轻松把玩HttpClient之封装HttpClient工具类(一)(现有网上分享中的最强大的工具类)

x33g5p2x  于2021-12-28 转载在 其他  
字(15.8k)|赞(0)|评价(0)|浏览(229)

     搜了一下网络上别人封装的HttpClient,大部分特别简单,有一些看起来比较高级,但是用起来都不怎么好用。调用关系不清楚,结构有点混乱。所以也就萌生了自己封装HttpClient工具类的想法。要做就做最好的,本工具类支持插件式配置Header、插件式配置httpclient对象,这样就可以方便地自定义header信息、配置ssl、配置proxy等。

     是不是觉得说的有点悬乎了,那就先看看调用吧:

public static void testSimple() throws HttpProcessException{ String url = "http://www.oschina.net"; //简单调用 String resp = HttpClientUtil.send(url); System.out.println("请求结果内容长度:"+ resp.length()); } public static void testOne() throws HttpProcessException{ String url = "https://sso.tgb.com:8443/cas/login"; //自定义HttpClient,设置超时、代理、ssl //HttpClient client= HCB.custom().timeout(10000).proxy("127.0.0.1", 8087).ssl().build();//采用默认方式(绕过证书验证) HttpClient client= HCB.custom().timeout(10000).ssl("D:\\keys\\wsriakey","tomcat").build(); //设置header信息 Header[] headers=HttpHeader.custom().keepAlive("false").connection("close").contentType(Headers.APP_FORM_URLENCODED).build(); //执行请求 String resp=HttpClientUtil.send(client, url, headers); System.out.println("请求结果如下:"); System.out.println(resp); }

     轻松配置了代理、自定义证书的ssl、以及各种header头信息,是不是觉得还凑合呢,那就继续看吧。

     写这个工具类时,抽象了一下所有的demo,最后封装了一个最基本的方法(拆分成了2个方法了),其所有参数列表有:HttpClient对象、url(必须有)、请求方式、请求参数parasMap、header数组、编码格式encoding。

     由于封装的是工具类,所以最好是无状态的,可以支持多线程的方式调用的,所以方法都是static类型的。这也是为什么要把HttpClient对象也是作为了一个参数传入而非成员变量了,而且这样也为扩展HttpClient的配置提供了便利。

     因为HTTP1.1规范中定义了6种HTTP方法:GET, HEAD, POST, PUT, DELETE, TRACE 和 OPTIONS,其实还有一个PATCH,这几个方法在HttpClient中都有一个对应的类:HttpGet,HttpHead,HttpPost,HttpPut,HttpDelete,HttpTrace、HttpOptions以及HttpPatch。所有的这些类均继承了HttpRequestBase超类,故可以作为参数使用(用枚举类作为参数,用另一个方法来创建具体的请求方法对象)。

     Header头信息也是作为一个重要的参数,在请求特定网站的时候需要设置不同的Header,而header又是比较繁杂的,所以这里也是作为了一个参数传入的,也是方便扩展。

     使用map来作为post方式传入参数是习惯使然,不做过多的解释。

     编码这个参数主要是为了为待提交的数据和反馈结果进行转码处理。

     简单说一下流程:

    1. 创建请求对象request;
  1. 为request设置header信息;
  2. 判断当前请求对象是否是HttpEntityEnclosingRequestBase的子类,如果是,则支持setEntity方法,来设置参数。
  3. 执行请求,并拿到结果(同步阻塞);
  4. 获取并解码请求结果实体;
  5. 关闭链接

     就是这么简单,具体来看看代码吧:

