Java调用第三方http接口的方式

2022-11-16 22:09:59

1. 概述

在实际开发过程中，我们经常需要调用对方提供的接口或测试自己写的接口是否合适。很多项目都会封装规定好本身项目的接口规范，所以大多数需要去调用对方提供的接口或第三方接口（短信、天气等）。

在Java项目中调用第三方接口的方式有：

①通过JDK网络类Java.net.HttpURLConnection；

②通过common封装好的HttpClient；

③通过Apache封装好的CloseableHttpClient；

④通过SpringBoot-RestTemplate；

2. Java调用第三方http接口的方式

2.1 通过JDK网络类Java.net.HttpURLConnection

比较原始的一种调用做法，这里把get请求和post请求都统一放在一个方法里面，直接上代码：

import java.io.*;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.URL;

/**

 * @Author: Yang JianQiu

 * @Date: 2019/4/26 11:34

 * jdk类HttpURLConnection调用第三方http接口

 *

 * 通常分get和post两种方式

 *

 * 参考资料：

 * http://www.cnblogs.com/angusbao/p/7727649.html

 */

public class HttpUrlConnectionToInterface {

    /**

     * 以post或get方式调用对方接口方法，

     * @param pathUrl

     */

    public static void doPostOrGet(String pathUrl, String data){

        OutputStreamWriter out = null;

        BufferedReader br = null;

        String result = "";

        try {

            URL url = new URL(pathUrl);

            //打开和url之间的连接

            HttpURLConnection conn = (HttpURLConnection) url.openConnection();

            //请求方式

            conn.setRequestMethod("POST");

            //conn.setRequestMethod("GET");

            //设置通用的请求属性

            conn.setRequestProperty("accept", "*/*");

            conn.setRequestProperty("connection", "Keep-Alive");

            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)");

            conn.setRequestProperty("Content-Type", "application/json;charset=utf-8");

            //DoOutput设置是否向httpUrlConnection输出，DoInput设置是否从httpUrlConnection读入，此外发送post请求必须设置这两个

            conn.setDoOutput(true);

            conn.setDoInput(true);

            /**

             * 下面的三句代码，就是调用第三方http接口

             */

            //获取URLConnection对象对应的输出流

            out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");

            //发送请求参数即数据

            out.write(data);

            //flush输出流的缓冲

            out.flush();

            /**

             * 下面的代码相当于，获取调用第三方http接口后返回的结果

             */

            //获取URLConnection对象对应的输入流

            InputStream is = conn.getInputStream();

            //构造一个字符流缓存

            br = new BufferedReader(new InputStreamReader(is));

            String str = "";

            while ((str = br.readLine()) != null){

                result += str;

            }

            System.out.println(result);

            //关闭流

            is.close();

            //断开连接，disconnect是在底层tcp socket链接空闲时才切断，如果正在被其他线程使用就不切断。

            conn.disconnect();

        } catch (Exception e) {

            e.printStackTrace();

        }finally {

            try {

                if (out != null){

                    out.close();

                }

                if (br != null){

                    br.close();

                }

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

    }

    public static void main(String[] args) {

        /**

         *手机信息查询接口：http://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=手机号

　　　　 *　　　　　　http://api.showji.com/Locating/www.showji.com.aspx?m=手机号&output=json&callback=querycallback

         */

        doPostOrGet("https://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=13026194071", "");

    }

}

2.2 通过apache common封装好的HttpClient

httpClient的get或post请求方式步骤：

  1. 生成一个HttpClient对象并设置相应的参数；
  2. 生成一个GetMethod对象或PostMethod并设置响应的参数；
  3. 用HttpClient生成的对象来执行GetMethod生成的Get方法；
  4. 处理响应状态码；
  5. 若响应正常，处理HTTP响应内容；
  6. 释放连接。

