HttpClient 工具类封装

1.添加依赖 mvn

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.5</version>
</dependency>

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
　　<version>3.8.1</version>
</dependency>


2.创建工具类 ：HttpClientUtils

import org.apache.http.client.methods.*;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.net.URI;
import java.util.Map;

public class HttpClientUtils {

    private static Logger logger = LoggerFactory.getLogger(HttpClientUtils.class);

    private static final String CHARSET_UTF8 = "UTF-8";
    private static final int HTTP_STATUS_200 = 200;

    /**
     * GET PARAM
     * @param url
     * @param param
     * @return
     */
    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();
            HttpGet httpGet = new HttpGet(uri);
            response = httpclient.execute(httpGet);

            // 判断返回状态是否为200
            if (HTTP_STATUS_200 == response.getStatusLine().getStatusCode()) {
                resultString = EntityUtils.toString(response.getEntity(), CHARSET_UTF8);
            }

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

        return resultString;

    }

    public static String doGet(String url) {
        return doGet(url, null);
    }

    /**
     * POST MAP PARAM
     * @param url
     * @param param
     * @return
     */
    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uri
            URIBuilder builder = new URIBuilder(url);
            if (param != null) {
                for (String key : param.keySet()) {
                    builder.addParameter(key, param.get(key));
                }
            }
            URI uri = builder.build();
            HttpPost httpPost = new HttpPost(uri);

            // 执行http请求
            response = httpClient.execute(httpPost);
            resultString = EntityUtils.toString(response.getEntity(), CHARSET_UTF8);

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return resultString;

    }

    public static String doPost(String url) {
        return doPost(url, null);
    }

    /**
     * POST JSON
     * @param url
     * @param json
     * @return
     */
    public static String doPostJson(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(), CHARSET_UTF8);

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return resultString;

    }

    /**
     * PUT JSON
     * @param url
     * @param json
     * @return
     */
    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(), CHARSET_UTF8);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return resultString;
    }

    /**
     * DELETE MAP PARAM
     * @param url
     * @param param
     * @return
     */
    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(), CHARSET_UTF8);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return resultString;
    }

}