/** * 请求资源或服务,自定义client对象,传入请求参数,设置内容类型,并指定参数和返回数据的编码 * * @param client client对象 * @param url 资源地址 * @param httpMethod 请求方法 * @param parasMap 请求参数 * @param headers 请求头信息 * @param encoding 编码 * @return 返回处理结果 * @throws HttpProcessException */ public static String send(HttpClient client, String url, HttpMethods httpMethod, Map<String,String>parasMap,  Header[] headers, String encoding) throws HttpProcessException { String body = ""; try { //创建请求对象 HttpRequestBase request = getRequest(url, httpMethod); //设置header信息 request.setHeaders(headers); //判断是否支持设置entity(仅HttpPost、HttpPut、HttpPatch支持) if(HttpEntityEnclosingRequestBase.class.isAssignableFrom(request.getClass())){ List<NameValuePair> nvps = new ArrayList<NameValuePair>(); //检测url中是否存在参数 url = Utils.checkHasParas(url, nvps); //装填参数 Utils.map2List(nvps, parasMap); //设置参数到请求对象中 ((HttpEntityEnclosingRequestBase)request).setEntity(new UrlEncodedFormEntity(nvps, encoding)); logger.debug("请求地址:"+url); if(nvps.size()>0){ logger.debug("请求参数:"+nvps.toString()); } }else{ int idx = url.indexOf("?"); logger.debug("请求地址:"+url.substring(0, (idx>0 ? idx-1:url.length()-1))); if(idx>0){ logger.debug("请求参数:"+url.substring(idx+1)); } } //调用发送请求 body = execute(client, request, url, encoding); } catch (UnsupportedEncodingException e) { throw new HttpProcessException(e); } return body; } /** * 请求资源或服务 * * @param client client对象 * @param request 请求对象 * @param url 资源地址 * @param parasMap 请求参数 * @param encoding 编码 * @return 返回处理结果 * @throws HttpProcessException */ private static String execute(HttpClient client, HttpRequestBase request,String url, String encoding) throws HttpProcessException { String body = ""; HttpResponse response =null; try { //执行请求操作,并拿到结果(同步阻塞) response = client.execute(request); //获取结果实体 HttpEntity entity = response.getEntity(); if (entity != null) { //按指定编码转换结果实体为String类型 body = EntityUtils.toString(entity, encoding); logger.debug(body); } EntityUtils.consume(entity); } catch (ParseException | IOException e) { throw new HttpProcessException(e); } finally { close(response); } return body; }

     第一个方法中,我们看到有HttpMethods类型的参数,在创建request对象时,用到了它。它是什么呢?其实只是一个枚举类:

/** * 枚举HttpMethods方法 * * @author arron * @date 2015年11月17日 下午4:45:59 * @version 1.0 */ public enum HttpMethods{ /** * 求获取Request-URI所标识的资源 */ GET(0, "GET"), /** * 向指定资源提交数据进行处理请求(例如提交表单或者上传文件)。数据被包含在请求体中。 * POST请求可能会导致新的资源的建立和/或已有资源的修改 */ POST(1, "POST"), /** * 向服务器索要与GET请求相一致的响应,只不过响应体将不会被返回。 * 这一方法可以在不必传输整个响应内容的情况下,就可以获取包含在响应消息头中的元信息 * 只获取响应信息报头 */ HEAD(2, "HEAD"), /** * 向指定资源位置上传其最新内容(全部更新,操作幂等) */ PUT (3, "PUT"), /** * 请求服务器删除Request-URI所标识的资源 */ DELETE (4, "DELETE"), /** * 请求服务器回送收到的请求信息,主要用于测试或诊断 */ TRACE(5, "TRACE"), /** * 向指定资源位置上传其最新内容(部分更新,非幂等) */ PATCH (6, "PATCH"), /** * 返回服务器针对特定资源所支持的HTTP请求方法。 * 也可以利用向Web服务器发送'*'的请求来测试服务器的功能性 */ OPTIONS (7, "OPTIONS"), // /** // * HTTP/1.1协议中预留给能够将连接改为管道方式的代理服务器 // */ // CONNECT(99, "CONNECT"), ; private int code; private String name; private HttpMethods(int code, String name){ this.code = code; this.name = name; } public String getName() { return name; } public int getCode() { return code; } }

