基本操作

1.1.2.1 HTTP请求报文

HTTP request is a message sent from the client to the server. The first line of that message includes the method to apply to the resource, the identifier of the resource, and the protocol version in use.

HTTP请求是从客户端发到服务器的请求。报文的第一行包含作用于资源的方法，资源的标示，和当前使用协议版本。

HttpRequest request = new BasicHttpRequest("GET", "/", HttpVersion.HTTP_1_1);

System.out.println(request.getRequestLine().getMethod());
System.out.println(request.getRequestLine().getUri());
System.out.println(request.getProtocolVersion());
System.out.println(request.getRequestLine().toString());

GET
/
HTTP/1.1
GET / HTTP/1.1

1.1.2.2 HTTP应答报文

HTTP应答是服务器端接受并解释请求报文之后，发回客户端的报文。报文的第一行包含协议版本，数字状态码，和相关文本。

HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1, HttpStatus.SC_OK, "OK");

System.out.println(response.getProtocolVersion());
System.out.println(response.getStatusLine().getStatusCode());
System.out.println(response.getStatusLine().getReasonPhrase());
System.out.println(response.getStatusLine().toString());

HTTP/1.1
200
OK
HTTP/1.1 200 OK

1.1.2.3 HTTP报文共有属性和方法

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

HTTP报文可以包含若干报文头部，用来描述报文的属性，例如HTTP报文内容长度、内容类型等等。HttpCore提供retrieve，add，remove，enumerate等方法。

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\"");
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);

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

使用HeaderIterator接口获得所有报文头的的方法。

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\"");
HeaderIterator it = response.headerIterator("Set-Cookie");
while (it.hasNext()) {
    System.out.println(it.next());
}

将HTTP报文解析成报文头的方法。

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]);
    }
}

HTTP报文头在需要是解析成各个报文头元素。HTTP报文头通过HTTP连接被接收到之后，以字符数组形式储存，在被访问时才被解析。