Interaction between Android and Servlet JSON data

Android customers

Package COM. comingx. xzz; import Org. apache. HTTP. httpresponse; import Org. apache. HTTP. client. httpclient; import Org. apache. HTTP. client. methods. httppost; import Org. apache. HTTP. entity. stringentity; import Org. apache. HTTP. impl. client. defaulthttpclient; import Org. apache. HTTP. util. entityutils; import Org. JSON. jsonobject; import android. app. activity; import android. app. progressdialog; import android. OS. asynctas K; import android. OS. bundle; import android. util. log; import android. view. view; import android. widget. button; import android. widget. edittext; public class main extends activity {Private Static final string tag = "Main"; private edittext nameedit; private edittext phoneedit; private edittext resultedit; private button sendbtn; private progressdialog; @ overridepublic void oncreate (bundle saved Instancestate) {super. oncreate (savedinstancestate); setcontentview (R. layout. main); nameedit = (edittext) findviewbyid (R. id. name); phoneedit = (edittext) findviewbyid (R. id. phone); resultedit = (edittext) findviewbyid (R. id. result); sendbtn = (button) findviewbyid (R. id. sendbtn); progressdialog = new progressdialog (this); sendbtn. setonclicklistener (New button. onclicklistener () {@ overridepublic void onclick (View v) {New at(cmd.exe cute (nameedit. gettext (). tostring (), phoneedit. gettext (). tostring () ;}});} class at extends asynctask {@ overrideprotected void onpreexecute () {progressdialog. show () ;}@ overrideprotected string doinbackground (string... params) {try {// request data httpclient Hc = new defaulthttpclient (); httppost HP = new httppost ("http: // 192.168.1.102: 8080/jsonservlet "); // request JSON message jsonobject Jo = new jsonobject (); If (Params. length> 1) {Jo. put ("name", Params [0]); Jo. put ("phone", Params [1]);} else {Jo. put ("Err", "error");} log. D (TAG, "Params:" + Jo. tostring (); HP. setentity (New stringentity (Jo. tostring (); httpresponse hR = hc.exe cute (HP); string result = NULL; // obtain the returned JSON packet if (HR. getstatusline (). getstatuscode () = 200) {result = entityutils. tostring (HR. getentity (); log. D (TAG, "Result:" + Result);} // close the connection if (HC! = NULL) {HC. getconnectionmanager (). shutdown ();} return result;} catch (exception e) {e. printstacktrace (); return NULL ;}@overrideprotected void onpostexecute (string result) {resultedit. settext (result); progressdialog. cancel ();}}}

Server code:

Package COM. comingx. xzz; import Java. io. bufferedreader; import Java. io. datainputstream; import Java. io. dataoutputstream; import Java. io. ioexception; import Java. io. inputstreamreader; import Java. io. printwriter; import Java. util. enumeration; import javax. servlet. servletexception; import javax. servlet. servletinputstream; import javax. servlet. HTTP. httpservlet; import javax. servlet. HTTP. httpservletrequest; impor T javax. servlet. HTTP. dependencies;/*** Servlet implementation class jsonservlet */public class jsonservlet extends httpservlet {Private Static final long serialversionuid = 1l; @ overrideprotected void dopost (httpservletrequest req, httpservletresponse resp) throws servletexception, ioexception {string result = ""; try {/* read data */bufferedreader BR = new bufferedreader (New inputstreamreader (( Servletinputstream) Req. getinputstream (), "UTF-8"); stringbuffer sb = new stringbuffer (""); string temp; while (temp = Br. Readline ())! = NULL) {sb. append (temp);} BR. close (); Result = sb. tostring (); system. out. println ("request message:" + result);} catch (exception e) {result = "{err: \" error \"}";} finally {/* returned data */system. out. println ("Returned message:" + result); printwriter PW = resp. getwriter (); PW. write (result); PW. flush (); PW. close ();}}}

The server has only one servlet for processing.

The code is obvious.

Android uses Apache's httpclient for network connection. It stores JSON data in stringentity and sets the object setentity () of httppost (). Use httpclient to implement network requests, then obtain the data result = entityutils. tostirng (HR. getentity (), and display the results on edittext.

The server code is also very simple.

Use bufferreader to block the inputstream obtained from request to read the Request Entity, obtain the request JSON message, and return it to the client in the output stream of the message result.