Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 U.pr} hq
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Eo {1y
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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 -wtTq
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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 1!;"bHpk
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分页支持类: S0.- >"L
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java代码: 1FD7~S|
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package com.javaeye.common.util; ^;)SFmjg%
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import java.util.List; "lU]tIpCu
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publicclass PaginationSupport { SA`J.4yn
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publicfinalstaticint PAGESIZE = 30; 7dufY
} }
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privateint pageSize = PAGESIZE; c+E//X|
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privateList items; Y uw
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privateint totalCount; L_
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privateint[] indexes = newint[0]; ,NaV
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privateint startIndex = 0; a8bX"#OR&N
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public PaginationSupport(List items, int Imh2~rw;
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totalCount){ =#.8$oa^
setPageSize(PAGESIZE); %)<oX9E
setTotalCount(totalCount); OUlxeo/
setItems(items); I*+LJy;j
setStartIndex(0); P;L)1 g
} uHUvntr
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public PaginationSupport(List items, int D y`W5_xSz
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totalCount, int startIndex){ x%IXwP0
setPageSize(PAGESIZE); 5A2Y'ms,/
setTotalCount(totalCount); oN&rq6eN
setItems(items); o7c%\v[
setStartIndex(startIndex); @H3 s2|
} _:ZFCDO
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public PaginationSupport(List items, int fR]p+\#8u*
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totalCount, int pageSize, int startIndex){ mc0sdb,c$
setPageSize(pageSize); 3ZW/$KP/
setTotalCount(totalCount); tf$PaA
setItems(items); 12:h49AP
setStartIndex(startIndex); Y91
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} NSMjr_
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publicList getItems(){ :c~9>GCE&
return items; PSP1>-7)w
} t5ny"k!
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publicvoid setItems(List items){ @MN}^umx`
this.items = items; dT0^-XSY
} vWqyZ-p,q
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publicint getPageSize(){ 2p$n*|T&c
return pageSize; \yJZvhUk
} @ 7Q*h
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publicvoid setPageSize(int pageSize){ VL_)]LR*)
this.pageSize = pageSize; "xe7Dl
} 4cXAT9
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publicint getTotalCount(){ 8Ehy9<
return totalCount; %mK3N2N$
} 8~&F/C*
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publicvoid setTotalCount(int totalCount){ W\I$`gyC/
if(totalCount > 0){ 4)z3X\u|Z2
this.totalCount = totalCount; i#L6UKe:Q
int count = totalCount / _9Dn\=g
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pageSize;
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if(totalCount % pageSize > 0) &K9VEMCEX
count++; pTa'.m
indexes = newint[count]; \b_-mnN"
for(int i = 0; i < count; i++){ im_w+h%^
indexes = pageSize * ^Ei*M0fF
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} SBCL1aM
}else{ _/8_,9H
this.totalCount = 0; |Q5H9<*
} k9*J*7l-m
} ax-=n (
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publicint[] getIndexes(){ +L`V[;
return indexes; RE ![O
} Du)B9s
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publicvoid setIndexes(int[] indexes){ J>f
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this.indexes = indexes; 3q'K5}
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} v;)BVv
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publicint getStartIndex(){ c+szU}(f6(
return startIndex; y-E1]4?})
} z7'n, [
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publicvoid setStartIndex(int startIndex){ a='IT 5
if(totalCount <= 0) z{_mEE49
this.startIndex = 0; 2"T8^r|U
elseif(startIndex >= totalCount) 98D{{j92
this.startIndex = indexes X?KGb{
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[indexes.length - 1]; EG F:xl
elseif(startIndex < 0) 9|J8]m?x
this.startIndex = 0; kA1RfSS
else{ 1k!D0f3qb
this.startIndex = indexes h=X7,2/<
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[startIndex / pageSize]; i0ILb/LS
} 3cmbK
} -0A@38, }
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publicint getNextIndex(){ 6tOP}X
int nextIndex = getStartIndex() + "AT&!t[J
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pageSize; QH& %mr.S
if(nextIndex >= totalCount) qsI{ b<n
return getStartIndex(); |!$ Q<-]f
else ^bF}_CSE
return nextIndex; ~wfoK7T}
} k%"$$uo
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publicint getPreviousIndex(){ 929#Q#TT
int previousIndex = getStartIndex() - ^it4z gx@
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pageSize; S{o@QVbl
if(previousIndex < 0) .?A'6
return0; ^/G?QR
else 8r5xs-
return previousIndex; 5fU!'ajaN7
} )URwIe{
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抽象业务类 HTxB=Q|
java代码: )8:n}w
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/** 7}gA0fP9
* Created on 2005-7-12 Q?Wr7
*/ ,Yo: &>As
package com.javaeye.common.business; {PL,VY)Z
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import java.io.Serializable; 7^HpVcSM
import java.util.List; rZ pbu>S
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import org.hibernate.Criteria; 8a7YHUL<3i
import org.hibernate.HibernateException; QT_Srw@
import org.hibernate.Session; L+_8QK <
import org.hibernate.criterion.DetachedCriteria; wbBE@RU>!
