Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 TwZvz[u
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 %5_eos&<^)
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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 ,x+_/kqx
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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 Z?%j5G=4w
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分页支持类: 7p?6j)rj
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java代码: xNNoB/DR
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package com.javaeye.common.util; qj71
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import java.util.List; Zq|oj^
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publicclass PaginationSupport { kWfNgu$xK
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publicfinalstaticint PAGESIZE = 30; @o+T<}kW X
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privateint pageSize = PAGESIZE; I `44}oJ
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privateList items; +q]
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privateint totalCount; s)HbBt-
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privateint[] indexes = newint[0]; !MB %
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privateint startIndex = 0; gKg2Ntxj
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public PaginationSupport(List items, int +G&h
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totalCount){ }>xgzhdT
setPageSize(PAGESIZE); $ 8w
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setTotalCount(totalCount); oKTIoTb
setItems(items); w\Q3h`.
setStartIndex(0); T\:3(+uK
} ewgcpV|spn
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public PaginationSupport(List items, int \%NhggS*
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totalCount, int startIndex){ uLb-
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setPageSize(PAGESIZE); (0W%YZ!&
setTotalCount(totalCount); ^ h^2='p
setItems(items); ew4IAF
setStartIndex(startIndex); _]tR1T5e
} ,ewg3mYHC&
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public PaginationSupport(List items, int /-$`GT?l
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totalCount, int pageSize, int startIndex){ N|Ua|^
setPageSize(pageSize); | qHWM
setTotalCount(totalCount); V#!ypX]AB[
setItems(items); 44?5]C7
setStartIndex(startIndex); h^>kjMM
} X3]E8)645N
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publicList getItems(){ |1 is!leP
return items; 5"y
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} 5%?La`C9[
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publicvoid setItems(List items){ ;k7` `
this.items = items; Dt1{]~30
} U3lr<(r*
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publicint getPageSize(){ q) /;|h
return pageSize; ~<v.WP<:
} \\hZlCV,
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publicvoid setPageSize(int pageSize){ [p!C+|rro
this.pageSize = pageSize; N,'JQch},8
} 1y0.tdI(
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publicint getTotalCount(){ Z6>:k,-Ot
return totalCount; =oT@h
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} ~uC4>+dk
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publicvoid setTotalCount(int totalCount){ 6{azzk8
if(totalCount > 0){
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this.totalCount = totalCount; ;
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int count = totalCount / EemKYcE@Nr
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pageSize; 4C01=,6ye
if(totalCount % pageSize > 0) bHS2;K~
count++; @dCu]0oNI
indexes = newint[count]; \U !<-
for(int i = 0; i < count; i++){ q3NS?t!
indexes = pageSize * J@Zm8r<
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} 9d[0i#` :q
}else{ 1LPfn(
this.totalCount = 0; 0M8JE9 Kx
}
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} Fa+PN9M`?.
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publicint[] getIndexes(){ j{U-=[$'
return indexes; ^Y'J0v2
} zZ32K@
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publicvoid setIndexes(int[] indexes){ bq(*r:`"
this.indexes = indexes; n"FOCcTIs
}
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publicint getStartIndex(){ =l7LEkR
return startIndex; @bqCs^U35
}
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publicvoid setStartIndex(int startIndex){ "BFW&<1
if(totalCount <= 0) (6h7 'r $
this.startIndex = 0; er#we=h
elseif(startIndex >= totalCount) @{CpC
this.startIndex = indexes t&P5Zw*B
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[indexes.length - 1]; zi-+@9T
elseif(startIndex < 0) cF(9[8c{
this.startIndex = 0; v Q_ B2#U:
else{ yPQ{tS*t
this.startIndex = indexes FwW%@Y
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[startIndex / pageSize]; w
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} CIaabn
} 23OVy^b
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publicint getNextIndex(){ %[Ds-my2
int nextIndex = getStartIndex() + $ 1dI
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pageSize; ^@19cU?q
if(nextIndex >= totalCount) i@I %$!cB
return getStartIndex(); %@xYg{
else ?x[>g!r
return nextIndex; unX^ MPpw
} }`M6+.z3F
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publicint getPreviousIndex(){ qt:->yiq+
int previousIndex = getStartIndex() - EV(/@kN2
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pageSize; KJ#c(yb9zR
if(previousIndex < 0) |n|2)hC
return0; VuBp$H(U
else 785iY865
return previousIndex; -qEr-[z
} l2v}PALs
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} Y$Ke{6 4
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抽象业务类 wS^-o
java代码: nSC>x:jY5/
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/** [<`+9R
* Created on 2005-7-12 37[C^R!1c
*/ 0IdD
package com.javaeye.common.business; WE"'3u^k
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import java.io.Serializable; <f*0 XJ#
import java.util.List; jl@8pO$
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import org.hibernate.Criteria; a&[n Vu+
import org.hibernate.HibernateException; gi6_la+
import org.hibernate.Session; 3OZ}&[3
import org.hibernate.criterion.DetachedCriteria; [KKoEZ
import org.hibernate.criterion.Projections; `2oi~^.
