学习整理HttpClient4.5成http访问服务类

末蓝、 2022-07-11 07:57 247阅读 0赞

在项目中经常有访问http的需要，HttpClient是一个Apache下一个传统又实用的http工具包，看了介绍，每个版本变化挺大，网上资料也好多是3.X版本，如下是我整理的对4.5.2版本的封装，提供了get和post方法的简便使用，这里使用的方法比较传统，下篇再介绍使用Fluent API封装get和post方法，代码将是简洁流畅。

### HttpClient官网： ###

> [https://hc.apache.org/index.html][https_hc.apache.org_index.html]

HttpClient分为5大组件，我用了其中两个。

### mavne依赖： ###

<dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpmime</artifactId>
        <version>4.5.2</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.1</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.velocity</groupId>
        <artifactId>velocity</artifactId>
        <version>1.7</version>
    </dependency>

### get和post方法的封装： ###

import com.google.common.collect.Lists;
    import org.apache.commons.collections.CollectionUtils;
    import org.apache.commons.collections.MapUtils;
    import org.apache.commons.lang3.StringUtils;
    import org.apache.http.*;
    import org.apache.http.client.entity.UrlEncodedFormEntity;
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.client.methods.HttpPost;
    import org.apache.http.client.utils.URLEncodedUtils;
    import org.apache.http.entity.ContentType;
    import org.apache.http.entity.mime.MultipartEntityBuilder;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.impl.conn.DefaultProxyRoutePlanner;
    import org.apache.http.message.BasicNameValuePair;
    import org.apache.http.util.EntityUtils;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.util.Assert;
    
    import java.io.File;
    import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.util.List;
    import java.util.Map;
    
    /** * @author wzx * @time 2017/1/19 */
    public class HttpService { 
    
        private static final Logger LOGGER = LoggerFactory.getLogger(HttpService.class);
    
        public String doGet(String url) {
            return doGet(url, null);
        }
    
        public String doGet(String url, Map<String, String> parameters) {
            return doGet(url, null, null, null, parameters);
        }
    
        public String doGet(String url, String hostName, Integer port, String schemeName, Map<String, String> parameters) {
            CloseableHttpClient client = buildClient(hostName, port, schemeName);
            return executeGet(client, url, parameters);
        }
    
        public String doPost(String url) {
            return doPost(url, null);
        }
    
        public String doPost(String url, List<NameValuePair> nameValuePairs) {
            return doPost(url, null, null, null, nameValuePairs, null);
        }
    
        public void doPost(String url, List<NameValuePair> nameValuePairs, List<File> files) {
            doPost(url, null, null, null, nameValuePairs, files);
        }
    
        public String doPost(String url, String hostName, Integer port, String schemeName, List<NameValuePair> nameValuePairs, List<File> files) {
            CloseableHttpClient client = buildClient(hostName, port, schemeName);
            return executePost(client, url, nameValuePairs, files);
        }
    
        /** * 构建HttpClient * @param hostName 代理主机 * @param port 代理主机端口 * @param schemeName 默认是http * @return 不使用代理返回默认的httpClient */
        private CloseableHttpClient buildClient(String hostName, Integer port, String schemeName) {
            CloseableHttpClient httpClient;
            if(StringUtils.isEmpty(hostName) || port == null) {
                //不使用代理
                httpClient = HttpClients.createDefault();
            } else {
                //设置代理
                if (StringUtils.isEmpty(schemeName)) {
                    schemeName = HttpHost.DEFAULT_SCHEME_NAME;
                }
                HttpHost httpHost = new HttpHost(hostName, port, schemeName);
                DefaultProxyRoutePlanner routePlanner = new DefaultProxyRoutePlanner(httpHost);
                httpClient = HttpClients.custom().setRoutePlanner(routePlanner).build();
            }
            return httpClient;
        }
    
        /** * 执行GET请求 * @param client * @param url * @param paramMap * @return */
        private String executeGet(CloseableHttpClient client, String url, Map<String, String> paramMap) {
            Assert.notNull(url, "url is null");
            Assert.notNull(client, "closeableHttpClient is null");
    
            if(MapUtils.isNotEmpty(paramMap)) {
                List<NameValuePair> paramList = Lists.newArrayListWithCapacity(paramMap.size());
                for (String key : paramMap.keySet()) {
                    paramList.add(new BasicNameValuePair(key, paramMap.get(key)));
                }
                //拼接参数
                url += "?" + URLEncodedUtils.format(paramList, Consts.UTF_8);
            }
    
