Caij nplooj ntoos hlav Tutorial – Connecting database siv lub caij nplooj ntoos hlav
Txheej txheem cej luam:
Tus Caij nplooj ntoos hlav JDBC Template muab ib txoj kev zoo tshaj li uas yog JDBC tsav tsheb rau integrating Java hu lossis thov nrog cov kev pab cuam database. Thaum lub hom phiaj ntawm ob lub caij nplooj ntoos hlav JDBC thiab JDBC thiab ODBC yog tib yam, txoj kev zoo heev. Nyob rau tom kawg, Tus tsim tawm yuav tsum txhawj txog ntau overheads xws li qhib thiab kaw kev sib txuas thiab query tiav. Tiam sis Sprint JDBC template tso cai rau tus tsim tawm kom kub siab rau tus tub ntxhais ntawm cov neeg ua hauj lwm kev koom ua ke.
Cov paint ntsiab lus ntawm JDBC zoo li cas?
JDBC muab kev mus saib tau database programs los ntawm plaub tsav tsheb. Txhua tus neeg tsav tsheb muaj nws cov disadvantages uas yog piav hauv qab no.
JDBC-ODBC choj
- Qhov no yog siv thaum tsis muaj Java tsav tsheb muaj rau ib database. Tus tsav tsheb converts JDBC hu rau ODBC hu lossis thov uas ces tau routed rau lub database. Qhov no ua rau kev kawm overhead vim hais tias cov JDBC hu kom xub mus rau ODBC tsav mus txog rau JDBC-ODBC choj.
- Tus tsav ODBC yuav tsum tau ntsia rau lub tshuab neeg thiab vim tsis muaj Java tsav tsheb muaj rau lub database, Tus neeg tau kev pab software yuav tsis tsim rau cov applets.
Neeg tsav tsheb uas muaj neeg tsav tsheb
- Tsav tsheb no converts JDBC thov kom nug txog cov database API uas cov database to taub. Tus neeg tsav tsheb siv tus neeg siv lub tsev qiv ntawv client-sab. Xa JDBC hu rau lub database, Lub tsev qiv ntawv yuav tsum muab ntsia rau hauv lub tshuab neeg. Vim muaj ntau yam tshwm sim, Tus neeg tsav tsheb tsis tau siv hauv Internet.
- Tus neeg tsav tsheb tej zaum yuav redundant yog tus database poob rau nws cov tsev qiv ntawv.
Network-Protocol Tsav tsheb
- Txij thaum tsav tsheb no siv ib tier nruab nrab tier los yog ib daim ntawv thov kev pab kom ua li cas JDBC hu rau database programs, Nws muaj nws ib lub dag zog yuav tsum tau code rau lub tier nruab nrab.
- Ntxiv cov tier nruab nrab yuav siv sij hawm ntau heev.
Ceeb toom: Mus integrate Java thov nrog database programs, Tus tsav Native-Protocol pom tau qhov zoo tshaj plaws vim nws converts JDBC hu rau vendor-specific database hu.
Yuav tsum nyeem – Lawv muaj daim ntawv koj siv cov AngularJS thiab dhia tej ntaub ntawv JPA?
Dab tsi yog lub caij nplooj ntoos hlav JDBC?
Muaj ob peb cov teeb meem nrog tus JDBC tsav tsheb, raws li pom nyob rau hauv cov kev piav qhia saum toj no. JDBC tsav nyob ntawm lwm cov chaw xws li JDBC-ODBC choj, nruab nrab thiab database client libraries. Teeb meem yuav sawv hauv cov kev tshwm sim uas unavailability ntawm cov chaw. Thaum koj ua hauj lwm nrog JDBC tsav tsheb, tej zaum koj kuj yuav tau code ntau heev. Ntau dhau lawm ntawm lwm cov chaw ua hauj lwm ua database programs ib zaug. Lub caij nplooj ntoos hlav JDBC txawv?
Yuav kom daws tau qhov teeb meem ntawm integrating Java thov cov kev pab cuam database, Lub caij nplooj ntoos hlav JDBC yuav siv sij hawm cov nram qab no:
JDBC Template hoob kawm
Qhov no yog ib hoob kawm uas comprises ntau txoj kev uas ua tau txawv tasks. Piv txwv, Pej xeem hauv txoj kev hloov yus yuav insert, Hloov tshiab los yog delete records thiab cov pej xeem zam kev tuav tseg yuav tseg tau DL query. Cov muaj kev npaj txhij txog kev npaj ua tau hauj lwm tasks ua tau yooj yim.
Npe Namedarameter
Qhov no muaj peev xwm siv los saib tau cov ntaub ntawv los ntawm hu ua parameter. Siv daim ntawv no, tus neeg siv yuav tsum nco ntsoov cov ntaub ntawv rau tus ncej.
Yooj yim yooj yim
Qhov no qhwv tuaj rau JDBC Template chav kawm ntawv thiab tso cai rau tus neeg siv rau cov lus dhau mus saib cov database.
