Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 .{-yveE
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 0Nu]N)H5<l
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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 _iu|*h1y
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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 ?N
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分页支持类: 1Tq$ E[
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java代码: v~\ 45eEA
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package com.javaeye.common.util; 7gwZ9Fob
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import java.util.List; 4AYc8Z#'
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publicclass PaginationSupport { Z?.*.<"Sj
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publicfinalstaticint PAGESIZE = 30; dYd~9
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privateint pageSize = PAGESIZE; |S{P`)z%f
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privateList items; Q/c
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privateint totalCount; _6!/}Fm
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privateint[] indexes = newint[0]; shT[|@"C
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privateint startIndex = 0; lrhAO"/1
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public PaginationSupport(List items, int fWyDWU
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totalCount){ !&O/7ywe
setPageSize(PAGESIZE); x\.i`ukx
setTotalCount(totalCount); rfRo*u2"
setItems(items); $ud>Z;X=P
setStartIndex(0); 'w[d^L
} O&w3@9KJ?
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public PaginationSupport(List items, int cWO
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totalCount, int startIndex){ i\;&CzC:
setPageSize(PAGESIZE); `E=rh3 L0o
setTotalCount(totalCount); cqY.^f.
setItems(items); \>Rwg=Lh
setStartIndex(startIndex); .)>/!|i
} N&APqT
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public PaginationSupport(List items, int =t$mbI
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totalCount, int pageSize, int startIndex){ P0 ltN
setPageSize(pageSize); )O@^H
setTotalCount(totalCount); !X%!7wsc
setItems(items); 5
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setStartIndex(startIndex); "42$AaS
} o
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publicList getItems(){ >zg8xA1zL
return items; &]6K]sWJK{
} 0ITA3v8{
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publicvoid setItems(List items){ &n]Z1e}5
this.items = items; rtL9cw5
} f=_?<I{
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publicint getPageSize(){ cm@ oun
return pageSize; 1LE^dS^V
} e4qk>Cw
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publicvoid setPageSize(int pageSize){ I^O:5x>[l
this.pageSize = pageSize; /P!X4~sTM
} wYQ1Z
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publicint getTotalCount(){ y-<PsP-I
return totalCount; B:- KZuO
} <]Pix)
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publicvoid setTotalCount(int totalCount){ df4^C->:
if(totalCount > 0){ >9tkx/J
this.totalCount = totalCount; >\7RIy3
int count = totalCount / EkStb#
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pageSize; "UoCT7X
if(totalCount % pageSize > 0) )fd-IYi-3
count++; Rhv".epz
indexes = newint[count]; _X%6 +0M
for(int i = 0; i < count; i++){ QE#-A@c
indexes = pageSize * I"cQ5gF?A
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} jO&f*rxN
}else{ E8iadf49
this.totalCount = 0; Gp ^ owr
} ;h-G3>Il
} DtF![0w/
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publicint[] getIndexes(){ }`9fZK{. @
return indexes; e(n2+S#N
} 1Fvv/Tj
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publicvoid setIndexes(int[] indexes){ ZU|V+yT
this.indexes = indexes; =>:% n
} &FJU%tFA
}GNkB
publicint getStartIndex(){ R5NRCI
return startIndex; 7<R6T9g
} C*{15!d:G
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publicvoid setStartIndex(int startIndex){ vN0L(B
if(totalCount <= 0) a(x.{}uG,
this.startIndex = 0; Ng."+&
elseif(startIndex >= totalCount) XU;{28P
this.startIndex = indexes 4lY&=_K[)
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[indexes.length - 1]; uD ?I>7
elseif(startIndex < 0) p9&gEW
this.startIndex = 0; 3)C6OF>7
else{ OP|.I._I
this.startIndex = indexes xyS2_Q
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[startIndex / pageSize]; f
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} 2w x[D
} 3Y1TQ;i,wQ
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publicint getNextIndex(){ sxN>+v11z
int nextIndex = getStartIndex() + c?p0#3%L#
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pageSize; [NCXn>Z
if(nextIndex >= totalCount)
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return getStartIndex(); s]F?=yEp
else }"&n[/8~
return nextIndex; f*|8n$%
} ubzb
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publicint getPreviousIndex(){ I*+LJy;j
int previousIndex = getStartIndex() - )I Y 5Y