导入如下jar包：

        <!--HttpClient-->

        <dependency>

            <groupId>commons-httpclient</groupId>

            <artifactId>commons-httpclient</artifactId>

            <version>3.1</version>

        </dependency>

代码如下：

import com.alibaba.fastjson.JSONObject;

import org.apache.commons.httpclient.*;

import org.apache.commons.httpclient.methods.GetMethod;

import org.apache.commons.httpclient.methods.PostMethod;

import org.apache.commons.httpclient.params.HttpMethodParams;

import java.io.IOException;

import java.io.InputStream;

/**

 * @Author: Yang JianQiu

 * @Date: 2019/4/28 11:07

 *

 * HttpClient模拟get、post请求并发送请求参数（json等）

 * 【参考资料】

 * https://javasam.iteye.com/blog/2117845

 * https://blog.csdn.net/qq_28379809/article/details/82898792

 */

public class HttpClientToInterface {

    /**

     * httpClient的get请求方式

     * 使用GetMethod来访问一个URL对应的网页实现步骤：

     * 1.生成一个HttpClient对象并设置相应的参数；

     * 2.生成一个GetMethod对象并设置响应的参数；

     * 3.用HttpClient生成的对象来执行GetMethod生成的Get方法；

     * 4.处理响应状态码；

     * 5.若响应正常，处理HTTP响应内容；

     * 6.释放连接。

     * @param url

     * @param charset

     * @return

     */

    public static String doGet(String url, String charset){

        /**

         * 1.生成HttpClient对象并设置参数

         */

        HttpClient httpClient = new HttpClient();

        //设置Http连接超时为5秒

        httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(5000);

        /**

         * 2.生成GetMethod对象并设置参数

         */

        GetMethod getMethod = new GetMethod(url);

        //设置get请求超时为5秒

        getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 5000);

        //设置请求重试处理，用的是默认的重试处理：请求三次

        getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler());

        String response = "";

        /**

         * 3.执行HTTP GET 请求

         */

        try {

            int statusCode = httpClient.executeMethod(getMethod);

            /**

             * 4.判断访问的状态码

             */

            if (statusCode != HttpStatus.SC_OK){

                System.err.println("请求出错：" + getMethod.getStatusLine());

            }

            /**

             * 5.处理HTTP响应内容

             */

            //HTTP响应头部信息，这里简单打印

            Header[] headers = getMethod.getResponseHeaders();

            for (Header h: headers){

                System.out.println(h.getName() + "---------------" + h.getValue());

            }

            //读取HTTP响应内容，这里简单打印网页内容

            //读取为字节数组

            byte[] responseBody = getMethod.getResponseBody();

            response = new String(responseBody, charset);

            System.out.println("-----------response:" + response);

            //读取为InputStream，在网页内容数据量大时候推荐使用

            //InputStream response = getMethod.getResponseBodyAsStream();

        } catch (HttpException e) {

            //发生致命的异常，可能是协议不对或者返回的内容有问题

            System.out.println("请检查输入的URL!");

            e.printStackTrace();

        } catch (IOException e){

            //发生网络异常

            System.out.println("发生网络异常!");

        }finally {

            /**

             * 6.释放连接

             */

            getMethod.releaseConnection();

        }

        return response;

    }

    /**

     * post请求

     * @param url

     * @param json

     * @return

     */

    public static String doPost(String url, JSONObject json){

        HttpClient httpClient = new HttpClient();

        PostMethod postMethod = new PostMethod(url);

        postMethod.addRequestHeader("accept", "*/*");

        postMethod.addRequestHeader("connection", "Keep-Alive");

        //设置json格式传送

        postMethod.addRequestHeader("Content-Type", "application/json;charset=utf-8");

        //必须设置下面这个Header

        postMethod.addRequestHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36");

        //添加请求参数

        postMethod.addParameter("commentId", json.getString("commentId"));

        String res = "";

        try {

            int code = httpClient.executeMethod(postMethod);

            if (code == 200){

                res = postMethod.getResponseBodyAsString();

