Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 !p/%lU65
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 2d>hi32I
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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 v"& pQ
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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 SMH<'F7i
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分页支持类: pCh2SQ(Q>
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java代码: ]i<[d,
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package com.javaeye.common.util; eB>s=}|
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import java.util.List; $d S@y+
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publicclass PaginationSupport { 9^Fz iM
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publicfinalstaticint PAGESIZE = 30; QqNW}:#
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privateint pageSize = PAGESIZE; $$APgj"|<
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privateList items;
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privateint totalCount; DGW+>\G
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privateint[] indexes = newint[0]; 05yZad*
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privateint startIndex = 0; W&(k!6<x
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public PaginationSupport(List items, int
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totalCount){ $$b
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setPageSize(PAGESIZE); m5mu:
setTotalCount(totalCount); !`1'2BC
setItems(items); 8r"+bhGx~
setStartIndex(0); xx{!3 F
} eW5SFY.
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public PaginationSupport(List items, int No]~jnqDM
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totalCount, int startIndex){ (C4fG@n
setPageSize(PAGESIZE); Lip4)Y [
setTotalCount(totalCount); 3(TsgP>`
setItems(items); 2(5ebe[
setStartIndex(startIndex); z#BR5jF
} su*Pk|6%
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public PaginationSupport(List items, int K\"R&{+=
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totalCount, int pageSize, int startIndex){ lL1k.&|5m
setPageSize(pageSize); pym!U@$t
setTotalCount(totalCount); F}Vr:~
setItems(items); 9zYVC[o
setStartIndex(startIndex);
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} uqz]J$
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publicList getItems(){ g&/T*L
return items; iq(
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} `al<(FwGE
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publicvoid setItems(List items){ jZ NOt
this.items = items; jw-0M1B
} PkI:*\R
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publicint getPageSize(){ &0f5:M{P
return pageSize; %v20~xW:o
} df7wN#kO+
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publicvoid setPageSize(int pageSize){ :y7c k/>
this.pageSize = pageSize; w$JvB5O
} Eke5Nb
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publicint getTotalCount(){ 2-Y<4'>
return totalCount; TB0
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} 8M!:N(a
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publicvoid setTotalCount(int totalCount){ <b,~:9*?
if(totalCount > 0){ I? ,>DHUX
this.totalCount = totalCount; D3|I:Xm
int count = totalCount / 9on@Q_7m
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pageSize; |sJSN.8
if(totalCount % pageSize > 0) E>l~-PaZY
count++; ~"A+G4jl
indexes = newint[count]; `OSN\"\ad
for(int i = 0; i < count; i++){ !47n[Zs
indexes = pageSize * `ts$(u.w
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} X9W@&zQ
}else{ X!TpYUZ'
this.totalCount = 0; Tztu}t]N
} [
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} Hw}Xbp[y
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publicint[] getIndexes(){ @zW]2 c
return indexes; K7_UP&`=J
} BU/"rv"(Fg
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publicvoid setIndexes(int[] indexes){ &
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this.indexes = indexes; NRs13M<ftf
} dd %6t
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publicint getStartIndex(){ e5ZX
return startIndex; 24 ' J
} z% ?+AM)P
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publicvoid setStartIndex(int startIndex){ ?Jm^<
if(totalCount <= 0) ].w4$OJ?
