Java: inkulumo ejwayelekile, nezinhlamvu ezikhethekile

Namuhla, izinhlelo ze-Java, cishe, akekho ngeke bamangale. Inqubekela kule ndawo omkhulu kangangokuthi empeleni wesimanje yethu kwakungezwakala iminyaka ijwayelekile 50-60 edlule kule ndaba kusukela movie a la "Emuva Ikusasa."

Umsuka ulimi Java

Java - ulimi into-ngamakhasimende izinhlelo, okuyinto ekuqaleni lakhiwa Sun Microsystems, futhi kamuva kwaba ukusekelwa nokuthuthukiswa eyenziwa Oracle.

Hhayi kudidaniswe ukuthuthukiswa kolimi noma ukusebenza imvelo platform isofthiwe. By yokugcina kumele iqoqo a sebuningini izingxenye ezahlukene okuyinto ndawonye inikeze ukukhishwa-Java code hardware ezindaweni ezihlukahlukene waqonda. Izinhlelo abhalwe Java zihunyushelwa olimini lwesi-ngesakhiwo ekhethekile okuthiwa bytecode, okwathi ngokuhamba kwesikhathi wenziwa esebenzisa umshini virtual (JVM) - ingxenye platform isofthiwe.

Ukufakwa kanye Ukuqalisa

Ukuze ngempumelelo ukusebenzisa izicelo ithuthukiswe lolu limi, kufanele ufake i-iphakethe olukhethekile-Java izingxenye, elitholakala kwi-Oracle web site. Le nkampani inikeza kukaMoya ezahlukene, okuyinto zingafani platform target, kanye ongakhetha ahlukahlukene. Umsebenzisi isilinganiso akadingi ukusebenzisa Java inguqulo lihlukile lokugcina, yakamuva. Kuwukuhlakanipha konjiniyela abadinga amasu ethize ngezici ezithile namakhono.

Ukufaka Java kukhompyutha yakho, umsebenzisi kumele okokuqala yenza isiqiniseko sokuthi izimfanelo imishini ihlangabezana ezincane zesistimu izidingo. Oracle onjiniyela baye bazikhandla ukuze kuncishiswe embundwini nezidingo zomshini, kodwa namanje abantu bakhona, futhi kumelwe icatshangelwe. Umsebenzisi kufanele uthole indawo udinga ukusatshalaliswa esekelwe yesistimu yokusebenza, okuyinto efuna ukufaka isofthiwe. Ukuze Ngokwesibonelo, i-Java -Windows 7 Kuyinto elisebenzisekayo .exe-ifayela, okuyinto kuzodinga kuphela ucacise ukufakwa lwemibhalo, bese uyokwenza konke yena. Kuyaphawuleka ukuthi uhlelo ingafakwa ngesikhathi esifanayo ikhophi eyodwa kuphela ye-igobolondo isofthiwe. Ngakho-ke, ngaphambi kokufaka kunesidingo sokuqinisekisa ukuthi isihumusho Java asuswe uhlelo. Uma ungaphenduki, isifaki uzokubuza ukususa uhlelo engqubuzanayo ngaphambi kokuqhubeka ukufakwa.

Qala asathuthuka Java

Ngemva umsebenzisi ifakwe ngempumelelo imvelo software, izotholakala izindlela ezihlukahlukene kubulawa izinhlelo ebhaliwe kakade, futhi ukuthi badale owabo. Ukuze uqale uHlelo e nge-Java, akudingeki yimuphi izinhlelo ezengeziwe. Sidinga kuphela isifiso sokuba ngifunde izinto ezintsha futhi ukuqonda ulimi bokwakha. Uma umsebenzisi wakwazi ngempumelelo ukufaka i-Java, futhi inqubo abanalo liphambana nezinye izinhlelo, ungaqala ikhodi ukubhala kunoma iyiphi sombhalo.

Oracle uye waqikelela ukunikeza isethi esiphezulu amathuluzi konjiniyela. Ngo-Java, iphakethe kuhlanganisa umhlanganisi (Javac Umbuso), okuyinto, ukuthatha njengoba agumenti indlela kunoma yiliphi ifayela umbhalo, iyiguqule ibe bytecode ewumshini kuyaqondakala.

Umsebenzisi abasuke bengakakwazi ukusebenzisa isicelo futhi ubone imiphumela emihle yomsebenzi wabo. Ukuze ufake uhlelo lwe-Java-Windows 7, kubalulekile ukuba "iphakethe" embizeni-ingobo yomlando.

Ifomethi jar lisuselwa nokwehlisa Java Ingobo yomlando, futhi uhlobo olukhethekile ajwayelekile kubo bonke-ZIP-ifayela, elibuye yakhiwa incazelo amakilasi kanye nemizana futhi ukhombe lokho yokungena (isigaba esiyinhloko) e isicelo. Ukudala .jar-ifayela igama elifanayo esetshenziswa Umbuso indawo, okuyilona elisebenzayo futhi kufakwe iphakethe ejwayelekile kusukela Oracle. Ngemva kokusebenza yayo ngempumelelo, umsebenzisi angakwazi ukugijima uhlelo lokusebenza wadala noma Java ovela umugqa wemiyalo noma console, noma ngokumane kabili ngokucindezela.

