Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 fB4zqMSfE
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 vL;=qkTCQ
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 tKi^0vE8
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 m&_!*3BAG
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。 d5W=?
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分页支持类: _ UF'Cf+Y
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java代码: FlH=Pqc
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#
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package com.javaeye.common.util; {]y!2r
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import java.util.List; U}-hV@y
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publicclass PaginationSupport { *^\u%Ir"
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publicfinalstaticint PAGESIZE = 30; *+ O
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privateint pageSize = PAGESIZE; f(-3d*g
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privateList items; BQ!_i*14+
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privateint totalCount; #W L>ha
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privateint[] indexes = newint[0]; Q>/[*(.Wd
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privateint startIndex = 0; ?=Mg"QU
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public PaginationSupport(List items, int %bTXu1
*&F~<HC2+
totalCount){ }M(XHw
setPageSize(PAGESIZE); _^w^tfH]
setTotalCount(totalCount); UO>S2u
setItems(items); S'q4va"
setStartIndex(0); $0;Dk,
}
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public PaginationSupport(List items, int k/%n7 ;1
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totalCount, int startIndex){ Zu^J X/um
setPageSize(PAGESIZE); /}-LaiS
setTotalCount(totalCount); !ma'*X
setItems(items); 0 ^ $6U
setStartIndex(startIndex); ?OWJ UmQ
} =Wl}Pgo!
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public PaginationSupport(List items, int +q~dS.
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totalCount, int pageSize, int startIndex){ GEfTs[
setPageSize(pageSize); WcE/,<^*
setTotalCount(totalCount); ^@xn 3zJ
setItems(items); 9iOTT%pq
setStartIndex(startIndex); :#spL*FIx
} 4kf8Am(
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publicList getItems(){ kT{d pGU9
return items; 8Jf4";
} }tH6E
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publicvoid setItems(List items){ #j${R={
this.items = items; C?VNkBJ>\
} kT4Tb%7KM
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publicint getPageSize(){ NT [~AK9M
return pageSize; LD)P.
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} W&0KO-}ot
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publicvoid setPageSize(int pageSize){ SH M@H93
this.pageSize = pageSize; p EbyQ[
} S9S%7pE
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publicint getTotalCount(){ 6"Rw&3D?
return totalCount; i;}mIsNBY
} zvnR'\A_
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publicvoid setTotalCount(int totalCount){ 5Qgh\4
if(totalCount > 0){ nJ~5ICyd
this.totalCount = totalCount; x1R<oB|
int count = totalCount / +HNM$yp
$/;;}|hqi
pageSize; L)j<;{J/Q0
if(totalCount % pageSize > 0) IH~[/qNk
count++; $|bdeQPr\
indexes = newint[count]; \ POQeZ
for(int i = 0; i < count; i++){ <;nhb
indexes = pageSize * H)l7:a
I Z{DR
i; %w3"B,k'9D
} n|f Huv
}else{ 8P3"$2q
this.totalCount = 0; 5]yby"Z?}
} 'Q F@@ 48
} h1.<\GO
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publicint[] getIndexes(){ Ow4H7sl
return indexes; ^26}j uQ
} El#"vIg(\
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publicvoid setIndexes(int[] indexes){ B`<K]ut
this.indexes = indexes; rWB/#m
} $z5
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publicint getStartIndex(){ 2 VyJ
return startIndex; R\d)kcy4
} 1A.e cv'
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publicvoid setStartIndex(int startIndex){ V+&C_PyC
if(totalCount <= 0) M|xs>+r*
this.startIndex = 0; -{rUE +
elseif(startIndex >= totalCount) bL]NSD
this.startIndex = indexes |Y&&g=7
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[indexes.length - 1]; /[RO>Z9
elseif(startIndex < 0) #[.aj2
this.startIndex = 0; 2\J-7o=P
else{ ErXzKf
this.startIndex = indexes u</LgOP`-
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[startIndex / pageSize]; 5isqBu
} @X g5E
} o{?R z3z
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publicint getNextIndex(){ '$\O*e'
int nextIndex = getStartIndex() + EwKFT
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pageSize; pa8R;A70Dl
if(nextIndex >= totalCount) >#~>!cv6D
return getStartIndex(); e'0BP,\f_}
else @\s*f7
return nextIndex; s2*~n_B
} >JckN4v
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publicint getPreviousIndex(){ zVyMmw\
int previousIndex = getStartIndex() - vA&MJD{
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pageSize; r:-,qy
if(previousIndex < 0) ]L{diD2G
return0; @Tz}y"VG
else !
