Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Fd.d(
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 [)c|oh%
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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 1D DOUV
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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 >7Q7H#~w
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分页支持类: JPKZU<:+V
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java代码: wajhFBJ
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package com.javaeye.common.util; _3>zi.J/
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import java.util.List; >xgd<
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publicclass PaginationSupport { j)*nE./3
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publicfinalstaticint PAGESIZE = 30; yBKlp08J
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privateint pageSize = PAGESIZE; F
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privateList items; #0H[RU?
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privateint totalCount; [)u{ -
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privateint[] indexes = newint[0]; [GM<Wt0
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privateint startIndex = 0; E+ 20->
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public PaginationSupport(List items, int X|G+N(`|(
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totalCount){ @kymL8"2w
setPageSize(PAGESIZE); r U5'hK
setTotalCount(totalCount); ?yK\L-ad
setItems(items); ^123.Ru|t
setStartIndex(0); >^N:A
} gp2)35
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public PaginationSupport(List items, int "
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totalCount, int startIndex){ s6uAF(4,
setPageSize(PAGESIZE); h65j,v6B
setTotalCount(totalCount); \$"Xr
setItems(items); ;_\P;s
setStartIndex(startIndex); K(S/D(\
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} p7er04/}\
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public PaginationSupport(List items, int Fwqf4&/
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totalCount, int pageSize, int startIndex){ 2=EKAg=S
setPageSize(pageSize); Ymom 0g+f
setTotalCount(totalCount); :DJ@HY
setItems(items); _#B/#^a
setStartIndex(startIndex); pM3BBF%
} 2oLa`33c1
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publicList getItems(){ W[s>TDc`v
return items; R3A^VE;qP
} #J_i 5KmXJ
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publicvoid setItems(List items){ @35shLs
this.items = items; ZbUf|#GTB
} 'o L8Z
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publicint getPageSize(){ ri
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return pageSize; g=Di2j{A
} s=4.Ovd\
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publicvoid setPageSize(int pageSize){ {J$aA6t:"T
this.pageSize = pageSize; 3I+pe;
}
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publicint getTotalCount(){ k7*q.2 0
return totalCount; T^_9R;
} HenJlo
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publicvoid setTotalCount(int totalCount){
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if(totalCount > 0){ E3!twR*Aw
this.totalCount = totalCount; "RLb wm~
int count = totalCount / Df (6DuW
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pageSize; 43XuQg4
if(totalCount % pageSize > 0) CggEAi~
count++; Cx[4
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indexes = newint[count]; oWmla*nCKL
for(int i = 0; i < count; i++){ WmA578|l!
indexes = pageSize * jxvVp*-=<j
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} F*f)Dv$p
}else{ *rLs!/[Z_
this.totalCount = 0; Bh?;\D'YC
} JN_#
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} kN)ev?pQ[
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publicint[] getIndexes(){ PW}.`
return indexes; .FU EF)
} 3>+;G4
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publicvoid setIndexes(int[] indexes){ #82B`y<<y/
this.indexes = indexes; D6w0Y:A{.
} `;;!>rm
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publicint getStartIndex(){ Y~R wsx
return startIndex; lK-I[i!
} y.zQ `
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publicvoid setStartIndex(int startIndex){ &>o)7H];
if(totalCount <= 0) gA6C(##0
this.startIndex = 0; #_d%hr~d
elseif(startIndex >= totalCount) @lwqkJ
this.startIndex = indexes #XsqTK_nk
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[indexes.length - 1]; o#i{/#oF
elseif(startIndex < 0) X6)LpMm
this.startIndex = 0; (k?OYz]c
else{ KjadX&JD
this.startIndex = indexes -Q;
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[startIndex / pageSize]; Z(L>~+%
} /?sV\shy
} :|a[6Uwl\V
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publicint getNextIndex(){ /y}
int nextIndex = getStartIndex() + d1-QkW^0y
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pageSize; =["GnL*!0
if(nextIndex >= totalCount) ;>~iCFk]?
return getStartIndex(); .eE5pyw+C
else L-XTIL$$
return nextIndex; WCH>9Z>cj
} 6
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publicint getPreviousIndex(){ /=N`P &R#
int previousIndex = getStartIndex() - ,0~=9dR
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pageSize; &b_duWs
if(previousIndex < 0) bu]bfnYi9
return0; 2h=RNU|
else "ggq7cJ}_
return previousIndex; N$?q Aek
} IoC,\$s,
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} <%5ny!]