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pageSize; fw:7Q7
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if(previousIndex < 0) 2rR@2Vsw2
return0; ?b*/ddIs
else Eo7 _v
return previousIndex; 0,1L e$)6
} @wYQLZ
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} E !Oz|q
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抽象业务类 3P+4S|@q(4
java代码: nJldz;
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/** `zElBD
* Created on 2005-7-12 Pg*?[^*
*/ OQytgXED
package com.javaeye.common.business; Edf=?K+\!i
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import java.io.Serializable; wc6
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import java.util.List; 36kc4=
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import org.hibernate.Criteria; 6o[0sM_];
import org.hibernate.HibernateException; xE G+%Uk{
import org.hibernate.Session; vI
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import org.hibernate.criterion.DetachedCriteria; 3t"~F%4-}
import org.hibernate.criterion.Projections; v{mv*`~nA\
import RMS.1: O
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org.springframework.orm.hibernate3.HibernateCallback; 4f{[*6 GX
import k8InbX[
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org.springframework.orm.hibernate3.support.HibernateDaoS Eonq'Re$
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upport; G?Qe"4
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import com.javaeye.common.util.PaginationSupport; [ -9)T
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public abstract class AbstractManager extends (ZE%tbm2
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HibernateDaoSupport { -,K*~z.l
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privateboolean cacheQueries = false; E<D+)A
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privateString queryCacheRegion; a-T*'F
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publicvoid setCacheQueries(boolean 1zb$5 {,|
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cacheQueries){ Qq`3S>
this.cacheQueries = cacheQueries; NDB*BmG
} bjM-Hd/K
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publicvoid setQueryCacheRegion(String 07$/]eO%C
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queryCacheRegion){ Qv&T E3
this.queryCacheRegion = #W>x\
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queryCacheRegion; QE7+rBa
} 0=N4O!X9
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publicvoid save(finalObject entity){ 3gxf~$)?
getHibernateTemplate().save(entity); U-Af7qO
} #t"9TP
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publicvoid persist(finalObject entity){ 9>A-$a4R>
getHibernateTemplate().save(entity); u~#%P&3_W
} #@nZ4=/z
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publicvoid update(finalObject entity){ EHH|4;P6
getHibernateTemplate().update(entity); IT8B~I\OY
} JiKImz
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publicvoid delete(finalObject entity){ Y;fuh[#
getHibernateTemplate().delete(entity); Am2*-
} hVlyEsLg
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publicObject load(finalClass entity, !d:tIu{)
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finalSerializable id){ 0^J*+
return getHibernateTemplate().load (P2[5d|
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(entity, id); D"`%|`O
} {@Blj3 ;w}
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publicObject get(finalClass entity, 1t0bUf;(M
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finalSerializable id){ ! a86iHU
return getHibernateTemplate().get =L:[cIRrT;
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(entity, id); X32RZ9y
} lKf Mp1
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publicList findAll(finalClass entity){
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return getHibernateTemplate().find("from Sv.KI{;v$
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" + entity.getName()); M#=Y~PU
} ]MC/t5vC u
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publicList findByNamedQuery(finalString xg(<oDn+\
;
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namedQuery){ 60~v
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return getHibernateTemplate "\NF
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().findByNamedQuery(namedQuery); -sP9E|/:'3
} ^/G?QR
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publicList findByNamedQuery(finalString query, 5fU!'ajaN7
)URwIe{
finalObject parameter){ wG_4$kyj
return getHibernateTemplate (:ZPt(1
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().findByNamedQuery(query, parameter); 4;?1Kb#
} Y3D3.T6Q
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publicList findByNamedQuery(finalString query, |p;4dL
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finalObject[] parameters){ oz Vpfs
return getHibernateTemplate *^n^nnCwp
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().findByNamedQuery(query, parameters); #g,H("Qy({
} AzZi{Q ?
