Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 _7=LSf,9
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 P7D__hoE
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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 s"-gnW
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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 sO$X5S C9
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分页支持类: 40$- ]i
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java代码: =b_/_b$q
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package com.javaeye.common.util; J]4pPDm
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import java.util.List; |SSe n#PYp
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publicclass PaginationSupport { 3D^!U}E
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publicfinalstaticint PAGESIZE = 30; J2avt
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privateint pageSize = PAGESIZE; %k=c9ll@:
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privateList items; zbgH}6b
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privateint totalCount; Dhze2q)o
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privateint[] indexes = newint[0]; H7?Sd(U
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privateint startIndex = 0; 0 P2lq
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public PaginationSupport(List items, int $az9Fmta
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totalCount){ hUP?r/B
setPageSize(PAGESIZE); >hv8zHOO:
setTotalCount(totalCount); kA4bv}
setItems(items); h\lyt(.s
setStartIndex(0); hq*"S-N
} 7w5C
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public PaginationSupport(List items, int Ge^(Ag}vE
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totalCount, int startIndex){ 32z2c:G
setPageSize(PAGESIZE); (;cKv
setTotalCount(totalCount); ,"U|gJn|^
setItems(items); 9r=yfc!cS
setStartIndex(startIndex); %v)+]Ds{
} 'BX
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public PaginationSupport(List items, int ,Fzuo:{uy
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totalCount, int pageSize, int startIndex){ 4WXr~?Vq9
setPageSize(pageSize); THy{r_dx
setTotalCount(totalCount); J*D3=5&
setItems(items); /WMJ#IE
setStartIndex(startIndex); UFGUP]J>
} ]FEsN6
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publicList getItems(){ 7;@o]9 W
return items; 8SOfX^;o
} k2:mIp\
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publicvoid setItems(List items){ 6QePrf
this.items = items; Jix;!("
} _#y=T20'3
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publicint getPageSize(){ NszqI
return pageSize; H,Yrk(O-
} KvmXRf*z
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publicvoid setPageSize(int pageSize){ sNs Hl
this.pageSize = pageSize; qDPl( WXb
} 8V@\$4@b!#
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publicint getTotalCount(){ Xu& v3Y~k
return totalCount; C
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} %o_CD>yD
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publicvoid setTotalCount(int totalCount){ UQO?hZ!y/.
if(totalCount > 0){ cv9-ZOxJ
this.totalCount = totalCount; #C+7~ns'
int count = totalCount / DEt;$>tl
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pageSize; \9k{h08s
if(totalCount % pageSize > 0) q],/%W
count++; G\#dMCk?
indexes = newint[count]; (``|5;T\
for(int i = 0; i < count; i++){ @T)>akEOt
indexes = pageSize * eb7~\|9l1i
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} [-2Tj)P
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}else{ m_b_)/
this.totalCount = 0; 9ZG__R3B1\
} N[wyi&m4
} ZqfoO!Ta
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publicint[] getIndexes(){ M4K>/-9X+V
return indexes; >/7[HhBT
} I ka
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publicvoid setIndexes(int[] indexes){ !==C@cH<N
this.indexes = indexes; `.YMbj#T
} vf?m-wh
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publicint getStartIndex(){ M(.Up
return startIndex; wu19Pg?F
} !N\i9w}
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publicvoid setStartIndex(int startIndex){ m ?jF:]^
if(totalCount <= 0) g/OL^A
this.startIndex = 0; Rs53R$PIR
elseif(startIndex >= totalCount) MJG)fFl]O
this.startIndex = indexes S/Gy:GIf
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[indexes.length - 1]; \ O+Hmi^
elseif(startIndex < 0) v v]rXJu1
this.startIndex = 0; 2IFEl-IB[
else{ ,dSP%?vV
this.startIndex = indexes z+X DN:
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[startIndex / pageSize]; #<gD@Jyb u
} jmva0K},SE
} fC!+"g55
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publicint getNextIndex(){ {KM5pK?,BJ
int nextIndex = getStartIndex() + !T1)tGrH
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pageSize; 0uS6F8x@
if(nextIndex >= totalCount) .{66q#.
return getStartIndex(); 'v_VyK*w
else zn/b\X/
return nextIndex; {{Z3M>Q
} 9vJ'9Z2\
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publicint getPreviousIndex(){ lwp(Pq
int previousIndex = getStartIndex() - 75RQ\_zDu
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pageSize; o 9{~F`{p
if(previousIndex < 0) y<*/\]t9L[
return0; IjnO2X
else UeN+}`!l
return previousIndex; T`SpIdzB.
} UN7J6$!Cx7
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} 9xIz[`)i.
