Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 w4uY/!~k
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 2ZMVYa2%(
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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 Eds{-x|10
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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 d6e]aO=g
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分页支持类: "4QD\k5
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java代码: G"prq&
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package com.javaeye.common.util; d
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import java.util.List; 8&y3oxA,
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publicclass PaginationSupport { =/^{Pn
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publicfinalstaticint PAGESIZE = 30; u6p
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privateint pageSize = PAGESIZE; J*f..:m
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privateList items; R%%h=]
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privateint totalCount; nTXM/
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privateint[] indexes = newint[0]; BxXP]od
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privateint startIndex = 0; kD4J{\
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public PaginationSupport(List items, int X7 fJ+Cn
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totalCount){ ^Ea^t.c}_
setPageSize(PAGESIZE); P*8DM3':
setTotalCount(totalCount); %-, -:e
setItems(items); T#G
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setStartIndex(0); (Z};(Hn
} F5EsaF'e4
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public PaginationSupport(List items, int zF=E5TL-,4
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totalCount, int startIndex){ [=KA5c<
setPageSize(PAGESIZE); F$&{@hd
setTotalCount(totalCount); =5X(RGK
setItems(items); hXsH9R
setStartIndex(startIndex); VZ$FTM^b8
} w^aI1M50
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public PaginationSupport(List items, int km#Rh^
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totalCount, int pageSize, int startIndex){ "':u#UdS
setPageSize(pageSize); tm280
setTotalCount(totalCount); 6`hHx=L
setItems(items); o;Ma)/P
setStartIndex(startIndex); srfM"Lb'
} 3eS
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publicList getItems(){ =L?(mNHT
return items; <gc\,P<ru
} hiA%Tq?
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publicvoid setItems(List items){ +zLh<q 0
this.items = items; cv/
} k'$UA$2d
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publicint getPageSize(){ (GJW3
return pageSize; T*sB Wn'am
} `$,
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publicvoid setPageSize(int pageSize){ Qk.:b
this.pageSize = pageSize; `(7HFq<N
} F`\7&'I
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publicint getTotalCount(){ A#B6]j)
return totalCount; 34\:1z+s M
} \a6knd
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publicvoid setTotalCount(int totalCount){ .V:H~
if(totalCount > 0){ $x%VUms
this.totalCount = totalCount; VY=c_Gl
int count = totalCount / g<r'f"^
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pageSize; r % ]^(
if(totalCount % pageSize > 0) a\m@I_r.N
count++; JQ.w6aE
indexes = newint[count]; QX j4cg
for(int i = 0; i < count; i++){ <n:j@a\up0
indexes = pageSize * zf>r@>S!L
}TS4D={1
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} tv1Z%Mx?Cp
}else{ =8F]cW'1`
this.totalCount = 0; QjlwT 2o'
} qc-4;m o
} 3bp'UEF^k
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publicint[] getIndexes(){ d;D8$q)8Q
return indexes;
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} pK~K>8\
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publicvoid setIndexes(int[] indexes){ _,JdL'[d
this.indexes = indexes; KvrcO#-sL
} ^SouA[
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publicint getStartIndex(){ #D-L>7,jA
return startIndex; qs]7S^yw
} p kR+H|
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publicvoid setStartIndex(int startIndex){ ,!RbFME&H
if(totalCount <= 0) P|OjtI
this.startIndex = 0; ,^UNQO*{GI
elseif(startIndex >= totalCount) `/mcjKQ&9y
this.startIndex = indexes iYJzSVO
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[indexes.length - 1]; !?7c2QRN
elseif(startIndex < 0) >dW~o_u'QN
this.startIndex = 0; i$A0_ZJKjZ
else{ T53|*~u
this.startIndex = indexes /Af:{|'$%
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[startIndex / pageSize]; P'4jz&4
} mqg[2VTRP
} [o=v"s't)
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publicint getNextIndex(){ 9)a:8/Y
int nextIndex = getStartIndex() + iS{8cN3R
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pageSize; ,
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if(nextIndex >= totalCount) ;@$B{/Q
return getStartIndex(); %y/8i%@6
else ]oN:MS4r
return nextIndex; 5mD]uB9
} vbeYe2;(
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publicint getPreviousIndex(){ q>T7};5m2
int previousIndex = getStartIndex() - xsq+RBJi
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pageSize; SV4a_m?
if(previousIndex < 0) luyU!
return0; 6Y|jK<n?H
else ",\,lqV
return previousIndex; APgP*,
} qn+b*4
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} [4qx+ypT
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抽象业务类 :dtX^IT
java代码: .CClc(bO_/
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/** Kzw)Q
* Created on 2005-7-12 wsyG~^>
*/ 6[<*C?
