HttpClient使用笔记

依赖

   <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.13</version>
        </dependency>

工具类

public class HttpUtil {

    private static CloseableHttpClient httpClient;

    static {
        PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
        cm.setMaxTotal(100);
        cm.setDefaultMaxPerRoute(20);
        cm.setDefaultMaxPerRoute(50);
        httpClient = HttpClients.custom().setConnectionManager(cm).build();
    }

    public static String get(String url) {
        CloseableHttpResponse response = null;
        BufferedReader in = null;
        String result = "";
        try {
            HttpGet httpGet = new HttpGet(url);
            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(30000).setConnectionRequestTimeout(30000).setSocketTimeout(30000).build();
            httpGet.setConfig(requestConfig);
            httpGet.setConfig(requestConfig);
            httpGet.addHeader("Content-type", "application/json; charset=utf-8");
            httpGet.setHeader("Accept", "application/json");
            response = httpClient.execute(httpGet);
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
            StringBuffer sb = new StringBuffer("");
            String line = "";
            String NL = System.getProperty("line.separator");
            while ((line = in.readLine()) != null) {
                sb.append(line + NL);
            }
            in.close();
            result = sb.toString();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != response) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

    public static String post(String url, String jsonString) {
        CloseableHttpResponse response = null;
        BufferedReader in = null;
        String result = "";
        try {
            HttpPost httpPost = new HttpPost(url);
            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(30000).setConnectionRequestTimeout(30000).setSocketTimeout(30000).build();
            httpPost.setConfig(requestConfig);
            httpPost.setConfig(requestConfig);
            httpPost.addHeader("Content-type", "application/json; charset=utf-8");
            httpPost.setHeader("Accept", "application/json");
            httpPost.setEntity(new StringEntity(jsonString, Charset.forName("UTF-8")));
            response = httpClient.execute(httpPost);
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
            StringBuffer sb = new StringBuffer("");
            String line = "";
            String NL = System.getProperty("line.separator");
            while ((line = in.readLine()) != null) {
                sb.append(line + NL);
            }
            in.close();
            result = sb.toString();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != response) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }


}

使用

//获取微信的AccessToken    
private JSONObject invokeWxAccessToken(){
        StringBuffer stringBuffer = new StringBuffer();
        stringBuffer.append(wxAccessConfig.getAccessTokenUrl());
        stringBuffer.append(WechatConstant.APP_ID).append(wxAccessConfig.getAppId());
        stringBuffer.append(WechatConstant.APP_SECRET).append(wxAccessConfig.getDecryptAppSecret());
        stringBuffer.append(wxAccessConfig.getGrandType());
        //获取access_token
        String url = stringBuffer.toString();
        String response = HttpUtil.get(url);
        JSONObject resultJson = JSON.parseObject(response);
        if (resultJson.containsKey(WechatConstant.API_ERROR_CODE) && WX_SUCCESS_CODE != resultJson.getInteger(WechatConstant.API_ERROR_CODE)) {
            throw new BusinessException(String.valueOf(resultJson.get(WechatConstant.API_ERROR_MSG)), String.valueOf(resultJson.get(WechatConstant.API_ERROR_CODE)));
        }
        return resultJson;
    }