4.2.4. ibrowser¶

ibrowse有两种许可证:LGPL或BSD license
% 启动app
5> ibrowse:start().

发送一个json类型的html請求:

erl>>ibrowse:send_req("http://<url>", [{"Accept","application/json"}], get, [], []).
注意:
url地址必须以 ``http://`` 开头
用 ``{"Accept", "application/json"}`` 来表示json类型的請求,默认是 ``text/html`` 类型

实例:

ibrowse:send_req("http://<url>", [{"Accept","application/json"}], post, ["{\"id\":\"1234567890\", \"timestamp\":\"23421321421532143\"}"], []).

一个简单的get应用:

6> ibrowse:send_req("http://intranet/messenger/", [], get).
{ok,"200",
    [{"Server","Microsoft-IIS/5.0"},
    {"Content-Location","http://intranet/messenger/index.html"},
    {"Date","Fri, 17 Dec 2004 15:16:19 GMT"},
    {"Content-Type","text/html"},
    {"Accept-Ranges","bytes"},
    {"Last-Modified","Fri, 17 Dec 2004 08:38:21 GMT"},
    {"Etag","\"aa7c9dc313e4c41:d77\""},
    {"Content-Length","953"}],
    "<html>\r\n\r\n<head>\r\n<title>Messenger</title></head><body>......"
}

一个代理的get应用:

7> ibrowse:send_req("http://www.google.com/", [], get, [],
    [{proxy_user, "XXXXX"},
    {proxy_password, "XXXXX"},
    {proxy_host, "proxy"},
    {proxy_port, 8080}], 1000
).

{ok,"302",
     [{"Date","Fri, 17 Dec 2004 15:22:56 GMT"},
     {"Content-Length","217"},
     {"Content-Type","text/html"},
     {"Set-Cookie", "PREF=ID=f58155c797f96096; expires=Sun, 17-Jan-2038 19:14:07 GMT;"},
     {"Server","GWS/2.1"},
     {"Location", "http://www.google.co.uk/cxfer?c=PREF%3D:TM%3D1103296999:S%3Do8bEY2FIHwdyGenS&prev=/"},
     {"Via","1.1 netapp01 (NetCache NetApp/5.5R2)"}],
     "<HTML><HEAD><TITLE>302 Moved</TITLE></HEAD><BODY>\n<H1>302 Moved</H1>\r\n</BODY></HTML>\r\n"}

把get請求后的結果存放到文件中:

创建一个临时文件, 返回这个刚创建的临时文件的文件名
只有返回状态是200区间的才把請求的結果写入到这个临时文件中
下载的目录可以用应用环境变量 `download_dir` ,默认是当前工作目录

8> ibrowse:send_req("http://www.747.cn/", [], get, [],
                          [{save_response_to_file, true}], 1000).
{ok,"200",
    [{"Server","nginx/0.8.46"},
    {"Date","Thu, 01 Mar 2012 10:10:40 GMT"},
    {"Content-Type","text/html"},
    {"Content-Length","3796"},
    {"Last-Modified","Mon, 27 Feb 2012 11:20:36 GMT"},
    {"Connection","keep-alive"},
    {"Vary","Accept-Encoding"},
    {"Accept-Ranges","bytes"}],
    {file,"/home/gordon/tmp/ibrowser_test/ibrowse_tmp_file_1330597007674127"}}

设置连接池与管道大小,下面这个例子設定连接到服务的最大连接数到10,并把管道大小设置为1:

Connections are setup a required
11> ibrowse:set_dest("www.hotmail.com", 80, [{max_sessions, 10},
                                     {max_pipeline_size, 1}]).
ok

使用HEAD方法的实例:

56> ibrowse:send_req("http://www.erlang.org", [], head).
{ok,"200",
   [{"Date","Mon, 28 Feb 2005 04:40:53 GMT"},
   {"Server","Apache/1.3.9 (Unix)"},
   {"Last-Modified","Thu, 10 Feb 2005 09:31:23 GMT"},
   {"Etag","\"8d71d-1efa-420b29eb\""},
   {"Accept-ranges","bytes"},
   {"Content-Length","7930"},
   {"Content-Type","text/html"}],
[]}

使用OPTIONS方法的实例:

62> ibrowse:send_req("http://www.sun.com", [], options).
  {ok,"200",
    [{"Server","Sun Java System Web Server 6.1"},
    {"Date","Mon, 28 Feb 2005 04:44:39 GMT"},
    {"Content-Length","0"},
    {"P3p",
        "policyref=\"http://www.sun.com/p3p/Sun_P3P_Policy.xml\", CP=\"CAO DSP COR CUR ADMa DEVa TAIa PSAa PSDa CONi TELi OUR  SAMi PUBi IND PHY ONL PUR COM NAV INT DEM CNT STA POL PRE GOV\""},
    {"Set-Cookie",
        "SUN_ID=X.X.X.X:169191109565879; EXPIRES=Wednesday, 31-Dec-2025 23:59:59 GMT; DOMAIN=.sun.com; PATH=/"},
    {"Allow",
          "HEAD, GET, PUT, POST, DELETE, TRACE, OPTIONS, MOVE, INDEX, MKDIR, RMDIR"}],
  []}

使用Asynchronous請求的实例:

18> ibrowse:send_req("http://www.google.com", [], get, [], [{stream_to, self()}]).
{ibrowse_req_id,{1115,327256,389608}}
19> flush().
... ...

用async选项請求失败的实例:

这儿没有返回 {ibrowse_req_id, ReqId}格式，而是返回错误代码:
68> ibrowse:send_req("http://www.earlyriser.org", [], get, [], [{stream_to, self()}]).
{error,conn_failed}

即有代理又有用户认证的实例:

17> ibrowse:send_req("http://www.erlang.se/lic_area/protected/patches/erl_756_otp_beam.README",
     [], get, [],
     [{proxy_user, "XXXXX"},
      {proxy_password, "XXXXX"},
      {proxy_host, "proxy"},
      {proxy_port, 8080},
      {basic_auth, {"XXXXX", "XXXXXX"}}]).
      ... ...

ibrowse是一个HTTP客户端,下面是ibrowse的特性:

- RFC2616 compliant (AFAIK)
- 支持 GET, POST, OPTIONS, HEAD, PUT, DELETE, TRACE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MOVE and COPY
- 支持 HTTP/0.9, HTTP/1.0 and HTTP/1.1
- 支持 chunked encoding
- Can generate requests using Chunked Transfer-Encoding
- Pools of connections to each webserver
- Pipelining support
- 下载到文件
- Asynchronous requests. Responses are streamed to a process
- 基本的认证
- 支持代理认证
- 可以用SSL与安全webservers交互
- 其他特性