Using Java to get HTTP response headers and request resources

Code instance

Import Java.io.bufferedinputstream;import Java.io.bufferedoutputstream;import Java.io.file;import Java.io.fileoutputstream;import Java.io.ioexception;import Java.io.inputstream;import Java.io.InputStreamReader; Import Java.io.reader;import java.net.urisyntaxexception;import Java.net.url;import Java.net.urlconnection;import Java.util.iterator;import java.util.list;import java.util.map;import Java.util.map.entry;import java.util.Set; public class Urltest {public static void main (string[] args) throws URISyntaxException {InputStream Inputstream=null;try { Create a URL object, for example: Baidu search China good sound//wd The value of the keyword is the UTF-8 encoding for "good sound in China", and you can encode the character using Urlencoder string str= "http://www.baidu.com/s?wd=%E4 %b8%ad%e5%9b%bd%e5%a5%bd%e5%a3%b0%e9%9f%b3 "+" &rsv_spt=1&issp=1&f=8&rsv_bp=0&rsv_idx=2& Ie=utf-8&tn=baiduhome_pg "+" &rsv_enter=1&inputt=1498 "; URL url = new URL (str);//Create URLConnection object URLConnection openconnection = Url.openconnection ();//encoding type string encoding= null;//Print the response header section below System.out.println ("-----------The response header begins-----------"); map<string, list<string>> headerfields = Openconnection.getheaderfields (); set<entry<string, list<string>>> entryset = Headerfields.entryset (); Iterator<Entry<String, List<string>>> iterator = Entryset.iterator (); while (Iterator.hasnext ()) {entry<string, list< String>> next = Iterator.next (); String key = Next.getkey (); list<string> value = Next.getvalue (); String string = Value.tostring (); System.out.println (key+ ":" +string), if ("Content-type". Equals (key)) {int indexOf = String.IndexOf ("charset="); encoding = string.substring (Indexof+8,string.length ()-1);}} SYSTEM.OUT.PRINTLN ("-----------Response header End-----------");//Gets the input stream of the URLConnection object inputstream= Openconnection.getinputstream ();//read stream via IO, write file int c;int count=0; File File=new file ("baiduosc.html"); FileOutputStream FileOutputStream = new FileOutputStream (file); Bufferedoutputstream outputstream = new Bufferedoutputstream (fileoutputstream); Inputstream=new BUFFEREDINPUtstream (InputStream); Reader InputStreamReader = new InputStreamReader (inputstream,encoding); while ((C=inputstreamreader.read ())!=-1) { Outputstream.write (c); count++;} Inputstreamreader.close (); Outputstream.close (); SYSTEM.OUT.PRINTLN (the size of "file" +file.getname () + "is" +math.ceil (count/1024.0) + "KB"); System.out.println ("Download End");} catch (IOException e) {System.err.println ("Cannot Download"),} finally {if (inputstream!=null) {try {inputstream.close ();} catch ( Exception ex) {//Not processed}}}}

Running an instance

-----------response header starts-----------bdpagetype:[3]transfer-encoding:[chunked]null:[http/1.1 ok]server:[bws/1.1]cxy_ex : [1438852608+2445156729+D41D8CD98F00B204E9800998ECF8427E]BDQID:[0XC8CF935400001D62]CONNECTION:[KEEP-ALIVE]P3P: [cp= "OTI DSP cor IVA our ind com", cp= "OTI DSP cor IVA our ind com"] Date:[thu, 09:16:48 gmt]x-ua-compatible:[ie=edge,chrome=1]cache-control:[private]cxy_all:[baiduhome_pg+ 66d9c0f29a9055c1f190fe638dacaa45]set-cookie:[h_ps_pssid=11193_16469_1438_12867_14668_16520_16513_16662_16424_ 16515_15459_12141_13932_16721; path=/; Domain=.baidu.com, bdsvrtm=187; path=/, bd_ck_sam=1;path=/, bdrcvfr[fewj1vr5u3d]=mk3slvn4hkm; path=/; Domain=.baidu.com, pstm=1438852608; Expires=thu, 31-dec-37 23:55:55 GMT; max-age=2147483647; path=/; Domain=.baidu.com, bidupsid=5dae500615a53e18fdb62639c686768b; Expires=thu, 31-dec-37 23:55:55 GMT; max-age=2147483647; path=/; Domain=.baidu.com, baiduid=5dae500615a53e18fdb62639c686768b:fg=1; Expires=thu, 31-dec-37 23:55:55 GMT; Max-age=2147483647; path=/; domain=.baidu.com]vary:[accept-encoding]bduserid:[0]x-powered-by:[hphp]content-type:[text/html;charset=utf-8]- ----------response header ends-----------file baiduosc.html the size of 491.0kb download ends

Using Java to get HTTP response headers and request resources