Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 KCu6:)6'
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 {q)B@#p
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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 16y$;kf8
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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
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分页支持类: L8zqLDi&
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java代码: ;40m goN
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package com.javaeye.common.util; >FHsZKJ
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import java.util.List; ."X~?Nk
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publicclass PaginationSupport { =Q}mJs
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publicfinalstaticint PAGESIZE = 30; h6e$$-_
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privateint pageSize = PAGESIZE; l{U 3;
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privateList items; [J`G`s!
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privateint totalCount; cQ41NX@I
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privateint[] indexes = newint[0]; N]}+F w\5
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privateint startIndex = 0; 0_
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public PaginationSupport(List items, int +-\9'Q
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totalCount){ ;QQ7vo
setPageSize(PAGESIZE); 5#)<rK
setTotalCount(totalCount); 7 !.8#A':
setItems(items); d-sh6q5
setStartIndex(0); BznA)EK?@
} ebe@.ZVSi
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public PaginationSupport(List items, int b=UMoWS
(VAL.v*
totalCount, int startIndex){ j2 ^T:q[
setPageSize(PAGESIZE); BDRVT Y(s
setTotalCount(totalCount); Vk_&W.~
setItems(items); t)Q@sKT6
setStartIndex(startIndex); Y^Q|l%Qrb
} ?1:/
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public PaginationSupport(List items, int =k=2~
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totalCount, int pageSize, int startIndex){ Wky S Tc
setPageSize(pageSize); (y=o]Vy
setTotalCount(totalCount); FTnQqDuT
setItems(items); [0ffOTy
setStartIndex(startIndex); Ju7C?)x
} idS
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publicList getItems(){ _1> 4Q%
return items; qetP93N_*
} fsc~$^.~\
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publicvoid setItems(List items){ wV&f|JO0+
this.items = items; doO
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} ]MLLr'6?
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publicint getPageSize(){ !K3cf]2UD
return pageSize; (E}cA&{
} *.]E+MYi*
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publicvoid setPageSize(int pageSize){ fEG3b#t N
this.pageSize = pageSize; ;3}EBcw)
} H
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publicint getTotalCount(){ d3G{0PX
return totalCount; "E|r 3cN
} )R)$T'
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publicvoid setTotalCount(int totalCount){ lhA
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if(totalCount > 0){ 9>&tMq
this.totalCount = totalCount; EY&C[=
int count = totalCount / QiE<[QP{g
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pageSize; px}7If
if(totalCount % pageSize > 0) U?F^D4CV\
count++; hY=
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indexes = newint[count]; JM-ce8U
for(int i = 0; i < count; i++){ ?)[zLnxc&
indexes = pageSize * J&"?m.~@
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i; aMvK8C%7
} mOgOHb2
}else{ q$?7
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this.totalCount = 0; uz#PBV8Q
} q _]
} )ehB)X
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publicint[] getIndexes(){ HCx%_9xlm
return indexes; 'ztL3(|X6
} Vo 6y8@\
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publicvoid setIndexes(int[] indexes){ \l]pe|0EW
this.indexes = indexes; 'y6!%k*
} =,d* {m~A
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publicint getStartIndex(){ w38c
return startIndex; NB3Syl8g
} XiRT|%j
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publicvoid setStartIndex(int startIndex){ % O&m#)|
if(totalCount <= 0) sUbz)BS#.
this.startIndex = 0; :PD`PgQ
elseif(startIndex >= totalCount) (~7m"?
this.startIndex = indexes Z<N&UFw7QJ
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[indexes.length - 1]; ].-J.
elseif(startIndex < 0) prlyaq;4
this.startIndex = 0; G/fP(o-Wd
else{ c+8>EU AW
this.startIndex = indexes Oj"pj:fB
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[startIndex / pageSize]; 1<W4>~,wj
} ,qe]fo >
} 5BU%%fBJ.
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publicint getNextIndex(){ \,l.p_<
int nextIndex = getStartIndex() + 8|5Gv
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pageSize; yE.495
if(nextIndex >= totalCount) )l#%.Z9
return getStartIndex(); :Hzz{'
else w>6"Sc7oc2
return nextIndex; pHj[O?F
} nIyROhZ
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publicint getPreviousIndex(){ #QTfT&m+G}
int previousIndex = getStartIndex() - AaVI%$
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pageSize; DJViy
if(previousIndex < 0) "ep `
return0; mq
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else .'^6QST
return previousIndex; YPha9M$AgU
} M<{5pH(K
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} 9h:jFhsA9
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抽象业务类 %\}dbYS
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java代码: |rE!