Summarise, Lub caij nplooj ntoos hlav JDBC yooj yim lub integration ntawm Java hu nrog databases nrog txoj kev npaj ua hauj lwm nrog rau kev ua hauj lwm.
Yuav tsum nyeem – Nrhiav kom paub cov kev pab Batch caij nplooj ntoos hlav
Lub caij nplooj ntoos hlav JDBC template?
Lub caij nplooj ntoos hlav JDBC template yog ib txoj kev haib rau integrate Java hu nrog database programs. Thaum muaj lwm txoj kev xws li cov JDBC thiab ODBC thaum lawv tseem mus cuag Java hu nrog databases, Lub caij nplooj ntoos hlav JDBC cia tus tsim tawm ntawm lub sam xeeb thiab teb thaum noj lwm yam kev ua ub no uas tsis muaj kev ua ub no xws li txheej txheem kos, txhais tes, qhib thiab kaw kev sib txuas, nqe lus executing, teem caij mus loops los ntawm qhov txheeb xyuas tau thiab kaw cov nqe lus thiab teev tseg.
Qhov zoo dua yog cov zoo dua lub caij nplooj ntoos hlav JDBC template?
Lub ntsiab kom zoo dua ntawm lub caij nplooj ntoos hlav JDBC template yog nws ua rau kev txuas nrog database ib yooj yim thiab hassle-dawb rau tus tsim tawm. Nrog lwm cov kev pab xws li cov JDBC tsav tsheb, tus tsim tawm yuav tsum mus ua hauj lwm rau lwm overheads xws li coding rau tier nruab nrab, Fulfilling dependency Java hu thiab qiv ntawv thiab database APIs thiab thiaj li. Lub caij nplooj ntoos hlav JDBC Template yuav siv sij hawm tam sim ntawd ntau. Tom qab no yog ib txhia tseem ceeb tswj los ntawm lub caij nplooj ntoos hlav JDBC template.
- Qhib kev twb kev txuas
- Npaj thiab tso nqe lus executing
- Teem mus loop rau iterating los ntawm kev sojntsuam
- Tshwj cov txheej txheem
- Tuav kev txhawb
- Kaw kev sib txuas
Yuav tsum nyeem – Kauj ruam los mus teem lub sij hawm pab raws qib kev siv moj khaum caij nplooj ntoos hlav
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 Java.
Coj daim ntawv:
Nyob rau hauv seem no peb yuav code tej kev pab cuam piv txwv li cas lub caij nplooj ntoos hlav JDBC template ua hauj lwm nrog databases
Peb yuav tsim tau ib tug kawm kwv thiab insert cov ntaub ntawv nyob hauv ib database. Peb yuav tau xyuas cov ntaub ntawv inserted.
Qhia 1: Qhov no yog tus neeg kawm ntawv phij xej
pob com.com techalpine.demo;
pej xeem hoob Menyuam {
lwm yam qub txeeg qub tes;
lwm yam Hlua semail;
pej xeem Txoj hlua coj tau tus mob no() {
rov qab mus zoo tib yam;
}
pej xeem khoob lug setSname(qub txeeg qub tes) {
no.tib yam nkaus li =;
}
pej xeem Txoj hlua coj tau tus mobSemail() {
rov qab mus semail;
}
pej xeem khoob lug setSemail(Hlua semail) {
no.semail = semail;
}
@Override
pej xeem Txoj hlua toString() {
rov qab mus “Menyuam [npe hu ua =” + zoo tib yam + “, email yog =” + semail + “]”;
}
}
Tom qab no yog cov hoob KAWM DAO kom tus menyuam kawm ntawv nyob rau hauv ib lub database MySQL database. Thiab kuj fetch cov ntaub ntawv los ntawm tus DB.
Qhia 2: Qhov no yog tus me nyuam kawm ntawv DAO caij nyoog
pob com.com techalpine.demo;
ntshuam java.util.List;
ntshuam org.springframework.jdbc.core.JdbcTemplate;
pej xeem hoob Neeg Kawm Ntawv {
lwm yam JdbcTemplate jdbctemplate;
pej xeem JdbcTemplate getJdbctemplate() {
rov qab mus djbcemplate;
}
pej xeem khoob lug setJdbemplate(JdbcTemplate jdbctemplate) {
no.djbctemplate = djbctemplate;
}
pej xeem khoob lug ntxig(Tub ntxhais kawm ntawv){
Kauj ruam sqlinser =”NTXIG RAU TUS MENYUAM KAWM NTAWV (LUB NPE, Tus email) QHOV TSEEM CEEB(?,?);”;
Kev hlua xwv txhij = menyuam kawm ntawv.tau txais kev pab();
Txoj hlua semail = tus me nyuam kawm ntawv.getSemail();
tau txais kev pab los ntawm DJDCTemplate().hloov yus(slinser,tshiab Nruas[]{zoo tib yam,semail});
}
pej xeem Sau<Menyuam> xaiv(){
Hlua selectAllSql = “XAIV * NTAWM ME NYUAM KAWM NTAWV;”;
rov qab mus tau txais kev pab los ntawm DJDCTemplate().lus nug(selectAllSql, tshiab Neeg Kawm Ntawv Muaj Kev Tsis Taus());
}
}
Tom qab cov kev pab no yog cov kev pab qhia ntawv rau cov me nyuam kawm ntawv.
