Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 )+L.$h
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 _4^#VD#f
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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 mssCnr;
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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 V;@kWE>3
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分页支持类: lJ>OuSd
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java代码: yUY* l@v]
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package com.javaeye.common.util; 4arqlzlo
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import java.util.List; "Qci+Qq
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publicclass PaginationSupport { x%]5Q/|Ur
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publicfinalstaticint PAGESIZE = 30; BK*Bw,KQ<
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privateint pageSize = PAGESIZE; MdKkj[#
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privateList items; mu$0x)
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privateint totalCount; 1^v?Ly8
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privateint[] indexes = newint[0]; K+P:g%M
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privateint startIndex = 0; myq:~^L
;
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public PaginationSupport(List items, int e09('SON(
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totalCount){ D^-6=@<3KD
setPageSize(PAGESIZE); [Z-S0
setTotalCount(totalCount); x )w6
setItems(items); pVN) k
setStartIndex(0); VC T~"T2R
} n,l{1 q
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public PaginationSupport(List items, int T*3>LY+bb
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totalCount, int startIndex){ =}pPr]Cc
setPageSize(PAGESIZE); N"k
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setTotalCount(totalCount); IN!,|)8s
setItems(items); %p d-{KR
setStartIndex(startIndex); @a]O(S>Ub
} }<=4A\LZ
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public PaginationSupport(List items, int UB9n7L(@c
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totalCount, int pageSize, int startIndex){ B&},W* p
setPageSize(pageSize); {vf4l4J(
setTotalCount(totalCount); KEfx2{k b
setItems(items); rEfo)jod
setStartIndex(startIndex); 3v?R"2\qS
} aePLP
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publicList getItems(){ 9V/:1I0?&0
return items; ^hy Y,X
} _*1{fvv0{
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publicvoid setItems(List items){ @b]?Gg
this.items = items; 9vL n#_
} V/,@hv`+
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publicint getPageSize(){ BXj]]S2
return pageSize; {37v.4d;
} 9]]isE8r
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publicvoid setPageSize(int pageSize){ _X/`7!f
this.pageSize = pageSize; p*ic@n*G
} rAwuWM@BIg
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publicint getTotalCount(){ m]"13E0*x
return totalCount; }j\_XaB
} y}
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publicvoid setTotalCount(int totalCount){ ;jZfVRl
if(totalCount > 0){ E(p*B8d
this.totalCount = totalCount; qh)10*FB
int count = totalCount / SSH 1Ge5|
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pageSize; Ro:DAxi@L
if(totalCount % pageSize > 0) #=V[vbTY
count++; $!q(-+(
indexes = newint[count]; W+5<=jXFB
for(int i = 0; i < count; i++){ nP5T*-~
indexes = pageSize * }Kt1mmo:`
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} tQYkH$e`/{
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this.totalCount = 0; HA# 9y;\
} kS)azV
} XcH_Y
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publicint[] getIndexes(){ *rH#k?
return indexes; |9*8u>|RC
} }\Ri:&?
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publicvoid setIndexes(int[] indexes){ aFf(m-
this.indexes = indexes; Nfo`Q0\[P
} 8Ts_;uId
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publicint getStartIndex(){ N:%
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return startIndex; *k^'xL
} T
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publicvoid setStartIndex(int startIndex){
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if(totalCount <= 0) +>Xe_
this.startIndex = 0; 2^f6@;=M
elseif(startIndex >= totalCount) *{fL t
this.startIndex = indexes JK=0juv<E
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[indexes.length - 1]; 79MF;>=tV
elseif(startIndex < 0) Gw@]w;ed
this.startIndex = 0; -:~"c@D
else{ MIx,#]C&
this.startIndex = indexes ziXZJ^(FI
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[startIndex / pageSize]; X Z4q{^o
} -?}Z0e(w
} &cuDGo.
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publicint getNextIndex(){ !U[/P6
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int nextIndex = getStartIndex() + W^8MsdM
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pageSize; =,w(D~ps
if(nextIndex >= totalCount) bZf}m=C!
return getStartIndex(); W^" C|4G }
else K}a3Bj,
return nextIndex; (@nEe?
