[httpcomments-client-4.5.2]--源碼分析(Working with message headers)

An HTTP message can contain a number of headers describing properties of the message such as the content length, content type and so on. HttpClient provides methods to retrieve, add, remove and enumerate headers.

一個HTTP訊息可以包含多個標題描述性質的資訊等內容的長度、內容類型等。HttpClient提供檢索，添加方法，刪除和列舉了頭。

HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1,     HttpStatus.SC_OK, "OK");response.addHeader("Set-Cookie",     "c1=a; path=/; domain=localhost");response.addHeader("Set-Cookie",     "c2=b; path=\"/\", c3=c; domain=\"localhost\"");Header h1 = response.getFirstHeader("Set-Cookie");System.out.println(h1);Header h2 = response.getLastHeader("Set-Cookie");System.out.println(h2);Header[] hs = response.getHeaders("Set-Cookie");System.out.println(hs.length);

stdout>

Set-Cookie: c1=a; path=/; domain=localhostSet-Cookie: c2=b; path="/", c3=c; domain="localhost"2

The most efficient way to obtain all headers of a given type is by using the HeaderIterator interface.

HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1,     HttpStatus.SC_OK, "OK");response.addHeader("Set-Cookie",     "c1=a; path=/; domain=localhost");response.addHeader("Set-Cookie",     "c2=b; path=\"/\", c3=c; domain=\"localhost\"");HeaderIterator it = response.headerIterator("Set-Cookie");while (it.hasNext()) {    System.out.println(it.next());}

stdout >

Set-Cookie: c1=a; path=/; domain=localhostSet-Cookie: c2=b; path="/", c3=c; domain="localhost"

It also provides convenience methods to parse HTTP messages into individual header elements.
它還提供了對HTTP報文分成單獨的標題元素的簡便方法。

HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1,     HttpStatus.SC_OK, "OK");response.addHeader("Set-Cookie",     "c1=a; path=/; domain=localhost");response.addHeader("Set-Cookie",     "c2=b; path=\"/\", c3=c; domain=\"localhost\"");HeaderElementIterator it = new BasicHeaderElementIterator(    response.headerIterator("Set-Cookie"));while (it.hasNext()) {    HeaderElement elem = it.nextElement();     System.out.println(elem.getName() + " = " + elem.getValue());    NameValuePair[] params = elem.getParameters();    for (int i = 0; i < params.length; i++) {        System.out.println(" " + params[i]);    }}

stdout>

c1 = apath=/domain=localhostc2 = bpath=/c3 = cdomain=localhost