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/** S'Z70 zJ
* Created on 2005-7-12 dGbU{#"3s
*/ yhcNE8mkQ/
package com.javaeye.common.business; =vqsd4
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import java.io.Serializable; ^&+zA,aL,A
import java.util.List; 7tpAZ<{
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import org.hibernate.Criteria; 3>-[B`dD(
import org.hibernate.HibernateException; y|q@;*rGNa
import org.hibernate.Session; jlu`lG*e&
import org.hibernate.criterion.DetachedCriteria; (NH8AS<
import org.hibernate.criterion.Projections; @-'/__cgt
import ^M`>YOU2+
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org.springframework.orm.hibernate3.HibernateCallback; `z9)YH
import k$e D(cW$
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org.springframework.orm.hibernate3.support.HibernateDaoS >_;kT y,
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upport; +
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import com.javaeye.common.util.PaginationSupport; &$mZ?%^C
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public abstract class AbstractManager extends eWb0^8_
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HibernateDaoSupport { 8weSrm
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privateboolean cacheQueries = false; R%>jJ[4\[
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privateString queryCacheRegion; W|)GV0YM
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publicvoid setCacheQueries(boolean E%<w5d.lq
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cacheQueries){ nd.57@*M
this.cacheQueries = cacheQueries; J.1O/Pw!.a
} S5uJX#*;
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publicvoid setQueryCacheRegion(String Yo >`h2C4
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queryCacheRegion){ CQ@LmTW[
this.queryCacheRegion = $Mdbto~ <
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queryCacheRegion; R<"2%oY
} %tT"`%(+
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publicvoid save(finalObject entity){ T>d\%*Q+B
getHibernateTemplate().save(entity); C">`' G2
} hHcJN
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publicvoid persist(finalObject entity){ TqIAWbb&
getHibernateTemplate().save(entity); "gFxfWIA
} s(Z(e %
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publicvoid update(finalObject entity){ a
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getHibernateTemplate().update(entity); %1Yz'AiW[
} oFWt(r
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publicvoid delete(finalObject entity){ ZAMeqPt
getHibernateTemplate().delete(entity); DW#Bfo
} ,Kuk_@(}5~
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publicObject load(finalClass entity, 1Fv8T'
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finalSerializable id){ G 0hYFc u
return getHibernateTemplate().load @&;(D!_&
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(entity, id); vkJ)FEar
} M)L/d_4ka
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publicObject get(finalClass entity, zG_p"Z7,
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finalSerializable id){ KE<kj$
return getHibernateTemplate().get .Y;b)]@f
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(entity, id); n|WfaJQZ
} +#4]o
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publicList findAll(finalClass entity){ T=WNBqKo]
return getHibernateTemplate().find("from UH[<&v
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" + entity.getName()); hi!`9k
} %dc3z"u
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publicList findByNamedQuery(finalString *.oKI@
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namedQuery){ Ejv%,q/T(
return getHibernateTemplate cph~4wCS[U
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().findByNamedQuery(namedQuery); ;J]25j]]
} NetYg]8`
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publicList findByNamedQuery(finalString query, _K'7(d0z
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finalObject parameter){ 9RH"d[%yc}
return getHibernateTemplate BWh}^3?l
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().findByNamedQuery(query, parameter); OOok hZd`
} /Y,r@D
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publicList findByNamedQuery(finalString query, zN%97q_
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finalObject[] parameters){ 1]T|6N?
return getHibernateTemplate {6h|6.S2
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().findByNamedQuery(query, parameters); obO}NF*g^
} yYY Nu`
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publicList find(finalString query){ B8 H75sz
return getHibernateTemplate().find ;$7v%Ls=
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(query); Z,
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} y%S})9
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publicList find(finalString query, finalObject h./P\eDc
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parameter){ 4 /'N|c.
return getHibernateTemplate().find XV>@B $hu
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(query, parameter); }$&xTW_
} 6V1:qp/6
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public PaginationSupport findPageByCriteria %?9Ok
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(final DetachedCriteria detachedCriteria){ ^z~~VBv
return findPageByCriteria /ylc*3e'4
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 0}]SUe^
}
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public PaginationSupport findPageByCriteria e"k/d<
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(final DetachedCriteria detachedCriteria, finalint QB&BTT=!