                System.out.println(res);

            }

        } catch (IOException e) {

            e.printStackTrace();

        }

        return res;

    }

    public static void main(String[] args) {

        doGet("http://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=13026194071", "UTF-8");

        System.out.println("-----------分割线------------");

        System.out.println("-----------分割线------------");

        System.out.println("-----------分割线------------");

        JSONObject jsonObject = new JSONObject();

        jsonObject.put("commentId", "13026194071");

        doPost("http://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=13026194071", jsonObject);

    }

}

2.3 通过Apache封装好的CloseableHttpClient

CloseableHttpClient是在HttpClient的基础上修改更新而来的，这里还涉及到请求头token的设置（请求验证），利用fastjson转换请求或返回结果字符串为json格式，当然上面两种方式也是可以设置请求头token、json的，这里只在下面说明。

导入如下jar包：

        <!--CloseableHttpClient-->

        <dependency>

            <groupId>org.apache.httpcomponents</groupId>

            <artifactId>httpclient</artifactId>

            <version>4.5.2</version>

        </dependency>

        <dependency>

            <groupId>com.alibaba</groupId>

            <artifactId>fastjson</artifactId>

            <version>1.2.28</version>

        </dependency>

代码如下：

import com.alibaba.fastjson.JSONObject;

import org.apache.http.HttpResponse;

import org.apache.http.HttpStatus;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.entity.StringEntity;

import org.apache.http.impl.client.CloseableHttpClient;

import org.apache.http.impl.client.HttpClientBuilder;

import org.apache.http.util.EntityUtils;

import java.io.IOException;

/**

 * @Author: Yang JianQiu

 * @Date: 2019/4/26 11:41

 * Apache封装好的CloseableHttpClient

 * 【参考资料】

 *  https://www.cnblogs.com/siv8/p/6222709.html

 *  https://blog.csdn.net/qq_35860138/article/details/82967727

 */

public class CloseableHttpClientToInterface {

    private static String tokenString = "";

    private static String AUTH_TOKEN_EXPIRED = "AUTH_TOKEN_EXPIRED";

    private static CloseableHttpClient httpClient = null;

    /**

     * 以get方式调用第三方接口

     * @param url

     * @return

     */

    public static String doGet(String url, String token){

        //创建HttpClient对象

        CloseableHttpClient httpClient = HttpClientBuilder.create().build();

        HttpGet get = new HttpGet(url);

        try {

            if (tokenString != null && !tokenString.equals("")){

                tokenString = getToken();

            }

            //api_gateway_auth_token自定义header头，用于token验证使用

            get.addHeader("api_gateway_auth_token", tokenString);

            get.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36");

            HttpResponse response = httpClient.execute(get);

            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){

                //返回json格式

                String res = EntityUtils.toString(response.getEntity());

                return res;

            }

        } catch (IOException e) {

            e.printStackTrace();

        }

        return null;

    }

    /**

     * 以post方式调用第三方接口

     * @param url

     * @param json

     * @return

     */

    public static String doPost(String url, JSONObject json){

        try {

            if (httpClient == null){

                httpClient = HttpClientBuilder.create().build();

            }

            HttpPost post = new HttpPost(url);

            if (tokenString != null && !tokenString.equals("")){

                tokenString = getToken();

            }

            //api_gateway_auth_token自定义header头，用于token验证使用

            post.addHeader("api_gateway_auth_token", tokenString);

            post.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36");

            StringEntity s = new StringEntity(json.toString());

            s.setContentEncoding("UTF-8");

            //发送json数据需要设置contentType

            s.setContentType("application/x-www-form-urlencoded");

            //设置请求参数

            post.setEntity(s);

            HttpResponse response = httpClient.execute(post);

            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){

                //返回json格式

                String res = EntityUtils.toString(response.getEntity());

                return res;

