Caij nplooj ntoos hlav Tutorial – Caij Nplooj ntoos hlav Lus (EL)
Txheej txheem cej luam:
Lub caij nplooj ntoos hlav Qhia Lus, abbreviated li SpEL, yog ib qho lus piav qhia. Nws tseem haib heev nyob rau hauv nws cov hauj lwm thiab muaj kev txhawb zog rau queries thiab manipulation ntawm tus kwv yees duab thaum khiav. Qhov feature tawm nrog caij nplooj ntoos hlav 3.0 nyob rau hauv 2009.
Thaum cov syntax ntawm cov lus no zoo nkauj zoo xws li EL Unified EL, nws yog ib qho nta ntau nta. Ntawm lawv, Nyiam tuaj sawv daws yuav txoj hlua templates thiab txoj kev invocation. Muaj ntau Java kev qhia tau cov lus, Lawv yog JBoss EL, KUV TUS KHEEJ, ONGL thiab ntxiv. Txawm li cas los, Tus creation ntawm ib cais nplooj ntoos hlav Lus yog los xyuas kom meej tias lub caij nplooj ntoos hlav lub caij nplooj ntoos hlav yuav tsum siv txhua yam nyob rau hauv lub caij nplooj ntoos hlav. Ntau yam ntawm nws cov nta yog vim muaj qhov uas txug tej yaam yuav muaj nyob rau hauv lub caij nplooj ntoos hlav spring, xws li cuab yeej ua kom tiav Caij nplooj ntoos hlav Cuab yig. Spel yog xyuas los ntawm API, qab hau lwm cov lus qhia yuav tau integrated thaum nws tseem tsim nyog ua li ntawd. Dua li ntawm lub caij nplooj ntoos hlav foundation framework rau uas qhia tej hauj lwm, nws tsis yog nyob ntawm nws. Nws yog ywj siab thiab yuav tsum saib raws li ib tug ywj siab hais txog lus.
Yuav tsum nyeem – Caij nplooj ntoos hlav AOP kawm tau nyob rau hauv 30 feeb
VIM LI CAS SPEL?
Xav txog tias muaj ntau hom lus uas yuav siv tau rau cov kev tshuaj ntsuam uas qhia, Lub caij nplooj ntoos hlav tawm rau ob peb yam. Ntawm no yog ob peb yam txheej xwm seb vim li cas koj yuav tsum xav txog lub caij nplooj ntoos hlav Qhia.
- Syntax
SpEL yuav siv tau nyob rau hauv ob lub annotation metadata (Lub caij nplooj ntoos hlav configuration) thiab XML. Ob leeg raug tus mob no, cov designation yuav siv qhov chaw uas siv cov syntax #{"qhia txoj hlua rau hauv SpEL"} kev kuaj ntawd.
- Txo qhov chaws
SpEL yog ib tug yooj yim heev rau ntau lwm cov lus qhia uas muaj ntau hom lus uas muaj. qhov tseeb, nws yuav txo tau ntau txoj kev cai rau koj.
- Yooj yim zog
Thaum siv hlau phuam, Tus coder tsuas yuav tsum tau saib xyuas cov lus qhia nyob rau hauv tej cov ntaub ntawv zog. Lub framework code yog lub luag hauj lwm rau extraction tuav ntawm cov ntaub ntawv tshiab.
Cov yam ntxwv yog dab tsi?
Lub caij nplooj ntoos hlav Qhia Lus los nrog ib tug xov tooj ntawm cov nta uas tau raug hais hauv qab no –
- Kev ntxhov siab
- Kev qhia literal
- Chav Kawm Ntawv Qhia
- Boolean thiab relational tswv
- Cov neeg teb xov tooj
- Templated qhia
- Txoj kev invocation
- Hu rau constructors
- Phau ntawv sau los lus xaiv tsa thiab kev tiv thaiv
- Ntau yam
- Tus neeg teb xov tooj
- Array siv
- Neeg siv cov kev nplua
- Hauv internet npe
- Taum references
- Accessing txheej txheem, teev, khoom, maps
Tej cov nta yuav tau them rau hauv qab no piv txwv. Lwm yam nta kuj tseem yuav tau soj ntsuam siv cov ntaub ntawv kuaj. Tab sis daim ntawv thov qauv yuav nyob zoo li qub.
Yuav tsum nyeem – Cov kauj ruam yuav ua hauj lwm nrog lub caij nplooj ntoos hlav xws li
Teeb ib puag ncig:
Teem tau qhov chaw rau lub caij nplooj ntoos hlav raws li txoj kev loj hlob uas yog peb kauj ruam loj.
- Teem java kev loj hlob Java txoj kev loj hlob
Download JDK Ntawm qhov chaw Oracle thiab ces, nruab nrab thiab configure. Ces cov PATH thiab JAVA_HOME chaw yuav tsum muab teev tseg.
- Teev ntawm Eclipse tswv yim
Eclipse yuav tsum downloaded ntawm nom website. Ib zaug downloaded, tsis them cov binaries thiab ces muab lub PATH thiab.
- Teem caij nplooj ntoos hlav lub caij nplooj ntoos hlav
Lub caij nplooj ntoos hlav lub caij nplooj ntoos hlav (Spring libraries). http://repo.spring.io/release/org/springframework/spring/. Dua, tseem ceeb heev uas yuav tau teem caij rau CLASSPATH kom yog.
Tam sim no koj ib puag ncig yuav pib lub caij nplooj ntoos hlav Bava.