import ?l (hS\N,
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org.springframework.orm.hibernate3.HibernateCallback; ] QEw\4M?=
import {8MF!CG]
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org.springframework.orm.hibernate3.support.HibernateDaoS b2Hpuej
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import com.javaeye.common.util.PaginationSupport; LQjqwsuN{
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public abstract class AbstractManager extends N#:"X;
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HibernateDaoSupport { >xjy
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privateboolean cacheQueries = false; dB5DJ:$W$
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privateString queryCacheRegion; r:cUAe7#
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publicvoid setCacheQueries(boolean fjFy$NX&>
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cacheQueries){ {;zPW!G
this.cacheQueries = cacheQueries; 8\9EDgT
} h]#)41y<
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publicvoid setQueryCacheRegion(String xlLS`
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queryCacheRegion){ ?2TH("hV$
this.queryCacheRegion = Fk(5y)
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queryCacheRegion; ?zEF?LJoK
} SXEiyy[7v
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publicvoid save(finalObject entity){ %8Z,t+'
getHibernateTemplate().save(entity); `{Jb{L@f
} kXr%73s
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publicvoid persist(finalObject entity){ u_BSWhiW
getHibernateTemplate().save(entity); =+p+_}C
} I,eyL$x
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publicvoid update(finalObject entity){ pA'A<|)K0
getHibernateTemplate().update(entity); F?=u:
} 0pFHE>
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publicvoid delete(finalObject entity){ 5[_8N{QC;
getHibernateTemplate().delete(entity); (zBQ^97]
} 3o>t~Sfi
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publicObject load(finalClass entity, lND[anB!
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finalSerializable id){ N6;Z\\&0^q
return getHibernateTemplate().load 7o. 'F
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(entity, id); >Il`AR;D
} I8?[@kg5b'
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publicObject get(finalClass entity, QGd- 9UEA]
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finalSerializable id){ {%{GZ
return getHibernateTemplate().get sd53 _sV
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(entity, id); =]e^8;e9
}
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publicList findAll(finalClass entity){ "N]o5d
return getHibernateTemplate().find("from !\1 W*6U8;
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" + entity.getName()); )_cv}.xe
} I?>T"nV +'
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publicList findByNamedQuery(finalString N_D+d4@
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namedQuery){ =joXP$n^
return getHibernateTemplate Nl`ry2"<
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().findByNamedQuery(namedQuery); *K'ej4"u
} Jr)`shJ"
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publicList findByNamedQuery(finalString query, OPW"ABJ
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finalObject parameter){ ]0 RX o3
return getHibernateTemplate % Au$E&sj
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().findByNamedQuery(query, parameter); ,hLSRj{
} k &iDJt
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publicList findByNamedQuery(finalString query, RJwIN,&1.
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finalObject[] parameters){ aLt{X)?
return getHibernateTemplate <0)ud)~u
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().findByNamedQuery(query, parameters); Wxau]uix
} ?7)(qnbe"
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publicList find(finalString query){ AUsQj\Nm%
return getHibernateTemplate().find {$YD-bqY
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(query); F*t_lN5{
} ir:~*|
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publicList find(finalString query, finalObject V9u\;5oL
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parameter){ zL`uiZl
return getHibernateTemplate().find ,M.!z@
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(query, parameter); 6h6?BQSE
} rw[ {@|)'z
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public PaginationSupport findPageByCriteria 8KwCwv
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(final DetachedCriteria detachedCriteria){ ywynx<Wg
return findPageByCriteria Q &7)vs
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); tQ/
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} SiqX1P
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public PaginationSupport findPageByCriteria aT:AxYn8
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(final DetachedCriteria detachedCriteria, finalint 6$s0-{^
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startIndex){ r p
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return findPageByCriteria B$TChc3B
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(detachedCriteria, PaginationSupport.PAGESIZE, FaE #\Q
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startIndex); 9/1+BQ
} )HX:U0
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public PaginationSupport findPageByCriteria gZl w
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(final DetachedCriteria detachedCriteria, finalint "WbVCT'i
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pageSize, .6ngo0<g
finalint startIndex){ mvq7G
return(PaginationSupport) 7ec0Xh1
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getHibernateTemplate().execute(new HibernateCallback(){ 6L,lq;
publicObject doInHibernate 9Ue7
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(Session session)throws HibernateException { ihiuSF<NaQ
Criteria criteria = tpa^k
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detachedCriteria.getExecutableCriteria(session); )nNCB=YF!