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publicList find(finalString query){ X )I/%{
return getHibernateTemplate().find 3QH(4N
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(query); n1_ %Td
} @v"T~6M
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publicList find(finalString query, finalObject \{kHSV%z
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parameter){ b7Yq_%+
return getHibernateTemplate().find L%f-L.9`u
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(query, parameter); y*_K=}pk
} RTA%hCr!
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public PaginationSupport findPageByCriteria AD(xaQ&T
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(final DetachedCriteria detachedCriteria){ %j%%Rn
return findPageByCriteria 6{L F-`S%
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); )#C_mB$-#
} S45'j(S=
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public PaginationSupport findPageByCriteria Ks|gL#)*Ku
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(final DetachedCriteria detachedCriteria, finalint R;%^j=Q
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startIndex){ EVWA\RO'\
return findPageByCriteria {K+.A 9!
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(detachedCriteria, PaginationSupport.PAGESIZE, YRXK@'[=
{798=pC<.
startIndex); AYt*'Zeg!s
} ]Uu
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public PaginationSupport findPageByCriteria r9<V%PHv
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(final DetachedCriteria detachedCriteria, finalint P>|Ef~j
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pageSize, K@HLIuz4t
finalint startIndex){ Q
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return(PaginationSupport) 70{RDj6{
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getHibernateTemplate().execute(new HibernateCallback(){ L+7*NaPY*
publicObject doInHibernate 7$K}qsr<
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(Session session)throws HibernateException { iEe#aO"D!
Criteria criteria = iFSJ4 W(
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detachedCriteria.getExecutableCriteria(session); |"_ )zQ
int totalCount = )t5;d
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((Integer) criteria.setProjection(Projections.rowCount s~=g*99H
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()).uniqueResult()).intValue(); S3QaYq"v
criteria.setProjection 1}`2\3,
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(null); hc"6u\>
List items = <M=';h^w2
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criteria.setFirstResult(startIndex).setMaxResults W|0My0y
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(pageSize).list(); )]3L/
PaginationSupport ps = b##1hm~+9
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new PaginationSupport(items, totalCount, pageSize, 4Q$!c{Y
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startIndex); 6oYIQ'hc
return ps; pG~'shD~Dn
} .ByU
}, true); @\!ww/QT
} (xbIUz.
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public List findAllByCriteria(final 2?*||c==*
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DetachedCriteria detachedCriteria){ {-J:4*`
return(List) getHibernateTemplate ,b4g.CV
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().execute(new HibernateCallback(){ v:?o3
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publicObject doInHibernate 9Eu #lV
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(Session session)throws HibernateException { 6A.P6DW
Criteria criteria = {79qtq%W{
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detachedCriteria.getExecutableCriteria(session); vn ``0!FX
return criteria.list(); (m/aV
} =D}4X1l
}, true); ~x\Cmu9`
} d[S#Duz<&
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public int getCountByCriteria(final Nkx0CG*
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DetachedCriteria detachedCriteria){ _Yy:s2I8B
Integer count = (Integer) [t$4Tdd
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getHibernateTemplate().execute(new HibernateCallback(){ K0v.3
publicObject doInHibernate ?3Pazc]+|
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(Session session)throws HibernateException { jAZ >mo[
Criteria criteria = H }B2A"
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detachedCriteria.getExecutableCriteria(session); `2,a(Sk#
return LZ4xfB(
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criteria.setProjection(Projections.rowCount Fav^^vf*1
}s(C^0x
()).uniqueResult(); ljuNs@q
} 1TIlINlJ
}, true); Ww=O=c5uOu
return count.intValue(); JdO)YlM-
} e$32
} KXq_K:r?