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return previousIndex; zW9/[Db
} PB(I3R9
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} 1 3K|=6si
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抽象业务类 51-@4E2:l:
java代码: {j[a'Gb
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/**
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* Created on 2005-7-12 </]a`h]
*/ GW,RE\Q:
package com.javaeye.common.business; $q*hE&x
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import java.io.Serializable; _Nacqa
import java.util.List; )0?u_Z]w9
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import org.hibernate.Criteria; !q!5D`
import org.hibernate.HibernateException; .OcI.1H [
import org.hibernate.Session; z07Xj%zX9
import org.hibernate.criterion.DetachedCriteria; F4DJML-(
import org.hibernate.criterion.Projections; pc2;2^U_
import %sCG}?
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org.springframework.orm.hibernate3.HibernateCallback; Z;~ 7L*|
import F[KM0t!
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org.springframework.orm.hibernate3.support.HibernateDaoS o@sL/5,
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upport; ~$d(@T&
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import com.javaeye.common.util.PaginationSupport; Qv6-,6<
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public abstract class AbstractManager extends j:E3c\a
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HibernateDaoSupport { {uN-bl?o
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privateboolean cacheQueries = false; s"5wnp6pW
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privateString queryCacheRegion; B&m6N,
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publicvoid setCacheQueries(boolean &}r-C97
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cacheQueries){ S$ n?
this.cacheQueries = cacheQueries; 0+T:};]
} ,H>'1~q
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publicvoid setQueryCacheRegion(String <w3_EO
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queryCacheRegion){ 4JRQ=T|P7I
this.queryCacheRegion = _B0C]u3D
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queryCacheRegion; [ J4n%
} -ImVXy]?
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publicvoid save(finalObject entity){ \aN7[>R.Q
getHibernateTemplate().save(entity); VS3lz?o?6g
} :. u2^*<
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publicvoid persist(finalObject entity){ i0F6eqe=J
getHibernateTemplate().save(entity); %bS1$
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} ?x/Lb*a^
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publicvoid update(finalObject entity){ o)n=n!A
getHibernateTemplate().update(entity); :7~DiH:Q
} mt~E&Z(A
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publicvoid delete(finalObject entity){ k$GtzjN
getHibernateTemplate().delete(entity); + w'q5/`
} |K" nSXzk
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publicObject load(finalClass entity, >qBJK)LHOv
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finalSerializable id){ h>F"GR?U_(
return getHibernateTemplate().load C3'?E<F
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(entity, id); Y]7 6y>|e
} Xzl$Qc
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publicObject get(finalClass entity, WL?qulC}h1
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finalSerializable id){ !hjF"Pa
return getHibernateTemplate().get R3>c\mA
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(entity, id); f!H/X%F
} &8I}q]'k
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publicList findAll(finalClass entity){ p[&b@U#
return getHibernateTemplate().find("from %CrTO(
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" + entity.getName()); WrS>^\:
} 6AoKuT;
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publicList findByNamedQuery(finalString B*t1Y<>x
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namedQuery){ DIfQ~O+u
return getHibernateTemplate GG"6O_
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().findByNamedQuery(namedQuery); Z*ag{N
} fjy7 gC2
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publicList findByNamedQuery(finalString query, ^C92R"*Qu
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finalObject parameter){ @vB-.XU
return getHibernateTemplate _90<*{bt.