} 5SQqE@g%
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publicint getPreviousIndex(){ Z#znA4;)
int previousIndex = getStartIndex() - T6^H%;G
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pageSize; [L`w nP
if(previousIndex < 0) ic=tVs
return0; H9+[T3b
else /]>8V'e\
return previousIndex; }_|qDMk+
} ,(y6XUV~
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} 0hv}*NYd
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抽象业务类 ZgI ?#e
java代码: efXiZ
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/** Wz&[cj
* Created on 2005-7-12 Rn9e#_ Az
*/ H7?Sd(U
package com.javaeye.common.business; q<Z`<e
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import java.io.Serializable; E
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import java.util.List; DNu-Ce%
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import org.hibernate.Criteria; }O+`X) 9
import org.hibernate.HibernateException; oa<%R8T?@
import org.hibernate.Session; M"!{Dx~
import org.hibernate.criterion.DetachedCriteria; o~`KOe
import org.hibernate.criterion.Projections; yBkcYHT
import 6R'z3[K9
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org.springframework.orm.hibernate3.HibernateCallback; 5Ei4$T
import r(OH
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org.springframework.orm.hibernate3.support.HibernateDaoS ArVW2gL
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upport; 4`zK`bRcK#
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import com.javaeye.common.util.PaginationSupport; PfjD!=yS=h
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public abstract class AbstractManager extends _X)`S"EsJ
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HibernateDaoSupport { ?X^.2+]*&
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privateboolean cacheQueries = false; ]Il}ymkIZ
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privateString queryCacheRegion; BG^)?_69
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publicvoid setCacheQueries(boolean y"Ios:v@-
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cacheQueries){ ]Wg&r Y0
this.cacheQueries = cacheQueries; z*e`2n#\
} ,{Ga7rH*
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publicvoid setQueryCacheRegion(String M~l\rg8
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queryCacheRegion){ .kc{)d*0K
this.queryCacheRegion = r,Tq";N'
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queryCacheRegion; ZfVw33z
} OfPv'rW{x
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publicvoid save(finalObject entity){ o-+H-
getHibernateTemplate().save(entity); Y,M2D
} b NR@d'U
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publicvoid persist(finalObject entity){ @pN6uDD}R
getHibernateTemplate().save(entity); -Ic<.ix
} @S)p{T5G
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publicvoid update(finalObject entity){ yi:1cLq2
getHibernateTemplate().update(entity); 1k!$#1d<
} =;{8)m
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publicvoid delete(finalObject entity){ ge|Cvv
getHibernateTemplate().delete(entity); ;7U"wI_~c
} Jix;!("
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publicObject load(finalClass entity, C:ntr=3J
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finalSerializable id){ @r]1;KG
return getHibernateTemplate().load 1xj w=
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(entity, id); u85?f
} f"Kl?IN8
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publicObject get(finalClass entity, ~F13}is
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finalSerializable id){ !~`aEF3
return getHibernateTemplate().get {nH*Wu*^
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(entity, id); oH1]-Nl$
} n0b{Jg *
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publicList findAll(finalClass entity){ j"9Zaq_
return getHibernateTemplate().find("from 1O+$"5H
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" + entity.getName()); 4\y>pXML-U
} &uXu$)IZ
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publicList findByNamedQuery(finalString Dpkc9~z
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namedQuery){ 6.6x$y3v
return getHibernateTemplate CO{AC~
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().findByNamedQuery(namedQuery); b|u,[jEB
} v-XB\|f
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publicList findByNamedQuery(finalString query, %h}3}p#4
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finalObject parameter){ r<pt_Cd
return getHibernateTemplate XL`i9kV?
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().findByNamedQuery(query, parameter); j1K?QH=e#{
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publicList findByNamedQuery(finalString query, T#ehJq 5
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finalObject[] parameters){ F32U;fp3
return getHibernateTemplate LsaRw-4.c
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().findByNamedQuery(query, parameters); vg\fBHzn
} oB%j3aAH
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publicList find(finalString query){ `g'z6~c7n
return getHibernateTemplate().find
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(query); seA=7c5E
} |3=tF"h
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publicList find(finalString query, finalObject Xagz(tm/
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parameter){ |VmQ
return getHibernateTemplate().find J-W8wCq`
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(query, parameter); dwz{Yw(
} L87=*_!B;
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public PaginationSupport findPageByCriteria >:P-3#e*
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(final DetachedCriteria detachedCriteria){ Jqqt@5Ni
return findPageByCriteria g&O!w!T
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); -XWlmw*i(g
} #$v,. Yk
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public PaginationSupport findPageByCriteria 6mC% zXR5
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(final DetachedCriteria detachedCriteria, finalint V#\ iO
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startIndex){ \g:Bg%43h
return findPageByCriteria e`;U9Z
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(detachedCriteria, PaginationSupport.PAGESIZE, 5<Y-?23
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startIndex); -_fh=}.n+"
} v}&J*}_XZ
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public PaginationSupport findPageByCriteria bf$4Z: Y
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(final DetachedCriteria detachedCriteria, finalint leO..M
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pageSize, 8~v E
finalint startIndex){ k[/`G5
return(PaginationSupport) v v]rXJu1
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getHibernateTemplate().execute(new HibernateCallback(){ 5j#XNc)"
publicObject doInHibernate zzZK S
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(Session session)throws HibernateException { cfUG)-]P~
Criteria criteria = FWuk@t[<O
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detachedCriteria.getExecutableCriteria(session); RyZy2^0<
int totalCount = EALgBv>#ZL
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((Integer) criteria.setProjection(Projections.rowCount )U:W
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()).uniqueResult()).intValue(); CYN")J8V
criteria.setProjection _rfGn,@BH
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(null); w[s}#Q
List items = lvIdYf$?