Qhia 3: Qhov no yog tus neeg kawm ntawv pab cov hoob kawm
pob com. techalpine.demo;
ntshuam java.util.List;
pej xeem hoob Neeg Kawm Ntawv {
lwm yam Tub Ntxhais Hluas Kawm Ntawv;
pej xeem Me Nyuam Kawm Ntawv Tau Zoo Tshaj() {
rov qab mus studentDao;
}
pej xeem khoob lug Txheej Txheem Kev Kawm(Tub Ntxhais Hluas Kawm Ntawv) {
no.Tub Ntxhais kawm ntawv = menyuam kawm ntawv;
}
pej xeem khoob lug neeg kawm ntawv(Tub ntxhais kawm ntawv) {
Tau Cov Neeg Kawm Ntawv().ntxig(Menyuam);
}
pej xeem Sau<Menyuam> FetchAllStud() {
rov qab mus Tau Cov Neeg Kawm Ntawv().xaiv();
}
}
Tom qab yog tus leej mapper hoob kawm kom phim cov ntaub ntawv teev cov ntaub ntawv uas tus corresponding columns.
Qhia 4: Qhov no yog lub npe mapper hoob kawm
pob com. techalpine.demo;
ntshuam java.sql.ResultSet;
ntshuam java.sql.SQLException;
ntshuam org.springframework.jdbc.core.RowMapper;
pej xeem hoob Neeg Kawm Ntawv Muaj Kev Tsis Taus qiv RowMapper<Menyuam>{
@Override
pej xeem Me Nyuam Kawm Ntawv Daim Ntawv Qhia Kev Txhim Kho(Sojntsuam sojntsuam, rau cov menyuam rownumber) throws SQLException {
Tub ntxhais kawm ntawv = tshiab Menyuam();
me nyuam kawm ntawv.setSname(tshwm sim..tau rhuav(1));
tub ntxhais kawm ntawv setSemail(tshwm sim..tau rhuav(2));
rov qab mus Menyuam;
}
}
Tam sim no, Tom qab no yog cov hoob kawm kom insert cov ntaub ntawv thiab fetch nws ntawm tus DB uas siv lub caij nplooj ntoos hlav JDBC template thiab configuration.
Qhia 5: Qhov no yog qhov tseem ceeb chav kawm ntawv
pob com.com techalpine.demo;
ntshuam java.util.List;
ntshuam org.springframework.context.application;
ntshuam org.springframework.context.classPathMAPLPAPlication;
pej xeem hoob Kev Kuaj Cev Ntas (TestspringDemo). {
pej xeem zoo li qub khoob lug ntsiab(Txoj hlua[] args) {
Application Application context = tshiab ClassPathmaPlplication(“caij nplooj ntoos hlav.xml”);
Neeg Kawm Ntawv Cov Me Nyuam Kawm Ntawv = (Neeg Kawm Ntawv) context.getBean(“me nyuam kawm ntawv”);
Tub ntxhais kawm ntawv = tshiab Menyuam();
me nyuam kawm ntawv.setSname(“Siav”);
tub ntxhais kawm ntawv setSemail(“nick@gmail.com”);
Me Nyuam Kawm Ntawv Cov Neeg Kawm Ntawv Kev Kawm(Menyuam);
Tsim.tawm.println(“Menyuam : ” + me nyuam kawm ntawv.getSname() + ” ntxiv ntse”);
Sau<Menyuam> Cov me nyuam kawm ntawv = cov me nyuam kawm ntawv cov naiskhu.fetchAllStudents();
Tsim.tawm.println(“Daim Ntawv Teev Cov Me Nyuam Kawm Ntawv = ” + me nyuam kawm ntawv);
}
}
Thaum qhov kev pab cuam tseg nws yuav qhia cov tso zis li nram qab no.
Menyuam kawm ntawv Nick ntxiv ntse
Sau yog cov tub ntxhais kawm ntawv = Nick
Xaus:
Lub caij nplooj ntoos hlav JDBC template yog obviously haib tshaj cov JDBC thiab ODBC thaum nws tawm mus cuag database programs. Tej zaum tus zoo txaus nyiam feature tseem yooj yim li cas nws yuav ua rau kev koom ua ke nrog database programs. Nws los txog loaded nrog txoj kev uas yuav tsum ua tau tej hauj lwm kev ua hauj lwm. Yog li ntawd, txuag lub sij hawm thiab dag zog.