Izingxenye ezisemqoka ulimi Java

Ukuze ngempumelelo ukuthuthukisa izinhlelo zokusebenza ngolimi Java, ukufunda idinga ukuqala kakhulu izisekelo. program Novice ngezinye izikhathi kunzima ukuqonda eside ulimi "into-ngamakhasimende". Abantu abaningi ngephutha bakholelwa ukuthi likhuluma yokuthi zonke izinhlangano ukuthi ongasebenza ngolimi kukhona izinto. Nokho, lokho akulona iqiniso. Olimini Java, ngaphandle izindawo, kukhona iqoqo izinhlobo lasekuqaleni. Lokhu inamba uhlobo idatha (Byte, dlala, int, eside ), okuyizinto integers ezahlukene izwi obuphelele, ayingxenye nedatha (iflothi, kabili), kanye imigqa uhlamvu izinhlobo (String futhi wezinhlamvu) ngokulandelana.

Ukuze ngamunye wabo kukhona okuthiwa amakilasi - wrappers, ezisetshenziswa ukudala ireferensi into zohlobo oluthile. Lokhu kuyiqiniso zonke izinhlobo bakudala ngaphandle idatha yezinhlamvu.

Izici ukuqaliswa isigaba string Java

-Java umugqa - lena isigaba esikhethekile. It kungenziwa labizwa ngokuthi into engaguquki. Uma uhambisa inkumbulo isicelo njengoba inqwaba (inqwaba), equkethe umucu kabi amandla akhe, bese operation ngamunye kuso (ukukhethwa olungaphansi, concatenation, uhlamvu esikhundleni, nokunye. D.) Ingabe ukudala isenzakalo esisha the starting line, okuzokwenza zehluke yi yokuqala ukusebenza.

Ngakho-ke, i-string njalo kunesidingo ukusebenza kahle, naphezu kweqiniso lokuthi udoti kumemori siphela omkhulu, uMklami kumelwe niqaphelisise ukuvimbela inkumbulo ukuchichima inkomba ngokungadingekile yezinhlamvu. Ngenhlanhla, ngoba lokhu kukhona okuningi umsizi emakilasini. Ngokwesibonelo, zisebenzisa StringBuilder futhi StringBuffer, okukuvumela ukuba bangasizakali strings, kodwa ungawakhi ngemva isenzakalo esisha ngasinye.

I-Java ulimi - izinkulumo njalo. ukubukeka injongo yabo

Izengezo ezivamile bavele ngaphambi kwekhulu lamashumi amabili futhi yashintsha ubuchwepheshe processing umbhalo electronic.

Ngaphambili, sesha izigaba ezithile embhalweni noma olungaphansi nenkinga evamile, okuyinto yona yayidinga umzamo omkhulu futhi isikhathi sokwenza amahlelo asebenze. Program kwadingeka ukuba uhlole cishe njalo isayithi ngqo afanayo ecacisiwe yokusesha ipharamitha noma ukuqhathanise eziningi izimo. Nokho, nge obhekwe izinkulumo njalo nethuba ukusebenzisa izinhlamvu meta, ngalo baba etholakalayo ukuhlathulula iphetheni ngawo kwadingeka ukuba ukuseshwa. Ngo-Java izinkulumo njalo uvele version 5, futhi liye kusukela baba Imfanelo ebalulekile imvelo isofthiwe.

Ukusebenza izinkulumo njalo e-Java

Ngo-Java, wonke amakilasi, ngandlela-thile asetshenziselwa ukusebenza izinkulumo njalo, iphasela elihlukile okuthiwa java.util.regex. Ngo -Java ejwayelekile uchaza ekilasini Iphethini, okuyinto elihunyushwe English lisho "iphethini". Lesi sigaba amukela i-agumenti string kuya umakhi, engasetshenziswa ukwakha isifanekiso. Uma ufuna ukuchaza ke, esikhundleni izincwadi ezilula kangcono ukusetshenziswa wildcards.

Ukuze ucacise kahle osesho, kungcono ukufunda imibhalo esemthethweni esuka Oracle, njengoba akusizona izinhlamvu eziningi meta kungasho ukuthi umsebenzisi abavamile noma imfundamakhwela uMklami ungase ucabange. Ngokwesibonelo, uphawu "+" ibonisa ukuthi iphethini iwela eyodwa noma ngaphezulu izimo element ngokushesha okwandulela. Lapho ukusebenza ngo-Java ejwayelekile, nezinhlamvu ezikhethekile ziyefana nganoma ngaluphi ulimi izinhlelo. Ngakho-ke, ukuthuthela kwenye ingxenyekazi kufanele kube buhlungu.

izicelo Okungenzeka eboniswa njalo

Kufanele kuqashelwe ukuthi kungenzeka eboniswa njalo kuthiwa kangcono ukusingatha inani elikhulu umbhalo. Ngokwesibonelo, abanye ukhiye wokusesha, noma izwi inhlanganisela e irejista ngalo mbandela wokuba leyo icala lapho ukhiye kulotshiwe ayibalulekile. Hand kulandzelana nekuhlunga umbhalo kungaba kakhulu ukungasebenzi kahle ukuxazulula inkinga enjalo, futhi esakhelwe Java izinkulumo njalo bungatholakala ambalwa imigqa yekhodi.

Yingakho izincwadi esizifundayo ekutadisheni ulimi nganoma iyiphi indlela awukwazi miss ebalulekile njengoba ezivamile. Ngo-Java, ingasetshenziswa emikhakheni ehlukahlukene - kusukela ekuqinisekiseni kufakwa ifomu (e-mail, izinombolo zekhadi lokuthenga ngesikweletu) ukuhlaziya izicelo traffic futhi umsebenzisi.