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用户在web层构造查询条件detachedCriteria,和可选的 !VFem~'d
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 qF'~F`6
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PaginationSupport的实例ps。 cLAesj
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ps.getItems()得到已分页好的结果集 TW2Z=ks=
ps.getIndexes()得到分页索引的数组 x2@,9OUx
ps.getTotalCount()得到总结果数 $
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ps.getStartIndex()当前分页索引 SHwRX?
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ps.getNextIndex()下一页索引 yjFe'
ps.getPreviousIndex()上一页索引 WcU@~05b
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 vtZ?X';wh
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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 1AT'S;`
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一下代码重构了。 FQ!Oxlq,Q
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我把原本我的做法也提供出来供大家讨论吧: R^6Zafp
Mi?}S6bp
首先,为了实现分页查询,我封装了一个Page类: m:3J!1
java代码: Z7KXWu+6`m
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/*Created on 2005-4-14*/ 2uL9.q
package org.flyware.util.page; c.0]1
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/** ABZ06S/
* @author Joa Z%e|*GS{
* 5
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*/ >C# kqxfg
publicclass Page { cQn)^jx=
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/** imply if the page has previous page */ A="fj
privateboolean hasPrePage; q#'VJA:A5&
n,sY\=vB
/** imply if the page has next page */ `m, Ki69.
privateboolean hasNextPage; N+J>7_k
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/** the number of every page */ nE7JLtbH
privateint everyPage; SOj`Y|6^:
X4'kZ'Sy<
/** the total page number */ OXCQfT@\
privateint totalPage; r0{]5JZt/
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/** the number of current page */ Ihqs%;V
privateint currentPage; c
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fv2=B)8$
/** the begin index of the records by the current 4.'JLArw
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query */ C_Gzv'C"L
privateint beginIndex; e9:P9Di(b
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/** The default constructor */ />F.Nsujy
public Page(){ Hk9U&j$
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} /WYh[XKe
dhtb?n{
/** construct the page by everyPage OpQ8\[X+
* @param everyPage KuXkI;63J>
* */ H`el#tt_
public Page(int everyPage){ KoF
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this.everyPage = everyPage; vYdlSe=6G
} L
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/** The whole constructor */ !.-.#<<_a
public Page(boolean hasPrePage, boolean hasNextPage, )8'jxiGs
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int everyPage, int totalPage, /< QSe
int currentPage, int beginIndex){ 7xT[<?,
this.hasPrePage = hasPrePage; Ow)R|/e/
this.hasNextPage = hasNextPage; nh0&'hA
this.everyPage = everyPage; agT7=hX].
this.totalPage = totalPage; j3 P$@<
this.currentPage = currentPage; eM }W6vIn
this.beginIndex = beginIndex; 8[R1A
} m8AAp1=
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/** gQ+9xT d
* @return ]nc2/S%
* Returns the beginIndex. ._,trb>o
*/ 50Ad,mn<
publicint getBeginIndex(){ FWY[=S
return beginIndex; p:tN642
} km4g}~N</
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/** jCQho-1QN
* @param beginIndex K(3&27sGN
* The beginIndex to set. P^zy; Qs7
*/ A{(T'/~"
publicvoid setBeginIndex(int beginIndex){ 41}/w3Z4
this.beginIndex = beginIndex; DxfMqH[vs
} ;"@ :}_t
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/** (}"S)#C
* @return n1 v,#GE
* Returns the currentPage. ?0z)EPQ|
*/ f[}|rf
publicint getCurrentPage(){ c[:Wf<%|
return currentPage; t:T?7-XIE
} Nb1J ~v
oyW00]ka
/** &^+3errO
* @param currentPage Spo+@G
* The currentPage to set. L|J~9FM
*/ 9wMEvX70
publicvoid setCurrentPage(int currentPage){ a(|xw
this.currentPage = currentPage; sg$4G:l
} [#Fg\2bq_y
@yKZRwg
/** rS,j;8D-
* @return ~p.%.b;~t
* Returns the everyPage. \JU{xQMB
*/ bKUyBk,\#
publicint getEveryPage(){ J7n5Ps\M
return everyPage; w_3xKnMT\
} Mz\yPT;Y
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/** =ybGb7?