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().findByNamedQuery(query, parameter); G4rzx%W?
} +prUau*
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publicList findByNamedQuery(finalString query, &er,Wyc(
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finalObject[] parameters){ CO9PQ`9+
return getHibernateTemplate ~KV{m
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().findByNamedQuery(query, parameters); =z]rZSq*o
} jgS3#
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publicList find(finalString query){ 5S,Kq35$(
return getHibernateTemplate().find _]- 4UA-
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(query); *l;S"}b*,_
} k DXQpe
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publicList find(finalString query, finalObject |rG)Q0H,
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parameter){ q]?)c
return getHibernateTemplate().find *X{7m]5
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(query, parameter); N&eo;Ti
} RRpY%-8M
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public PaginationSupport findPageByCriteria seRf q&
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(final DetachedCriteria detachedCriteria){ ![nL/
return findPageByCriteria ];"40 /X
N/ '
(detachedCriteria, PaginationSupport.PAGESIZE, 0); D9NQ3[R 9
} 2g~ @99`
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public PaginationSupport findPageByCriteria .9WOTti
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(final DetachedCriteria detachedCriteria, finalint c~O
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startIndex){ aSu^
return findPageByCriteria $(+xhn(O
*v]s&$WyO
(detachedCriteria, PaginationSupport.PAGESIZE, !>D[Y
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startIndex); D[?;+g/
} @x!,iT
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public PaginationSupport findPageByCriteria /H"fycZ
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(final DetachedCriteria detachedCriteria, finalint UP$>,05z6
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pageSize, 3;VH'hh_
finalint startIndex){ ,|3_@tUl
return(PaginationSupport) a!/\:4-uc
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getHibernateTemplate().execute(new HibernateCallback(){ x;$ESPPg
publicObject doInHibernate ~*"ZF-c,
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(Session session)throws HibernateException { ok0ZI>=,
Criteria criteria = L\UGC%]9
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detachedCriteria.getExecutableCriteria(session); KvEv0L<ky
int totalCount = ot[ZFF\
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((Integer) criteria.setProjection(Projections.rowCount ep?D;g
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()).uniqueResult()).intValue(); dNNXMQ0"
criteria.setProjection J(@" 7RX
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(null); 2oV6#!{Z
List items = %8|lAMTY7/
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criteria.setFirstResult(startIndex).setMaxResults .r{t&HO;Y
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(pageSize).list(); [ 5!}+8]W
PaginationSupport ps = @'):rFr@F
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new PaginationSupport(items, totalCount, pageSize, "igA^^?X1N
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startIndex); gd]S;<Jh
return ps; )B"{B1(
} *$|f9jVh
}, true); Z37Dv;&ZD
} JVkuSIR>
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public List findAllByCriteria(final M!5=3>Z
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DetachedCriteria detachedCriteria){ mRRZ/m?A(
return(List) getHibernateTemplate ;tVd+[8
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().execute(new HibernateCallback(){ :wXiz`VH
publicObject doInHibernate EyVu-4L:#
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(Session session)throws HibernateException { .\T!oSb4[
Criteria criteria = " "m-5PGYo
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detachedCriteria.getExecutableCriteria(session); @vyEN.K%mm
return criteria.list(); !reOYt|
} WZn;u3,R