通过getRequest方法,来实例化对应方法的请求对象。

/** * 根据请求方法名,获取request对象 * * @param url 资源地址 * @param method 请求方式 * @return */ private static HttpRequestBase getRequest(String url, HttpMethods method) { HttpRequestBase request = null; switch (method.getCode()) { case 0:// HttpGet request = new HttpGet(url); break; case 1:// HttpPost request = new HttpPost(url); break; case 2:// HttpHead request = new HttpHead(url); break; case 3:// HttpPut request = new HttpPut(url); break; case 4:// HttpDelete request = new HttpDelete(url); break; case 5:// HttpTrace request = new HttpTrace(url); break; case 6:// HttpPatch request = new HttpPatch(url); break; case 7:// HttpOptions request = new HttpOptions(url); break; default: request = new HttpPost(url); break; } return request; }

当然最后的关闭链接也是一个小方法:

/** * 尝试关闭response * * @param resp HttpResponse对象 */ private static void close(HttpResponse resp) { try { if(resp == null) return; //如果CloseableHttpResponse 是resp的父类,则支持关闭 if(CloseableHttpResponse.class.isAssignableFrom(resp.getClass())){ ((CloseableHttpResponse)resp).close(); } } catch (IOException e) { logger.error(e); } }

     当然各种参数的组合方法也简单提供一下(为了节约空间,已去掉注释):