this.startIndex = 0; v!~fs)cdE|
elseif(startIndex >= totalCount) G:<aB
this.startIndex = indexes &AeX
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[indexes.length - 1]; :'X &bn
elseif(startIndex < 0) >C>.\
this.startIndex = 0; ?=Z?6fw
else{ C`hU]
this.startIndex = indexes ~d.Y&b
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[startIndex / pageSize]; K<3A1'_
} X]TG<r
} )hsgC'H{~]
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publicint getNextIndex(){ w3ResQ
int nextIndex = getStartIndex() + 2~)`N>@
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pageSize; ~^:A{/
if(nextIndex >= totalCount) T4Uev*A
return getStartIndex(); <44G]eb
else hD 82tr
return nextIndex; oWT3apGO
} n:?a$Ldgm
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publicint getPreviousIndex(){ I^-Sb=j?Z
int previousIndex = getStartIndex() - NIry)'"
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pageSize; Q->sV$^=T
if(previousIndex < 0) i>`%TW:g
return0; rpha!h>w1%
else q"lSZ;
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return previousIndex; -=Q*Ml#I
} +5*95-;0
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} V~3a!-m\
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抽象业务类 iOghb*aW
java代码: Dcgo%F-W
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/** zY{A'<\O
* Created on 2005-7-12 jvL[
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*/ Ynj,pl
package com.javaeye.common.business; TF\C@4Z
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import java.io.Serializable; b2Fe<~S{
import java.util.List; K($Npuu]
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import org.hibernate.Criteria; r#p9x[f<Y
import org.hibernate.HibernateException; 1.GQau~
import org.hibernate.Session; O,f?YJ9S
import org.hibernate.criterion.DetachedCriteria; <iC(`J$D
import org.hibernate.criterion.Projections; g*_&
import |0b`fOS
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org.springframework.orm.hibernate3.HibernateCallback; #=A)XlZMd
import L L~%f
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org.springframework.orm.hibernate3.support.HibernateDaoS :g0zT[f
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upport; KkbD W3-
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import com.javaeye.common.util.PaginationSupport; hL{KRRf>
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public abstract class AbstractManager extends [RhO$c$[\
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HibernateDaoSupport { ^}o 2
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privateboolean cacheQueries = false; ~B?y{
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privateString queryCacheRegion; 0S!K{xyR
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publicvoid setCacheQueries(boolean @qAS*3j
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cacheQueries){ }S-O&Z
this.cacheQueries = cacheQueries; _]H&,</
} c-5)QF) z
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publicvoid setQueryCacheRegion(String ?CPahU
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queryCacheRegion){ <>rneHl8
this.queryCacheRegion = 0aB;p7~&
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queryCacheRegion; 9rf)gU3{+L
} `d}2O%P
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publicvoid save(finalObject entity){ @:#eb1<S
getHibernateTemplate().save(entity); +cN8Y}V
} 64tvP^kp
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publicvoid persist(finalObject entity){ u^ ~W+
getHibernateTemplate().save(entity); eeB{c.#
} ZUd-<y
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publicvoid update(finalObject entity){ (f"4,b^]
getHibernateTemplate().update(entity); yY q,*<G
} [{,1=AB
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publicvoid delete(finalObject entity){ o>pJPV
getHibernateTemplate().delete(entity); SwMc
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}
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publicObject load(finalClass entity, vr=#3>
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finalSerializable id){ X'iWJ8
return getHibernateTemplate().load wFZP,fQ9l
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(entity, id); 4.t-i5
} ^ [@,
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publicObject get(finalClass entity, 4Fr
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finalSerializable id){ D*d]aC
return getHibernateTemplate().get ]t"Ss_,
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(entity, id); =UWI9M*sz
} |yPu!pfl
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publicList findAll(finalClass entity){ pEA:L$&
return getHibernateTemplate().find("from F:S}w
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" + entity.getName()); =T7.~W
} Y.p;1"
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publicList findByNamedQuery(finalString _H@DLhH|=
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namedQuery){ }O
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return getHibernateTemplate u>vL/nI
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().findByNamedQuery(namedQuery); 9hyn`u.
} )8ZH-|N`!E
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publicList findByNamedQuery(finalString query, CU!Dhm/U
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finalObject parameter){ 2D5StCF$O
return getHibernateTemplate La[V$+Y
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().findByNamedQuery(query, parameter); ]7A'7p$Y
} 493*{
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publicList findByNamedQuery(finalString query, hM!a_'
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finalObject[] parameters){ d&>^&>?$zh
return getHibernateTemplate cH2K )~
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().findByNamedQuery(query, parameters); GTHt'[t@;
} R=\IEqqsi
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publicList find(finalString query){ 5[0?g@aO
return getHibernateTemplate().find f
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(query); ))Za&S*<
} ;$Jo+#
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publicList find(finalString query, finalObject Dw"\/p:-3
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parameter){ {n=|Db~S
return getHibernateTemplate().find uXiN~j &Be
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(query, parameter); \w8\1~#
} &7s.`
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public PaginationSupport findPageByCriteria k}rbim
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(final DetachedCriteria detachedCriteria){ %z$#6?OK^
return findPageByCriteria _#8MkW#]~
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ?V=CB,^
} J[kTlHMD
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public PaginationSupport findPageByCriteria cz$2R
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(final DetachedCriteria detachedCriteria, finalint !5N.B|Nt
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startIndex){ %
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return findPageByCriteria }QmqoCAE~m
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(detachedCriteria, PaginationSupport.PAGESIZE, &5R&k0i r
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startIndex); Alq(QDs
} %}T6]S)%u
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public PaginationSupport findPageByCriteria (tO\)aS=
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(final DetachedCriteria detachedCriteria, finalint oL<St$1
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pageSize, tl>7^hH
finalint startIndex){ o !7va"
return(PaginationSupport) i-&yH
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getHibernateTemplate().execute(new HibernateCallback(){ 3$JoDL(Z
publicObject doInHibernate =BrRYA
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(Session session)throws HibernateException { jj>]9z
Criteria criteria = Z6m)tZVM
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detachedCriteria.getExecutableCriteria(session); j+YJbL v
int totalCount = DV{=n C
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((Integer) criteria.setProjection(Projections.rowCount -K$)DvV^(E
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()).uniqueResult()).intValue(); y?#
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criteria.setProjection g,Y/M3>(
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(null); 2?i7UvV
List items = NEF#
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criteria.setFirstResult(startIndex).setMaxResults rLT!To
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(pageSize).list(); B-ESFATc
PaginationSupport ps = C*lJrFpB
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new PaginationSupport(items, totalCount, pageSize, A\;U3Zu
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startIndex); U;I9 bK8
return ps; Vz[C=_m
} M:V_/@W.