}, true); )Sb-e(sl
} A+8)VlE\
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public int getCountByCriteria(final ;`LG WT-<F
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DetachedCriteria detachedCriteria){ jT$J~MpHh
Integer count = (Integer) f_n
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getHibernateTemplate().execute(new HibernateCallback(){ }xt^}:D
publicObject doInHibernate 21tv(x
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(Session session)throws HibernateException { #}B1W&\sw
Criteria criteria = *cCx]C.~
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detachedCriteria.getExecutableCriteria(session); e
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return No6-i{HZ
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criteria.setProjection(Projections.rowCount ;lb
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()).uniqueResult(); iTq&h=(n
} jY%.t)>)
}, true); \ui'~n_t]
return count.intValue(); 0Zwx3[bq6K
} >I5Wf/$
} ]tT=jN&(
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用户在web层构造查询条件detachedCriteria,和可选的 {+_p?8X
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 x$` lQ%
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PaginationSupport的实例ps。 O.X;w<F/V
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ps.getItems()得到已分页好的结果集 NYP3u_
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ps.getIndexes()得到分页索引的数组 sV2D:%\K:
ps.getTotalCount()得到总结果数 R/"-r^j
ps.getStartIndex()当前分页索引 >'q]ypA1
ps.getNextIndex()下一页索引 '+{yg+#/wV
ps.getPreviousIndex()上一页索引 y*X.DS 1(w
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 DFQ`(1Q
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 4(P<'FK $
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一下代码重构了。 %vy,A*
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我把原本我的做法也提供出来供大家讨论吧: f/8&-L
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首先,为了实现分页查询,我封装了一个Page类: =>c0NT
java代码: OET/4(C
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/*Created on 2005-4-14*/ e8dZR3JL
package org.flyware.util.page; ;`pIq-=
F%$ q]J[
/** ;}f {o^ ]'
* @author Joa k"gm;,`
* ]U'zy+
*/ am3.Dt2\
publicclass Page { n=JV*h0
ob/<;SrU<
/** imply if the page has previous page */ 3=oxT6"k
privateboolean hasPrePage; !ck~4~J
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/** imply if the page has next page */ V6d,}Z+"z'
privateboolean hasNextPage; |,`"Omb9+m
!m~r0M7
/** the number of every page */ [^}bc-9?i
privateint everyPage; RAu(FJ
k=kkF"
/** the total page number */ q:M'|5P
privateint totalPage; {aV,h@>
:}fA98S
/** the number of current page */ R"HV|Dm|m
privateint currentPage; r*mSnPz\q
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/** the begin index of the records by the current ;PG=
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query */ Ws0)B8y,|
privateint beginIndex; MtPdpm6\
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/** The default constructor */ `5oXf
public Page(){ V\L%*6O
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} )i.pE]!+
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/** construct the page by everyPage 'lpCwH
* @param everyPage KwaxNb5
* */ x%H,ta%
public Page(int everyPage){ XPdqE`w=$p
this.everyPage = everyPage; QX}JQ<8
} p`\>GWuT!
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/** The whole constructor */ Dpu?JF]
public Page(boolean hasPrePage, boolean hasNextPage, Nc[N 11?O
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int everyPage, int totalPage, +3XaAk
int currentPage, int beginIndex){ N8kNi4$mp=
this.hasPrePage = hasPrePage; ; }T+ImjA
this.hasNextPage = hasNextPage; F/LMk8RgR
this.everyPage = everyPage; 0uM&F[.x@g
this.totalPage = totalPage; pZ*%zt]-a
this.currentPage = currentPage; -@]b7J?`k
this.beginIndex = beginIndex; b?,%M^9\`
} #1*7eANfr
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/** Q1yXdw
* @return ':tdb$h
* Returns the beginIndex. Qa:[iF
*/ ,H.5TQ#
publicint getBeginIndex(){ ]n"RPktx
return beginIndex; !'[?cEog
} [lSQMoi3
P {n*X
/** o+XQMg
* @param beginIndex =w`uZ;l$Q
* The beginIndex to set. l.
