Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 rM}0%J'
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 MZv]s
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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 FjfN3#qlg
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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 j|fd-<ng
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分页支持类: nt1CTWKM8^
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java代码: qNgd33u1
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package com.javaeye.common.util; 7Ey#u4Q
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import java.util.List; 8ovM\9qT
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publicclass PaginationSupport { .\3`2
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publicfinalstaticint PAGESIZE = 30; H!IshZfktn
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privateint pageSize = PAGESIZE; LE^G&<!
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privateList items; P'Q$d+F,
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privateint totalCount; 4EP<tV
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privateint[] indexes = newint[0]; '(+<UpG_Q}
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privateint startIndex = 0; v`[Eb27W.
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public PaginationSupport(List items, int qOV[TP,
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totalCount){ T $4P_*
setPageSize(PAGESIZE);
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setTotalCount(totalCount); K ?$#ntp
setItems(items); !<@J6??a}s
setStartIndex(0); ?kw&=T!
} {04"LAE
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public PaginationSupport(List items, int ~}ml*<z@
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totalCount, int startIndex){ 4pU>x$3$
setPageSize(PAGESIZE); D<{{ :7n
setTotalCount(totalCount); !G5a*8]
setItems(items); ~|Y>:M+0Z
setStartIndex(startIndex); `BFIC7a
} ._:nw=Y0<}
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public PaginationSupport(List items, int ZUXr!v/R:1
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totalCount, int pageSize, int startIndex){ W1aa:hEf
setPageSize(pageSize); C.MoKa3
setTotalCount(totalCount); 1r)kR@!LNG
setItems(items); YA(@5CZ
setStartIndex(startIndex); 8G%yB}pa
} )x,8D ~p'
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publicList getItems(){ 'rP]Nw
return items; @R~5-m
} 36m5bYMd)
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publicvoid setItems(List items){ #1-xw~_
this.items = items; ~vdkFc(8B
} W{cY6@
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publicint getPageSize(){ a@d=>CT$
return pageSize; s Wjy6;
} ({}( qm
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publicvoid setPageSize(int pageSize){ @MR?6 n*k
this.pageSize = pageSize; !hxIlVd{
} O!1TthI
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publicint getTotalCount(){ 6X
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return totalCount; p^m5`{1]x
} 0Sl]!PZR1
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publicvoid setTotalCount(int totalCount){ 96Wp!]*
if(totalCount > 0){ =;~I_)Pg1
this.totalCount = totalCount; M<?Q4a'Q
int count = totalCount / 2h30\/xkU
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pageSize; JMBK{J K>
if(totalCount % pageSize > 0) cX!Pz.C
count++; or ;f&![w
indexes = newint[count]; ~rbIMF4T`]
for(int i = 0; i < count; i++){ rPzQ8<
indexes = pageSize * >"X\>M`"
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} q]&.#&h
}else{ [BbutGvj
this.totalCount = 0; 1MkI0OZE
} XhU@W}}
} dpZ;l 9
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publicint[] getIndexes(){ ?0*8RK
return indexes; )w~Fo,
} Nf,Z;5e
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publicvoid setIndexes(int[] indexes){ <S"~vKD'
this.indexes = indexes; De
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} {-zMHVw=}
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publicint getStartIndex(){ Tn-C>=tR~%
return startIndex; DdV'c@rq+
} iyx>q!P
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publicvoid setStartIndex(int startIndex){ '$|UwT`s
if(totalCount <= 0) 8Q`WB0E<|
this.startIndex = 0; [jx0-3s:X
elseif(startIndex >= totalCount) }b3/b
this.startIndex = indexes Hq &"+1F
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[indexes.length - 1]; "+ "{+k5t
elseif(startIndex < 0) PnT)LqEF
this.startIndex = 0; &FdWFt=X
else{ gA#RM5x@
this.startIndex = indexes
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[startIndex / pageSize]; XP[uF ;w
} K5Wg"^AHY/
} I lR\
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publicint getNextIndex(){ ^[:9fs
int nextIndex = getStartIndex() + wl=61Mb
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pageSize; ^:, l\Y
if(nextIndex >= totalCount) RH0>ZZR
return getStartIndex(); c2l_$p
else _hf4A8ak
return nextIndex; Kz8:UG(
} "kMzmo=Pv5
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publicint getPreviousIndex(){ Ths_CKwgWY
int previousIndex = getStartIndex() - / RZR}
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pageSize; wHjLd$ +o
if(previousIndex < 0) FwKj+f"
return0; vZ7gS
else FaTa(3$%
return previousIndex; #PvB/3
} !{,F~i9
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} ;|%dY{L-
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抽象业务类 }n,Zl>T9
java代码: :!&;p
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/** 1&=0Wg0ig