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startIndex){ @pFj9[N
return findPageByCriteria vN65T$g7
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(detachedCriteria, PaginationSupport.PAGESIZE, dz-y}J11
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startIndex); zXZir7NfM
} 6S1m<aH6
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public PaginationSupport findPageByCriteria bMm3F%FFq&
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(final DetachedCriteria detachedCriteria, finalint d(;4`kd*N
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pageSize, 19t{|w<
finalint startIndex){ z)-c#F@%
return(PaginationSupport) c?E{fD"Fc3
rjk ( X|R*
getHibernateTemplate().execute(new HibernateCallback(){ X(Qu{HhI
publicObject doInHibernate &;c>O
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(Session session)throws HibernateException { (dqCa[
Criteria criteria = =-#G8L%Q
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detachedCriteria.getExecutableCriteria(session); h/)_)
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int totalCount = asVX82<
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((Integer) criteria.setProjection(Projections.rowCount o6a0'vU><
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()).uniqueResult()).intValue(); }^%xvmQ\]
criteria.setProjection taWqSq!
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(null); 5l{Ts04k%
List items = Kct@87z
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criteria.setFirstResult(startIndex).setMaxResults KpHw-6"
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(pageSize).list(); @S^ASDuQU7
PaginationSupport ps = <RXw M6G2
/M=3X||
new PaginationSupport(items, totalCount, pageSize, ' cIEc1y
/7"I#U^u/
startIndex); FX}Gt=
return ps; ezm&]F`
} n3KI+I%nQ
}, true); (xpn`NA
} *O~e
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public List findAllByCriteria(final 5(m(xo6
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DetachedCriteria detachedCriteria){ iE].&>w
return(List) getHibernateTemplate F@YKFk+a
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().execute(new HibernateCallback(){ B?bW1
publicObject doInHibernate >jg0s)RA'
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(Session session)throws HibernateException { ?C-Towo=i
Criteria criteria = 78 f$6J q
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detachedCriteria.getExecutableCriteria(session); @N@F,~[RR2
return criteria.list(); 3gEMRy*+
} 9=`W p6Gmn
}, true); bulS&dAX
} QzvHm1,@
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public int getCountByCriteria(final 2JGL;U$
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DetachedCriteria detachedCriteria){ (Z]HX@"{J
Integer count = (Integer) Smw QET<H
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getHibernateTemplate().execute(new HibernateCallback(){ zi@]83SS#
publicObject doInHibernate cVnJ^*Z
/] ^#b
(Session session)throws HibernateException { 8^/I>0EZ
Criteria criteria = sgUud_r)4
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detachedCriteria.getExecutableCriteria(session); !]yO^Ob.E
return KngTc(^_D
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criteria.setProjection(Projections.rowCount mHc>"^R
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()).uniqueResult(); as yZe
} 2Os1C}m
}, true); q? qC
return count.intValue(); H,unpZ(
} I#F!N6;
} w8S!%abl1
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用户在web层构造查询条件detachedCriteria,和可选的 4`m~FNVS
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 N["W Ir
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PaginationSupport的实例ps。
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ps.getItems()得到已分页好的结果集 ,l YE
ps.getIndexes()得到分页索引的数组 'rp }G&m
ps.getTotalCount()得到总结果数 bV+(b9
ps.getStartIndex()当前分页索引 tG vG
ps.getNextIndex()下一页索引 -VxTx^)>
ps.getPreviousIndex()上一页索引 4fk8*{Y
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 #} ~qqJ G2
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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 vE@!{*
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一下代码重构了。 f`9
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我把原本我的做法也提供出来供大家讨论吧: C2LL|jp*
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首先,为了实现分页查询,我封装了一个Page类: AjcX N
java代码: MYJg8 '[j
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/*Created on 2005-4-14*/ :I -V_4b
package org.flyware.util.page; .+7;)K
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/** NH$r
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* @author Joa \^ghdU
* Dd;Nz
*/ (?_S6HE
publicclass Page { qmO6,T-|
-F'b8:m
/** imply if the page has previous page */ 8Ac)'2t;U
privateboolean hasPrePage; Bm&kkx.9P
~|<WHHN(
/** imply if the page has next page */ \fA{1
privateboolean hasNextPage; bM8If"
mPI8_5V8]
/** the number of every page */ =mA: ctu~v
privateint everyPage; }ci#>
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/** the total page number */ s!n<}C
privateint totalPage; (WJ${OW
?A(QyaKz
/** the number of current page */ xX*H7#
privateint currentPage; wP[t0/dl
fP.F`V_Y
/** the begin index of the records by the current XGP6L 0j
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query */ Y3Vlp/"rB"
privateint beginIndex; $)3%U?AP
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/** The default constructor */ 0a-:<zm
public Page(){ oc8:r
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}
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/** construct the page by everyPage EwOV;>@T?