package com.javaeye.common.business; l%?D%'afN
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import java.io.Serializable; TS9=A1J#
import java.util.List; i9.~cnk
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import org.hibernate.Criteria; 6]%79?'A
import org.hibernate.HibernateException; Mb6#97
import org.hibernate.Session; yB&+2
import org.hibernate.criterion.DetachedCriteria; mr+J#
import org.hibernate.criterion.Projections; f((pRP
import \(PC#H%
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org.springframework.orm.hibernate3.HibernateCallback; Cz2OGM*mz?
import *uAsKU
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org.springframework.orm.hibernate3.support.HibernateDaoS Y!VYD_'P
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upport; Md9b_&'
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import com.javaeye.common.util.PaginationSupport; Fg3VD(D^U
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public abstract class AbstractManager extends P&@:''
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HibernateDaoSupport { "#4p#dM0e
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privateboolean cacheQueries = false; 8#OcrJzC
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privateString queryCacheRegion; D@V1}/$UoN
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publicvoid setCacheQueries(boolean xS) njuq4
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cacheQueries){ |fMjg'%{}
this.cacheQueries = cacheQueries; c5K@<=?,E
} _`>F>aP
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publicvoid setQueryCacheRegion(String EK^B=)q6:W
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queryCacheRegion){ 9]AiaV9
this.queryCacheRegion = *t{$GBP
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queryCacheRegion; _c=[P@
} qRg^Bp'VD#
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publicvoid save(finalObject entity){ gO*:<B g
getHibernateTemplate().save(entity); pu(a&0
} 03ol!|X"9
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publicvoid persist(finalObject entity){ yub|
getHibernateTemplate().save(entity); D|W^PR:@h
} oT7=
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publicvoid update(finalObject entity){ tn-_3C
getHibernateTemplate().update(entity); m_Owe/BC#m
} IL?mt2I Q>
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publicvoid delete(finalObject entity){ wD}ojA&DU
getHibernateTemplate().delete(entity); sh []OSM
} `C~RA,M
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publicObject load(finalClass entity, ;P9P2&c8c
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finalSerializable id){ cqzd9L6=
return getHibernateTemplate().load mE3^5}[>
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(entity, id);
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} rlEp&"+|M
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publicObject get(finalClass entity, H6ff b)&
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finalSerializable id){ ;[*jLi,uc
return getHibernateTemplate().get =VMV^[&>
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(entity, id); 7\sJ=*
} 6fvzTd},
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publicList findAll(finalClass entity){ c[:OK9TH
return getHibernateTemplate().find("from yvxdl=s
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" + entity.getName()); O$}p}%%y7
} i)nb^
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publicList findByNamedQuery(finalString ^dB~#A1
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namedQuery){ 2Yd0:$a
return getHibernateTemplate BJI}gm2y
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().findByNamedQuery(namedQuery); s hbPy
}
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publicList findByNamedQuery(finalString query, a []Iz8*6e
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finalObject parameter){ H"|xG;cf
return getHibernateTemplate ncg5%(2
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().findByNamedQuery(query, parameter); V[-4cu,Ph^
} TJ@@kSSbl
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publicList findByNamedQuery(finalString query, L8K=Q
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finalObject[] parameters){ O5HK2Xg,C
return getHibernateTemplate V5y8VT=I
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().findByNamedQuery(query, parameters); p<1z!`!P
} _@CY_`a
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publicList find(finalString query){ $:M *$r^u
return getHibernateTemplate().find Jy)E!{#x
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(query);
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} y,&UST
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publicList find(finalString query, finalObject h^klP: Q
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parameter){ 0z)
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return getHibernateTemplate().find O)n LV~X
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(query, parameter); aEr<(x!|"
} ji(W+tQ2Y'
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public PaginationSupport findPageByCriteria 1{N73]-M:
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(final DetachedCriteria detachedCriteria){ <
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return findPageByCriteria g z!q
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); )(~s-x^\z@
} oJC-?
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public PaginationSupport findPageByCriteria K;jV"R<9
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(final DetachedCriteria detachedCriteria, finalint CZB!vh0
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startIndex){ yidUtSv=,
return findPageByCriteria FQdz":5
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(detachedCriteria, PaginationSupport.PAGESIZE, !mNXPqnN
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startIndex); 9"mOjL
} IXb]\ )
} ).rD
public PaginationSupport findPageByCriteria mG4myQ?$
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(final DetachedCriteria detachedCriteria, finalint n<
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pageSize, Uc,D&Og
finalint startIndex){ 6^U8Utx
return(PaginationSupport) s%h|>l[lKT
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getHibernateTemplate().execute(new HibernateCallback(){ Oo'IeXQ9(
publicObject doInHibernate zbH Nj(~
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(Session session)throws HibernateException { "Y(stRa
Criteria criteria = j^ L"l;m
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detachedCriteria.getExecutableCriteria(session); )cA#2mlS'1
int totalCount = dQ6:c7hp>D
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((Integer) criteria.setProjection(Projections.rowCount 4;anoqiG\
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()).uniqueResult()).intValue(); /DOV/>@5%
criteria.setProjection _`yd"0Ux
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(null); ,|hM`<"?