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抽象业务类 4h|vd.t
java代码: C<3An_Dy
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/** /O9z-!Jz
* Created on 2005-7-12 QZX+E
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package com.javaeye.common.business; =#W6+=YN8
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import java.io.Serializable; o\N),;LM
import java.util.List; R7#B_^ $
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import org.hibernate.Criteria; s^cHR1^
import org.hibernate.HibernateException; e.[h
import org.hibernate.Session; HxjhP(
import org.hibernate.criterion.DetachedCriteria; JH 8^ZP:d'
import org.hibernate.criterion.Projections; },l3N K
import q N>j2~
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org.springframework.orm.hibernate3.HibernateCallback; ;*8$BuD
import .k}h'nE
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org.springframework.orm.hibernate3.support.HibernateDaoS 7XaRi@uG
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upport; &W1cc#(
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import com.javaeye.common.util.PaginationSupport; =7a9~&|
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public abstract class AbstractManager extends G=DRz F
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HibernateDaoSupport { ,+WDa%R
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privateboolean cacheQueries = false; OmsNo0OA
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privateString queryCacheRegion; 9Z}-%Z[,)
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publicvoid setCacheQueries(boolean 2TdcZ<k}J
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cacheQueries){ A," u~6Bn
this.cacheQueries = cacheQueries; b^0=X!bg
} y:m Xv<g
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publicvoid setQueryCacheRegion(String n;[d{bU
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queryCacheRegion){ U2;_{n*g%
this.queryCacheRegion = 0y*8;7-|r)
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queryCacheRegion; mk}8Cu4
} $%ps:ui~X
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publicvoid save(finalObject entity){ />H9T[3=
getHibernateTemplate().save(entity); H8X{!/,^
} +ps(9O/B>
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publicvoid persist(finalObject entity){ 'vBuQinn
getHibernateTemplate().save(entity); dW6sA65<Y
} 04o(05K
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publicvoid update(finalObject entity){ +Y-Gp4"
getHibernateTemplate().update(entity); T< D&%)
} umI@ej+D
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publicvoid delete(finalObject entity){ b:2#3;)
getHibernateTemplate().delete(entity); Lc=t,=OhGe
} c1Skt
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publicObject load(finalClass entity, W|4:3c4
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finalSerializable id){ 3v\}4)A[
return getHibernateTemplate().load N:_.z~>%
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(entity, id); !ap}+_IA7^
} f["c,,[
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publicObject get(finalClass entity, -V7dSi
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finalSerializable id){ \I( g70
return getHibernateTemplate().get Qu|H_<8g
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(entity, id); #ozui-u>
} 508v:?^'
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publicList findAll(finalClass entity){ %g: 6QS|
return getHibernateTemplate().find("from &.F]-1RN[
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" + entity.getName()); evjj~xkte
} 3?5JY;}h>"
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publicList findByNamedQuery(finalString WUrE1%u
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namedQuery){ ^,}1^?*
return getHibernateTemplate gamE^Ee
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().findByNamedQuery(namedQuery); Ym% XCl
} DaP,3>M
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publicList findByNamedQuery(finalString query, *O_>3Hgl
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finalObject parameter){ Y
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return getHibernateTemplate 6dgwsl~
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().findByNamedQuery(query, parameter); >
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} [n4nnmM
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publicList findByNamedQuery(finalString query, KT[ZOtu
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finalObject[] parameters){ gu|=uW K
return getHibernateTemplate Wn2'uZ5If
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().findByNamedQuery(query, parameters); w p\-LO~
} rU+3~|m
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publicList find(finalString query){ t'1g+g
return getHibernateTemplate().find _ _!LTpp
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(query); (\ge7sE-oo
} ncqAof(/
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publicList find(finalString query, finalObject 4O<sE@X
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parameter){ X$e*s\4
return getHibernateTemplate().find C#-HWoSi
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(query, parameter); ,~ q:rh+
} }yVx"e)
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public PaginationSupport findPageByCriteria O uNPD q%
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(final DetachedCriteria detachedCriteria){ 3\2%i6W6