int totalCount = 1<a@ p}
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((Integer) criteria.setProjection(Projections.rowCount 0SMQDs5j
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()).uniqueResult()).intValue(); t1w2u.]
criteria.setProjection xY2}Wr
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(null); NSS4vtA
List items = FE+7X=y
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criteria.setFirstResult(startIndex).setMaxResults p,w|=@=
hqs $yb
(pageSize).list(); 7a:*Y"f,~
PaginationSupport ps = f2 ydL/M,
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new PaginationSupport(items, totalCount, pageSize, @A2/@]H Bm
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startIndex); xvR?~
return ps; tE]5@b,R
} x2C/L
}, true); 7|QGY7Tf
} &[5n0e[
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public List findAllByCriteria(final j|[(*i%7|
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DetachedCriteria detachedCriteria){ `6Ureui2?
return(List) getHibernateTemplate ls"b#eFC#
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().execute(new HibernateCallback(){ ,!6M*|
publicObject doInHibernate _%wK}eH+sy
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(Session session)throws HibernateException { #\pP2
Criteria criteria = b/sOfQ
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detachedCriteria.getExecutableCriteria(session); wJ+U[a
return criteria.list(); 3P//H88LY
} dD/t_ {h
}, true); H>? :U]
} ,`<^F:xl
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public int getCountByCriteria(final pi`;I*f/
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DetachedCriteria detachedCriteria){ 7E$eN8H
Integer count = (Integer) >ik1]!j]Lv
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getHibernateTemplate().execute(new HibernateCallback(){ J` w]}GlH
publicObject doInHibernate )A="eW_>
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(Session session)throws HibernateException { s$DGd
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Criteria criteria = Z#-k.|}
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detachedCriteria.getExecutableCriteria(session); -<Jq
return f.||PH
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criteria.setProjection(Projections.rowCount 9i0M/vx
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()).uniqueResult(); 7p)N_cJD
} `Kh]x9Z
}, true); .Y!;xB/
return count.intValue(); 6nh]* /
}
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用户在web层构造查询条件detachedCriteria,和可选的 I> {!U$
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 nO~b=qO
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PaginationSupport的实例ps。 h$70H ^r
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ps.getItems()得到已分页好的结果集 9#uIC7M
ps.getIndexes()得到分页索引的数组 }2lO _i}L
ps.getTotalCount()得到总结果数 `dDa}b
ps.getStartIndex()当前分页索引 "Y7+{
ps.getNextIndex()下一页索引 V1<ow'^i
ps.getPreviousIndex()上一页索引 &i5:)d]L
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 S?L#N
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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 |xh&p(
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一下代码重构了。 6B#('gxO
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我把原本我的做法也提供出来供大家讨论吧: wepwXy"
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首先,为了实现分页查询,我封装了一个Page类: 5SUN.%y
java代码: IZ*}idlkn/
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/*Created on 2005-4-14*/ 1 tPVP
package org.flyware.util.page; 3?2<WEYr
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/** qe$33f*
* @author Joa !EOQhh
* r|
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*/ MTb,Kmw<(
publicclass Page { %ISq>A)%
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/** imply if the page has previous page */ %x2uP9
privateboolean hasPrePage; /Pvk),ca
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/** imply if the page has next page */ 9_ZBV{
privateboolean hasNextPage; 2ev*CX6.
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/** the number of every page */ T~Ly^|Ihz
privateint everyPage; J!hFN]M<<
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/** the total page number */ _A{+H^,
privateint totalPage; f#$|t>
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/** the number of current page */ M+poB+K.
privateint currentPage; mu[Op*)
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/** the begin index of the records by the current B>z?ClH$R
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query */ /[K_
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