Muaj ntau txoj hauv kev los sib piv Java hnub. Sab hauv, hnub tim tau sawv cev raws li (ntev) taw tes hauv lub sijhawm - tus naj npawb ntawm cov milliseconds uas tau dhau mus txij li Lub Ib Hlis 1 1970. Hauv Java, Hnub yog hnub tim, uas txhais tau tias nws suav nrog ntau txoj hauv kev rau kev sib piv. Txhua txoj hauv kev los sib piv ob hnub yuav zoo ib yam piv cov hnub tim.
Cov kauj ruam
Txoj Kev 1 ntawm 4: Siv pivTo
Kauj Ruam 1. Siv pivTo
Hnub ua piv txwv Sib piv thiab yog li ob hnub tuaj yeem sib piv ncaj qha nrog qhov pivTo txoj kev. Yog tias cov hnub yog rau tib lub ntsiab lus hauv lub sijhawm, txoj kev rov qab xoom. Yog tias hnub raug piv yog ua ntej hnub sib cav, tus nqi tsawg dua xoom raug xa rov qab. Yog tias hnub raug piv yog tom qab hnub sib cav, tus nqi ntau dua xoom raug xa rov qab. Yog tias cov hnub sib npaug, tus nqi 0 tau xa rov qab.
Kauj Ruam 2. Tsim cov khoom hnub tim
Koj yuav tsum tsim txhua hnub khoom ua ntej koj tuaj yeem pib sib piv lawv. Ib txoj hauv kev los ua qhov no yog siv chav kawm SimpleDateFormat. Nws tso cai rau nkag yooj yim ntawm cov hnub tseem ceeb rau hauv cov khoom hnub.
SimpleDateFormat sdf = tshiab SimpleDateFormat ("yyyy-MM-dd"); // Rau tshaj tawm qhov tseem ceeb hauv cov khoom hnub tshiab. siv tib hom ntawv thaum tsim cov hnub Date1 = sdf.parse ("1995-02-23"); // date1 yog Lub Ob Hlis 23, 1995 Hnub tim 2 = sdf.parse ("2001-10-31"); // date2 yog Lub Kaum Hli 31, 2001 Hnub tim 3 = sdf.parse ("1995-02-23"); // hnub 3 yog Lub Ob Hlis 23, 1995
Kauj Ruam 3. Sib piv cov khoom hnub tim
Cov cai hauv qab no yuav qhia koj txhua kis - tsawg dua, sib npaug, thiab ntau dua.
date1.compareTo (hnub tim 2); // date1 <date2, rov qab tsawg dua 0 date2.compareTo (date1); // date2> date1, xa rov qab ntau dua 0 date1.compareTo (date3); // date1 = date3, yog li yuav luam 0 rau console
Txoj Kev 2 ntawm 4: Siv Sib npaug, Tom Qab, thiab Ua Ntej
Kauj Ruam 1. Siv qhov sib npaug, tom qab thiab ua ntej
Cov hnub tuaj yeem sib piv nrog qhov sib npaug, tom qab thiab ua ntej txoj hauv kev. Yog tias ob hnub yog rau tib lub ntsiab lus hauv lub sijhawm, txoj hauv kev sib npaug yuav rov qab muaj tseeb. Cov piv txwv yuav siv cov hnub tsim yav dhau los los ntawm kev sib pivTo txoj kev.
Kauj Ruam 2. Sib piv siv cov txheej txheem ua ntej
Cov cai hauv qab no qhia qhov tseeb thiab tsis raug. Yog hnub 1 yog ua ntej hnub tim 2, ua ntej yuav rov muaj tseeb. Yog tias nws tsis yog, ua ntej rov qab cuav.
System.out.print (date1.before (date2)); // luam tawm qhov tseeb System.out.print (date2.before (date2)); // prints tsis tseeb
Kauj Ruam 3. Sib piv siv cov txheej txheem tom qab
Cov cai hauv qab no qhia qhov tseeb thiab tsis raug. Yog hnub 2 yog tom qab hnub 1, tom qab rov qab muaj tseeb. Yog tias nws tsis yog, tom qab rov qab tsis tseeb.
System.out.print (date2.after (date1)); // prints tseeb System.out.print (date1.after (date2)); // prints cuav
Kauj Ruam 4. Sib piv siv cov txheej txheem sib npaug
Cov cai hauv qab no qhia qhov tseeb thiab tsis raug. Yog tias cov hnub sib npaug, sib npaug rov qab muaj tseeb. Yog tias lawv tsis yog, sib npaug rov qab cuav.
System.out.print (date1.equals (date3)); // prints tseeb System.out.print (date1.equals (date2)); // prints cuav
Txoj Kev 3 ntawm 4: Siv Daim Ntawv Teev Sijhawm
Kauj Ruam 1. Siv daim ntawv qhia hnub
Daim ntawv qhia hnub kuj tseem muaj pivTo, sib npaug, tom qab thiab ua ntej cov txheej txheem uas ua haujlwm tib yam li tau piav qhia saum toj no rau hnub kawm. Yog li yog tias cov ntaub ntawv hnub tau muaj nyob rau hauv daim ntawv qhia hnub, tsis tas yuav tsum rho tawm hnub tsuas yog ua qhov sib piv.
