Java: uluvo lwarhoqo, abasebenzi abathile

Namhlanje, lwenkqubo kwi Java, mhlawumbi, akayi kuba ukumangaliswa kungabikho mntu. Lwenkqubela kulo mmandla mkhulu kangangokuba ngokwenene owayephila wethu okwakubonakala iminyaka eziqhelekileyo ukuya 50-60 eyadlulayo kweli bali evela movie a la "Back to the Future."

Imvelaphi ulwimi Java

Java - into ulwimi lokuprograma into ebomini, nolwathi lwaphuhliswa kuqala Sun Microsystems, yaye kamva yaba inkxaso nophuhliso olwenziwa yi-Oracle.

Mazingabhidaniswa kuphuhliso lolwimi okanye ukusebenza kokusingqongileyo platform software. Yi mithandazo ukuze ziqondwe isethi kukho ezininzi izifundo ezahlukileyo apho kunye zinika ukubulawa Java-ikhowudi kwiindawo hardware ezahlukeneyo. Iinkqubo okubhaliweyo kwiJava ziguqulelwa ngendlela eyodwa ebizwa ngokuba bytecode, elo kamva senziwa ngokusebenzisa i kumatshini onesiqhamo (jvm) - inxalenye kweqonga software.

Ukufakwa Isiqalo

Ukuze isebenze ngempumelelo izicelo eziphuhliswe kolu lwimi, kufuneka ufake impahla okhethekileyo Java-amacandelo, efumaneka kwi-web sayithi Oracle. Le nkampani ibonelela yezinikezelo ezahlukeneyo, ezahluke neqonga setekeni, kwakunye iinketho ezahlukeneyo. Umsebenzisi avareji akuyomfuneko ukuba usebenzise inguqulelo Java into eyahlukileyo ukusuka wokugqibela, zakutsha nje. Oku kwenza kuphela kengoku for abaphuhlisi abafuna izicwangciso ezithile iimpawu ezithile nezakhono.

Ukufakela Java kwi computer yakho, umsebenzisi kufuneka kuqala uqinisekise ukuba iimpawu izixhobo uyahlangabezana neemfuneko inkqubo ubuncinane. iinjineli Oracle baye basebenza nzima ukuze ukunciphisa embundwini iimfuno zendlela, kodwa kusekhona apho, yaye kufuneka ulicingele. Umsebenzisi kufuneka ukufumana isiza kufuneka unikezelo esekelwe kwinkqubo yokusebenza, leyo ufuna ukuba zifake isoftware. Hi xikombiso, Java for Windows 7 Kuyinto i eliphunyeziweyo exe-ifayile, nto leyo eza kufuna kuphela ucacise ukufakwa, yaye uya kwandula ke yonke into ngokwakhe. Kubalulekile ukuqaphela ukuba le nkqubo ingafakwa ngexesha elifanayo enye ikopi kuphela yeqokobhe software. Ngoko ke, ngaphambi kokuba ufake imfuneko ukuqinisekisa ukuba inguquko yangaphambili ye Java isusiwe kwinkqubo. Ukuba akwenzekanga njalo, Umfaki iya kucela ukususa udweliso lwenkqubo ezingquzulanayo phambi kokuba aqhubeke ufakelo.

Qala yokuzenzela Java

Emva kokuba umsebenzisi ifakwe ngempumelelo bume software, kuya kubakho iintlobo ngeentlobo ngeendlela uphumezo iinkqubo esele kwathiwa, kunye nokudala ezabo. Ukuze uqale lwenkqubo yi Java, awufuni naziphi na iinkqubo ezongezelelweyo. Sifuna nje umnqweno ukuba bafunde izinto ezintsha ukuqonda ulwimi izakhiwo. Ukuba umsebenzisi unako ukufaka ngempumelelo kwi Java, kwaye inkqubo kuba akukho ngquzulwano kunye nezinye iinkqubo, ungaqalisa ukubhala ikhowudi kwi nayiphi kumhleli wokubhaliweyo.

Oracle uye waqinisekisa ukuba unike iseti ubuninzi lwezixhobo developers. E Java, iphakheji luquka compiler (Javac into eluncedo), nto leyo, ukuthatha njengoko argument umendo nayiphi na ifayile yombhalo, iyiguqule ibe bytecode kumatshini onesiqhamo iyaqondakala.

Umsebenzisi abanakukwazi ozakusebenza isicelo uze ubone imiphumo yomsebenzi wabo. Ukuze ufake isicelo Java for Windows 7, kuyimfuneko ukuba "pack" osengqayini-yomlando.

Ifomati mbiza livela ekunciphiseni Java-nkcukacha, kunye uhlobo olulodwa kakuhle ngabo bonke ZIP-ifayile, nto leyo iquka ngakumbi inkcazo iiklasi kunye izixhomekeki uze walathe kwindawo yokungena (class eziphambili) kwisicelo. Ukudala .jar-ifayile ye efanayo igama esetyenziswa yi eluncedo, nto leyo nayo iqukwe kwiphakheji eqhelekileyo ukususela Oracle. Emva ukuphunyezwa kwayo ngempumelelo, umsebenzisi akanokukwazi ukubaleka isicelo wadala okanye Java umyalelo kwilayini yomyalelo okanye console, okanye nje enqakraza kabini.

