json object convert to string java -

i have json file , want convert json string using org.simple.json

{    "header":        {          "issuerid": "000141",          "authenticationid": "e07020c0d040a050a0808099",          "authenticationdatetime": "20151103093035",          "authenticationdatetimegmt": "20151103093035",          "signature": "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"       },     "body":        {          "transactiondatetime": "0151103093035",          "transactionid": " sp020110216",          "iasauthenticationrequestreferenceid": "h0irqhqboupucisv17nb0vhvabiuxhgcurjzfzuwdzjz9txyio",          "verificationid": "h0irqhqboupucisv17nb0vhvabiuxhgcurjzfzuwdzjz9txyio ",          "acquirer_id": "000014",          "merchantname": " twin hotel ",          "currencycodeiso": "360",          "amount": "970000.00",          "cardnumber": " bmahlufrg4sapnagb07t5fnrhxr/lyoa ",          "authenticationresponsecode": "00",          "authenticationresponsedetails": "success",          "validitydatetimeexpiregmt": "20151103094035",          "expiry_period": "10"       } } 

when convert using script

    //  json parser array untuk extract json ke string  jsonparser parser = new jsonparser(); object obj = parser.parse(input); jsonobject jsonobject = (jsonobject) obj;   jsonarray msg = (jsonarray) jsonobject.get("header"); //jsonarray array = new jsonarray(); //array.add("header");  iterator<jsonobject> iterator = msg.iterator();                 system.out.println("header ");         while (iterator.hasnext()) {  jsonobject factobj = (jsonobject) iterator.next();   issuerid = (string) factobj.get("issuerid");  system.out.println("issuer id : " + issuerid);    authenticationid = (string) factobj.get("authenticationid");  system.out.println("authenticationid : " +authenticationid);    authenticationdatetime = (string) factobj.get("authenticationdatetime");  system.out.println("authentication date time : " + authenticationdatetime);    authenticationdatetimegmt = (string) factobj.get("authenticationdatetimegmt");  system.out.println("authenticationdatetimegmt : " + authenticationdatetimegmt);   signature = (string) factobj.get("signature");  system.out.println("signature : " + signature);  }   //loop array  jsonarray msg1 = (jsonarray) jsonobject.get("body");                  system.out.println("body");  iterator<jsonobject> iterator1 = msg1.iterator();   while (iterator1.hasnext()) {  jsonobject factobj = (jsonobject) iterator1.next();   transactiondatetime = (string) factobj.get("transactiondatetime");  system.out.println("transaction datetime: " + transactiondatetime );   transactionid = (string) factobj.get("transactionid");  system.out.println("transaction id : " + transactionid);     iasauthenticationrequestreferenceid = (string) factobj.get("iasauthenticationrequestreferenceid");  system.out.println("iasauthenticationrequestreferenceid : " + iasauthenticationrequestreferenceid);     verificationid  = (string) factobj.get("verificationid");  system.out.println("verificationid : " + verificationid);    acquirer_id= (string) factobj.get("acquirer_id");  system.out.println("acquirer id : " + acquirer_id);    merchantname = (string) factobj.get("merchantname");  system.out.println("merchant name: " + merchantname);  currencycodeiso = (string) factobj.get("currencycodeiso");  system.out.println("currencycodeiso : " + currencycodeiso);   amount = (string) factobj.get("amount");  system.out.println("amount : " + amount);   cardnumber= (string) factobj.get("cardnumber");  system.out.println("card number : " + cardnumber);    authenticationresponsecode = (string) factobj.get("authenticationresponsecode");  system.out.println("authentication response code: " + authenticationresponsecode);     authenticationresponsedetails = (string) factobj.get("authenticationresponsedetails");  system.out.println("authentication response detail : " + authenticationresponsedetails);     validitydatetimeexpiregmt    = (string) factobj.get("validitydatetimeexpiregmt"); system.out.println("validity datetime expire gmt : " + validitydatetimeexpiregmt);    expiry_period = (string) factobj.get("expiry_period");  system.out.println("expiry period : " + expiry_period);  } 

i got error

java.lang.classcastexception: org.json.simple.jsonobject cannot cast org.json.simple.jsonarray @ artajasa.gateway.subsystem.process.requestthread.run(requestthread.java:636) @ java.lang.thread.run(thread.java:745)

when add [ ] in front of header , body got correct result, problem it's not json array insted json object can give me solution

according json structure , stack trace, header , body both jsonobjects not jsonarrays why error when try cast them jsonarray, try cast them jsonobject instead next:

jsonobject msg = (jsonobject) jsonobject.get("header"); ... jsonobject msg1 = (jsonobject) jsonobject.get("body"); 

to build jsonarray use square brackets, check simple json introduction more details.