}, true); @|)Z"m7
} L8n|m!MOD
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public List findAllByCriteria(final ~_ a-E
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DetachedCriteria detachedCriteria){ Qci]i)s$js
return(List) getHibernateTemplate -{_PuJ "
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().execute(new HibernateCallback(){ 3mni>*q7d
publicObject doInHibernate y3ikWnx
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(Session session)throws HibernateException { ,2)6s\]/b
Criteria criteria = (9h`3#
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detachedCriteria.getExecutableCriteria(session); "*H`HRi4T
return criteria.list(); h7 I{
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} E!AE4B1bd
}, true); c:g'.'/*
} 8i,K~Bu=
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public int getCountByCriteria(final '3H_wd
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DetachedCriteria detachedCriteria){ (tQc
Integer count = (Integer) vcd\GN*4f
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getHibernateTemplate().execute(new HibernateCallback(){ G#1GXFDO{
publicObject doInHibernate PxE3K-S)G
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(Session session)throws HibernateException { [1KuzCcK}
Criteria criteria = b u"!jHPB
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detachedCriteria.getExecutableCriteria(session); &VcV$8k
return ]+$?u&0?w
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criteria.setProjection(Projections.rowCount bJ;'`sw1
;UP $yM;
()).uniqueResult(); E.>4C[O
} 2Hv+W-6v
}, true); YAmb`CP
return count.intValue(); 8sCv]|cn
} ],v=]+R
} {}Za_(Y,]
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用户在web层构造查询条件detachedCriteria,和可选的 n-OL0$Xu
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 k;L6R!V
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PaginationSupport的实例ps。 E+JqWR5
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ps.getItems()得到已分页好的结果集 ?pZOeqqu$
ps.getIndexes()得到分页索引的数组 kSh( u
ps.getTotalCount()得到总结果数 z$xo$R(
ps.getStartIndex()当前分页索引 GM<-&s!Uj
ps.getNextIndex()下一页索引 Wxe0IXq3Nn
ps.getPreviousIndex()上一页索引 e 3TI|e_
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ?3xzd P
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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 @|%2f@h
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一下代码重构了。 Wiu"k%Qsh
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我把原本我的做法也提供出来供大家讨论吧: (J!+(H8
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首先,为了实现分页查询,我封装了一个Page类: &9)\wnOS
java代码: Ez=Olbk
#
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/*Created on 2005-4-14*/ d<N:[Y\4l
package org.flyware.util.page; N*&1GT#9
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/** e@OX_t_
* @author Joa 9
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* \} :PLCKT
*/ 5o8EC"
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publicclass Page { {jX2}
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/** imply if the page has previous page */ & 9 ?\b7
privateboolean hasPrePage; [1
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/** imply if the page has next page */ Hg$lXtn]
privateboolean hasNextPage; ,Vk3kmuvr]
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/** the number of every page */ $H>W|9Kg,
privateint everyPage; *w&Y$8c(
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/** the total page number */ 6b \&~b@T
privateint totalPage; `lt"[K<
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/** the number of current page */ A=wh@"2
privateint currentPage; ~O&:C{9=
)/?$3h;
/** the begin index of the records by the current ?m?::R H
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query */ K&K