整理HttpClient4.5的Fluent API的用法

我会带着你远行 2022-07-11 08:11 243阅读 0赞

这是接着上一篇对HttpClient4.5的使用总结，HttpClient真是一个好东西，一直保持更新，还推出流畅的写法，使得代码更加简洁易懂，非常好用。

HttpClient Tutorial：

> [https://hc.apache.org/httpcomponents-client-4.5.x/tutorial/html/index.html][https_hc.apache.org_httpcomponents-client-4.5.x_tutorial_html_index.html]

这篇blog介绍的是Fluent API的用法，我把最常用的的get和post方法封装成服务类，如下介绍。

### 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.httpcomponents</groupId>
        <artifactId>httpclient-osgi</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>

### 服务类HttpFluentService，封装get和post方法： ###

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.Consts;
    import org.apache.http.HttpEntity;
    import org.apache.http.HttpHost;
    import org.apache.http.NameValuePair;
    import org.apache.http.client.entity.UrlEncodedFormEntity;
    import org.apache.http.client.fluent.Request;
    import org.apache.http.client.utils.URLEncodedUtils;
    import org.apache.http.entity.ContentType;
    import org.apache.http.entity.mime.MultipartEntityBuilder;
    import org.apache.http.message.BasicNameValuePair;
    import org.apache.http.util.Args;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    import java.io.File;
    import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.util.List;
    import java.util.Map;
    
    /** * @author wzx * @time 2017/1/20 */
    public class HttpFluentService { 
    
        private static final Logger LOGGER = LoggerFactory.getLogger(HttpFluentService.class);
    
        public String doGet(String url) {
            try {
                return Request.Get(url).execute().returnContent().asString(Consts.UTF_8);
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
    
        public String doGet(String url, Map<String, String> paramMap) {
            return doGet(url, null, null, null, paramMap);
        }
    
        public String doGet(String url, String hostName, Integer port, String schemeName, Map<String, String> paramMap) {
            return executeGet(url, hostName, port, schemeName, paramMap);
        }
    
        private String executeGet(String url, String hostName, Integer port, String schemeName, Map<String, String> paramMap) {
            Args.notNull(url, "url");
    
            url = buildGetParam(url, paramMap);
            Request request = Request.Get(url);
            request = buildProxy(request, hostName, port, schemeName);
            try {
                return request.execute().returnContent().asString(Consts.UTF_8);
            } catch (IOException e) {
                LOGGER.error(e.getMessage(), e.toString());
            }
            return null;
        }
    
        private String buildGetParam(String url, Map<String, String> paramMap) {
            Args.notNull(url, "url");
            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);
            }
            return url;
        }
    
        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) {
            return executePost(url, hostName, port, schemeName, nameValuePairs, files);
        }
    
        private String executePost(String url, String hostName, Integer port, String schemeName, List<NameValuePair> nameValuePairs, List<File> files) {
            Args.notNull(url, "url");
            HttpEntity entity = buildPostParam(nameValuePairs, files);
            Request request = Request.Post(url).body(entity);
            request = buildProxy(request, hostName, port, schemeName);
            try {
                return request.execute().returnContent().asString(Consts.UTF_8);
            } catch (IOException e) {
                LOGGER.error(e.getMessage(), e.toString());
            }
            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;
        }
    
        /** * 设置代理 * @param request * @param hostName * @param port * @param schemeName * @return */
        private Request buildProxy(Request request, String hostName, Integer port, String schemeName) {
            if(StringUtils.isNotEmpty(hostName) && port != null) {
                //设置代理
                if (StringUtils.isEmpty(schemeName)) {
                    schemeName = HttpHost.DEFAULT_SCHEME_NAME;
                }
                request.viaProxy(new HttpHost(hostName, port, schemeName));
            }
            return request;
        }
    
    }

### 单元测试： ###

private String url = "https://hc.apache.org/httpcomponents-client-4.5.x/examples.html";
    
    @Test
        public void testGet() {
            String result = fluentService.doGet(url);
            LOGGER.info("返回结果：{}", result);
        }
    
        @Test
        public void testGetParam() {
            HashMap<String, String> map = Maps.newHashMap();
            map.put("name", "wang");
            map.put("value", "hello");
            String result = fluentService.doGet(url, map);
            LOGGER.info("返回结果：{}", result);
        }
    
        @Test
        public void testGetProxy() {
            HashMap<String, String> map = Maps.newHashMap();
            map.put("name", "wang");
            map.put("value", "hello");
            String result = fluentService.doGet(url, "localhost", 8888, null, map);
            LOGGER.info("返回结果:{}", result);
        }
    
        @Test
        public void testPost() {
            String result = fluentService.doPost(url, null);
            LOGGER.info("返回结果:{}", result);
        }
    
        @Test
        public void testPostProxy() {
            String result = fluentService.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 = fluentService.doPost(url, "localhost", 8888, HttpHost.DEFAULT_SCHEME_NAME, nameValuePairs, fileList);
            LOGGER.info("返回结果:{}", result);
        }

[https_hc.apache.org_httpcomponents-client-4.5.x_tutorial_html_index.html]: https://hc.apache.org/httpcomponents-client-4.5.x/tutorial/html/index.html