Java4android HttpClient Getting started using the code set

This article will guide how to use the various functions and features of httpclient from a code perspective.

First Program

Import Org.apache.commons.httpclient.*;import Org.apache.commons.httpclient.methods.*;import Org.apache.commons.httpclient.params.httpmethodparams;import java.io.*;p Ublic class Httpclienttutorial {private  static String URL = "http://www.apache.org/";    public static void Main (string[] args) {//Create an instance of HttpClient.    HttpClient client = new HttpClient ();    Create a method instance.        GetMethod method = new GetMethod (URL); Provide custom retry handler is necessary Method.getparams (). Setparameter (Httpmethodparams.retry_handler, New De    Faulthttpmethodretryhandler (3, false));      try {//Execute the method.      int StatusCode = Client.executemethod (method);      if (statusCode! = HTTPSTATUS.SC_OK) {System.err.println ("Method failed:" + method.getstatusline ());      }//Read the response body.      byte[] Responsebody = Method.getresponsebody ();      Deal with the response. Use caution:ensure correct character EncodiNg and is not binary data System.out.println (new String (responsebody));      } catch (HttpException e) {System.err.println ("Fatal protocol violation:" + e.getmessage ());    E.printstacktrace ();      } catch (IOException e) {System.err.println ("Fatal Transport Error:" + e.getmessage ());    E.printstacktrace ();      } finally {//Release the connection.    Method.releaseconnection (); }    }}

Impersonate HTTP Web page log in

Package Org.apache.http.examples.client;import Java.net.uri;import Java.util.list;import Org.apache.http.httpentity;import Org.apache.http.client.methods.closeablehttpresponse;import Org.apache.http.client.methods.httpget;import Org.apache.http.client.methods.httpurirequest;import Org.apache.http.client.methods.requestbuilder;import Org.apache.http.cookie.cookie;import Org.apache.http.impl.client.basiccookiestore;import Org.apache.http.impl.client.closeablehttpclient;import Org.apache.http.impl.client.httpclients;import org.apache.http.util.entityutils;/** * A example that demonstrates how HttpClient APIs can be used to perform * form-based logon. */public class Clientformlogin {public static void main (string[] args) throws Exception {Basiccookiestore Cook        Iestore = new Basiccookiestore (); Closeablehttpclient httpclient = Httpclients.custom (). Setdefaultcookiestore (Cookiestore). b        Uild (); try {httpget HttpGet = new HTTPGET ("https://someportal/");            Closeablehttpresponse response1 = Httpclient.execute (HttpGet);                try {httpentity entity = response1.getentity ();                System.out.println ("Login form get:" + response1.getstatusline ());                Entityutils.consume (entity);                System.out.println ("Initial Set of Cookies:");                list<cookie> cookies = cookiestore.getcookies ();                if (Cookies.isempty ()) {System.out.println ("None");  } else {for (int i = 0; i < cookies.size (); i++) {System.out.println ("-" +                    Cookies.get (i). toString ());            }}} finally {Response1.close ();                    } httpurirequest Login = Requestbuilder.post (). Seturi (New URI ("https://someportal/")) . Addparameter ("IDToken1", "username"). Addparameter("IDToken2", "password"). Build ();            Closeablehttpresponse response2 = httpclient.execute (login);                try {httpentity entity = response2.getentity ();                System.out.println ("Login form get:" + response2.getstatusline ());                Entityutils.consume (entity);                System.out.println ("Post Logon Cookies:");                list<cookie> cookies = cookiestore.getcookies ();                if (Cookies.isempty ()) {System.out.println ("None");  } else {for (int i = 0; i < cookies.size (); i++) {System.out.println ("-" +                    Cookies.get (i). toString ());            }}} finally {Response2.close ();        }} finally {Httpclient.close (); }    }}

