实例详解Java调用第三方接口方法实例详解Java调用第三方接口方

一、通过JDK网络类Java.net.HttpURLConnection

1.java.net包下的原生java api提供的http请求
2.HttpClientUtil工具类
3.第三方api接口
4.测试类

二、通过Apache common封装好的HttpClient

1.引入依赖
2.httpClientUtil
3.第三方api接口
4.测试类

三、通过Spring的RestTemplate

1.引入依赖
2.RestTemplate配置类
3.RestTemplate实现类
4.第三方api接口
5.测试类

总结

一、通过JDK网络类Java.net.HttpURLConnection
1.java.net包下的原生java api提供的http请求

使用步骤：
1、通过统一资源定位器（java.net.URL）获取连接器（java.net.URLConnection）。
2、设置请求的参数。
3、发送请求。
4、以输入流的形式获取返回内容。
5、关闭输入流。

2.HttpClientUtil工具类

/** * jdk 调用第三方接口 * @author hsq */public class HttpClientUtil2 {/*** 以post方式调用对方接口方法* @param pathUrl*/public static String doPost(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(); //设定请求的方法为"POST"，默认是GET//post与get的不同之处在于post的参数不是放在URL字串里面，而是放在http请求的正文内。conn.setRequestMethod("POST"); //设置30秒连接超时conn.setConnectTimeout(30000); //设置30秒读取超时conn.setReadTimeout(30000); // 设置是否向httpUrlConnection输出，因为这个是post请求，参数要放在http正文内，因此需要设为true, 默认情况下是false; conn.setDoOutput(true); // 设置是否从httpUrlConnection读入，默认情况下是true; conn.setDoInput(true); // Post请求不能使用缓存conn.setUseCaches(false); //设置通用的请求属性conn.setRequestProperty("accept", "*/*"); conn.setRequestProperty("connection", "Keep-Alive"); //维持长链接conn.setRequestProperty("Content-Type", "application/json; charset=utf-8"); //连接，从上述url.openConnection()至此的配置必须要在connect之前完成，conn.connect(); /*** 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//此处getOutputStream会隐含的进行connect(即：如同调用上面的connect()方法，所以在开发中不调用上述的connect()也可以)。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(); }}return result; }/*** 以get方式调用对方接口方法* @param pathUrl*/public static String doGet(String pathUrl){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(); //设定请求的方法为"GET"，默认是GET//post与get的不同之处在于post的参数不是放在URL字串里面，而是放在http请求的正文内。conn.setRequestMethod("GET"); //设置30秒连接超时conn.setConnectTimeout(30000); //设置30秒读取超时conn.setReadTimeout(30000); // 设置是否向httpUrlConnection输出，因为这个是post请求，参数要放在http正文内，因此需要设为true, 默认情况下是false; conn.setDoOutput(true); // 设置是否从httpUrlConnection读入，默认情况下是true; conn.setDoInput(true); // Post请求不能使用缓存(get可以不使用)conn.setUseCaches(false); //设置通用的请求属性conn.setRequestProperty("accept", "*/*"); conn.setRequestProperty("connection", "Keep-Alive"); //维持长链接conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=utf-8"); //连接，从上述url.openConnection()至此的配置必须要在connect之前完成，conn.connect(); /*** 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, "UTF-8")); 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 (br != null){br.close(); }} catch (IOException e) {e.printStackTrace(); }}return result; }}

3.第三方api接口

/** * @author hsq */@RestController@RequestMapping("/api")public class HelloWorld {private static final Logger log= LoggerFactory.getLogger(HelloWorld.class); @GetMapping ("/getHello")public Result getHelloWord(){log.info("进入到api接口......."); return Result.success("hello world api get 接口数据"); }@PostMapping("/postHello")public Result postHelloWord(@RequestBody User user){log.info("进入post 方法....."); System.out.println(user.toString()); return Result.success("hello world api post接口数据"); }}

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4.测试类

@Testpublic void testJDKApi(){//测试get方法String s = HttpClientUtil2.doGet("http://localhost:9092/api/getHello"); System.out.println("get方法:"+s); //测试post方法User user = new User(); user.setUname("胡萝卜"); user.setRole("普通用户"); //把对象转换为json格式String s1 = JsonUtil.toJson(user); String postString = HttpClientUtil2.doPost("http://localhost:9092/api/postHello",s1); System.out.println("post方法:"+postString); }

结果：

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二、通过Apache common封装好的HttpClient