Eyona engundoqo amacandelo ulwimi Java

Ukuze bakwazi ukwenza ngempumelelo izicelo ngolwimi Java, ukufunda kufuneka uqale kanye ezisisiseko. badwelisi benkqubo makhwelo ngamanye amaxesha kunzima ukuqonda ixesha ulwimi "injongo ebomini" lo. Abantu abaninzi ngempazamo abakholelwa ukuba libhekisela kwinto yokuba onke amaqumrhu anokuthi ukusebenza kwi zolwimi izinto. Noko ke, oku akuyonyaniso. Ngolwimi Java, ngaphandle kwezakhiwo, kukho kwakhona iseti lweentlobo kwakudala. Olu elipheleleyo Uhlobo lwedatha (byte, elifutshane, int, elide ), ezo integers ubude ezahlukeneyo ilizwi, iindidi zedata iqhezu (edadayo, kabini), kwakunye imigca kunye neentlobo nomlinganiswa (Umtya kunye Isakare) ngokulandelelana.

Ngokuba elowo kubo kukho ekuthiwa iiklasi - ambala, ezisetyenziselwa ukwenza kukhankanywa into ethile uhlobo. Oku kuyinyaniso kuzo zonke iintlobo kwakudala ngaphandle data umtya.

Iimpawu zokuphunyezwa lodidi lomtya Java

Java-line - oku iklasi okhethekileyo. Oko kubizwa ngokuba yinto lecebo. Ukuba nomfanekiso kwisikhumbuzo nesicelo njengemfumba (yimfumba), equlethe umtrya ngendlela engaqondakaliyo, ngoko umsebenzi ngasinye kuyo (kukhethwa umtya osezantsi, concatenation, endaweni abalinganiswa, njalo njalo. D.) Iya kuyila kumzekelo omtsha we umgca yokuqala, nto leyo iya kwahluka sisiphumo wokuqala ukusebenza.

Ngoko ke, lo umtya usoloko kuyimfuneko ukusebenza ngenyameko, nangona udoti kwinkumbulo ihamba enkulu, uhlelo kufuneka silumke kakhulu ukuthintela memory kuphuphuma reference engeyomfuneko ukuya umtya. Ngethamsanqa, ngokuba kukho ezininzi iiklasi umncedi. Umzekelo, sebenzisa StringBuilder kunye StringBuffer, ezivumela ukuba baziguqugule imitya, kodwa musa ukwenza emva Umzekelo ngamnye omtsha.

The Java ulwimi - amabinzana rhoqo. ukubonakala kwazo nenjongo

amabinzana rhoqo wabonakala kwinkulungwane yamashumi amabini ezifike yaguqula netheknoloji processing ngeletroniki okubhaliweyo.

Ngaphambili, khangela amacandelo ezithile kwisicatshulwa okanye umtya osezantsi ingxaki eqhelekileyo, leyo kufuneka umgudu kunye nexesha ukuze isetyenziswe. Program kwafuneka khangela phantse yonke indawo kwi ngqo nasekulinganiseni elichaziweyo parameter yokukhangela okanye uthelekise a lot of iimeko. Nangona kunjalo, nokufika amabinzana rhoqo babe nethuba lokusebenzisa abalinganiswa meta, apho waba ifumaneke ukuchaza ipateni apho kwafuneka kusetshwa. In Java amabinzana rhoqo wabonakala kwinguqulelo-5, yaye ukususela ngoko ibe lophawu ebalulekileyo bume software.

Ukusebenza amabinzana rhoqo Java

E Java, zonke iiklasi, indlela enye okanye omnye zisetyenziswa ekusebenzisaneni amabinzana rhoqo, yaye uqiniseke eyahlukileyo ebizwa java.util.regex. In Java Ukutsho rhoqo ichaza udidi ipatheni, leyo kwisi IsiNgesi lithetha "umzekelo". Le iklasi wamkela umtya ingxoxo ukuya umbangi wawo, nto leyo ezinokusetyenziswa ukwenza itemplate. Xa ufuna nilibhale, endaweni iincwadi ezilula ngcono ukusetyenziswa wildcards.

Ukuze ucacise kakuhle parameters yokukhangela, kungcono ukufunda amaxwebhu esemthethweni asuka Oracle, efana nabalinganiswa abaninzi meta ayikwazi ukuba kuyintoni na umsebenzisi esiqhelekileyo okanye wenkqubo mafikizolo ucinga. Umzekelo, umqondiso "+" libonisa ukuba ipateni beyela Kwiimeko enye okanye ngaphezulu element kwangoko owandulelayo. Xa kuqaliswa Java wochazo lwarhoqo, abalinganiswa ezikhethekileyo ziyafana kuyo nayiphi na enye ulwimi lokuprograma. Ngoko ke, ukufuduka kwelinye iqonga kufuneka elula.

izicelo kunokwenzeka eboniswa njalo

Kufuneka kuqatshelwe ukuba kungenzeka amabinzana qho zivunywa ukusingatha izixa ezikhulu kakhulu yombhalo. Ngokomzekelo, abanye iqhosha lokukhangela, okanye izayamaniso igama kubhaliso wonke phantsi kwento ethi kwimeko apho isitshixo elibhaliweyo ayibalulekanga. Hand Ukulungiswa yombhalo kuya kuba kakuhle kakhulu zokusombulula ingxaki enjalo, kunye eyakhelwe-ngaphakathi Java amabinzana rhoqo aokusetyenziswa isibini yemigca khowudi.

Yiloo nto esixubusha ukufunda ulwimi nangayiphi na indlela zilubona yinxalenye ebalulekileyo efana uluvo lwarhoqo. E Java, inokusetyenziswa kwiinkalo ezahlukeneyo - ukusuka yokuqinisekisa ifom yedatha yokungenela (iidilesi ze-imeyile, amanani ekhadi lokuthenga ngetyala) ukuhlalutya izicelo yezithuthi umsebenzisi.