Kawm tau kab zauv mus hauv Java

Kawm tau kab zauv mus hauv Java

Txheej txheem cej luam:

Java muab mus qhia tej pob khoom uas yuav pab tau rau software developers thiab testers xwm yeem. Kab zauv mus varied Java, ntau yam thiab pub developers los txhais tau txoj hlua qauv uas yuav siv tau los mus nrhiav, kho kom raug los yog muab cov ntawv nyeem. Tus java.util.regex API comprises ntau uas neb muaj lub luag hauj lwm kev kawm. Piv txwv, tus java.util.regex txawv yog siv defining ntxwv thaum lub java.util.regex.Matcher yog siv txuam haujlwm raws tus qauv sau tseg los ntawm cov java.util.regex.Pattern hoob. Nws cia li siv hauv chav kawm ntawv kom tsim nyog rau lub hom phiaj.

Nyob rau cov tshooj no, peb yuav xyuas nyuj li cas kab zauv tau muab sau rau hauv daim ntaub ntawv Java.

koj puas paub – Cov kauj ruam yuav ua hauj lwm nrog Java Persistence API?

Vim li cas peb yuav tsum mus qhia?

Kab zauv mus yuav tau immensely siv tshwj xeeb txug tej yaam kev software loj uas kav ntev ntawm qhov chaws. Nyob li tej yaam num, software developers yuav tau ua ntau yam xws li tsim reusable blocks cov lis dej num; refactoring los yog tu lis dej num thiab muab lus rau lis dej num. Tam sim no, xav txog tej yam koj ua ntawd manually tag ib codebase loj. Uas yuav muab khib nyiab ntawm sij hawm thiab productivity colossal. Qhov no yog qhov twg mus kab zauv muaj heev thiaj yuav pab tau. Software developers lossis lub testers txawm yuav txhais tau ib kab zauv mus rau tej hom phiaj thiab cia li rov qab siv lub qhov kev qhia. Piv txwv, yog tus tsim tawm xav mus nrhiav ib lub sij hawm "muab" hla lub chaws txoos tsis tshawb tau case-sensitive, ces tus tsim tawm yuav txhais tau ib cov kev qhia kom haum nyiam cov nram qab no:

Kaj ntsiab lus = “Qhov no yog ib qho khoom”;

Kaj patternString = “.*kev pab.”;

Txawv pattern=Pattern.compile (patternString, Pattern.CASE_INSENSITIVE);

Re-usability thiab efficiency yog ob leeg lub ntsiab zoo tsis ntau ib txwm qhia. Qhov loj tshaj plaws yog tias ntau kab zauv mus yuav tau hais tseg nyob rau ntawm lub hom phiaj.

Yuav tsum nyeem – Cov kauj ruam yuav ua hauj lwm nrog Java generics?

Cheebtsam ntawm Java mus qhia pob

Ua ntej peb tau sau kab zauv mus hauv Java, peb yuav tsum tau muaj ib tug to taub ntawm lub cheebtsam uas muaj nyob hauv java.util.regex.

Muaj cov hoob mas peb muaj nyob rau hauv lub hnab. Peb tau saib ua li cas lawv ua tau.

Qauv kawm: Cuag kab zauv muaj feem ntau uas muaj tuaj raws li lawv liag ib cim cim/cim/tshwj xeeb thiab lwm yam. Li ntawd, tus txheej txheem basic yog xav kom nws ib yam twj paj nruas ua ntej nws usable. Thaum cov kev qhia yog compiled, nws yuav ib yam twj paj nruas txawv. Qauv kawm tsis tau tej pej xeem constructor. Nws muaj ib tug pej xeem zoo li qub tsis muaj dabtsis hom hu ua ' compile’. Kev qhia yog tau mus no txoj kev ua ib tug sib cav thiab tus kwv tuaj yog ib yam twj paj nruas txawv. Raws li peb tau siv nyob rau hauv peb cov qauv ntaub ntawv.

Txawv test_pattern = Pattern.compile (“\\s ”, Pattern.CASE_INSENSITIVE);

Nyeem – JSON Java – cov ntaub ntawv thiab cov nws xwb li cas?

Hoob kawm matcher: Tam sim no, Thaum tus tsav haus dejcawv qauv yog tsim, peb yuav tsum muaj ib co mechanism piv txoj hlua rau lub txawv input. Ntawm no los ntawm kev kawm Matcher, nws ua raws li tus regex cav kom me zog-lub tswv yim thiab tus qauv. Nws tsis muaj tej pej xeem constructor, theej cov txujci matcher uas txawv nruas yog siv los muab cov tswv yim thiab rov qab ib yam twj paj nruas Matcher. Tom qab no lub ' qhov yuam kev’ hom hoob kawm Matcher yuav siv tau cov nqi no, nws rov ib Boolean tus nqi ntawm seb cov no yeej muaj tseeb (matched) los yog cuav (tsis matched).

Piv txwv li hauv qab no qhia tau hais tias qhov kev siv.