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抽象业务类 J G3#(DVc;
java代码: ad'C&^o5
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/** m{C
* Created on 2005-7-12 Q:sw*7"F
*/ rT{+ h}vO
package com.javaeye.common.business;
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import java.io.Serializable; "[p-Iy1
import java.util.List; w}
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import org.hibernate.Criteria; ;PF!=8dW
import org.hibernate.HibernateException; fKjUEMRK
import org.hibernate.Session; )%=oJ!)
import org.hibernate.criterion.DetachedCriteria; MNZD-[
import org.hibernate.criterion.Projections; 5p`.RWls
import cuW&X9\m,
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org.springframework.orm.hibernate3.HibernateCallback; B|(M xR6m
import FT+[[9i
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org.springframework.orm.hibernate3.support.HibernateDaoS Ht!]%
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upport; +YK/^;Th
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import com.javaeye.common.util.PaginationSupport; D4e!A@LJ
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public abstract class AbstractManager extends -=CZhp
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HibernateDaoSupport { L!
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privateboolean cacheQueries = false; qL?`l;+
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privateString queryCacheRegion; CBvvvgI o
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publicvoid setCacheQueries(boolean 9et%Hn.K'
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cacheQueries){ HbXYinG%
this.cacheQueries = cacheQueries; vRn"0Mzl8
} 98x&2(N
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publicvoid setQueryCacheRegion(String -U#e
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queryCacheRegion){ />q?H)6
this.queryCacheRegion = D?:AHj%gW
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queryCacheRegion; (h3f$
} _bm8m4Lk
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publicvoid save(finalObject entity){ mM6X0aM
getHibernateTemplate().save(entity); 'ZboLoS*-
} ltH?Ew<]
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publicvoid persist(finalObject entity){ py8)e7gX=
getHibernateTemplate().save(entity); WQ>y;fi5/{
} r{pbUk
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publicvoid update(finalObject entity){ ,KyG^;Riy
getHibernateTemplate().update(entity); #'&&&_Hu3
} U&}v1wdZ3
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publicvoid delete(finalObject entity){ rMy(NAo_
getHibernateTemplate().delete(entity); 6b6rM%B.oD
} 7j22KQ|EX^
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publicObject load(finalClass entity, ,6iXl ch
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finalSerializable id){ #D2.RN
return getHibernateTemplate().load Q eZg l!
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(entity, id); b|'{f?
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publicObject get(finalClass entity, a\@k5?
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finalSerializable id){ jM%8h$&E
return getHibernateTemplate().get []I_r=
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(entity, id); c ?(X(FQ
} s`63
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publicList findAll(finalClass entity){ 8v V<A*`
return getHibernateTemplate().find("from )U5Ba^"fI
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" + entity.getName()); =)Z~w`
} L55VS:'
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publicList findByNamedQuery(finalString 8uD%
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namedQuery){ j+6`nN7L
return getHibernateTemplate QGoBugU
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().findByNamedQuery(namedQuery); :5,
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} wk[4Qsk<
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publicList findByNamedQuery(finalString query,
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finalObject parameter){ I/`\>Hk
return getHibernateTemplate mDX
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().findByNamedQuery(query, parameter); 2[QyH'"^E
} ul!e!^qwx
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publicList findByNamedQuery(finalString query, 9J4gDw4<
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finalObject[] parameters){ c)B
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return getHibernateTemplate "IuPg=|#
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().findByNamedQuery(query, parameters); x4^*YZc$,
} D wtvtglqV
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publicList find(finalString query){ DR
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return getHibernateTemplate().find ~;D5j ) 9I
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(query); r[W
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} OkfnxknZ|
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publicList find(finalString query, finalObject </-aG[Fi
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parameter){ 9~ rYLR(v
return getHibernateTemplate().find W~Ae&gcn#
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(query, parameter); ['JIMcD
} r$<4_*
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public PaginationSupport findPageByCriteria G/y;o3/[Z
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(final DetachedCriteria detachedCriteria){ i=AQ1X\s
return findPageByCriteria .X;DI<K
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); -W'T3_
} 9D,/SZ-v
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public PaginationSupport findPageByCriteria &E0L 2gbI
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(final DetachedCriteria detachedCriteria, finalint .ovG_O
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startIndex){ =niT]xf
return findPageByCriteria Q~zs]{\
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(detachedCriteria, PaginationSupport.PAGESIZE, C|-QU
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startIndex); 0.z\YTZ9
} &[qJ=HMm I
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public PaginationSupport findPageByCriteria Qa@]
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(final DetachedCriteria detachedCriteria, finalint SK t&BnW
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pageSize, qj1Fj
finalint startIndex){ &at>sQ'
return(PaginationSupport) Rg\D-F6:
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getHibernateTemplate().execute(new HibernateCallback(){ ?G<.W[3
publicObject doInHibernate A#Ne07d
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(Session session)throws HibernateException { h)pYV>!d
Criteria criteria = q:<vl^<j
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detachedCriteria.getExecutableCriteria(session); ,lb >
int totalCount = k<QZ_*x}G
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((Integer) criteria.setProjection(Projections.rowCount /j"aOLL|
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()).uniqueResult()).intValue();
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criteria.setProjection .kp3<.
