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java對接第三方接口的3種常用方式

更新時間：2024年04月27日 15:39:58 作者：acgchan

java語言中調(diào)用第三方接口,可以使用的方法有很多,下面這篇文章主要給大家介紹了關(guān)于java對接第三方接口的3種常用方式,文中通過代碼介紹的非常詳細,需要的朋友可以參考下

HttpURLConnection調(diào)用方法

HTTP正文的內(nèi)容是通過OutputStream流寫入,向流中寫入的數(shù)據(jù)不會立即發(fā)送到網(wǎng)絡(luò),而是存在于內(nèi)存緩沖區(qū)中,待流關(guān)閉時，根據(jù)寫入的內(nèi)容生成HTTP正文。

調(diào)用getInputStream()方法時,會返回一個輸入流,用于從中讀取服務(wù)器對于HTTP請求的返回報文

@Slf4j
public class HttpURLConnectionUtil {
   /**
     *
     * Description: 發(fā)送http請求發(fā)送post和json格式
     * @param url          請求URL
     * @param params    json格式的請求參數(shù)
     */
    public static String doPost(String url, String params) throws Exception {

        OutputStreamWriter out = null;
        BufferedReader reader = null;
        StringBuffer response = new StringBuffer();
        URL httpUrl = null; // HTTP URL類 用這個類來創(chuàng)建連接
        try {
            // 創(chuàng)建URL
            httpUrl = new URL(url);
            log.info("--------發(fā)起Http Post 請求 ------------- url:" + url + "---------params:" + params);

            // 建立連接
            HttpURLConnection conn = (HttpURLConnection) httpUrl.openConnection();
            //設(shè)置請求的方法為"POST"，默認是GET
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Content-Type", "application/json");
            conn.setRequestProperty("connection", "keep-alive");
            conn.setUseCaches(false);// 設(shè)置不要緩存
            conn.setInstanceFollowRedirects(true);
            //由于URLConnection在默認的情況下不允許輸出，所以在請求輸出流之前必須調(diào)用setDoOutput(true)
            conn.setDoOutput(true);
            // 設(shè)置是否從httpUrlConnection讀入
            conn.setDoInput(true);
            //設(shè)置超時時間
            conn.setConnectTimeout(30000);
            conn.setReadTimeout(30000);
            conn.connect();
            // POST請求
            out = new OutputStreamWriter(conn.getOutputStream());
            out.write(params);
            out.flush();
            // 讀取響應(yīng)
            reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), "utf-8"));
            String lines;
            while ((lines = reader.readLine()) != null) {
                response.append(lines);
            }
            reader.close();
            // 斷開連接
            conn.disconnect();
        } catch (Exception e) {
            log.error("--------發(fā)起Http Post 請求 異常 {}-------------", e);
            throw new Exception(e);
        }
        // 使用finally塊來關(guān)閉輸出流、輸入流
        finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (reader != null) {
                    reader.close();
                }
            } catch (IOException ex) {
                log.error(String.valueOf(ex));
            }
        }
        return response.toString();
    }
}

CloseableHttpClient調(diào)用

CloseableHttpClient 是一個抽象類，實現(xiàn)了httpClient接口，也實現(xiàn)了java.io.Closeable;

支持連接池管理，可復(fù)用已建立的連接 PoolingHttpClientConnectionManager

通過 httpClient.close() 自動管理連接釋放

支持HTTPS訪問 HttpHost proxy = new HttpHost(“127.0.0.1”, 8080, “http”);

@Slf4j
public class CloseableHttpClientUtil {
    /**
    *url 第三方接口地址
    *json 傳入的報文體，可以是dto對象，string、json等
    *header 額外傳入的請求頭參數(shù)
    */    
  public static String doPost(String url, Object json,Map<String,String> header) {

        CloseableHttpClient httpclient = HttpClientBuilder.create().build();
        HttpPost httpPost= new HttpPost(url);//post請求類型
        String result="";//返回結(jié)果
        String requestJson="";//發(fā)送報文體
        try {
            requestJson=JSONObject.toJSONString(json);
            log.info("發(fā)送地址："+url+"發(fā)送報文："+requestJson);
            //StringEntity s = new StringEntity(requestJson, Charset.forName("UTF-8"));
            StringEntity s= new StringEntity(requestJson, "UTF-8");
               // post請求是將參數(shù)放在請求體里面?zhèn)鬟^去的;這里將entity放入post請求體中
               httpPost.setHeader("Content-Type", "application/json;charset=utf8");
            httpPost.setEntity(s);
            if(header!=null){
                Set<String> strings = header.keySet();
                for(String str:strings){
                    httpPost.setHeader(str,header.get(str));
                }
            }
            HttpResponse res = httpclient.execute(httpPost);
            if (res.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                    result = EntityUtils.toString(res.getEntity());
                    //也可以把返回的報文轉(zhuǎn)成json類型
                    // JSONObject  response = JSONObject.parseObject(result);
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        finally {
             //此處可以加入記錄日志的方法
            // 關(guān)閉連接,釋放資源
           if (httpclient!= null){
                try {
                    httpclient.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
    }
        return result;
    }
}

RestTemplate調(diào)用

//可以在項目啟動類中添加RestTemplate 的bean,后續(xù)就可以在代碼中@Autowired引入。

@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}

@Slf4j
@Component
public class RestTemplateUtils {
    @Autowired
    private RestTemplate restTemplate;

    /**
     * get 請求 參數(shù)在url后面  http://xxxx?aa=xxx&page=0&size=10";
     * @param urls 
     * @return string
     */
    public String doGetRequest(String urls) {
        
        URI uri = UriComponentsBuilder.fromUriString(urls).build().toUri();
        log.info("請求接口:{}", urls);
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        HttpEntity<String> httpEntity = new HttpEntity<>(headers);
        //通用的方法exchange,這個方法需要你在調(diào)用的時候去指定請求類型，可以是get,post,也能是其它類型的請求
        ResponseEntity<String> responseEntity = restTemplate.exchange(uri, HttpMethod.GET, httpEntity, String.class);
        if (responseEntity == null) {
            return null;
        }
        log.info("返回報文:{}", JSON.toJSONString(responseEntity));
        
        return responseEntity.getBody();
    }
    
    /**
     * post 請求 參數(shù)在 request里;
     * @param url, request
     * @return string
     */
    public String doPostRequest(String url, Object request){
        URI uri = UriComponentsBuilder.fromUriString(url).build().toUri();

        String requestStr= JSONObject.toJSONString(request);
        log.info("請求接口:{}, 請求報文:{}", url, requestStr);
        HttpHeaders headers = new HttpHeaders();    
        headers.setContentType(MediaType.APPLICATION_JSON);
        HttpEntity<String> httpEntity = new HttpEntity<>(requestStr, headers);
        ResponseEntity<String> responseEntity = restTemplate.exchange(uri, HttpMethod.POST, httpEntity, String.class);
                
        if (responseEntity == null) {
            return null;
        }
        
        String seqResult = "";
        try {
            if(responseEntity.getBody() != null ) {        
                if(responseEntity.getBody().contains("9001")) {
                    seqResult = new String(responseEntity.getBody().getBytes("ISO8859-1"),"utf-8");
                }else {
                    seqResult = new String(responseEntity.getBody().getBytes(),"utf-8");    
                }                                            
            }
            
            log.info("返回報文:{}", seqResult);
            
        } catch (UnsupportedEncodingException e) {
            log.error("接口返回異常", e);
        }

        return seqResult;
    }
}