Kauj Ruam 2. Tsim cov xwm txheej ntawm Calendar
Txhawm rau siv Daim Ntawv Teev Sijhawm, koj yuav xav tau ob peb yam xwm txheej. Hmoov zoo, koj tsuas tuaj yeem tuav lub sijhawm los ntawm cov xwm txheej uas twb tau tsim lawm.
Daim ntawv qhia hnub cal1 = Calendar.getInstance (); // tshaj tawm cal1 Calendar cal2 = Calendar.getInstance (); // tshaj tawm cal2 Calendar cal3 = Calendar.getInstance (); // tshaj tawm cal3 cal1.setTime (date1); // siv hnub tim rau cal1 cal2.setTime (date2); cal3.setTime (hnub tim 3);
Kauj Ruam 3. Sib piv cal1 thiab cal2 siv ua ntej
Cov cai hauv qab no yuav tsum luam tawm qhov tseeb txij li cal1 yog ua ntej cal2.
System.out.print (cal1.before (cal2)); // yuav luam tawm qhov tseeb
Kauj Ruam 4. Sib piv cal1 thiab cal2 siv tom qab
Cov cai hauv qab no yuav tsum luam tawm cuav vim cal1 yog ua ntej cal2.
System.out.print (cal1.after (cal2)); // prints tsis tseeb
Kauj Ruam 5. Sib piv cal1 thiab cal2 siv qhov sib npaug
Cov cai hauv qab no yuav qhia qhov piv txwv ntawm ob qhov tseeb thiab qhov tseeb. Qhov xwm txheej nyob ntawm cov xwm txheej sib piv piv. Txoj cai yuav tsum luam tawm "tseeb," tom qab ntawd "tsis tseeb" ntawm kab tom ntej.
System.out.println (cal1.equals (cal3)); // prints tseeb: cal1 == cal3 System.out.print (cal1.equals (cal2)); // prints cuav: cal1! = cal2
Txoj kev 4 ntawm 4: Siv getTime
Kauj Ruam 1. Siv getTime
Nws tseem tuaj yeem sib piv ncaj qha rau lub sijhawm ntawm ob hnub, txawm hais tias ib qho ntawm cov hauv kev yav dhau los zoo li yuav nyeem tau ntau dua thiab yog li nyiam dua. Qhov no yuav yog kev sib piv ntawm ob hom ntaub ntawv qub, yog li nws tuaj yeem ua tiav nrog "", thiab "==".
Kauj Ruam 2. Tsim cov khoom ntev
Ua ntej koj tuaj yeem sib piv cov hnub, koj yuav tsum tsim cov lej ntev nrog cov ntaub ntawv los ntawm cov khoom Hnub uas tau tsim yav dhau los. Hmoov zoo, txoj haujlwm getTime () yuav ua haujlwm ntau rau koj.
sijhawm ntev1 = getTime (hnub tim 1); // tshaj tawm thawj lub sijhawm 1 txij hnub 1 ntev ntev2 = getTime (date2); // tshaj tawm thawj lub sijhawm 2 txij hnub tim 2
Kauj Ruam 3. Ua qhov tsawg dua kev sib piv
Siv tsawg dua cim (<) los sib piv ob qhov tseem ceeb no. Txij li lub sijhawm 1 tsawg dua lub sijhawm 2, thawj cov lus yuav tsum luam tawm. Lwm nqe lus suav nrog rau cov lus tsim nyog.
yog (time1 <time2) {System.out.println ("date1 yog ua ntej date2"); // yuav luam tawm txij li time1 <time2} lwm {System.out.println ("date1 tsis yog ua ntej date2"); }
Kauj Ruam 4. Ua kom ntau tshaj qhov sib piv
Siv lub cim loj dua (>) los sib piv ob qhov tseem ceeb no. Txij li lub sijhawm 1 loj dua lub sijhawm 2, thawj cov lus yuav tsum luam tawm. Lwm nqe lus suav nrog rau cov lus tsim nyog.
yog (time2> time1) {System.out.println ("date2 yog tom qab date1"); // yuav luam tawm txij lub sijhawm 2> sijhawm 1} ntxiv {System.out.println ("date2 tsis yog tom qab hnub tim 1"); }
Kauj Ruam 5. Ua qhov sib piv sib npaug
Siv lub cim los txheeb xyuas qhov sib luag (==) los sib piv ob qhov tseem ceeb no rau kev sib luag. Txij li lub sijhawm 1 sib npaug rau lub sijhawm 3, thawj cov lus yuav tsum luam tawm. Yog tias txoj haujlwm tau txais mus rau lwm nqe lus, uas txhais tau tias lub sijhawm tsis sib npaug.
yog (time1 == time2) {System.out.println ("cov hnub sib npaug"); } lwm {System.out.println ("cov hnub tsis sib npaug"); // yuav luam tawm txij lub sijhawm 1! = sijhawm 2}