import org.hibernate.criterion.Projections; C2NzP & FD
import {>S4#^@}
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org.springframework.orm.hibernate3.HibernateCallback; 2%bhW,?I
import :g&>D#{
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org.springframework.orm.hibernate3.support.HibernateDaoS MdLj,1_T
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upport; cnbo+U
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import com.javaeye.common.util.PaginationSupport; =+`D
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public abstract class AbstractManager extends %@>YNPD`E
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HibernateDaoSupport { 0xv\D0
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privateboolean cacheQueries = false; I I&<
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privateString queryCacheRegion; ehU"*9
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publicvoid setCacheQueries(boolean 2mQOj$Lv
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cacheQueries){ %z=`JhE"Q
this.cacheQueries = cacheQueries; [@g ~
} " l.!Ed
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publicvoid setQueryCacheRegion(String {JTmP `&l
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queryCacheRegion){ )4PB<[u
this.queryCacheRegion = ^[0"vtb
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queryCacheRegion; STw oYn
} bea|?lK
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publicvoid save(finalObject entity){ f KHse$?_
getHibernateTemplate().save(entity);
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} $%B5$+
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publicvoid persist(finalObject entity){ <H!O:Mf_p
getHibernateTemplate().save(entity); ~bWhth2*
} JXL'\De ;
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publicvoid update(finalObject entity){ >n(F4C-pl
getHibernateTemplate().update(entity); s~=g*99H
} KLW&bJ$|j
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publicvoid delete(finalObject entity){ R#D#{cC(
getHibernateTemplate().delete(entity); Y!F!@`%G
} Q~8y4=|#CY
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publicObject load(finalClass entity, &eU3(F`.
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finalSerializable id){ `6UtxJSx
return getHibernateTemplate().load hw*1g m
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(entity, id); L(;.n>/
} .3( ;9};
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publicObject get(finalClass entity, b1H7
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finalSerializable id){ ,2,W^HJ
return getHibernateTemplate().get j|k@MfA
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(entity, id); +3)[>{~1Z
} i]dz}= j'
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publicList findAll(finalClass entity){ 4aA9\\hfGY
return getHibernateTemplate().find("from moaodmt]x
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" + entity.getName()); 4Mi~1iZj
} ;sCU[4
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publicList findByNamedQuery(finalString Hl/7(FJqc>
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namedQuery){ zPHy2H$28
return getHibernateTemplate [#>{4qY2
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().findByNamedQuery(namedQuery); 86y%=! bS
} 0lBat_<8
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publicList findByNamedQuery(finalString query, i2`#
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finalObject parameter){ 'd+:D'
return getHibernateTemplate i0iez9B
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().findByNamedQuery(query, parameter); 6W$rY] h!
} FZH-q!"^cK
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publicList findByNamedQuery(finalString query, ?3Pazc]+|
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finalObject[] parameters){ jAZ >mo[
return getHibernateTemplate H }B2A"
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().findByNamedQuery(query, parameters); `2,a(Sk#
} LZ4xfB(
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publicList find(finalString query){ Fav^^vf*1
return getHibernateTemplate().find Oi6Eo~\f
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(query); $HxS:3D%D
} JdO)YlM-
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publicList find(finalString query, finalObject KXq_K:r?
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parameter){ .>wFztK
return getHibernateTemplate().find b[yE~EQxr
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(query, parameter); KxX[S.C
} !VFem~'d
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public PaginationSupport findPageByCriteria bQ"N
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(final DetachedCriteria detachedCriteria){ Ch7Egzl7?
return findPageByCriteria i%MA"I\9
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); @+:4J_N
} gvGi%gq
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public PaginationSupport findPageByCriteria d@Q][7
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(final DetachedCriteria detachedCriteria, finalint QkL@JF]Re
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startIndex){ ol<lCp
return findPageByCriteria ~$Y|ca
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(detachedCriteria, PaginationSupport.PAGESIZE, 7
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startIndex); ~{P:sjsU
} rd"
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public PaginationSupport findPageByCriteria 1AT'S;`
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(final DetachedCriteria detachedCriteria, finalint "$DldHC
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pageSize, _Z.cMYN
finalint startIndex){ {-h, ZdH^
return(PaginationSupport) G5;V.#"Z[
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getHibernateTemplate().execute(new HibernateCallback(){ Z\' wm'
publicObject doInHibernate PtqGX=u
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(Session session)throws HibernateException { :!']p2B
Criteria criteria = 'W(xgOP1
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detachedCriteria.getExecutableCriteria(session); n/ AW?'
int totalCount = e3g_At\
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((Integer) criteria.setProjection(Projections.rowCount 7*;^UqGjz
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()).uniqueResult()).intValue(); ZV(
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criteria.setProjection l&Q!mU}
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(null); jtCZfFD?
