Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 7b+OIZB
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 dadOjl)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 /T#<g:
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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 6i.'S5.
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分页支持类: ^+`vh0TPQ
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java代码: ,Lv}Xku
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package com.javaeye.common.util;
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import java.util.List; yl 0?Y
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publicclass PaginationSupport { O b8[P=
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publicfinalstaticint PAGESIZE = 30; m*i~Vjxj-m
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privateint pageSize = PAGESIZE; =v:_N.Fh-c
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privateList items; W**=X\"'
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privateint totalCount; q/;mxq$
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privateint[] indexes = newint[0]; .&sguAyG
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privateint startIndex = 0; *uEU9fX
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public PaginationSupport(List items, int `b\4h/~
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totalCount){ Ne^#5 T
setPageSize(PAGESIZE); jb7=1OPD_
setTotalCount(totalCount); 'Fonn
setItems(items); e3S6+H),I
setStartIndex(0); ++dV5
} ]G1j\ wnF
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public PaginationSupport(List items, int HhqqJEp0
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totalCount, int startIndex){ dtF6IdAf
setPageSize(PAGESIZE); @%#(Hse
setTotalCount(totalCount); kk~{2
setItems(items); >,] #~d
setStartIndex(startIndex); dtg Ja_
} PU'v o4
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public PaginationSupport(List items, int Gi<f/xQk>
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totalCount, int pageSize, int startIndex){ dt5gQ9(B
setPageSize(pageSize); wSAm[.1i
setTotalCount(totalCount); Xrz0ch
setItems(items); ADR`j;2
setStartIndex(startIndex); [")0{LSA=
} =pk'a_P8-
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publicList getItems(){ y.O? c&!
return items; A%GJ|h,i
} PH7L#H^
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publicvoid setItems(List items){ s]I],>}RU
this.items = items; 3R{-\ZMd
} mdZELRu
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publicint getPageSize(){ #-@{ rgH
return pageSize; ;8T<L[ ^U
} .1pEq~>
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publicvoid setPageSize(int pageSize){ $<aBawLZO
this.pageSize = pageSize; "|Pl(HX
} /C(L(X
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publicint getTotalCount(){ a 6 ]!4
return totalCount; sW]n~kTt'
} N!m%~},s//
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publicvoid setTotalCount(int totalCount){ r[,KE.^6~#
if(totalCount > 0){ @"~\[z5
this.totalCount = totalCount; G`
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int count = totalCount / m_Rgv.gE^
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pageSize; y&CUT:M6
if(totalCount % pageSize > 0) E$1^}RGT)
count++; 9:Y:Vx
indexes = newint[count]; jqLyX
for(int i = 0; i < count; i++){ cr/|dc'
indexes = pageSize * H 0h
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} >ciq4H43Q|
}else{ [qXpi'q[
this.totalCount = 0; 7'8O*EoB'
} -m@s
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publicint[] getIndexes(){ x)?\g{JH
return indexes; ms{R|vU%b
} +/X'QB$R
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publicvoid setIndexes(int[] indexes){ e"2QV vB
this.indexes = indexes; c[YjGx
} zm"\D
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publicint getStartIndex(){ Ya_6Zd4O
return startIndex; roA1=G\Q
} .( J/*H
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publicvoid setStartIndex(int startIndex){ g}D$`Nx:
if(totalCount <= 0) K@i*Nl
this.startIndex = 0; 0l##M06>
elseif(startIndex >= totalCount) 7^iAc6QSy3
this.startIndex = indexes *Q>:|F[vM
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[indexes.length - 1]; 6+FON$8
elseif(startIndex < 0) b1#=q0Zl
this.startIndex = 0; t#q>U%!
else{ J#kdyBmuO
this.startIndex = indexes w*
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[startIndex / pageSize]; ZX0c_Mk=
}
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} 3dbf!