            CloseableHttpResponse response = null;
            try {
                HttpGet get = new HttpGet(url);
                response = client.execute(get);
                return processResponse(response);
            } catch (Exception e) {
                LOGGER.error(e.getMessage(), e.toString());
            } finally {
                close(client, response);
            }
            return null;
        }
    
        /** * 执行POST请求 * @param httpClient * @param url * @param nameValuePairs * @return */
        private String executePost(CloseableHttpClient httpClient, String url, List<NameValuePair> nameValuePairs, List<File> files) {
            Assert.notNull(url, "url is null");
            Assert.notNull(httpClient, "closeableHttpClient is null");
            CloseableHttpResponse response = null;
            try {
                HttpPost post = new HttpPost(url);
                HttpEntity entity = buildPostParam(nameValuePairs, files);
                if(entity != null) {
                    post.setEntity(entity);
                }
                response = httpClient.execute(post);
                return processResponse(response);
            } catch(Exception e) {
                LOGGER.error(e.getMessage(), e.toString());
            } finally {
                close(httpClient, response);
            }
            return null;
        }
    
        /** * 构建POST方法请求参数 * @return */
        private HttpEntity buildPostParam(List<NameValuePair> nameValuePairs, List<File> files) {
            if(CollectionUtils.isEmpty(nameValuePairs) && CollectionUtils.isEmpty(files)) {
                return null;
            }
            if(CollectionUtils.isNotEmpty(files)) {
                MultipartEntityBuilder builder = MultipartEntityBuilder.create();
                for (File file : files) {
                    builder.addBinaryBody(file.getName(), file, ContentType.APPLICATION_OCTET_STREAM, file.getName());
                }
                for (NameValuePair nameValuePair : nameValuePairs) {
                    //设置ContentType为UTF-8,默认为text/plain; charset=ISO-8859-1,传递中文参数会乱码
                    builder.addTextBody(nameValuePair.getName(), nameValuePair.getValue(), ContentType.create("text/plain", Consts.UTF_8));
                }
                return builder.build();
            } else {
                try {
                    return new UrlEncodedFormEntity(nameValuePairs);
                } catch (UnsupportedEncodingException e) {
                    LOGGER.error(e.getMessage(), e.toString());
                }
            }
            return null;
        }
    
        private String processResponse(CloseableHttpResponse response) {
            try {
                if (response != null && response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                    HttpEntity entity = response.getEntity();
                    if (entity != null) {
                        return EntityUtils.toString(entity, Consts.UTF_8);
                    }
                }
            } catch(Exception e) {
                LOGGER.error(e.getMessage(), e.toString());
            } finally {
                close(null, response);
            }
            return null;
        }
    
        private void close(CloseableHttpClient httpClient, CloseableHttpResponse response) {
            try {
                if (response != null) {
                    response.close();
                }
                if (httpClient != null) {
                    httpClient.close();
                }
            } catch (IOException e) {
                LOGGER.error(e.getMessage(), e.toString());
            }
        }
    
    }

### 单元测试： ###

private String url = "https://hc.apache.org/httpcomponents-client-4.5.x/examples.html";
    
    @Test
    public void testGet() {
        String result = httpService.doGet(url);
        LOGGER.info("返回结果:{}", result);
    }
    
    @Test
    public void testGetParameter() {
        HashMap<String, String> map = Maps.newHashMap();
        map.put("name", "wang");
        map.put("value", "hello");
        String result = httpService.doGet(url, null);
        LOGGER.info("返回结果:{}", result);
    }
    
    @Test
    public void testGetProxy() {
        String result = httpService.doGet(url, "119.28.99.246", 8998, null, null);
        LOGGER.info("返回结果:{}", result);
    }
    
    @Test
    public void testPost() {
        String result = httpService.doPost(url, null);
        LOGGER.info("返回结果:{}", result);
    }
    
    @Test
    public void testPostProxy() {
        String result = httpService.doPost(url, "119.28.99.246", 8998, null, null, null);
        LOGGER.info("返回结果:{}", result);
    }
    
    @Test
    public void testPostParam() throws IOException, URISyntaxException {
        List<NameValuePair> nameValuePairs = Lists.newArrayList();
        nameValuePairs.add(new BasicNameValuePair("name", "王志雄"));
        List<File> fileList = Lists.newArrayList();
        fileList.add(new File("D:\\response.html"));
        String result = httpService.doPost(url, "localhost", 8888, HttpHost.DEFAULT_SCHEME_NAME, nameValuePairs, fileList);
        LOGGER.info("返回结果:{}", result);
    }

有问题可以留言探讨。

[https_hc.apache.org_index.html]: https://hc.apache.org/index.html