* Created on 2005-7-12 ;.sl*q1A
*/ t,)N('m}=
package com.javaeye.common.business; bZ_mYyBh
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import java.io.Serializable; Wx'Kp+9'
import java.util.List; +eX)48
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import org.hibernate.Criteria; X8eJ4%
import org.hibernate.HibernateException; A?Q a 4i
import org.hibernate.Session; 3q[WHwmm
import org.hibernate.criterion.DetachedCriteria; W|k0R4K]]
import org.hibernate.criterion.Projections; ajl
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import ChryJRuwv5
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org.springframework.orm.hibernate3.HibernateCallback; UAF<m1
import $$Vt7"F
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org.springframework.orm.hibernate3.support.HibernateDaoS ~Aad9yyi
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upport; 9&%fq)gS
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import com.javaeye.common.util.PaginationSupport; C8N{l:1f]
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public abstract class AbstractManager extends gQSNU_o Z
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HibernateDaoSupport { z7.|fE)<6
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privateboolean cacheQueries = false; C9n}6Er=,
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privateString queryCacheRegion; lor8@Qz
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publicvoid setCacheQueries(boolean ~d{.ng 4K
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cacheQueries){ ? ]sM8Bd}
this.cacheQueries = cacheQueries; R)?{]]v
} HJ?+A-n/
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publicvoid setQueryCacheRegion(String ?8dVH2W.
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queryCacheRegion){ 39U5jj7i
this.queryCacheRegion = +eQe%U
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queryCacheRegion; 6}~pq1IF{
} Y /TlE?
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publicvoid save(finalObject entity){ -
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getHibernateTemplate().save(entity); gMWBu~;!
} .o%^'m"=D[
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publicvoid persist(finalObject entity){ Sydh2d
getHibernateTemplate().save(entity); ,7Y-k'7Kop
} a~h:qpgc
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publicvoid update(finalObject entity){ V{-AP=C7
getHibernateTemplate().update(entity); n;HHogA
} eC
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publicvoid delete(finalObject entity){ c;f!!3&
getHibernateTemplate().delete(entity); Hi!Jj
} Mj>}zbpk/
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publicObject load(finalClass entity, Z.L?1V8Q1
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finalSerializable id){ >t,M
return getHibernateTemplate().load %1
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(entity, id); djQv[Vc{
} o!TQk{0
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publicObject get(finalClass entity, %OR|^M
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finalSerializable id){ _R|Ify#J
return getHibernateTemplate().get 7T``-:`[
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(entity, id); 3:/'t{ ^B
} xVB;s.'!
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publicList findAll(finalClass entity){ Agh`]XQ2
return getHibernateTemplate().find("from ,y`CRlr:
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" + entity.getName()); #mR4fst
} iq#b#PYA
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publicList findByNamedQuery(finalString 2N#$X'8
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namedQuery){ h/eR
return getHibernateTemplate !"Yj|Nu6
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().findByNamedQuery(namedQuery); iO/XhSD
} |LG4=j.l
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publicList findByNamedQuery(finalString query, -Lu)'+
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finalObject parameter){ Kr'f- {
return getHibernateTemplate hD,:w%M
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().findByNamedQuery(query, parameter); Ok5<TZ6t4k
}
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publicList findByNamedQuery(finalString query, W+wA_s2&D
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finalObject[] parameters){ ulT8lw='
return getHibernateTemplate WFR?fDtE
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().findByNamedQuery(query, parameters); $w)~O<_U
} TlL^7f}
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publicList find(finalString query){ 1sE?YJP-
return getHibernateTemplate().find 8*SDiZ
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(query); 9Gy
} _cTh#t ^
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publicList find(finalString query, finalObject onCKI,"
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parameter){ 7 J^rv9i4
return getHibernateTemplate().find q>f<u&
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(query, parameter); r0t^g9K0
} pA.J@,>`}
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public PaginationSupport findPageByCriteria !IU.a90V
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(final DetachedCriteria detachedCriteria){ T J^u"j-'
return findPageByCriteria dF0,Y?
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 84HUBud76Y
} ^L1L=c;,
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public PaginationSupport findPageByCriteria Vt^3iX{!