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publicint getNextIndex(){ gfYB|VyWo
int nextIndex = getStartIndex() + 3/AUV%+
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pageSize; v<SEGv-
if(nextIndex >= totalCount) !lF^~x
return getStartIndex(); 8F*
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else s]N-n?'G"
return nextIndex; f+920/>!Z
} e!yw"Cf*
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publicint getPreviousIndex(){
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int previousIndex = getStartIndex() - {H V,2-z
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pageSize; q?L(V+X
if(previousIndex < 0) _);Kb/
return0; ?~.&Y
else J7GsNFL
return previousIndex; fYy.>m+P1
} 6\;1<Sw*
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} \zU5G#LQ
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抽象业务类 [MS.5+1Y
java代码: !j9i=YDb
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/** \NU[DHrMP
* Created on 2005-7-12 l;A_Aii(
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package com.javaeye.common.business; 3.X0!M;x
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import java.io.Serializable; YSo7~^1W"
import java.util.List; qD*\}b]9I
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import org.hibernate.Criteria; 4P!DrOB
import org.hibernate.HibernateException; df*#?Ok
import org.hibernate.Session; .4> s2
import org.hibernate.criterion.DetachedCriteria; TEyx((SK
import org.hibernate.criterion.Projections; }G+A_HF ^
import 5Kj4!Ai
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org.springframework.orm.hibernate3.HibernateCallback; ATM:As:<@
import ^~qs-.?
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org.springframework.orm.hibernate3.support.HibernateDaoS X3{1DY3@u
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upport; U!:!]DX(
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import com.javaeye.common.util.PaginationSupport; _M[[vXH
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public abstract class AbstractManager extends %D(prA_w
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HibernateDaoSupport { ;-pvc<_c<
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privateboolean cacheQueries = false; qYZ7Zt;
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privateString queryCacheRegion; F9P0cGDs
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publicvoid setCacheQueries(boolean yVHlT
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cacheQueries){ %K'*P56
this.cacheQueries = cacheQueries; m}[~A@qD
} N5s|a5
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publicvoid setQueryCacheRegion(String i
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queryCacheRegion){ 7.
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this.queryCacheRegion = ynZ[c8.
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queryCacheRegion; eH%L?"J~:
} H!r
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publicvoid save(finalObject entity){ BrH;(*H)8
getHibernateTemplate().save(entity); I.+)sB?5
} ESxC{
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publicvoid persist(finalObject entity){ Di<J6xu
getHibernateTemplate().save(entity);
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} r@[VY g~
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publicvoid update(finalObject entity){ 0*Km}?;0-
getHibernateTemplate().update(entity); #VdI{IbW
} M=[q+A
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publicvoid delete(finalObject entity){ 7s8<FyFsjd
getHibernateTemplate().delete(entity); fE%[j?[
} 0uIV6LI
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publicObject load(finalClass entity, i\Pr3
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finalSerializable id){ 9MB\z"b?A
return getHibernateTemplate().load 6+$d
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(entity, id); 40Qzo%eL
} OKZam ik~
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publicObject get(finalClass entity, m-'(27
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finalSerializable id){ #i +P(xV
return getHibernateTemplate().get Qw<kX*fxrI
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(entity, id); K\KO5A
} N=Uc=I7C
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publicList findAll(finalClass entity){ h76NR
return getHibernateTemplate().find("from \'??
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" + entity.getName()); LPapD@Z
} t}XB|h
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publicList findByNamedQuery(finalString we\b]
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namedQuery){ %<wQ
return getHibernateTemplate u3M`'YCb
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().findByNamedQuery(namedQuery); zY+t ,2z
} WAwfL?