* @param everyPage zX~}]?|9
* The everyPage to set. )S Q('vwg
*/ H%C\Uz"o
publicvoid setEveryPage(int everyPage){ yQwVQUW8B
this.everyPage = everyPage; waQtr,m)
} ~p^7X2% !
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/** )E~_rDTl
* @return QkE,T0,/?h
* Returns the hasNextPage. Ut_mrb+W
*/ nsl*Dm"*F
publicboolean getHasNextPage(){ 9A+M|;O
return hasNextPage; 9GPb$gtx
} j{"[Ec
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/** J#(,0h
* @param hasNextPage _.=`>%,
* The hasNextPage to set. [TEcg^
*/ Z(UD9wY5m
publicvoid setHasNextPage(boolean hasNextPage){ 4|F#gK5E
this.hasNextPage = hasNextPage; 8}z3CuM
} 4 l1 i>_R
@G(xaU'u
/** JCcQd01z
* @return
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* Returns the hasPrePage. =)*JbwQ
*/ .+vd6Uc5a
publicboolean getHasPrePage(){ XNlhu^jh
return hasPrePage; C fSl
54
} n}:t<
AsAFUuI
/** n.Vtc-yZU
* @param hasPrePage "*bk{)dz}
* The hasPrePage to set. bP03G=`6w
*/ m#MlH=-
publicvoid setHasPrePage(boolean hasPrePage){ agW9Go_F[
this.hasPrePage = hasPrePage; B52H(sm
} o\60n
pUhc3L
/** *:j-zrwu&
* @return Returns the totalPage. C#$6O8O
* P\T| [%E'
*/ 5&*zY)UL
publicint getTotalPage(){ ;Z4o{(/zU
return totalPage; AWL[zixR
} ~v\hIm3=m
s ^3[W0hL
/** oXbI5XY)wb
* @param totalPage 3G.r-
* The totalPage to set. avy=0Jmj
*/ J&_3VKrN
publicvoid setTotalPage(int totalPage){ 6qDfcs
this.totalPage = totalPage; | lE-&a$xd
} y7La_FPrl
Wxs>osq
} bKByU{t
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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 <N-=fad]
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个PageUtil,负责对Page对象进行构造: [9HYO
java代码: 117c,yM0
pX^=be_
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/*Created on 2005-4-14*/ y<v|X2
package org.flyware.util.page; T g{UK
cyHU\!Z*Zq
import org.apache.commons.logging.Log; X\mz+al>[
import org.apache.commons.logging.LogFactory; IhwN],-V
x,f>X;04
/** Mlwdha0
* @author Joa !3?yG
* +0dT^Jkqg
*/ .OV-`TNWj
publicclass PageUtil { Y-= /,
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privatestaticfinal Log logger = LogFactory.getLog D>Ua#<52q
|mvM@V;^8{
(PageUtil.class); UFIjW[h
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/** i3d y
* Use the origin page to create a new page LGfmUb-{]
* @param page iU XM(]
* @param totalRecords >+SZd7p
* @return >"b[r
*/ 8(^
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publicstatic Page createPage(Page page, int u6pIdt
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totalRecords){ 'mUI-1GkT
return createPage(page.getEveryPage(), 4@mso+tk
/L$NE$D} "
page.getCurrentPage(), totalRecords); ~M; gM]r;
} s{B_N/^
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/** &\c5!xQ9*
* the basic page utils not including exception Zsgi{
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handler 1EuK,:x
* @param everyPage EzUPah
* @param currentPage (s;zRb!4L
* @param totalRecords 9':/Sab:7v
* @return page
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*/ H<XlUCr_~+
publicstatic Page createPage(int everyPage, int E)Srj~$d
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currentPage, int totalRecords){ 97(n\Wt2
everyPage = getEveryPage(everyPage); 3r`<(%\
currentPage = getCurrentPage(currentPage); {>A
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int beginIndex = getBeginIndex(everyPage, k5C>_(
A
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currentPage); ^7<[}u;qF
int totalPage = getTotalPage(everyPage, -? Ejbko
,uO?;!t
totalRecords); "&}mAWT%If
boolean hasNextPage = hasNextPage(currentPage, g&XhQ.aa
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totalPage); ,.h$&QFj;
boolean hasPrePage = hasPrePage(currentPage); g/6nwa
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returnnew Page(hasPrePage, hasNextPage, [m
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everyPage, totalPage, @| P3