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(final DetachedCriteria detachedCriteria, finalint Y^Nuz/
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startIndex){ U~{du;\
return findPageByCriteria sAo&
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(detachedCriteria, PaginationSupport.PAGESIZE, MUOa@O,
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startIndex); 4p;aS$Q
} 5tJ,7Y'
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public PaginationSupport findPageByCriteria A,su;Qh
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(final DetachedCriteria detachedCriteria, finalint KKA~#iCk
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pageSize, tH=P6vY
finalint startIndex){ ,Vd\m"K{
return(PaginationSupport) b[z]CP
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getHibernateTemplate().execute(new HibernateCallback(){ }:: S0l
publicObject doInHibernate MT(o"ltQ
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(Session session)throws HibernateException { f>BWG`
Criteria criteria =
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detachedCriteria.getExecutableCriteria(session); xI,2LGO
int totalCount = Sxjub&=
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((Integer) criteria.setProjection(Projections.rowCount q'pK,uNW
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()).uniqueResult()).intValue(); (R`B'OtGg
criteria.setProjection r&-m=Kk$
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(null); 'mI'dG
List items = |AZg*T3:W
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criteria.setFirstResult(startIndex).setMaxResults /iG*)6*^k
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(pageSize).list(); P"sA
PaginationSupport ps = w\)|
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new PaginationSupport(items, totalCount, pageSize, u3Gjg{-N7
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startIndex); nRd)++
return ps; .q+0pj
} zByT$P-
}, true); ceNix!P
} :Hxv6
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public List findAllByCriteria(final Nn>'^KZNG
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DetachedCriteria detachedCriteria){ c1X1+b,
return(List) getHibernateTemplate 0"~i^
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().execute(new HibernateCallback(){ M$f7sx
publicObject doInHibernate O25lLNmO
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(Session session)throws HibernateException { =4d (b ;
Criteria criteria = HF|oBX$_
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detachedCriteria.getExecutableCriteria(session); q7u'_R,;
return criteria.list(); UMX@7a,[3
} (a9d/3M
}, true); tTd\|
} |bgo;J/
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public int getCountByCriteria(final fM^[7;]7e
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DetachedCriteria detachedCriteria){ R$zH]
Integer count = (Integer) 6q
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getHibernateTemplate().execute(new HibernateCallback(){ 3Hf0MAt
publicObject doInHibernate iR"N13
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(Session session)throws HibernateException { G:g69=x y
Criteria criteria = O|_h_I-2
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detachedCriteria.getExecutableCriteria(session); QeF3qXI
return 6'xsG?{JY
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criteria.setProjection(Projections.rowCount gv5*!eI
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()).uniqueResult();
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} J90v!p-
}, true); YJ$1N!rG
return count.intValue(); m,fAeln
} -*.-9B~u
} ! VjFW5'{
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用户在web层构造查询条件detachedCriteria,和可选的 (5\NB0
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 O$4yAaD
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PaginationSupport的实例ps。 [=~ pe|8:
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ps.getItems()得到已分页好的结果集 sH\5/'?
ps.getIndexes()得到分页索引的数组 o.I6ulY8
ps.getTotalCount()得到总结果数 l&?ii68/
ps.getStartIndex()当前分页索引 )=Jk@yj8x
ps.getNextIndex()下一页索引 w6j/ Dq!
ps.getPreviousIndex()上一页索引 Dd`Mv$*d8
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 <tioJG{OT
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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 Sfdu`MQR
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一下代码重构了。 ,i@X'<;y
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我把原本我的做法也提供出来供大家讨论吧: f5 `g
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首先,为了实现分页查询,我封装了一个Page类: 4bgqg0z>
java代码: J`2"KzR0w"
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/*Created on 2005-4-14*/ Pi|o` d
package org.flyware.util.page; =9T$Gr
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/** 8U_{|]M
* @author Joa W6Y@U$P#G
* D+>1]ij
*/ 0iJue&
publicclass Page { }}<z/zN&^
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/** imply if the page has previous page */ x#:| }pR
privateboolean hasPrePage; "^Ybs'-
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/** imply if the page has next page */ 71l%MH
privateboolean hasNextPage; TiH)5
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/** the number of every page */ )5
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privateint everyPage; k?7 X3/O
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/** the total page number */ x,'!eCKN
privateint totalPage; KZeQ47|
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/** the number of current page */ >]c*'~G&