* @param everyPage V(Ub!n:j
* */ K|dso]b/
public Page(int everyPage){ w@N
this.everyPage = everyPage; h;6lK$!c
} ByCnD
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/** The whole constructor */ 7o8{mp'_
public Page(boolean hasPrePage, boolean hasNextPage, V<Z[ nq
MEwo}=B
v4C{<8:X
int everyPage, int totalPage, 5 ~TdD6}
int currentPage, int beginIndex){ [Q=dCX9%
this.hasPrePage = hasPrePage; ABUSTf<
this.hasNextPage = hasNextPage; FQ=@mjh
this.everyPage = everyPage; zN
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this.totalPage = totalPage; eImn+_ N3
this.currentPage = currentPage; 0v9rv.Y"
this.beginIndex = beginIndex; HttiX/2~
} `w]s;G[
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/** Yo[;W
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* @return 7)s^8+
* Returns the beginIndex. "~D]E7Q3y
*/ E9;|'Vy<E
publicint getBeginIndex(){ (\SA*.)
return beginIndex; _q~=~nub
} ANgw"&&>(
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/** lbpq_=
* @param beginIndex V0)fZS@tf
* The beginIndex to set. $m42:a mM
*/ s8}@=]aA
publicvoid setBeginIndex(int beginIndex){ #5V9oKM
this.beginIndex = beginIndex; I'|$}/\`
} g]*#%Xa
:_O%/k1\@
/** 'nF2aD%A
* @return vd8{c7g:n
* Returns the currentPage. 0}b
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*/ ^<e.]F25M
publicint getCurrentPage(){ rwGKfoKI
return currentPage; YCP) %}
} z<yU-m2h
q5?# 3 T=
/** JU4qzi
* @param currentPage ^k]XEW{PG
* The currentPage to set. *hw\35%P`?
*/ b[`Yi1^]%g
publicvoid setCurrentPage(int currentPage){ B>2tZZko
this.currentPage = currentPage; M@5?ZZ4L
} f"<O0Qw
xP [n
/** /n>qCuw
* @return M%@ !cW
* Returns the everyPage. p`l0?^r
c"
*/ o_'p3nD
publicint getEveryPage(){ 8O38#{[S
return everyPage; kkQVNphc
} }I
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/** ^/r7@:
* @param everyPage WVI{oso#
* The everyPage to set. -?0qf,W.
*/ yxH ( c
publicvoid setEveryPage(int everyPage){ ?Orxmxc
2
this.everyPage = everyPage; ]wtb-PC
} QDu 2?EYZq
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/** U-|NY
* @return uXKERzg
* Returns the hasNextPage. Ry'= ke
*/ _A=$oVe
publicboolean getHasNextPage(){ ~m$Y$,uH
return hasNextPage; )gMG#>up@
} ={z*akn,
RRI"d~~F6
/** -:na:Vsi
* @param hasNextPage PbmDNKEh{
* The hasNextPage to set. S;)w.
*/ ;dJ1
publicvoid setHasNextPage(boolean hasNextPage){ -q*i_r:,
this.hasNextPage = hasNextPage; } q$ WvY/
} =F@Wgn,
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/** 4y+< dw
* @return #*KNPh
* Returns the hasPrePage. Wr( y)D<y}
*/ =17t-
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publicboolean getHasPrePage(){ D}mjN=Y
return hasPrePage; "OdXY"G
} C<P%CG&;
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/** }&[
* @param hasPrePage i(NdGL#P
* The hasPrePage to set. w$Rro)?}7
*/ sNLs\4v
publicvoid setHasPrePage(boolean hasPrePage){ aXoVy&x=
this.hasPrePage = hasPrePage; jJ5W>Q1mK$
} K|Di1)7=/
v+X)Qmzf~
/** 6#HK'7ClL
* @return Returns the totalPage. m_)FC-/pSl
* xjVS
*/ o:_Xv.HRZo
publicint getTotalPage(){ W`u[h0\c
return totalPage; fyByz=pl
} 1
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ayfFVTy1d
/** &8vCZN^
* @param totalPage < Pky9o;
* The totalPage to set. MZT23[+
*/ 6Q${U7%7
publicvoid setTotalPage(int totalPage){ y$_eCmq
this.totalPage = totalPage; "\3B^ e,
} egq67S
E/%9jDTQ
} HxIIO[h
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rl#p".4q
BBtzs^C|
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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 ]{ntt}3G,
50o~ P!Lz|
个PageUtil,负责对Page对象进行构造: <psZQdH
java代码: .n~M(59
Np"exFqN k
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/*Created on 2005-4-14*/ 70eb]\%
package org.flyware.util.page; R~S;sJ& c
&FF"nE*
import org.apache.commons.logging.Log; [rSR:V?"a
import org.apache.commons.logging.LogFactory; [D<1CF
C,NJb+J
/** /JWGifH
* @author Joa 7eV
di*
* ;e1ku|>$
*/ M)2VcDy
publicclass PageUtil { opc/e
~NpA".PB
privatestaticfinal Log logger = LogFactory.getLog [O?z@)dx
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)RH7M
(PageUtil.class); xo&]$W8
$7rq3y
/** z}*9uZ
* Use the origin page to create a new page -De9_0#R
* @param page -i%e!DgH
* @param totalRecords F;7dt@5;
* @return :{q<{^c
*/ u[DfzH
publicstatic Page createPage(Page page, int N-e @j4WU
IX>d`O61*g
totalRecords){ \uaJ@{Vug
return createPage(page.getEveryPage(), yrC7F`.