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(null); i<-a-Z+^
List items = ^Fg!.X_
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criteria.setFirstResult(startIndex).setMaxResults ,iMdv+
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(pageSize).list(); S t;@ZV
PaginationSupport ps = )(-aw,iK
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new PaginationSupport(items, totalCount, pageSize, -7(,*1Tk
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startIndex); 6wH:jd9,
return ps; CS\8ej}y
} 0`$fs.4c
}, true); &x)n K
} :uB(PeAv*
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public List findAllByCriteria(final Iwe
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DetachedCriteria detachedCriteria){ VfkQc$/
return(List) getHibernateTemplate ?eDZ-u9)
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().execute(new HibernateCallback(){ %hi]oz
publicObject doInHibernate 9yWSlbPr]
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(Session session)throws HibernateException { 3*#$:waGd
Criteria criteria = qflOi8
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detachedCriteria.getExecutableCriteria(session); kJpr:4;@_
return criteria.list(); 'tJxADK
} \]0+J
}, true); FZtT2Z4&i
} 9 e;8"rJ?C
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public int getCountByCriteria(final -%TwtO<$']
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DetachedCriteria detachedCriteria){ uTNy{RBD+
Integer count = (Integer) :
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getHibernateTemplate().execute(new HibernateCallback(){ 8^!ib/@v"
publicObject doInHibernate E&>;a!0b]
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(Session session)throws HibernateException { @?5pY^>DK
Criteria criteria = OmZK~$K_
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detachedCriteria.getExecutableCriteria(session); 6W9lKD_i
return 2/ejU,S
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criteria.setProjection(Projections.rowCount +>Pq]{Uf1j
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()).uniqueResult(); >N"=10
} s){R/2O3F
}, true); @ 1FWBH~
return count.intValue(); Se|h]+G
} B C R]K
} JPpNCC.b
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用户在web层构造查询条件detachedCriteria,和可选的 GQ}R xu]
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 q#`;G,rs
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PaginationSupport的实例ps。 U["IXR#
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ps.getItems()得到已分页好的结果集 R)Dh; XA
ps.getIndexes()得到分页索引的数组 %>t4ib_8
ps.getTotalCount()得到总结果数 jV' tcFr4
ps.getStartIndex()当前分页索引 mxICQ>s
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ps.getNextIndex()下一页索引 Ryn@">sVI
ps.getPreviousIndex()上一页索引 `[~LMV&2U
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 yppXecFJ
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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 Rk}=SB-
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一下代码重构了。 ;V^ I>-fnm
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我把原本我的做法也提供出来供大家讨论吧: Nrc-@ ]
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首先,为了实现分页查询,我封装了一个Page类: BXr._y, cr
java代码: Pcr;+'q
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/*Created on 2005-4-14*/ M B,Z4 ^
package org.flyware.util.page; aWb5w
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/** N~B'gJJDx
* @author Joa MsA)Y
* #M92=IH
*/ sE0,b
publicclass Page { osTin*T.
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/** imply if the page has previous page */ s$VLVT*6
privateboolean hasPrePage; !}HT&N8[r
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/** imply if the page has next page */ -ha[xM05
privateboolean hasNextPage; RueL~$*6.~
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/** the number of every page */ iD2>-yf
privateint everyPage; .T}S[`Yx5
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/** the total page number */ ]j<&
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privateint totalPage; VB{G%!}
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/** the number of current page */ eXMl3Lxf
privateint currentPage; D]d2opBLj
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/** the begin index of the records by the current r;8$ 7C.
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query */ ZAMS;e+e
privateint beginIndex; mKBPIQ+ZS
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/** The default constructor */ T8a!"lPP7
public Page(){ *5;#+%A
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} h:'wtn@l(
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/** construct the page by everyPage %ck/ Z
* @param everyPage <4P"1#nHQ+
* */ 1fb!sbGD.k
public Page(int everyPage){ }4"T#
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this.everyPage = everyPage; rfxLCiV
} nD;8)VI'I
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/** The whole constructor */ Iw) 'Yyg
public Page(boolean hasPrePage, boolean hasNextPage, a]_eSU@
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7 {#^zr
int everyPage, int totalPage, n+uDg
int currentPage, int beginIndex){ *Ldno`1O
this.hasPrePage = hasPrePage; 4
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this.hasNextPage = hasNextPage; |\
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this.everyPage = everyPage; ;]Bkw6o
this.totalPage = totalPage; ;?0r,0l2$
this.currentPage = currentPage; >pn5nn1a
this.beginIndex = beginIndex; T)PH8 "
} DnW*q/=w
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/** F%>`?NG+c
* @return z gDc=
* Returns the beginIndex. \4|o5, +(@
*/ h*\/{$y
publicint getBeginIndex(){ Yn }Ivg
return beginIndex; vL"[7'
} !o&