public static String send(String url) throws HttpProcessException { return send(url, Charset.defaultCharset().name()); } public static String send(String url, String encoding) throws HttpProcessException { return send(url, new Header[]{},encoding); } public static String send(String url, Header[] headers) throws HttpProcessException { return send(url, headers, Charset.defaultCharset().name()); } public static String send(String url, Header[] headers, String encoding) throws HttpProcessException { return send(url, new HashMap<String,String>(), headers, encoding); } public static String send(String url, Map<String,String>parasMap) throws HttpProcessException { return send(url, parasMap, Charset.defaultCharset().name()); } public static String send(String url, Map<String,String>parasMap, String encoding) throws HttpProcessException { return send(url, parasMap, new Header[]{}, encoding); } public static String send(String url, Map<String,String>parasMap, Header[] headers) throws HttpProcessException { return send(url, parasMap, headers, Charset.defaultCharset().name()); } public static String send(String url, Map<String,String>parasMap, Header[] headers, String encoding) throws HttpProcessException { return send(url, HttpMethods.POST, parasMap, headers, encoding); } public static String send(String url, HttpMethods httpMethod) throws HttpProcessException { return send(url, httpMethod, Charset.defaultCharset().name()); } public static String send(String url, HttpMethods httpMethod, String encoding) throws HttpProcessException { return send(url, httpMethod, new Header[]{},encoding); } public static String send(String url, HttpMethods httpMethod, Header[] headers) throws HttpProcessException { return send(url, httpMethod, headers, Charset.defaultCharset().name()); } public static String send(String url, HttpMethods httpMethod, Header[] headers, String encoding) throws HttpProcessException { return send(url, httpMethod, new HashMap<String, String>(), headers, encoding); } public static String send(String url, HttpMethods httpMethod, Map<String,String>parasMap) throws HttpProcessException { return send(url, httpMethod, parasMap, Charset.defaultCharset().name()); } public static String send(String url, HttpMethods httpMethod, Map<String,String>parasMap, String encoding) throws HttpProcessException { return send(url, httpMethod, parasMap, new Header[]{}, encoding); } public static String send(String url, HttpMethods httpMethod, Map<String,String>parasMap, Header[] headers) throws HttpProcessException { return send(url, httpMethod, parasMap, headers, Charset.defaultCharset().name()); } public static String send(String url, HttpMethods httpMethod, Map<String,String>parasMap, Header[] headers, String encoding) throws HttpProcessException { return send(create(url), url, httpMethod, parasMap, headers, encoding); } public static String send(HttpClient client, String url) throws HttpProcessException { return send(client, url, Charset.defaultCharset().name()); } public static String send(HttpClient client, String url, String encoding) throws HttpProcessException { return send(client, url, new Header[]{}, encoding); } public static String send(HttpClient client, String url, Header[] headers) throws HttpProcessException { return send(client, url, headers, Charset.defaultCharset().name()); } public static String send(HttpClient client, String url, Header[] headers, String encoding) throws HttpProcessException { return send(client, url, new HashMap<String, String>(), headers, encoding); } public static String send(HttpClient client, String url, Map<String,String>parasMap) throws HttpProcessException { return send(client, url, parasMap, Charset.defaultCharset().name()); } public static String send(HttpClient client, String url, Map<String,String>parasMap, String encoding) throws HttpProcessException { return send(client, url, parasMap, new Header[]{}, encoding); } public static String send(HttpClient client, String url, Map<String,String>parasMap, Header[] headers) throws HttpProcessException { return send(client, url, parasMap, headers, Charset.defaultCharset().name()); } public static String send(HttpClient client, String url, Map<String,String>parasMap,Header[] headers,String encoding) throws HttpProcessException { return send(client, url, HttpMethods.POST, parasMap, headers, encoding); } public static String send(HttpClient client, String url, HttpMethods httpMethod) throws HttpProcessException { return send(client, url, httpMethod, Charset.defaultCharset().name()); } public static String send(HttpClient client, String url, HttpMethods httpMethod, String encoding) throws HttpProcessException { return send(client, url, httpMethod, new Header[]{}, encoding); } public static String send(HttpClient client, String url, HttpMethods httpMethod, Header[] headers) throws HttpProcessException { return send(client, url, httpMethod, headers, Charset.defaultCharset().name()); } public static String send(HttpClient client, String url, HttpMethods httpMethod, Header[] headers, String encoding) throws HttpProcessException { return send(client, url, httpMethod, new HashMap<String, String>(), headers, encoding); } public static String send(HttpClient client, String url, HttpMethods httpMethod, Map<String,String>parasMap) throws HttpProcessException { return send(client, url, httpMethod, parasMap, Charset.defaultCharset().name()); } public static String send(HttpClient client, String url, HttpMethods httpMethod, Map<String,String>parasMap, String encoding) throws HttpProcessException { return send(client, url, httpMethod, parasMap, new Header[]{}, encoding); } public static String send(HttpClient client, String url, HttpMethods httpMethod, Map<String,String>parasMap, Header[] headers) throws HttpProcessException { return send(client, url, httpMethod, parasMap, headers, Charset.defaultCharset().name()); }

     可以看到上面这一堆方法,其实主要分成2类,一类是传入client对象的,一组是没有传入的。也就是说该工具类提供了一种默认的client对象。这个将会在下一篇文章会有补充。

     当然,为了方便操作,还是提供了get、post、put、patch、delete、head、options、trace等方法,由于推荐使用send方法,所以这几个方法只是做了一个简单的调用:

