使用HttpClient封装get post put delete请求

　　　　　<dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.6</version>
        </dependency>

public static String doGet(String url, Map<String, String> param) {

        // 创建Httpclient对象
        CloseableHttpClient httpclient = HttpClients.createDefault();

        String resultString = "";
        CloseableHttpResponse response = null;
        try {
            // 创建uri
            URIBuilder builder = new URIBuilder(url);
            if (param != null) {
                for (String key : param.keySet()) {
                    builder.addParameter(key, param.get(key));
                }
            }
            URI uri = builder.build();

            // 创建http GET请求
            HttpGet httpGet = new HttpGet(uri);

            // 执行请求
            response = httpclient.execute(httpGet);
            // 判断返回状态是否为200
            if (response.getStatusLine().getStatusCode() == 200) {
                resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
            }
        } catch (Exception e) {

        } finally {
            try {
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {

            }
        }
        return resultString;
    }

 public static String doPost(String url, Map<String, String> param) {
        // 创建Httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 创建Http Post请求
            HttpPost httpPost = new HttpPost(url);
            // 创建参数列表
            if (param != null) {
                List<NameValuePair> paramList = new ArrayList<>();
                for (String key : param.keySet()) {
                    paramList.add(new BasicNameValuePair(key, param.get(key)));
                }
                // 模拟表单
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);
                httpPost.setEntity(entity);
            }
            // 执行http请求
            response = httpClient.execute(httpPost);
            resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
        } catch (Exception e) {

        } finally {
            try {
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {

            }
        }
        return resultString;
    }

 public static String doPost(String url, String json) {
        // 创建Httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 创建Http Post请求
            HttpPost httpPost = new HttpPost(url);
            // 创建请求内容
            StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);
            httpPost.setEntity(entity);
            // 执行http请求
            response = httpClient.execute(httpPost);
            resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
        } catch (Exception e) {


        } finally {
            try {
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {

            }
        }

        return resultString;
    }

 public static String doPut(String url, String json) {
        // 创建Httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 创建Http Put请求
            HttpPut httpPut = new HttpPut(url);
            // 创建请求内容
            StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);
            httpPut.setEntity(entity);
            // 执行http请求
            response = httpClient.execute(httpPut);
            resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
        } catch (Exception e) {


        } finally {
            try {
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {

            }
        }

        return resultString;
    }

public static String doDelete(String url, Map<String, String> param) {
        // 创建Httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 创建uri
            URIBuilder builder = new URIBuilder(url);
            if (param != null) {
                for (String key : param.keySet()) {
                    builder.addParameter(key, param.get(key));
                }
            }
            URI uri = builder.build();
            // 创建Http Delete请求
            HttpDelete httpDelete = new HttpDelete(uri);
            // 执行http请求
            response = httpClient.execute(httpDelete);
            resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
        } catch (Exception e) {


        } finally {
            try {
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {

            }
        }

        return resultString;
    }