Multi-Form Post example

/** * Example How to use Multipart/form encoded POST request. */public class Clientmultipartformpost {public static void main (string[] args) throws Exception {if (Args.leng            Th! = 1) {System.out.println ("File Path not given");        System.exit (1);        } closeablehttpclient httpclient = Httpclients.createdefault (); try {httppost httppost = new HttpPost ("http://localhost:8080" + "/servlets-examples/servlet            /requestinfoexample ");            Filebody bin = new Filebody (new File (Args[0]));            Stringbody comment = new Stringbody ("A binary file of some kind", contenttype.text_plain); Httpentity reqentity = Multipartentitybuilder.create (). Addpart ("Bin", bin). Addpart            ("comment", comment). build ();            Httppost.setentity (reqentity);            SYSTEM.OUT.PRINTLN ("Executing request" + httppost.getrequestline ()); CloseablehttpreSponse response = Httpclient.execute (HttpPost);                try {System.out.println ("----------------------------------------");                System.out.println (Response.getstatusline ());                Httpentity resentity = response.getentity (); if (resentity! = null) {System.out.println ("Response Content Length:" + resentity.getcontentlength ())                ;            } entityutils.consume (resentity);            } finally {response.close ();        }} finally {Httpclient.close (); }    }}

Use ResponseHandler to simplify handling of HTTP response and resource release

/** * This example demonstrates the use of the {@link ResponseHandler} to simplify * the process of processing the HTTP re Sponse and releasing associated resources. */public class Clientwithresponsehandler {public final static void main (string[] args) throws Exception {Close        Ablehttpclient httpclient = Httpclients.createdefault ();            try {httpget httpget = new HttpGet ("http://localhost/");            SYSTEM.OUT.PRINTLN ("Executing request" + httpget.getrequestline ()); Create A custom response handler responsehandler<string> ResponseHandler = new Responsehandler<stri Ng> () {public String handleresponse (final HttpResponse response) throws CLIENTP                    Rotocolexception, ioexception {int status = Response.getstatusline (). Getstatuscode ();     if (Status >= && status <) {Httpentity entity = response.getentity ();                   return entity! = null?                    Entityutils.tostring (entity): null;                    } else {throw new clientprotocolexception ("Unexpected response status:" + status);            }                }            };            String responsebody = Httpclient.execute (HttpGet, ResponseHandler);            System.out.println ("----------------------------------------");        System.out.println (responsebody);        } finally {httpclient.close (); }    }}

Example of use of Get methods in multithreaded environments

/** * An example this performs GETs from multiple threads. * */public class Clientmultithreadedexecution {public static void main (string[] args) throws Exception {//Cre        Ate an HttpClient with the Threadsafeclientconnmanager.        This connection manager must is used if more than one thread would//be using the HttpClient.        Poolinghttpclientconnectionmanager cm = new Poolinghttpclientconnectionmanager ();        Cm.setmaxtotal (100);        Closeablehttpclient httpclient = Httpclients.custom (). Setconnectionmanager (CM). Build (); try {//Create an array of URIs to perform GETs on string[] Uristoget = {"Htt p://hc.apache.org/"," http://hc.apache.org/httpcomponents-core-ga/"," http://hc.apache.org/h            Ttpcomponents-client-ga/",};            Create a thread for each URI getthread[] threads = new Getthread[uristoget.length]; FoR (int i = 0; i < threads.length; i++) {HttpGet httpget = new HttpGet (Uristoget[i]);            Threads[i] = new GetThread (httpclient, HttpGet, i + 1); }//Start the threads for (int j = 0; J < Threads.length; J + +) {Threads[j].start            (); }//Join the threads for (int j = 0; J < Threads.length, J + +) {Threads[j].join ()            ;        }} finally {Httpclient.close ();     }}/** * A thread that performs A GET.        */Static Class GetThread extends Thread {private final closeablehttpclient httpClient;        Private final HttpContext context;        Private final HttpGet HttpGet;        private final int id;            Public GetThread (Closeablehttpclient httpClient, httpget httpget, int id) {this.httpclient = httpClient;            This.context = new Basichttpcontext ();            This.httpget = HttpGet; THis.id = ID;         }/** * Executes the GetMethod and prints some status information. */@Override public void Run () {try {System.out.println (id + "-on-get so                Mething from "+ Httpget.geturi ());                Closeablehttpresponse response = Httpclient.execute (httpget, context);                    try {System.out.println (id + "-get executed");                    Get the response body as an array of bytes httpentity entity = response.getentity ();                        if (Entity! = null) {byte[] bytes = Entityutils.tobytearray (entity);                    System.out.println (id + "-" + bytes.length + "bytes read");                }} finally {Response.close ();            }} catch (Exception e) {System.out.println (id + "-error:" + E); }        }    }}

Java4android HttpClient Getting started using the code set