List items = )88nMH-
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criteria.setFirstResult(startIndex).setMaxResults : u-.T.zZl
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(pageSize).list(); b2s~%}T
PaginationSupport ps = s7"i.A
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new PaginationSupport(items, totalCount, pageSize, :XYy7xz<
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startIndex); B9^R8|V
return ps; jA<T p}$!
} CV3DMA
}, true); lhxdx
} s!de2z
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public List findAllByCriteria(final sOz sY7z3Z
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DetachedCriteria detachedCriteria){ ) Fx?%
return(List) getHibernateTemplate 0D~=SekQ9
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().execute(new HibernateCallback(){ 'F7VM?HBfg
publicObject doInHibernate %t[K36,p
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(Session session)throws HibernateException { >)3VbO
Criteria criteria = W+hV9
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detachedCriteria.getExecutableCriteria(session); !M^\f
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return criteria.list(); !DcX8~~@
} %E.S[cf%8&
}, true); gt@SuX!@{^
} `)tA
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public int getCountByCriteria(final ~K`1
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DetachedCriteria detachedCriteria){ Ow)R|/e/
Integer count = (Integer) R&Ci/
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getHibernateTemplate().execute(new HibernateCallback(){ 2*Q3.2 Z
publicObject doInHibernate Y&GuDLUF
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(Session session)throws HibernateException { $3#%aA!(#
Criteria criteria = FUqt)YHi
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detachedCriteria.getExecutableCriteria(session); 8W,*eke?
return ox4W$YdMG
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criteria.setProjection(Projections.rowCount U&Ab#m;
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()).uniqueResult(); HsH<m j
} HH zEQV Lh
}, true); >qpqQ;
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return count.intValue(); 8Zw]f-5x\
} ;"@ :}_t
} !FP"M+
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用户在web层构造查询条件detachedCriteria,和可选的 }#
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 (yGQa5v
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PaginationSupport的实例ps。 aTClw<6}
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ps.getItems()得到已分页好的结果集 L|J~9FM
ps.getIndexes()得到分页索引的数组 9wMEvX70
ps.getTotalCount()得到总结果数 a(|xw
ps.getStartIndex()当前分页索引 q,@+^aZ
ps.getNextIndex()下一页索引 @\PpA9ebg%
ps.getPreviousIndex()上一页索引
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 VA2<r(y~(
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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 1i+FL''
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一下代码重构了。 B1+ZFQo
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我把原本我的做法也提供出来供大家讨论吧: /RqhykgZ
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首先,为了实现分页查询,我封装了一个Page类: HlRAD|]\
java代码: oLP]N$'#
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/*Created on 2005-4-14*/ 6(.H3bu
package org.flyware.util.page; 1J'pB;.]s
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/** $',3Pv
* @author Joa !qw4mN
* ,R}Z=w#
*/ $}4K`Iu
publicclass Page { 2&x7W*
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/** imply if the page has previous page */ 4|F#gK5E
privateboolean hasPrePage; 8}z3CuM
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/** imply if the page has next page */ @G(xaU'u
privateboolean hasNextPage; JCcQd01z
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/** the number of every page */ :d({dF_k;p
privateint everyPage; Q"'V9m7
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/** the total page number */ X'@f"= v9k
privateint totalPage; I+~bCcgPi
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/** the number of current page */ OAVQ`ek
privateint currentPage; E*^9|Y[
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/** the begin index of the records by the current `Hd9\;NJ
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query */ iD`k"\>9
privateint beginIndex; HL8(lPgS
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/** The default constructor */ r w\D>}\
public Page(){ {U6"]f%
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} <tW:LU(!
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/** construct the page by everyPage YLmjEs%
* @param everyPage oXbI5XY)wb
* */ 3G.r-
public Page(int everyPage){ - `4Ty*K
this.everyPage = everyPage; O%VA)<
} _k|g@"
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/** The whole constructor */ V Y_f =
public Page(boolean hasPrePage, boolean hasNextPage, GmAj<