return findPageByCriteria ~UJ.A<>Fh
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 7Xx3s@
} 3Q'vVNFh<
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public PaginationSupport findPageByCriteria KLvAe>#,
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(final DetachedCriteria detachedCriteria, finalint ;plBo%EBV
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startIndex){ Mgr?D
return findPageByCriteria <rtKPlb//
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(detachedCriteria, PaginationSupport.PAGESIZE, KCO.8=y3
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startIndex); !m^;wkrY
} GF6 o
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public PaginationSupport findPageByCriteria "MU-&**
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(final DetachedCriteria detachedCriteria, finalint &#L C'
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pageSize, ^R=`<jx
finalint startIndex){ ]XU4nNi
return(PaginationSupport) G<M0KU(
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getHibernateTemplate().execute(new HibernateCallback(){ <Y."()}GeH
publicObject doInHibernate =WjHf8v;
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(Session session)throws HibernateException { tPl 4'tW_
Criteria criteria = "]#Ij6ml
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detachedCriteria.getExecutableCriteria(session); -=nk,cYn
int totalCount = 5CZyA`3V^5
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((Integer) criteria.setProjection(Projections.rowCount TKM^
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()).uniqueResult()).intValue(); h~7#$i
criteria.setProjection ~4khIz
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(null); dpTsTU!\
List items = =B9-}]DDO
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criteria.setFirstResult(startIndex).setMaxResults \?;
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(pageSize).list(); ?OLd
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PaginationSupport ps = M2Jf-2
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new PaginationSupport(items, totalCount, pageSize, x>}ml\R
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startIndex); AY{KxCrb^
return ps; iI{L>
} <mQXS87
}, true); db~^Gqv6k
} [
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public List findAllByCriteria(final ]:OrGD"
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DetachedCriteria detachedCriteria){ .26mB
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return(List) getHibernateTemplate S[1<Qrv]
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().execute(new HibernateCallback(){ &1$d`>fn
publicObject doInHibernate l::q
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(Session session)throws HibernateException { C<
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Criteria criteria = )GkJ%o#H2
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detachedCriteria.getExecutableCriteria(session); Ea&|kO|
return criteria.list(); -NXxxK
} rS{}[$Zpl
}, true); 8cG?p
} x"{aO6M
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public int getCountByCriteria(final B+K6(^j,,y
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DetachedCriteria detachedCriteria){ <{isWEW9]3
Integer count = (Integer) I.n,TJoz4J
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getHibernateTemplate().execute(new HibernateCallback(){ ZeP=}0TGjn
publicObject doInHibernate '{"Rjv7
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(Session session)throws HibernateException { .\ ;'>qy
Criteria criteria = 5tYo! f
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detachedCriteria.getExecutableCriteria(session); nF@**,C Q
return 5MVa;m
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criteria.setProjection(Projections.rowCount ,X.[37
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()).uniqueResult(); _~z
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} *4}_2"[
}, true); Co1d44Q
return count.intValue(); VBX)xQazU
} 0~bUW V
} pR61bl)
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用户在web层构造查询条件detachedCriteria,和可选的 g'7E6n"!,
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 gQ_<;'m)2
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PaginationSupport的实例ps。
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ps.getItems()得到已分页好的结果集 *'>_XX
ps.getIndexes()得到分页索引的数组 ubwM*P
ps.getTotalCount()得到总结果数 )[ V8YiyU
ps.getStartIndex()当前分页索引 k =5k)}i
ps.getNextIndex()下一页索引 UzxL" `^7
ps.getPreviousIndex()上一页索引 #*o0n>O
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 2_q/<8t
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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 #AJW-+1g.=
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一下代码重构了。 o701RG~)
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我把原本我的做法也提供出来供大家讨论吧: "w:h
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首先,为了实现分页查询,我封装了一个Page类: )x6&Y
java代码: QP(0
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/*Created on 2005-4-14*/ L/i'6(="
package org.flyware.util.page; 6u, g
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/** =A'>1N
* @author Joa 8 0tA5AP
* bo\ bs1
*/ 3"h*L8No
publicclass Page { p*Z<DEh#
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/** imply if the page has previous page */ Rw?w7?I
privateboolean hasPrePage; t\M6 d6
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/** imply if the page has next page */ C~ &E7w