上篇文章介绍了插件式配置HttpClient，本文将介绍插件式配置Header。

     为什么要配置header在前面已经提到了，还里再简单说一下，要使用HttpClient模拟请求，去访问各种接口或者网站资源，都有可能有各种限制，比如说java客户端模拟访问csdn博客，就必须设置User-Agent，否则就报错了。还有各种其他情况，必须的设置一些特定的Header，才能请求成功，或者才能不出问题。

     好了就说这么多，本次还是采用构造者模式的级联调用方式，来完成该工具类。在该工具类中，为所有常用的Http Request Header都提供了设置方法。具体参数参考的链接是HTTP Header 详解。

     不再多废话了，看具体代码吧：

package com.tgb.ccl.http.common; import java.util.HashMap; import java.util.Map; import org.apache.http.Consts; import org.apache.http.Header; import org.apache.http.message.BasicHeader; /** * 创建HttpReqHead * * @author arron * @date 2015年11月9日 上午10:37:23 * @version 1.0 */ public class HttpHeader { private HttpHeader() {}; public static HttpHeader custom() { return new HttpHeader(); } //记录head头信息 private Map<String, Header> headerMaps = new HashMap<String, Header>(); /** * 指定客户端能够接收的内容类型 * 例如：Accept: text/plain, text/html * * @param accept */ public HttpHeader accept(String accept) { headerMaps.put(HttpReqHead.ACCEPT, new BasicHeader(HttpReqHead.ACCEPT, accept)); return this; } /** * 浏览器可以接受的字符编码集 * 例如：Accept-Charset: iso-8859-5 * * @param acceptCharset */ public HttpHeader acceptCharset(String acceptCharset) { headerMaps.put(HttpReqHead.ACCEPT_CHARSET, new BasicHeader(HttpReqHead.ACCEPT_CHARSET, acceptCharset)); return this; } /** * 指定浏览器可以支持的web服务器返回内容压缩编码类型 * 例如：Accept-Encoding: compress, gzip * * @param acceptEncoding */ public HttpHeader acceptEncoding(String acceptEncoding) { headerMaps.put(HttpReqHead.ACCEPT_ENCODING, new BasicHeader(HttpReqHead.ACCEPT_ENCODING, acceptEncoding)); return this; } /** * 浏览器可接受的语言 * 例如：Accept-Language: en,zh * * @param acceptLanguage */ public HttpHeader acceptLanguage(String acceptLanguage) { headerMaps.put(HttpReqHead.ACCEPT_LANGUAGE, new BasicHeader(HttpReqHead.ACCEPT_LANGUAGE, acceptLanguage)); return this; } /** * 可以请求网页实体的一个或者多个子范围字段 * 例如：Accept-Ranges: bytes * * @param acceptRanges */ public HttpHeader acceptRanges(String acceptRanges) { headerMaps.put(HttpReqHead.ACCEPT_RANGES, new BasicHeader(HttpReqHead.ACCEPT_RANGES, acceptRanges)); return this; } /** * HTTP授权的授权证书 * 例如：Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ== * * @param authorization */ public HttpHeader authorization(String authorization) { headerMaps.put(HttpReqHead.AUTHORIZATION, new BasicHeader(HttpReqHead.AUTHORIZATION, authorization)); return this; } /** * 指定请求和响应遵循的缓存机制 * 例如：Cache-Control: no-cache * * @param cacheControl */ public HttpHeader cacheControl(String cacheControl) { headerMaps.put(HttpReqHead.CACHE_CONTROL, new BasicHeader(HttpReqHead.CACHE_CONTROL, cacheControl)); return this; } /** * 表示是否需要持久连接（HTTP 1.1默认进行持久连接） * 例如：Connection: close 短链接； Connection: keep-alive 长连接 * * @param connection * @return */ public HttpHeader connection(String connection) { headerMaps.put(HttpReqHead.CONNECTION, new BasicHeader(HttpReqHead.CONNECTION, connection)); return this; } /** * HTTP请求发送时，会把保存在该请求域名下的所有cookie值一起发送给web服务器 * 例如：Cookie: $Version=1; Skin=new; * * @param cookie */ public HttpHeader cookie(String cookie) { headerMaps.put(HttpReqHead.COOKIE, new BasicHeader(HttpReqHead.COOKIE, cookie)); return this; } /** * 请求内容长度 * 例如：Content-Length: 348 * * @param contentLength */ public HttpHeader contentLength(String contentLength) { headerMaps.put(HttpReqHead.CONTENT_LENGTH, new BasicHeader(HttpReqHead.CONTENT_LENGTH, contentLength)); return this; } /** * 请求的与实体对应的MIME信息 * 例如：Content-Type: application/x-www-form-urlencoded * * @param contentType */ public HttpHeader contentType(String contentType) { headerMaps.put(HttpReqHead.CONTENT_TYPE, new BasicHeader(HttpReqHead.CONTENT_TYPE, contentType)); return this; } /** * 请求发送的日期和时间 * 例如：Date: Tue, 15 Nov 2010 08:12:31 GMT * * @param date * @return */ public HttpHeader date(String date) { headerMaps.put(HttpReqHead.DATE, new BasicHeader(HttpReqHead.DATE, date)); return this; } /** * 请求的特定的服务器行为 * 例如：Expect: 100-continue * * @param expect */ public HttpHeader expect(String expect) { headerMaps.put(HttpReqHead.EXPECT, new BasicHeader(HttpReqHead.EXPECT, expect)); return this; } /** * 发出请求的用户的Email * 例如：From: user@email.com * * @param from */ public HttpHeader from(String from) { headerMaps.put(HttpReqHead.FROM, new BasicHeader(HttpReqHead.FROM, from)); return this; } /** * 指定请求的服务器的域名和端口号 * 例如：Host: blog.csdn.net * * @param host * @return */ public HttpHeader host(String host) { headerMaps.put(HttpReqHead.HOST, new BasicHeader(HttpReqHead.HOST, host)); return this; } /** * 只有请求内容与实体相匹配才有效 * 例如：If-Match: “737060cd8c284d8af7ad3082f209582d” * * @param ifMatch * @return */ public HttpHeader ifMatch(String ifMatch) { headerMaps.put(HttpReqHead.IF_MATCH, new BasicHeader(HttpReqHead.IF_MATCH, ifMatch)); return this; } /** * 如果请求的部分在指定时间之后被修改则请求成功，未被修改则返回304代码 * 例如：If-Modified-Since: Sat, 29 Oct 2010 19:43:31 GMT * * @param ifModifiedSince * @return */ public HttpHeader ifModifiedSince(String ifModifiedSince) { headerMaps.put(HttpReqHead.IF_MODIFIED_SINCE, new BasicHeader(HttpReqHead.IF_MODIFIED_SINCE, ifModifiedSince)); return this; } /** * 如果内容未改变返回304代码，参数为服务器先前发送的Etag，与服务器回应的Etag比较判断是否改变 * 例如：If-None-Match: “737060cd8c284d8af7ad3082f209582d” * * @param ifNoneMatch * @return */ public HttpHeader ifNoneMatch(String ifNoneMatch) { headerMaps.put(HttpReqHead.IF_NONE_MATCH, new BasicHeader(HttpReqHead.IF_NONE_MATCH, ifNoneMatch)); return this; } /** * 如果实体未改变，服务器发送客户端丢失的部分，否则发送整个实体。参数也为Etag * 例如：If-Range: “737060cd8c284d8af7ad3082f209582d” * * @param ifRange * @return */ public HttpHeader ifRange(String ifRange) { headerMaps.put(HttpReqHead.IF_RANGE, new BasicHeader(HttpReqHead.IF_RANGE, ifRange)); return this; } /** * 只在实体在指定时间之后未被修改才请求成功 * 例如：If-Unmodified-Since: Sat, 29 Oct 2010 19:43:31 GMT * * @param ifUnmodifiedSince * @return */ public HttpHeader ifUnmodifiedSince(String ifUnmodifiedSince) { headerMaps.put(HttpReqHead.IF_UNMODIFIED_SINCE, new BasicHeader(HttpReqHead.IF_UNMODIFIED_SINCE, ifUnmodifiedSince)); return this; } /** * 限制信息通过代理和网关传送的时间 * 例如：Max-Forwards: 10 * * @param maxForwards * @return */ public HttpHeader maxForwards(String maxForwards) { headerMaps.put(HttpReqHead.MAX_FORWARDS, new BasicHeader(HttpReqHead.MAX_FORWARDS, maxForwards)); return this; } /** * 用来包含实现特定的指令 * 例如：Pragma: no-cache * * @param pragma * @return */ public HttpHeader pragma(String pragma) { headerMaps.put(HttpReqHead.PRAGMA, new BasicHeader(HttpReqHead.PRAGMA, pragma)); return this; } /** * 连接到代理的授权证书 * 例如：Proxy-Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ== * * @param proxyAuthorization */ public HttpHeader proxyAuthorization(String proxyAuthorization) { headerMaps.put(HttpReqHead.PROXY_AUTHORIZATION, new BasicHeader(HttpReqHead.PROXY_AUTHORIZATION, proxyAuthorization)); return this; } /** * 只请求实体的一部分，指定范围 * 例如：Range: bytes=500-999 * * @param range */ public HttpHeader range(String range) { headerMaps.put(HttpReqHead.RANGE, new BasicHeader(HttpReqHead.RANGE, range)); return this; } /** * 先前网页的地址，当前请求网页紧随其后,即来路 * 例如：Referer: http://www.zcmhi.com/archives/71.html * * @param referer */ public HttpHeader referer(String referer) { headerMaps.put(HttpReqHead.REFERER, new BasicHeader(HttpReqHead.REFERER, referer)); return this; } /** * 客户端愿意接受的传输编码，并通知服务器接受接受尾加头信息 * 例如：TE: trailers,deflate;q=0.5 * * @param te */ public HttpHeader te(String te) { headerMaps.put(HttpReqHead.TE, new BasicHeader(HttpReqHead.TE, te)); return this; } /** * 向服务器指定某种传输协议以便服务器进行转换（如果支持） * 例如：Upgrade: HTTP/2.0, SHTTP/1.3, IRC/6.9, RTA/x11 * * @param upgrade */ public HttpHeader upgrade(String upgrade) { headerMaps.put(HttpReqHead.UPGRADE, new BasicHeader(HttpReqHead.UPGRADE, upgrade)); return this; } /** * User-Agent的内容包含发出请求的用户信息 * * @param userAgent * @return */ public HttpHeader userAgent(String userAgent) { headerMaps.put(HttpReqHead.USER_AGENT, new BasicHeader(HttpReqHead.USER_AGENT, userAgent)); return this; } /** * 关于消息实体的警告信息 * 例如：Warn: 199 Miscellaneous warning * * @param warning * @return */ public HttpHeader warning(String warning) { headerMaps.put(HttpReqHead.WARNING, new BasicHeader(HttpReqHead.WARNING, warning)); return this; } /** * 通知中间网关或代理服务器地址，通信协议 * 例如：Via: 1.0 fred, 1.1 nowhere.com (Apache/1.1) * * @param via * @return */ public HttpHeader via(String via) { headerMaps.put(HttpReqHead.VIA, new BasicHeader(HttpReqHead.VIA, via)); return this; } /** * 设置此HTTP连接的持续时间（超时时间） * 例如：Keep-Alive: 300 * * @param keepAlive * @return */ public HttpHeader keepAlive(String keepAlive) { headerMaps.put(HttpReqHead.KEEP_ALIVE, new BasicHeader(HttpReqHead.KEEP_ALIVE, keepAlive)); return this; } public String accept() { return get(HttpReqHead.ACCEPT); } public String acceptCharset() { return get(HttpReqHead.ACCEPT_CHARSET); } public String acceptEncoding() { return get(HttpReqHead.ACCEPT_ENCODING); } public String acceptLanguage() { return get(HttpReqHead.ACCEPT_LANGUAGE); } public String acceptRanges() { return get(HttpReqHead.ACCEPT_RANGES); } public String authorization() { return get(HttpReqHead.AUTHORIZATION); } public String cacheControl() { return get(HttpReqHead.CACHE_CONTROL); } public String connection() { return get(HttpReqHead.CONNECTION); } public String cookie() { return get(HttpReqHead.COOKIE); } public String contentLength() { return get(HttpReqHead.CONTENT_LENGTH); } public String contentType() { return get(HttpReqHead.CONTENT_TYPE); } public String date() { return get(HttpReqHead.DATE); } public String expect() { return get(HttpReqHead.EXPECT); } public String from() { return get(HttpReqHead.FROM); } public String host() { return get(HttpReqHead.HOST); } public String ifMatch() { return get(HttpReqHead.IF_MATCH); } public String ifModifiedSince() { return get(HttpReqHead.IF_MODIFIED_SINCE); } public String ifNoneMatch() { return get(HttpReqHead.IF_NONE_MATCH); } public String ifRange() { return get(HttpReqHead.IF_RANGE); } public String ifUnmodifiedSince() { return get(HttpReqHead.IF_UNMODIFIED_SINCE); } public String maxForwards() { return get(HttpReqHead.MAX_FORWARDS); } public String pragma() { return get(HttpReqHead.PRAGMA); } public String proxyAuthorization() { return get(HttpReqHead.PROXY_AUTHORIZATION); } public String referer() { return get(HttpReqHead.REFERER); } public String te() { return get(HttpReqHead.TE); } public String upgrade() { return get(HttpReqHead.UPGRADE); } public String userAgent() { return get(HttpReqHead.USER_AGENT); } public String via() { return get(HttpReqHead.VIA); } public