currentPage, P.!;Uf}32
[{?;c+[
beginIndex); *n,UOHlO
} m qpd
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privatestaticint getEveryPage(int everyPage){ F46O!xb%
return everyPage == 0 ? 10 : everyPage; l=,.iv=W
} }Py<qXH
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privatestaticint getCurrentPage(int currentPage){ EL"4E',
return currentPage == 0 ? 1 : currentPage; ~%/'0}F
} !}y8S'Yjw
98=XG1sQ@
privatestaticint getBeginIndex(int everyPage, int 5"[yFmP*
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currentPage){ vmMV n-\#
return(currentPage - 1) * everyPage; BJ"Ay@D*
} Na-q%ru
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privatestaticint getTotalPage(int everyPage, int XQ4dohGCP
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totalRecords){ 2=Jmi?k
int totalPage = 0; 7f[8ED[4
z(#=tC|
if(totalRecords % everyPage == 0) aam1tm#Q
totalPage = totalRecords / everyPage; -}NAb^d
else [O [FCn
totalPage = totalRecords / everyPage + 1 ; '8L(f w{k
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return totalPage; o%$<LaQG5
} |HNQ|r_5S
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privatestaticboolean hasPrePage(int currentPage){ r,QJG$ Jo
return currentPage == 1 ? false : true; #%;<FFu\
} Q.*'H_Y
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privatestaticboolean hasNextPage(int currentPage, UP5%C;
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int totalPage){ >\RDQ%z
return currentPage == totalPage || totalPage == 3LT+9ad2d
t
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0 ? false : true; kqQphKkL
} B#;s(O
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} >aX:gN
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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。 ^u= PdBY
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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 $,p.=j;P
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做法如下: *;>V2!N=U
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 nomu$|I
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的信息,和一个结果集List: yp( ?1
java代码: b/T20F{W\o
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/*Created on 2005-6-13*/ *pDXcURw
package com.adt.bo; |TC3*Y
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import java.util.List; f_^ix
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import org.flyware.util.page.Page; *2w_oKE'+5
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/** (YaOh^T:|
* @author Joa L3-<Kop
*/ 1v>
publicclass Result { WHZe)|n
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private Page page; hWl""66+5
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private List content; ,Zf
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/** MoC*tImWR
* The default constructor >u'/$k
*/ >#Grf)@"6
public Result(){ azz#@f1
super(); 5<'n
} 4SX3c:>
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/** KIXwx98
* The constructor using fields o06A=4I
* 'vqj5YTj
* @param page Qi(e`(,'
* @param content /1[}G!
*/ @5<]W+jk4
public Result(Page page, List content){ e'}ePvN
this.page = page; bCJ<=X,g`K
this.content = content; ~(w=U *
} V{7lltu
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/** ==PQ-Ia
* @return Returns the content. V{ 4i$'
*/ B}l}Aq8
publicList getContent(){ S,d ngb{
return content; E.5*Jr=J
} !#cKF6%
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/** GU;TK'Yy?
* @return Returns the page. uFA|rX
*/ *il]$i
public Page getPage(){ 0ECO/EuCg
return page; n $D}0wSM/
} A>&>6O4
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/** sWojQ-8}
* @param content Wo1V$[`Dy
* The content to set. F3H:I"4
*/ _oMs
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public void setContent(List content){ 5JXzfc9rL
this.content = content; u"Hd55"&
} <