Qhia 1: Kuaj tau Regex cheebtsam hauv Java

[chaws]

pob demo.techalpine.com;

ntshuam java.util.regex.*;

tsev kawm RegExComponents {

pej xeem tsis muaj dabtsis loj zoo li qub(Txoj hlua[] args) {

//Npaj cov qauv paj nruas

Txawv tst_pattern = Pattern.compile(“.duoni.”);

//Npaj cov kwv Matcher

Matcher tst_matcher = tst_pattern.matcher(“TechAlpine”);

//Soj ntsuam txoj hlua input

System.out.println(“Xyuas…Yog tias txoj hlua input ntais ntawv nrog rau lub txawv – “+tst_matcher.matches());

}

[/chaws]

Tam sim no compile thiab khiav cov chav kawm ntawv.

Hoob kawm PatternSyntaxException: Qhov no yog cov chav kawm kos rau tebchaws tej kev ua yuam kev syntax.

Teeb ib puag ncig:

Mus configure nyob nram qab no yog yam plaub rau tom qab

Download tau JDK ntawm qhov link hauv qab no thiab muab ib txog kev faib chav kawm ntawv

http://www.oracle.com/technetwork/java/javase/downloads/index.html

Teeb muaj IDE li NetBeans los sis Dab noj hnub thiab nruab

Tam sim no koj koj cheeb tsam yog muab sau kab zauv mus hauv Java. Nyob rau hauv cov seem tom ntej no peb yuav tsim ib cov qauv ntawv.

Koj yuav nyiam nyeem ntawv – Peb qhov Web site RESTful hauv Java

Wb muab ua ib cov qauv ntaub ntawv:

Ntawm ntu no peb yuav sau ib tsab ntawv teev npe qauv rau kev qhia los soj ntsuam. Tom qab txhaj tshuaj ntsuam pom tau tias yog ib qhov qauv rau cov ntawv.

Hauv qhov ua piv txwv peb yuav muaj ib txoj hlua yooj yooj yim rau tej qhov chaw neeg dawb. Txoj hlua no yuav bet lub tswv yim rau cov matcher. Tam sim no lub hom phiaj yog mus tshem cov tej lub dawb thiab hloov nrog ' **' hlua.

Peb yuav tsim ib tug qauv kawm thiab cov hoob kawm Matcher. Tom qab no cov hlua input yuav kis mus nrog rau lub txawv. Peb yuav tau tso saib lub indexes ntawm tus tej lub dawb hauv txoj hlua.

Ua raws li cov qauv yog ib qhov dab noj hnub puag ncig. Thaum cov kev pab cuam no sau ntawv, compile thiab khiav nws.

Qhia 2: Coj daim ntawv

[chaws]

pob demo.techalpine.com;

ntshuam java.util.regex.Matcher;

ntshuam java.util.regex.Pattern;

tsev kawm RegDemo {

// Txoj kev coj txoj hlua rau kuaj kom

pej xeem zoo li qub thaum kawg txoj hlua SAMPLE_STRING = “Peb cia saib kev qhia nyob rau hauv Java”;

pej xeem tsis muaj dabtsis loj zoo li qub(Txoj hlua[] args) {

Txawv test_pattern = Pattern.compile(“\\s ”, Pattern.CASE_INSENSITIVE);

Matcher test_matcher = test_pattern.matcher(SAMPLE_STRING);

//Peb cia sau cov matcher

System.out.println(“Printing lub matcher:- “+ test_matcher “\n”);

//Peb xyuas txoj indexes

System.out.println(“Printing indexes:- “+”\n”);

Thaum (test_matcher.find()) {

System.out.Print(“Pib Performance index: ” + test_matcher.Start());

System.out.Print(“Kaw Performance index: ” + test_matcher.END() + “\n”);

}

//Tam sim no compiles qhov txawv

Txawv replace_pattern = Pattern.compile(“\\s ”);

//Txuam tus qauv uas muaj cov qauv hlua

Matcher second_matcher = replace_pattern.matcher(SAMPLE_STRING);

//Printing thawj txoj hlua

System.out.println(“\n”+”Printing thawj txoj hlua:- “+”\n”);

System.out.println(SAMPLE_STRING);

//Hloov rau tej qhov chaw uas tam sim no ** cim

System.out.println(“\n”+”Printing txoj hlua hloov:- “+”\n”);

System.out.println(second_matcher.replaceAll(“**”));

}

[/chaws]

Tam sim no compile thiab khiav ntaub ntawv rau.

Nyeem – Kawm Log4j – txiav API rau Java

Xaus: Nyob rau cov tshooj no peb tau tham txawv Cheebtsam ntawm Java mus qhia nws. Peb muaj los ntsuam xyuas nws xwb li cas thiab vim li cas nws tseem ceeb heev. Kab zauv mus siv rau lub txawv scenarios zoo ib yam li lo lus zais validation, email chaw nyob validation thiab lwm yam. Cov tswv yim yooj yim yog tsim ua tus qauv as per lub thiab ces validate lub tswv yim. Qhov no yog li cas kab zauv mus yuav. Nws thiaj li tau lub sij hawm txoj kev loj hlob thiab ua ib qho reusable Cheebtsam. Li ntawd, tseem yuav kawm tsis tu ncua cov kab zauv thiab mam li sau nws as per tau.