java Http post请求发送json字符串

最近差点被业务逻辑搞懵逼，果然要先花时间思考，确定好流程再执行。目前最好用的jar包还是org.apache.http。

public class HttpClientHelper {

    private RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(15000).setConnectTimeout(15000)
            .setConnectionRequestTimeout(15000).build();

    private static HttpClientHelper instance = null;

    public HttpClientHelper() {
    }

    public static HttpClientHelper getInstance() {
        if (instance == null) {
            instance = new HttpClientHelper();
        }
        return instance;
    }

    /**
     * 发送 post请求
     *
     * @param httpUrl
     *            地址
     */
    public String sendHttpPost(String httpUrl) {
        HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost
        return sendHttpPost(httpPost);
    }

    /**
     * 发送 post请求
     *
     * @param httpUrl
     *            地址
     * @param params
     *            参数(格式:key1=value1&key2=value2)
     */
    public String sendHttpPost(String httpUrl, String params) {
        HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost
        try {
            // 设置参数
            StringEntity stringEntity = new StringEntity(params, "UTF-8");
            stringEntity.setContentType("application/x-www-form-urlencoded");
            httpPost.setEntity(stringEntity);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return sendHttpPost(httpPost);
    }

    /**
     * 发送 post请求
     *
     * @param httpUrl
     *            地址
     * @param maps
     *            参数
     */
    public String sendHttpPost(String httpUrl, Map<String, String> maps) {
        HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost
        // 创建参数队列
        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
        for (String key : maps.keySet()) {
            nameValuePairs.add(new BasicNameValuePair(key, maps.get(key)));
        }
        try {
            httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs, "UTF-8"));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return sendHttpPost(httpPost);
    }

    /**
     * 发送 post请求（带文件）
     *
     * @param httpUrl
     *            地址
     * @param maps
     *            参数
     * @param fileLists
     *            附件
     */
    public String sendHttpPost(String httpUrl, Map<String, String> maps, List<File> fileLists) {
        HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost
        MultipartEntityBuilder meBuilder = MultipartEntityBuilder.create();
        if (maps != null) {
            for (String key : maps.keySet()) {
                meBuilder.addPart(key, new StringBody(maps.get(key), ContentType.TEXT_PLAIN));
            }
        }
        if (fileLists != null) {
            for (File file : fileLists) {
                FileBody fileBody = new FileBody(file);
                meBuilder.addPart("files", fileBody);
            }
        }
        HttpEntity reqEntity = meBuilder.build();
        httpPost.setEntity(reqEntity);
        return sendHttpPost(httpPost);
    }

    /**
     * 发送Post请求
     *
     * @param httpPost
     * @return
     */
    private String sendHttpPost(HttpPost httpPost) {
        CloseableHttpClient httpClient = null;
        CloseableHttpResponse response = null;
        HttpEntity entity = null;
        String responseContent = null;
        try {
            // 创建默认的httpClient实例.
            httpClient = HttpClients.createDefault();
            httpPost.setConfig(requestConfig);
            // 执行请求
            response = httpClient.execute(httpPost);
            entity = response.getEntity();
            responseContent = EntityUtils.toString(entity, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                // 关闭连接,释放资源
                if (response != null) {
                    response.close();
                }
                if (httpClient != null) {
                    httpClient.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return responseContent;
    }

    public String sendJsonHttpPost(String url, String json) {

        CloseableHttpClient httpclient = HttpClients.createDefault();
        String responseInfo = null;
        try {
            HttpPost httpPost = new HttpPost(url);
            httpPost.addHeader("Content-Type", "application/json;charset=UTF-8");
            ContentType contentType = ContentType.create("application/json", CharsetUtils.get("UTF-8"));
            httpPost.setEntity(new StringEntity(json, contentType));
            CloseableHttpResponse response = httpclient.execute(httpPost);
            HttpEntity entity = response.getEntity();
            int status = response.getStatusLine().getStatusCode();
            if (status >= 200 && status < 300) {
                if (null != entity) {
                    responseInfo = EntityUtils.toString(entity);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                httpclient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return responseInfo;
    }

    /**
     * 发送 get请求
     *
     * @param httpUrl
     */
    public String sendHttpGet(String httpUrl) {
        HttpGet httpGet = new HttpGet(httpUrl);// 创建get请求
        return sendHttpGet(httpGet);
    }

    /**
     * 发送 get请求Https
     *
     * @param httpUrl
     */
    public String sendHttpsGet(String httpUrl) {
        HttpGet httpGet = new HttpGet(httpUrl);// 创建get请求
        return sendHttpsGet(httpGet);
    }

    /**
     * 发送Get请求
     *
     * @param httpGet
     * @return
     */
    private String sendHttpGet(HttpGet httpGet) {
        CloseableHttpClient httpClient = null;
        CloseableHttpResponse response = null;
        HttpEntity entity = null;
        String responseContent = null;
        try {
            // 创建默认的httpClient实例.
            httpClient = HttpClients.createDefault();
            httpGet.setConfig(requestConfig);
            // 执行请求
            response = httpClient.execute(httpGet);
            entity = response.getEntity();
            responseContent = EntityUtils.toString(entity, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                // 关闭连接,释放资源
                if (response != null) {
                    response.close();
                }
                if (httpClient != null) {
                    httpClient.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return responseContent;
    }

    /**
     * 发送Get请求Https
     *
     * @param httpGet
     * @return
     */
    private String sendHttpsGet(HttpGet httpGet) {
        CloseableHttpClient httpClient = null;
        CloseableHttpResponse response = null;
        HttpEntity entity = null;
        String responseContent = null;
        try {
            // 创建默认的httpClient实例.
            PublicSuffixMatcher publicSuffixMatcher = PublicSuffixMatcherLoader
                    .load(new URL(httpGet.getURI().toString()));
            DefaultHostnameVerifier hostnameVerifier = new DefaultHostnameVerifier(publicSuffixMatcher);
            httpClient = HttpClients.custom().setSSLHostnameVerifier(hostnameVerifier).build();
            httpGet.setConfig(requestConfig);
            // 执行请求
            response = httpClient.execute(httpGet);
            entity = response.getEntity();
            responseContent = EntityUtils.toString(entity, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                // 关闭连接,释放资源
                if (response != null) {
                    response.close();
                }
                if (httpClient != null) {
                    httpClient.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return responseContent;
    }

    public static void main(String[] args) {
        HttpClientHelper h = new HttpClientHelper();
        Map map = new HashMap();
        map.put("messageid", "test00201612210002");
        map.put("clientid", "test00");
        map.put("index_id", "买方会员");
        map.put("threshold", 0.9);
        List<String> data = new ArrayList<String>();
        data.add("wo xiang cha xun jin tian de yao pin jia ge lie biao");
        map.put("data", data);

        String json = JSON.toJSONString(map);

        String reply = h.sendJsonHttpPost("http://11.11.40.63:7777/algor/simclassify", json);
        System.out.println("reply->"+reply);
    }
}

java里遍历动态key:

LinkedHashMap<String, String> jsonMap = JSON.parseObject(jsonStr,new TypeReference<LinkedHashMap<String, String>>() {});
for (Map.Entry<String, String> entry : jsonMap.entrySet()) {
if (Float.valueOf(entry2.getValue()) > tempValue) {
key = entry.getKey());
value= entry.getValue();
}
}