public static String get(String url, Header[] headers,String encoding) throws HttpProcessException { return get(create(url), url, headers, encoding); } public static String get(HttpClient client, String url, Header[] headers,String encoding) throws HttpProcessException { return send(client, url, HttpMethods.GET, headers, encoding); } public static String post(String url, Map<String,String>parasMap,Header[] headers,String encoding) throws HttpProcessException { return post(create(url), url, parasMap, headers, encoding); } public static String post(HttpClient client, String url, Map<String,String>parasMap,Header[] headers,String encoding) throws HttpProcessException { return send(client, url, HttpMethods.POST, parasMap, headers, encoding); } public static String put(String url, Map<String,String>parasMap,Header[] headers,String encoding) throws HttpProcessException { return put(create(url), url, parasMap, headers, encoding); } public static String put(HttpClient client, String url, Map<String,String>parasMap,Header[] headers,String encoding) throws HttpProcessException { return send(client, url, HttpMethods.PUT, parasMap, headers, encoding); } public static String delete(String url, Header[] headers,String encoding) throws HttpProcessException { return delete(create(url), url, headers, encoding); } public static String delete(HttpClient client, String url, Header[] headers,String encoding) throws HttpProcessException { return send(client, url, HttpMethods.DELETE, headers, encoding); } public static String patch(String url, Map<String,String>parasMap,Header[] headers,String encoding) throws HttpProcessException { return patch(create(url), url, parasMap, headers, encoding); } public static String patch(HttpClient client, String url, Map<String,String>parasMap, Header[] headers,String encoding) throws HttpProcessException { return send(client, url, HttpMethods.PATCH, parasMap, headers, encoding); } public static String head(String url, Header[] headers,String encoding) throws HttpProcessException { return head(create(url), url, headers, encoding); } public static String head(HttpClient client, String url, Header[] headers,String encoding) throws HttpProcessException { return send(client, url, HttpMethods.HEAD, headers, encoding); } public static String options(String url, Header[] headers,String encoding) throws HttpProcessException { return options(create(url), url, headers, encoding); } public static String options(HttpClient client, String url, Header[] headers,String encoding) throws HttpProcessException { return send(client, url, HttpMethods.OPTIONS, headers, encoding); } public static String trace(String url, Header[] headers,String encoding) throws HttpProcessException { return trace(create(url), url, headers, encoding); } public static String trace(HttpClient client, String url, Header[] headers,String encoding) throws HttpProcessException { return send(client, url, HttpMethods.TRACE, headers, encoding); }

     差点忘记了,最后还有一个简单的通用工具类

/** * * @author arron * @date 2015年11月10日 下午12:49:26 * @version 1.0 */ public class Utils { /** * 检测url是否含有参数,如果有,则把参数加到参数列表中 * * @param url 资源地址 * @param nvps 参数列表 * @return 返回去掉参数的url */ public static String checkHasParas(String url, List<NameValuePair> nvps) { // 检测url中是否存在参数 if (url.contains("?") && url.indexOf("?") < url.indexOf("=")) { Map<String, String> map = buildParas(url.substring(url .indexOf("?") + 1)); map2List(nvps, map); url = url.substring(0, url.indexOf("?")); } return url; } /** * 参数转换,将map中的参数,转到参数列表中 * * @param nvps 参数列表 * @param map 参数列表(map) */ public static void map2List(List<NameValuePair> nvps, Map<String, String> map) { if(map==null) return; // 拼接参数 for (Entry<String, String> entry : map.entrySet()) { nvps.add(new BasicNameValuePair(entry.getKey(), entry .getValue())); } } /** * 生成参数 * 参数格式“k1=v1&k2=v2” * * @param paras 参数列表 * @return 返回参数列表(map) */ public static Map<String,String> buildParas(String paras){ String[] p = paras.split("&"); String[][] ps = new String[p.length][2]; int pos = 0; for (int i = 0; i < p.length; i++) { pos = p[i].indexOf("="); ps[i][0]=p[i].substring(0,pos); ps[i][1]=p[i].substring(pos+1); pos = 0; } return buildParas(ps); } /** * 生成参数 * 参数类型:{{"k1","v1"},{"k2","v2"}} * * @param paras 参数列表 * @return 返回参数列表(map) */ public static Map<String,String> buildParas(String[][] paras){ // 创建参数队列 Map<String,String> map = new HashMap<String, String>(); for (String[] para: paras) { map.put(para[0], para[1]); } return map; } }

     简单的封装就是这样了。

     由于HttpClient和Header都作为参数传入,所以也可以进行扩展,比如代理、ssl等都是对HttpClient进行配置的,下面的文章就分别分享一下如何插件式配置HttpClient以及Header。敬请期待。

     代码已上传至:https://github.com/Arronlong/httpclientUtil

       httpclientUtil (QQ交流群:548452686 


相关文章