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publicList findByNamedQuery(finalString query, y'_V/w s
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finalObject parameter){ S< EB&P
return getHibernateTemplate 7~kpRa@\P
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().findByNamedQuery(query, parameter); J-, H6u
} hsHVX[<5`
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publicList findByNamedQuery(finalString query, vLnq%@x
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finalObject[] parameters){ R0Ax$Cv{
return getHibernateTemplate vbRrk($`
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().findByNamedQuery(query, parameters); POqRHuFq
} IqhICC1V-
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publicList find(finalString query){ I~p8#<4#b
return getHibernateTemplate().find ']d!?>C@o
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(query); ,bZ"8Z"lss
} kyW6S+ #-
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publicList find(finalString query, finalObject JCw{ ?^F"
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parameter){ z:Xj_ `p
return getHibernateTemplate().find Y<p zy8z
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(query, parameter); ~vW)1XnK
} :DZLjC
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public PaginationSupport findPageByCriteria LPEjRG,
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(final DetachedCriteria detachedCriteria){ Bii6Z@kS
return findPageByCriteria 8_xnWMOe
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); u^`eKak"l
} OJMvn'y
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public PaginationSupport findPageByCriteria d^KBIz8$5l
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(final DetachedCriteria detachedCriteria, finalint G_V.H\w
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startIndex){ uz*d^gr}
return findPageByCriteria kRmj"9oA
~?FK ; (
(detachedCriteria, PaginationSupport.PAGESIZE, )-0[ra]
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startIndex); ' 2>l
} 84iJ[Fq{
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public PaginationSupport findPageByCriteria 0Vf)Rw1%I
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(final DetachedCriteria detachedCriteria, finalint ~_ *H)|
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pageSize, %lXbCE:[
finalint startIndex){ 7<^'DOs
return(PaginationSupport) FQ+8J 7
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getHibernateTemplate().execute(new HibernateCallback(){ Hab!qWK`
publicObject doInHibernate /wr6\53J
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(Session session)throws HibernateException { [!^cd%l
Criteria criteria = g<fP:/
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detachedCriteria.getExecutableCriteria(session); !d\t:0;
int totalCount =
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((Integer) criteria.setProjection(Projections.rowCount GOGt?iw*<
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()).uniqueResult()).intValue(); |,3l`o
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criteria.setProjection ~
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(null); 6{Ks`Af
List items = +i+tp8T+7
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criteria.setFirstResult(startIndex).setMaxResults J=):+F=
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(pageSize).list(); Y:wF5pp;
PaginationSupport ps = QeL{Wa-2F
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new PaginationSupport(items, totalCount, pageSize, )`<6taKx@n
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startIndex); e[}],W
return ps; i-,'.w
} Q? qjWZY
}, true); <^Nk.E
} lcCJ?!lsSW
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public List findAllByCriteria(final Yc
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DetachedCriteria detachedCriteria){ )=Zsv40O
return(List) getHibernateTemplate YwXXXh
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().execute(new HibernateCallback(){ !_dR'
publicObject doInHibernate 9\>sDSCx
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(Session session)throws HibernateException { QF.3c6O@
Criteria criteria = _W |R;Cz]
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detachedCriteria.getExecutableCriteria(session); 9^!wUwB
return criteria.list(); ,%Z&*n
} s@s/'^`
}, true); P_}/#N{C
} y@`~ 9$
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public int getCountByCriteria(final UWw}!1
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DetachedCriteria detachedCriteria){ >t0%?wj)Y
Integer count = (Integer) @zrNN>
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getHibernateTemplate().execute(new HibernateCallback(){ a.DX%C/5
publicObject doInHibernate [sj VRW-
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(Session session)throws HibernateException { /l6\^Xf{
Criteria criteria = H_Os4}
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detachedCriteria.getExecutableCriteria(session); $/paEn"
return _88QgThb
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criteria.setProjection(Projections.rowCount 8R}K?+]
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()).uniqueResult(); V&[eSVY?
} f05=Mc&)
}, true); x'qWM/
return count.intValue(); z]$>+MH_
} ?'wsIH]m
} [4XC#OgA
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用户在web层构造查询条件detachedCriteria,和可选的 e\9g->DUs
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 EZib1g&:R/
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PaginationSupport的实例ps。 !)c=1EX]"
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ps.getItems()得到已分页好的结果集 .45^=2NGmQ
ps.getIndexes()得到分页索引的数组 +j[`,5oS
ps.getTotalCount()得到总结果数 :Q-oV8t{
ps.getStartIndex()当前分页索引 d0
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ps.getNextIndex()下一页索引 HH8;J66I&
ps.getPreviousIndex()上一页索引 etyCrQ
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 TJOvyz`t
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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 S;=_;&68?
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一下代码重构了。 =j~Q/-`EC0
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我把原本我的做法也提供出来供大家讨论吧: +O+<Go@a
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首先,为了实现分页查询,我封装了一个Page类: Au5rR>W
java代码: 6peyh_
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/*Created on 2005-4-14*/ O?ktWHUx
package org.flyware.util.page; =& -[TPW
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/** zZ=$O-&%
* @author Joa T'1gy}
* `FJ|W6%
*/ {Q~7M$
publicclass Page { Hm9<