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*/ ]2|fc5G'
publicvoid setBeginIndex(int beginIndex){ Svo\+S
this.beginIndex = beginIndex; !kb:g]X
} XHJ`C\xR
z6B#F<h
/** aqQ+A:g
* @return 2cIbX
* Returns the currentPage. H =~7g3
*/ iV#A-9
publicint getCurrentPage(){ [N9yWuc
return currentPage; `s
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} P{QHG 3
^LB]
/** (.Ak*
* @param currentPage 0m> 8
* The currentPage to set. }hg2}g99
*/ eYlI };
publicvoid setCurrentPage(int currentPage){ id8QagJ
this.currentPage = currentPage; /~;!Ew|q
} uHmvHA~/c8
/hVwrt(
/** 2T(+VeMQ=
* @return rMjb,2*rC7
* Returns the everyPage. p"jze3mF
*/ I
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publicint getEveryPage(){ Pn.DeoHme
return everyPage; yk5K8D[tV
} -gt?5H h
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/** x6!Q''f7
* @param everyPage EH M 59s|B
* The everyPage to set. s]kzXzRC?
*/ ,~1k:>njY~
publicvoid setEveryPage(int everyPage){ 4J(-~
this.everyPage = everyPage; L1g0Dd\Ox
} cqs.[0 z#B
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/** 0MxK+8\y
* @return ~Sm6{L
* Returns the hasNextPage. QE)zH)(
*/ ?)k]Vg.
publicboolean getHasNextPage(){ z9OpxW@Ou
return hasNextPage; -D=Sj@G
} -+Yark
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/** SRk!HuXh
* @param hasNextPage 4~FRE)8
* The hasNextPage to set. O
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*/ (&v|,.c^)1
publicvoid setHasNextPage(boolean hasNextPage){ kb/BEJ
this.hasNextPage = hasNextPage; 7_)38
} Nz`v+sp
^_P?EJ,)`
/** xJ. kd
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* @return F?H=2mzKbz
* Returns the hasPrePage. fvi0gE@bd
*/ 2@z .ory.
publicboolean getHasPrePage(){ :@-yK8q's
return hasPrePage; m$v >r\*X
} CX\XaM)l
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/** >ZG$8y 'j
* @param hasPrePage C3f\E: D)
* The hasPrePage to set. ##xvuLy-6
*/ M
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publicvoid setHasPrePage(boolean hasPrePage){ GtZ.'?-
this.hasPrePage = hasPrePage; ty[p5%L1
} UXpp1/d|e
+By '6?22
/** Zxqlhq/)
* @return Returns the totalPage. v;;3 K*c>
* ~ |A0*
*/ $HQ4 o\~
publicint getTotalPage(){ /Qr`au
return totalPage; g.hYhg'KUh
} ^5TVm>F@3
6<fG;:
/** g\.$4N
* @param totalPage vBF9!6X .
* The totalPage to set. YCxwIzIR
*/ gVzIEE25
publicvoid setTotalPage(int totalPage){ Tjrb.+cua
this.totalPage = totalPage; rEj[XK
} Fc \]*
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} 3Xd:LDZ{
7f ub^'_
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 h
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个PageUtil,负责对Page对象进行构造: a%b E}
java代码: -XV+F@`Md
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/*Created on 2005-4-14*/ I%a-5f$0
package org.flyware.util.page; !\BZ_guz
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import org.apache.commons.logging.Log; Bz-jy.
import org.apache.commons.logging.LogFactory; |M5#jVXj
>Q=^X3to
/** 'gs P9
* @author Joa ug2W{D
* pUqC88*j
*/ _r\M}lDh*
publicclass PageUtil { t&{;6MiE
1a{r1([)
privatestaticfinal Log logger = LogFactory.getLog n^ fUKi*;
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a4
(PageUtil.class); /R=MX>JA;
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/** 4^2>KC_
* Use the origin page to create a new page -#;xfJE
* @param page ^-k"gLg
* @param totalRecords ^OWG9`p+
* @return ([<HFc`
*/ \b(&-=(
publicstatic Page createPage(Page page, int [F+W]Jk,
+@3+WD
totalRecords){ /ugyUpyg
return createPage(page.getEveryPage(), QE[<Y3M
[I4MK%YQ
page.getCurrentPage(), totalRecords); KU` *LB:
} Ri" hU/H{
vFR*3$R
/** ~r8<|$;
* the basic page utils not including exception q q&U)-`
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handler Sf*v#?