            }

        } catch (Exception e) {

            e.printStackTrace();

        }finally {

            if (httpClient != null){

                try {

                    httpClient.close();

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

        }

        return null;

    }

    /**

     * 获取第三方接口的token

     */

    public static String getToken(){

        String token = "";

        JSONObject object = new JSONObject();

        object.put("appid", "appid");

        object.put("secretkey", "secretkey");

        try {

            if (httpClient == null){

                httpClient = HttpClientBuilder.create().build();

            }

            HttpPost post = new HttpPost("http://localhost/login");

            post.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36");

            StringEntity s = new StringEntity(object.toString());

            s.setContentEncoding("UTF-8");

            //发送json数据需要设置contentType

            s.setContentType("application/x-www-form-urlencoded");

            //设置请求参数

            post.setEntity(s);

            HttpResponse response = httpClient.execute(post);

            //这里可以把返回的结果按照自定义的返回数据结果，把string转换成自定义类

            //ResultTokenBO result = JSONObject.parseObject(response, ResultTokenBO.class);

           //把response转为jsonObject

            JSONObject result = JSONObject.parseObject(response);

            if (result.containsKey("token")){

                token = result.getString("token");

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

        return token;

    }

    /**

     * 测试

     */

    public static void test(String telephone){

        JSONObject object = new JSONObject();

        object.put("telephone", telephone);

        try {

            //首先获取token

            tokenString = getToken();

            String response = doPost("http://localhost/searchUrl", object);

            //如果返回的结果是list形式的，需要使用JSONObject.parseArray转换

            //List<Result> list = JSONObject.parseArray(response, Result.class);

            System.out.println(response);

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

    public static void main(String[] args) {

        test("12345678910");

    }

}

2.4 通过SpringBoot-RestTemplate

springBoot-RestTemple是上面三种方式的集大成者，代码编写更加简单，目前可以采用的调用第三方接口有：

  • delete() 在特定的URL上对资源执行HTTP DELETE操作
  • exchange() 在URL上执行特定的HTTP方法，返回包含对象的ResponseEntity，这个对象是从响应体中映射得到的
  • execute() 在URL上执行特定的HTTP方法，返回一个从响应体映射得到的对象
  • getForEntity() 发送一个HTTP GET请求，返回的ResponseEntity包含了响应体所映射成的对象
  • getForObject() 发送一个HTTP GET请求，返回的请求体将映射为一个对象
  • postForEntity() POST 数据到一个URL，返回包含一个对象的ResponseEntity，这个对象是从响应体中映射得到的
  • postForObject() POST 数据到一个URL，返回根据响应体匹配形成的对象
  • headForHeaders() 发送HTTP HEAD请求，返回包含特定资源URL的HTTP头
  • optionsForAllow() 发送HTTP OPTIONS请求，返回对特定URL的Allow头信息
  • postForLocation() POST 数据到一个URL，返回新创建资源的URL
  • put() PUT 资源到特定的URL

注意：目前标红的为常用的

首先导入springboot的web包

<parent>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-parent</artifactId>

        <version>2.0.4.RELEASE</version>

    </parent>

    <dependencies>

        <!--CloseableHttpClient-->

        <dependency>

            <groupId>org.apache.httpcomponents</groupId>

            <artifactId>httpclient</artifactId>

            <version>4.5.2</version>

        </dependency>

        <!--spring restTemplate-->

        <!-- @ConfigurationProperties annotation processing (metadata for IDEs)

                生成spring-configuration-metadata.json类，需要引入此类-->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-configuration-processor</artifactId>

            <optional>true</optional>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-aop</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

            <exclusions>

                <exclusion>

                    <groupId>org.springframework.boot</groupId>

                    <artifactId>spring-boot-starter-tomcat</artifactId>

                </exclusion>

            </exclusions>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-jetty</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-test</artifactId>

