Examples of Java send get and POST request parameters

Example One

The code is as follows

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Package com.hongyuan.test; Import Java.io.BufferedReader; Import java.io.IOException; Import Java.io.InputStreamReader; Import Java.io.PrintWriter; Import java.net.HttpURLConnection; Import Java.net.URL; public class HttpClient { Send a GET request public static string get (String path) throws exception{ HttpURLConnection Httpconn=null; BufferedReader In=null; try { URL url=new url (path); Httpconn= (HttpURLConnection) url.openconnection (); Read response if (Httpconn.getresponsecode () ==HTTPURLCONNECTION.HTTP_OK) { StringBuffer content=new StringBuffer (); String tempstr= ""; In=new BufferedReader (New InputStreamReader (Httpconn.getinputstream ())); while ((Tempstr=in.readline ())!=null) { Content.append (TEMPSTR); } return content.tostring (); }else{ throw new Exception ("There is a problem with the request!"); } catch (IOException e) { E.printstacktrace (); }finally{ In.close (); Httpconn.disconnect (); } return null; } Send a GET request, Parameter form key1=value1&key2=value2 ... public static string post (string path,string params) throws exception{ HttpURLConnection Httpconn=null; BufferedReader In=null; PrintWriter Out=null; try { URL url=new url (path); Httpconn= (HttpURLConnection) url.openconnection (); Httpconn.setrequestmethod ("POST"); Httpconn.setdoinput (TRUE); Httpconn.setdooutput (TRUE);   //Send POST request Parameters    out=new printwriter (Httpconn.getoutputstream ());    OUT.PRINTLN (params);    Out.flush ();   /Read response    if (Httpconn.getresponsecode () ==httpurlconnection.http_ok) {      stringbuffer content=new stringbuffer ();     String tempstr= "";     in=new BufferedReader (New InputStreamReader (Httpconn.getinputstream ()));     while ((Tempstr=in.readline ())!=null) {      content.append (TEMPSTR) ;    }     return content.tostring ();   }else{     throw new Exception ("There is a problem with the request!");   }  } catch (IOException e) {    e.printstacktrace ();  }finally{    in.close ();    out.close ();    httpconn.disconnect ();  }   return null;  } public static void Main (string[] args) throws Exception { String resmessage=httpclient.get ("Http://localhost:3000/hello?hello=hello get"); String resmessage=httpclient.post ("Http://localhost:3000/hello", "Hello=hello post"); System.out.println (Resmessage); } }

Example Two

HTTP Request Class

The code is as follows

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Package Wzh. Http; Import Java.io.BufferedReader; Import java.io.IOException; Import Java.io.InputStreamReader; Import Java.io.PrintWriter; Import Java.net.URL; Import java.net.URLConnection; Import java.util.List; Import Java.util.Map; public class HttpRequest { /** * Request to send the Get method to the specified URL * * @param URL * Send the requested URL * @param param * Request parameter, request parameter should be the form of name1=value1&name2=value2. * @return The response result of the remote resource represented by the URL */ public static string Sendget (string url, string param) { String result = ""; BufferedReader in = null; try { String urlnamestring = URL + "?" + param; URL realurl = new URL (urlnamestring); Opening and linking to URLs URLConnection connection = Realurl.openconnection (); To set common request properties Connection.setrequestproperty ("Accept", "*/*"); Connection.setrequestproperty ("Connection", "keep-alive"); Connection.setrequestproperty ("User-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) "); Establish the actual connection Connection.connect (); Get all response header fields map<string, list<string>> map = Connection.getheaderfields (); Iterate through all the response header fields For (String Key:map.keySet ()) { SYSTEM.OUT.PRINTLN (key + "--->" + map.get (key)); } Defines the response of a bufferedreader input stream to read a URL in = new BufferedReader (New InputStreamReader ( Connection.getinputstream ())); String Line; while (line = In.readline ())!= null) { result + = line; } catch (Exception e) { SYSTEM.OUT.PRINTLN ("Send GET request exception!") "+ e); E.printstacktrace (); } Use the finally block to close the input stream finally { try { if (in!= null) { In.close (); } catch (Exception E2) { E2.printstacktrace (); } } return result; } /** * Request to send post method to specified URL * * @param URL * Send the requested URL * @param param * Request parameter, request parameter should be the form of name1=value1&name2=value2. * Response results for remote resources represented by the @return */ public static string Sendpost (string url, string param) { PrintWriter out = null; BufferedReader in = null; String result = ""; try { URL realurl = new URL (URL); Opening and linking to URLs URLConnection conn = Realurl.openconnection (); To set common request properties Conn.setrequestproperty ("Accept", "*/*"); Conn.setrequestproperty ("Connection", "keep-alive"); Conn.setrequestproperty ("User-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) "); Send POST request must be set as follows two lines Conn.setdooutput (TRUE); Conn.setdoinput (TRUE); Gets the output stream corresponding to the URLConnection object out = new PrintWriter (Conn.getoutputstream ()); Send Request parameters Out.print (param); Buffer of flush output stream Out.flush (); Defines the response of a bufferedreader input stream to read a URL in = new BufferedReader ( New InputStreamReader (Conn.getinputstream ())); String Line; while (line = In.readline ())!= null) { result + = line; } catch (Exception e) { SYSTEM.OUT.PRINTLN ("Send POST request exception!) "+e); E.printstacktrace (); } Use the finally block to turn off the output stream, the input stream finally{ try{ if (out!=null) { Out.close (); } if (in!=null) { In.close (); } } catch (IOException ex) { Ex.printstacktrace (); } } return result; } }

Call Method:

code is as follows	copy code
public static void Main (string[] args) {   & nbsp;    //Send GET request         String s= Httprequest.sendget ("http://localhost:6144/Home/RequestString", "key=123&v=456");         System.out.println (s);                //Send POST request         String sr=httprequest.sendpost ("http://localhost:6144/Home/ Requestpoststring "," key=123&v=456 ");         System.out.println (SR);    }