Coj daim ntawv:
Nyob rau hauv tshooj no peb yuav tshawb kawm lus siv nyob rau hauv ib daim ntawv XML. Cov lus qhia yuav siv tau los ua daim ntawv thov Java. Yog hais tias tus EL siv raws li kev npaj siab ua, Ces XML ntawv tsis tas yuav tsum tau txhaj. EL yog feem ntau sau ntawv li #{Kev qhia spEL}
Tom qab no yog ib lub tuam txhab yooj yim pib muaj kev siv ntawm cov khoom pib. Nws muaj cov khoom lub npe thiab nqi raws li qhia hauv qab no.
Qhia 1: Tuam txhab taum
pob com.com techalpine.spel;
pej xeem hoob Niaj hnub {
lwm yam khoom tsim kom muaj khoom;
lwm yam hlua prname;
lwm yam hlua txhuv;
pej xeem hlua kib() {
rov qab mus nqe;
}
pej xeem khoob lug sepprrice(hlua txhuv) {
no.nqe = nqe;
}
pej xeem Khoom tau txais kev rhuav() {
rov qab mus Khoom;
}
pej xeem khoob lug setProduct(khoom tsim kom muaj khoom) {
no.khoom = yam khoom =;
}
pej xeem Hlua kis() {
rov qab mus koob meej;
}
pej xeem khoob lug setPrname(hlua prname) {
no.prname = prname;
}
}
Tom qab no yog qhov khoom tau muaj lub npe thiab nqi. Nws yog xa mus rau lub tuam txhab pib saum toj no.
Qhia 2: khoom taum
pob com.com techalpine.spel;
pej xeem hoob Khoom {
lwm yam Txoj hlua npe;
lwm yam txoj hlua txhuv;
pej xeem Txoj hlua getName() {
rov qab mus lub npe;
}
pej xeem khoob lug setName(Txoj hlua npe) {
no.lub npe = lub npe;
}
pej xeem hlua tau() {
rov qab mus nqe;
}
pej xeem khoob lug septrice(txoj hlua txhuv) {
no.nqe nqe;
}
}
Tam sim no, Qhov no yog ib daim ntawv XML. Ntawm no yog yam khoom taum, Khoom lub npe thiab cov khoom uas hais txog cov nqe lus hais txog. Lub neej ntawd tseem teev nyob rau hauv cov ntaub ntawv XML. Li no yuav muaj nyob rau hauv lub tuam txhab kuj. Thov xyuas seb cov lus qhia hais tias yog siv nyob rau hauv cov ntaub ntawv ua ntej. Zoo li syntax no kuj siv nyob rau hauv cov ntaub ntawv uas annotation raws li qhov kev pab cuam.
Qhia 3: Configuration XML
<taum xmlns =“http://www.springframework.org/schema/beans”
xmlns:xsi =“http://www.w3.org/2001/XMLSchema-instance”
xsi:schemaLocation =“http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd”>
<taum daim id =“sojntsuam” hoob =“com.techalpine.txia ntshis. Khoom”>
<lub npe ntawm tus kheej =“lub npe” tus nqi =“Tsheb” />
<lub npe ntawm tus kheej =“nqe” tus nqi =“1000000” />
</taum>
<taum daim id =“tuam txhab” hoob =“com.techalpine.spel.company”>
<lub npe ntawm tus kheej =“Khoom” tus nqi =“#{sojntsuam}” />
<lub npe ntawm tus kheej =“koob meej” tus nqi =“#{prodBean.name}” />
<lub npe ntawm tus kheej =“nqe” tus nqi =“#{sojntsuam.nqe}” />
</taum>
</taum>
Qhov no yog lub ntsiab Java daim ntawv thov. Nws tau siv rau lub tuam txhab taum thiab ces prints cov khoom lub npe thiab nqi. Qee yam khoom ntau thiab lawv qhov tseem yuav raug txhaj nyob rau hauv ib txoj kev zoo sib xws thiab siv nyob rau hauv daim ntawv thov.
Qhia 4: Kev pab cuam Java mus ntsuam xyuas
pob com.com techalpine.spel;
ntshuam org.springframework.context.application;
ntshuam org.springframework.context.context.support.FileSystemPlContXAPLContx;
pej xeem hoob SpELMain {
pej xeem zoo li qub khoob lug ntsiab(Txoj hlua[] args) {
Application Application context = tshiab FileSystemMaXLplication(
“WebContent/WEB-INF/spelConfig.xml”);
Tuam txhab compob = (Niaj hnub) context.getBean(“tuam txhab”);
Tsim.tawm.println(“Khoom Lub Npe: “+compob.getPrname());
Tsim.tawm.println(“Khoom nqi: “+compob.getprrice());
}
}
Thaum koj khiav daim ntawv thov tom qab cov zis yuav muab zaub rau lub console.
Khoom Lub Npe: Tsheb
Khoom nqi: 1000000
Yuav tsum nyeem – Kawm khau raj caij nplooj ntoos hlav hauv 30 Feeb
Xaus:
Lub caij nplooj ntoos hlav Qhia Lus Yuav yog ib qho kev xaiv zoo yog hais tias koj nrhiav kev qhia tau cov lus qhia uas zoo ib yam li tus EL Unified EL. SpEL pub rau koj dynamically assignically qhov tseem ceeb ntawm runtime thiab thiaj li txuag coding rau ib feem ntawm qhov programmer. Besides, Nws kuj tseem yuav ua hauj lwm rau ob tug sib txawv configuration schemes – XML thiab annotation raws li. Li ntawd, yuav xaiv seb puas tsimnyog koj xav tau. Lub caij nplooj ntoos hlav EL yog haib heev thiab nws yuav ncua ntxiv ntxiv functionality hauv koj daim ntawv thov.
tshawb kawm – Caij nplooj ntoos hlav txheej txheem
