获取的正确，不然获取失败     if("null".equals(error_code)){
          //打印得到的access_token         System.out.println(String.valueOf(jsonObject.get("access_token")));     } }

在这里有一个小坑大家要注意，java中String.valueOf() 如果你传入的是NULL 那么java会给你返回"Null" 字符串

剩下的微信接口对接将于后面进一步详细讲解

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源码地址 https://gitee.com/DaiDaiDeXiaoMaNong/port.git

转载于:https://www.cnblogs.com/java-xxz/p/10607820.html

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