            <scope>test</scope>

        </dependency>

    </dependencies>

在启动类同包下创建RestTemplateConfig.java类

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.http.client.ClientHttpRequestFactory;

import org.springframework.http.client.SimpleClientHttpRequestFactory;

import org.springframework.web.client.RestTemplate;

/**

 * @Author: Yang JianQiu

 * @Date: 2019/4/28 14:01

 */

@Configuration

public class RestTemplateConfig {

    @Bean

    public RestTemplate restTemplate(ClientHttpRequestFactory factory){

        return new RestTemplate(factory);

    }

    @Bean

    public ClientHttpRequestFactory simpleClientHttpRequestFactory(){

        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();

        factory.setConnectTimeout(15000);

        factory.setReadTimeout(5000);

        return factory;

    }

}

然后在Service类（RestTemplateToInterface ）中注入使用

具体代码如下：

import com.alibaba.fastjson.JSONObject;

import com.swordfall.model.User;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.http.*;

import org.springframework.stereotype.Service;

import org.springframework.web.client.RestTemplate;

/**

 * @Author: Yang JianQiu

 * @Date: 2019/4/28 14:13

 *

 * 【参考资料】

 * https://blog.csdn.net/qq_15452971/article/details/79416469

 * https://blog.csdn.net/weixin_40461281/article/details/83540604

 */

@Service

public class RestTemplateToInterface {

    @Autowired

    private RestTemplate restTemplate;

    /**

     * 以get方式请求第三方http接口 getForEntity

     * @param url

     * @return

     */

    public User doGetWith1(String url){

        ResponseEntity<User> responseEntity = restTemplate.getForEntity(url, User.class);

        User user = responseEntity.getBody();

        return user;

    }

    /**

     * 以get方式请求第三方http接口 getForObject

     * 返回值返回的是响应体，省去了我们再去getBody()

     * @param url

     * @return

     */

    public User doGetWith2(String url){

        User user  = restTemplate.getForObject(url, User.class);

        return user;

    }

    /**

     * 以post方式请求第三方http接口 postForEntity

     * @param url

     * @return

     */

    public String doPostWith1(String url){

        User user = new User("小白", 20);

        ResponseEntity<String> responseEntity = restTemplate.postForEntity(url, user, String.class);

        String body = responseEntity.getBody();

        return body;

    }

    /**

     * 以post方式请求第三方http接口 postForEntity

     * @param url

     * @return

     */

    public String doPostWith2(String url){

        User user = new User("小白", 20);

        String body = restTemplate.postForObject(url, user, String.class);

        return body;

    }

    /**

     * exchange

     * @return

     */

    public String doExchange(String url, Integer age, String name){

        //header参数

        HttpHeaders headers = new HttpHeaders();

        String token = "asdfaf2322";

        headers.add("authorization", token);

        headers.setContentType(MediaType.APPLICATION_JSON);

        //放入body中的json参数

        JSONObject obj = new JSONObject();

        obj.put("age", age);

        obj.put("name", name);

        //组装

        HttpEntity<JSONObject> request = new HttpEntity<>(obj, headers);

        ResponseEntity<String> responseEntity = restTemplate.exchange(url, HttpMethod.POST, request, String.class);

        String body = responseEntity.getBody();

        return body;

    }

}

总结

【github地址】

https://github.com/SwordfallYeung/JavaInvokingHttpInterface.git

【参考资料】

http://www.cnblogs.com/angusbao/p/7727649.html 纯Java api HttpURLConnection

https://blog.csdn.net/chijiandi/article/details/81388240 纯Java api HttpURLConnection

https://www.cnblogs.com/xuegu/p/8490815.html 封装api HttpClient

https://www.cnblogs.com/unknows/p/8534713.html

https://blog.csdn.net/qq_35860138/article/details/82967727 封装api HttpClient

https://blog.csdn.net/a1032818891/article/details/81172478 SpringBoot-RestTemplate

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