List items = ,lK=m~
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criteria.setFirstResult(startIndex).setMaxResults U ObI&*2
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(pageSize).list(); ^):m^w.
PaginationSupport ps = $hexJzX
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new PaginationSupport(items, totalCount, pageSize, 9kmEg$WM
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startIndex); DG&
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return ps; (XtN3FTY
} eQh@.U*S)
}, true); ]IbX<
} {"Xn`@Y
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public List findAllByCriteria(final [RtTi<F^
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DetachedCriteria detachedCriteria){ 8bQ\7jb
return(List) getHibernateTemplate GE;S5X]X
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().execute(new HibernateCallback(){ @tQu3Rq@
publicObject doInHibernate 3vx5dUgl,
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(Session session)throws HibernateException { AF ,*bb
Criteria criteria = HUF],[N
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detachedCriteria.getExecutableCriteria(session); l1 (6*+
return criteria.list(); 0vN <0
} zrt \]h+
}, true); o+UCu`7e
} +O`3eP`u
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public int getCountByCriteria(final L%G/%*7;c
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DetachedCriteria detachedCriteria){ H CKD0xx
Integer count = (Integer) gDHgXDD_b
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getHibernateTemplate().execute(new HibernateCallback(){ T(LqR?xOo
publicObject doInHibernate !|!k9~v!
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(Session session)throws HibernateException { #_]/Mr1
Criteria criteria = '@4Myg* b
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detachedCriteria.getExecutableCriteria(session); S0,q@LV
return !*2cK>`
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criteria.setProjection(Projections.rowCount ZL!,s#
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()).uniqueResult(); >R9Q|
} +tsF.Is!t
}, true); _5<d'fBd
return count.intValue(); GyU9,>|~T
} XO[S(q
} W5C8$Bqm
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用户在web层构造查询条件detachedCriteria,和可选的 GYvD*?uBc
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 jA<(#lm;
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PaginationSupport的实例ps。 n7Em
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ps.getItems()得到已分页好的结果集 rGa@!^hk
ps.getIndexes()得到分页索引的数组 Ck`-<)uN
ps.getTotalCount()得到总结果数 E}^np[u7
ps.getStartIndex()当前分页索引 w ;;yw3
ps.getNextIndex()下一页索引 ^\<nOzU?
ps.getPreviousIndex()上一页索引 \X3Q,\H
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 O|Sbe%[*wW
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 ALcin))+B
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一下代码重构了。 UCu0Xqf
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我把原本我的做法也提供出来供大家讨论吧: 8'K~+L=}
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首先,为了实现分页查询,我封装了一个Page类: Q#k Sp8
java代码: }j+Af["W?
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/*Created on 2005-4-14*/ F747K);_
package org.flyware.util.page; BZJ\tPSR
=*0KH##%$
/** o7gYj\
* @author Joa w\V1pu^6@
* h#hx(5"6
*/ T]er_n
publicclass Page { /Pbytu);ds
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/** imply if the page has previous page */ -FOn%7r#Y
privateboolean hasPrePage; RB\
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/** imply if the page has next page */ uez"{ _I
privateboolean hasNextPage; b]0]*<~y
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/** the number of every page */ 9f(0
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privateint everyPage; DB~3(r?K
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/** the total page number */ $ol]G`+
privateint totalPage; _+sb~
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/** the number of current page */ }nEa9h
privateint currentPage; MQc<AfW3/
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/** the begin index of the records by the current bA_/6r)u
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query */ 7`s*
{
privateint beginIndex; <wH"{G3?
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/** The default constructor */ lr*p\vH
public Page(){ 1;*4yJ2
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} M2kvj'WWq
-(dtAo6
/** construct the page by everyPage Wtwo1pp
* @param everyPage pD@:]VP
* */ |2Vhj<6
public Page(int everyPage){ ]KQv]'
this.everyPage = everyPage; t)kc`3i<A
} n1!}d%:
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/** The whole constructor */ 12i<b
public Page(boolean hasPrePage, boolean hasNextPage, %nS(>X<B
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int everyPage, int totalPage, bI-uF8"
int currentPage, int beginIndex){ {gC?kp
this.hasPrePage = hasPrePage; ; Sd== *
this.hasNextPage = hasNextPage; "[QQ(]={
this.everyPage = everyPage; uGmv`R_
this.totalPage = totalPage; c$.Zg=
this.currentPage = currentPage; N&uRL_X.
this.beginIndex = beginIndex; 3 <