v~@pMA$(h
page.getCurrentPage(), totalRecords); ):b$xNn
} TX&Jt%
xUa{1!Y8
/** YLiSbLz1
* the basic page utils not including exception M!REygyx
F!]lU`z)=
handler 7~5ym15*
* @param everyPage K>DRJz
* @param currentPage Vnr[}<L
* @param totalRecords XYZ4TeW\1
* @return page +O*/"]h
*/
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publicstatic Page createPage(int everyPage, int z<##g
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currentPage, int totalRecords){ fvdU`*|n)
everyPage = getEveryPage(everyPage); B(n{e53 9f
currentPage = getCurrentPage(currentPage); hHT_V2*
int beginIndex = getBeginIndex(everyPage, z$?~Y(EY
t3&LO~Ye
currentPage); fngOeLVG
int totalPage = getTotalPage(everyPage, 5a hVeY
;;:-l99
totalRecords); l@\#Ywz
boolean hasNextPage = hasNextPage(currentPage, hNH'XQxO
rjp-Fw~1w
totalPage); !U'QqnT
boolean hasPrePage = hasPrePage(currentPage); L_wk~z
nh!a)]c[
returnnew Page(hasPrePage, hasNextPage, '8{Ne!y
everyPage, totalPage, :[hgxJu+
currentPage, |~X ;1j!
L;'"A#Pa
beginIndex); ?C&z]f3(:
} K0}pi+=
cM$P`{QrM
privatestaticint getEveryPage(int everyPage){ 8>WC5%f*
return everyPage == 0 ? 10 : everyPage; 2&^]k`Aj6D
} ihP|E,L=L
YW60q0:
privatestaticint getCurrentPage(int currentPage){ A8oo@z68n>
return currentPage == 0 ? 1 : currentPage; /7t>TYip!
} ](wvu(y\E
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privatestaticint getBeginIndex(int everyPage, int Q2F+?w;,
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currentPage){ {:]9Q Tq
return(currentPage - 1) * everyPage; e= .njMqW5
} Od5JG .]
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privatestaticint getTotalPage(int everyPage, int AigS!-
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totalRecords){ I~Zh@d%
int totalPage = 0; w6{TE(]zp
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if(totalRecords % everyPage == 0) * Of4o
totalPage = totalRecords / everyPage; Z`KC%!8K
else c%'RR?Tl
totalPage = totalRecords / everyPage + 1 ; %|oJ>+
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return totalPage; }DK7'K
} znaUB v_
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privatestaticboolean hasPrePage(int currentPage){ hR
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return currentPage == 1 ? false : true; [5+}rwm&W
} QUQu^p
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privatestaticboolean hasNextPage(int currentPage, lJis~JLd`
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int totalPage){ obNqsyc77R
return currentPage == totalPage || totalPage == 2VE9}%i
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0 ? false : true; ~nG(5:A5g/
} +E.GLn2/
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} h >s!K9
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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。 f^"N!f a
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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 Gq }U|Z
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做法如下: viMzR(JU
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 HFaj-~b
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的信息,和一个结果集List: TG+VEL |T
java代码: Ndcg/d
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/*Created on 2005-6-13*/ bj"J'
package com.adt.bo; :kf`?u
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import java.util.List; |]ZYa.+:
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import org.flyware.util.page.Page; OC<5E121>Y
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/** e^[H[d.WMC
* @author Joa }t%!9hr5D
*/ /S(zff[at
publicclass Result { vbD{N3p)?n
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private Page page; 5wh|=**/
I{*<