String warning() { return get(HttpReqHead.WARNING); } public String keepAlive() { return get(HttpReqHead.KEEP_ALIVE); } /** * 获取head信息 * * @return */ private String get(String headName) { if (headerMaps.containsKey(headName)) { return headerMaps.get(headName).getValue(); } return null; } /** * 返回header头信息 * * @return */ public Header[] build() { Header[] headers = new Header[headerMaps.size()]; int i = 0; for (Header header : headerMaps.values()) { headers[i] = header; i++; } headerMaps.clear(); headerMaps = null; return headers; } /** * Http头信息 * * @author arron * @date 2015年11月9日 上午11:29:04 * @version 1.0 */ private static class HttpReqHead { public static final String ACCEPT = "Accept"; public static final String ACCEPT_CHARSET = "Accept-Charset"; public static final String ACCEPT_ENCODING = "Accept-Encoding"; public static final String ACCEPT_LANGUAGE = "Accept-Language"; public static final String ACCEPT_RANGES = "Accept-Ranges"; public static final String AUTHORIZATION = "Authorization"; public static final String CACHE_CONTROL = "Cache-Control"; public static final String CONNECTION = "Connection"; public static final String COOKIE = "Cookie"; public static final String CONTENT_LENGTH = "Content-Length"; public static final String CONTENT_TYPE = "Content-Type"; public static final String DATE= "Date"; public static final String EXPECT = "Expect"; public static final String FROM = "From"; public static final String HOST = "Host"; public static final String IF_MATCH = "If-Match "; public static final String IF_MODIFIED_SINCE = "If-Modified-Since"; public static final String IF_NONE_MATCH = "If-None-Match"; public static final String IF_RANGE = "If-Range"; public static final String IF_UNMODIFIED_SINCE = "If-Unmodified-Since"; public static final String KEEP_ALIVE = "Keep-Alive"; public static final String MAX_FORWARDS = "Max-Forwards"; public static final String PRAGMA = "Pragma"; public static final String PROXY_AUTHORIZATION = "Proxy-Authorization"; public static final String RANGE = "Range"; public static final String REFERER = "Referer"; public static final String TE = "TE"; public static final String UPGRADE = "Upgrade"; public static final String USER_AGENT = "User-Agent"; public static final String VIA = "Via"; public static final String WARNING = "Warning"; } /** * 常用头信息配置 * * @author arron * @date 2015年11月18日 下午5:30:00 * @version 1.0 */ public static class Headers{ public static final String APP_FORM_URLENCODED="application/x-www-form-urlencoded"; public static final String TEXT_PLAIN="text/plain"; public static final String TEXT_HTML="text/html"; public static final String TEXT_XML="text/xml"; public static final String TEXT_JSON="text/json"; public static final String CONTENT_CHARSET_ISO_8859_1 = Consts.ISO_8859_1.name(); public static final String CONTENT_CHARSET_UTF8 = Consts.UTF_8.name(); public static final String DEF_PROTOCOL_CHARSET = Consts.ASCII.name(); public static final String CONN_CLOSE = "close"; public static final String KEEP_ALIVE = "keep-alive"; public static final String EXPECT_CONTINUE = "100-continue"; } }

       调用方式：

//设置header信息 Header[] headers=HttpHeader.custom().keepAlive("false").connection("close").contentType(Headers.APP_FORM_URLENCODED).build();

       就是这么简单。到此该工具类就完成了。下一篇将分享该工具类以及单次调用测试和多线程调用测试。

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

       httpclientUtil （QQ交流群:548452686 

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