* @param everyPage 9c)#j&2?H
* @param currentPage #vV]nI<MF.
* @param totalRecords a,RCK~GR
* @return page 04|ZwX$>+
*/ A3_p*n@
publicstatic Page createPage(int everyPage, int NC-K`)
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currentPage, int totalRecords){ YQG
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everyPage = getEveryPage(everyPage); bGeIb-|(
currentPage = getCurrentPage(currentPage); <L qJg
int beginIndex = getBeginIndex(everyPage, [ZSC]w^
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currentPage); k"i3$^v8
int totalPage = getTotalPage(everyPage, ZJBb%d1;
e~lFjr]
totalRecords); PtW2S 1?j
boolean hasNextPage = hasNextPage(currentPage, wX]$xZ!s
r]p3DQ
totalPage); VM\R-[
boolean hasPrePage = hasPrePage(currentPage); ~bb6NP;'L
|@JTSz*Or
returnnew Page(hasPrePage, hasNextPage, )f:i4.M
everyPage, totalPage, +M
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currentPage, )x/#sW%)
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beginIndex); mk1R~4v
} xE<H@@w
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privatestaticint getEveryPage(int everyPage){ ?{f6su@rW
return everyPage == 0 ? 10 : everyPage; 08nh y[
}
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privatestaticint getCurrentPage(int currentPage){ N
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return currentPage == 0 ? 1 : currentPage; :zKW[sF
} >EJ{ *
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privatestaticint getBeginIndex(int everyPage, int 9#:nlu9
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currentPage){ (rBsh6@)
return(currentPage - 1) * everyPage; :V+rC]0
} wz:e\ !
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privatestaticint getTotalPage(int everyPage, int \T_ZcV
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totalRecords){ jJiuq#;T3
int totalPage = 0; Ln,<|,fZN
% E1r{`p
if(totalRecords % everyPage == 0) >]~581fYf
totalPage = totalRecords / everyPage; 9/0H,qZc
else pwfQqPC#_
totalPage = totalRecords / everyPage + 1 ; Sr6'$8#>Y
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return totalPage; 1iz =i^}
} {k.:DH)
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privatestaticboolean hasPrePage(int currentPage){ WMtFXkf6"
return currentPage == 1 ? false : true; #h=V@Dh
} Q"FN"uQ}x
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privatestaticboolean hasNextPage(int currentPage, n zaDO-2!
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int totalPage){ fs#9~b3
return currentPage == totalPage || totalPage == ZiuD0#"!
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0 ? false : true; TzaeE
} ?fy37m(M}
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} b_ZvI\H
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 a%`Yz"<lQ
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 Q.B)?w m
),N,!15j,
做法如下: _?"y1L.
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 $5 G(_
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的信息,和一个结果集List: "7%jv[
java代码: i.6 b%
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/*Created on 2005-6-13*/ Gf.ywqE$Y$
package com.adt.bo; :(US um
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import java.util.List; x@43ZH_
Fj<*!J$,
import org.flyware.util.page.Page; >A{Dpsi\
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/** &l2xh~L
* @author Joa "G>d8GbIh
*/ ZOPK
publicclass Result { f{VV U/$
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private Page page; ddN(L`nd
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private List content; #^VZJ:2=|
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/** mF@7;dpr
* The default constructor Nxt:U{`T'
*/ X9?)P5h=
public Result(){ BmpAH}%T
super(); ~ `}),aA
} 1]''@oh{6U
eV}" L:bgJ
/** LI.WcI3uS
* The constructor using fields *yT>
* P0>2}/;o
* @param page }d;2[fR)
* @param content |1CX?8)b=
*/
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public Result(Page page, List content){ \9`E17i
this.page = page; '8)kFR^9
this.content = content; &