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criteria.setFirstResult(startIndex).setMaxResults OM#eJ,MH<)
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(pageSize).list(); 'v_VyK*w
PaginationSupport ps = 5hE mXZ%
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new PaginationSupport(items, totalCount, pageSize, LABLT;c
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startIndex); 17@#"uT0
return ps; 5/4q}U3
} *)um^O
}, true); QHbjZJ
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} AOR(1Qyo
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public List findAllByCriteria(final p^9u8T4l1
o 9{~F`{p
DetachedCriteria detachedCriteria){ hT[w" &3
return(List) getHibernateTemplate TW~9<c
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().execute(new HibernateCallback(){ /|aD,JVN"
publicObject doInHibernate %$}*y
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(Session session)throws HibernateException { GB`
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Criteria criteria = av4g/7=
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detachedCriteria.getExecutableCriteria(session); |-.r9;-b
return criteria.list(); E:S (v
} kc}&\y
}, true); S$1dXXT
} 2j*o[kAE
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public int getCountByCriteria(final Nk&$b
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DetachedCriteria detachedCriteria){ O`Ge|4
Integer count = (Integer) KImazS^
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getHibernateTemplate().execute(new HibernateCallback(){ GN@(!V#/4
publicObject doInHibernate K*fh`Kz
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(Session session)throws HibernateException { o~={M7m
Criteria criteria = $C~OV@I
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detachedCriteria.getExecutableCriteria(session); ;_?RPWZ;MO
return o+
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criteria.setProjection(Projections.rowCount hF7#i_UN<
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()).uniqueResult(); _S;Fs|p_
} <R@w0b>
}, true);
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return count.intValue(); @G:aW\Z
} N!W2O>VS
} 6A*k
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用户在web层构造查询条件detachedCriteria,和可选的 Gs)2HR@>
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 mQy!*0y
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PaginationSupport的实例ps。 C6cEt5
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ps.getItems()得到已分页好的结果集 B|(M xR6m
ps.getIndexes()得到分页索引的数组 ?Z[`sm
ps.getTotalCount()得到总结果数 >{huaN B
ps.getStartIndex()当前分页索引 ew{(@p+$
ps.getNextIndex()下一页索引 B0#JX
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ps.getPreviousIndex()上一页索引 6N {|;R@2
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 <u%&@G$F>
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 )Me$BK>
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一下代码重构了。 m C&*K
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我把原本我的做法也提供出来供大家讨论吧: w5tcO%+k1
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首先,为了实现分页查询,我封装了一个Page类: N56/\1R
java代码: \c.MIDp"
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/*Created on 2005-4-14*/ wtpz ef=
package org.flyware.util.page; C!Oz'~l
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/** LIZsDTU
* @author Joa XAF*jevr
* qH1&tW$
*/ E+xC1U
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publicclass Page { HbXYinG%
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/** imply if the page has previous page */ ytg' {)
privateboolean hasPrePage; c mI&R(
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/** imply if the page has next page */ 236,o
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privateboolean hasNextPage; 8%W(",nd
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/** the number of every page */ z.%K5vrO>
privateint everyPage; ^a+H`RD
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/** the total page number */ WY 'QhieH
privateint totalPage; lZ![?t}2`
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/** the number of current page */ Oj ?
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privateint currentPage; *8?0vkZZ2
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/** the begin index of the records by the current @0{vA\
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query */ 1?}5.*j<
privateint beginIndex; u|}p3-z|Y
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/** The default constructor */ ;H;c Sn5uL
public Page(){ RAps`)OR?
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} ZIo%(IT!c
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/** construct the page by everyPage \2Atm,#4
* @param everyPage v@^P4cu;
* */ ?f\ ~:Gm/
public Page(int everyPage){ "q,.O5q}Y
this.everyPage = everyPage; y(w&6:
} Zj]jE%AT
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/** The whole constructor */ zm7IkYF
public Page(boolean hasPrePage, boolean hasNextPage, zF-R$_]av
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int everyPage, int totalPage, $>csm
int currentPage, int beginIndex){ }>
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this.hasPrePage = hasPrePage; lujUEHzp
this.hasNextPage = hasNextPage; 7j22KQ|EX^
this.everyPage = everyPage; 7I0[Ii
this.totalPage = totalPage; w#Di
this.currentPage = currentPage; R@[gkj
this.beginIndex = beginIndex; Q?uHdmY*X
} xh) h#p.
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/** <