1.引入依赖

commons-httpclientcommons-httpclient3.1com.alibabafastjson1.2.28

2.httpClientUtil

/** *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。 * @author hsq */public class HttpClientUtil {/*** @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HeaderpostMethod.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("param", json.getString("param")); StringRequestEntity param = new StringRequestEntity(json.getString("param")); postMethod.setRequestEntity(param); String res = ""; try {int code = httpClient.executeMethod(postMethod); if (code == 200){byte[] responseBody = postMethod.getResponseBody(); res = new String(responseBody, "UTF-8"); //res = postMethod.getResponseBodyAsString(); System.out.println(res); }} catch (IOException e) {e.printStackTrace(); }return res; }}

3.第三方api接口

@RestController@RequestMapping("/api")public class HelloWorld {private static final Logger log= LoggerFactory.getLogger(HelloWorld.class); @GetMapping ("/getHello")public Result getHelloWord(){log.info("进入到api接口......."); return Result.success("hello world api get 接口数据"); }@PostMapping("/postHello")public Result postHelloWord(@RequestBody User user){log.info("进入post 方法....."); System.out.println(user.toString()); return Result.success("hello world api post接口数据"); }}

4.测试类

@Testpublic void testApi() {//测试get方法String s = HttpClientUtil.doGet("http://localhost:9092/api/getHello", "UTF-8"); System.out.println("get方法:"+s); //测试post方法User user = new User(); user.setUname("胡萝卜"); user.setRole("普通用户"); JSONObject jsonObject = new JSONObject(); String s1 = JsonUtil.toJson(user); jsonObject.put("param",s1); String postString = HttpClientUtil.doPost("http://localhost:9092/api/postHello", jsonObject); System.out.println("post方法:"+postString); }

结果：

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三、通过Spring的RestTemplate 1.引入依赖
导入springboot的web包

org.springframework.bootspring-boot-starter-parent2.1.4.RELEASE org.springframework.bootspring-boot-starter-weborg.springframework.bootspring-boot-starter-testtest

2.RestTemplate配置类

/** * @author hsq */@Configurationpublic class RestTemplateConfig {@Beanpublic RestTemplate restTemplate(ClientHttpRequestFactory factory){return new RestTemplate(factory); }@Beanpublic ClientHttpRequestFactory simpleClientHttpRequestFactory(){SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory(); factory.setConnectTimeout(15000); factory.setReadTimeout(5000); return factory; }}

3.RestTemplate实现类

/** * @author hsq */@Componentpublic class RestTemplateToInterface {@Autowiredprivate RestTemplate restTemplate; /*** 以get方式请求第三方http接口 getForEntity* @param url* @return*/public Result doGetWith1(String url){ResponseEntity responseEntity = restTemplate.getForEntity(url, Result.class); Result result = responseEntity.getBody(); return result; }/*** 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 Result doGetWith2(String url){Result result= restTemplate.getForObject(url, Result.class); return result; }/*** 以post方式请求第三方http接口 postForEntity* @param url* @param user* @return*/public String doPostWith1(String url,User user){ResponseEntity 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* 返回值返回的是响应体，省去了我们再去getBody()* @param url* @param user* @return*/public String doPostWith2(String url,User user){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 request = new HttpEntity<>(obj, headers); ResponseEntity responseEntity = restTemplate.exchange(url, HttpMethod.POST, request, String.class); String body = responseEntity.getBody(); return body; }}

4.第三方api接口

/** * @author hsq */@RestController@RequestMapping("/api")public class HelloWorld {private static final Logger log= LoggerFactory.getLogger(HelloWorld.class); @GetMapping ("/getHello")public Result getHelloWord(){log.info("进入到api接口......."); return Result.success("hello world api get 接口数据"); }@PostMapping("/postHello")public Result postHelloWord(@RequestBody User user){log.info("进入post 方法....."); System.out.println(user.toString()); return Result.success("hello world api post接口数据"); }}

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5.测试类

//注入使用@Autowiredprivate RestTemplateToInterface restTemplateToInterface; @Testpublic void testSpringBootApi(){Result result= restTemplateToInterface.doGetWith1("http://localhost:9092/api/getHello"); System.out.println("get结果："+result); User user = new User(); user.setUname("胡萝卜"); user.setRole("普通用户"); String s = restTemplateToInterface.doPostWith1("http://localhost:9092/api/postHello", user); System.out.println("post结果："+s); }

结果：