Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ~
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根
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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 Ck"db30.
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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 >lzXyT6x8
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分页支持类: nLv~)IQ}:
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java代码: cx&\oP
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package com.javaeye.common.util; 8ZM#.yBB
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import java.util.List; SBDGms
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publicclass PaginationSupport { _G'A]O/BZD
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publicfinalstaticint PAGESIZE = 30; eO*s,*
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privateint pageSize = PAGESIZE; F[!%,-*
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privateList items; NJ-Ji> w
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privateint totalCount; U,61 3G
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privateint[] indexes = newint[0]; -/0\_zq7
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privateint startIndex = 0; bqp^\yu-E
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public PaginationSupport(List items, int $|3zsi2
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totalCount){ 6-)WXJ@V
setPageSize(PAGESIZE); TJZ~Rpq
setTotalCount(totalCount); ]*lZFP~
setItems(items); [6_.Y*}N
setStartIndex(0); .P")S|
} mU?~s7
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public PaginationSupport(List items, int 7DoU7I\u
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totalCount, int startIndex){ WVOj;c
setPageSize(PAGESIZE); %iEdU V\$
setTotalCount(totalCount); NqNU:_}
setItems(items); ~1twGG_;
setStartIndex(startIndex); }HmkTk
} P3Lsfi.
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public PaginationSupport(List items, int vTK8t:JQ~
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totalCount, int pageSize, int startIndex){ V@b7$z
setPageSize(pageSize); H^@Hco>|
setTotalCount(totalCount); H-v[ShE
setItems(items); %Q &']
setStartIndex(startIndex); F'|e:h
} ?CC.xE
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publicList getItems(){ V+@ }dJS
return items; ,Tegrz&G
} y"'p#j
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publicvoid setItems(List items){ [)GRP
this.items = items; -$0}rfX
} ?~t5>PEonv
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publicint getPageSize(){ _5~|z$GW
return pageSize; K@g
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} ?*+U[*M
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publicvoid setPageSize(int pageSize){ J@E]Fl
this.pageSize = pageSize;
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} fHEIys,{
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publicint getTotalCount(){ "c]9Q%
return totalCount; {k-_+#W"
} GA[D@Wy
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publicvoid setTotalCount(int totalCount){ /HhA2 (g%
if(totalCount > 0){ fKqr$59>
this.totalCount = totalCount;
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int count = totalCount / p5vQ.Ni*\-
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pageSize; Us'JMZ~
if(totalCount % pageSize > 0) &oB*gGRw=7
count++; xR&:]M[Vg
indexes = newint[count]; 26nwUNak
for(int i = 0; i < count; i++){ N0kCdJv
indexes = pageSize * )j~{P
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i; t,8?Tf+i
} "#7Q}d!x
}else{ f77W{T4
this.totalCount = 0; L/-SWid)
} ol/@)k^s>
} nAl
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publicint[] getIndexes(){ +pYwc0~
return indexes; hp(MKfh H
} ,\P|%yv
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publicvoid setIndexes(int[] indexes){ YjTr49Af0
this.indexes = indexes; U,v`md@PX
} |UWIV
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publicint getStartIndex(){ /*Q3=Dse]
return startIndex; X=)L$Kd7
} *<:X3|3E
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publicvoid setStartIndex(int startIndex){ <ml?DXT
if(totalCount <= 0) N~CQh=<
this.startIndex = 0; |^UQVNJ
elseif(startIndex >= totalCount) )^s>2 1
this.startIndex = indexes ;7?oJH;
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[indexes.length - 1]; wZ\93W-}
elseif(startIndex < 0) X;6;v]
this.startIndex = 0; #xu1
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else{ =0Y0o_
this.startIndex = indexes UR_Ty59
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[startIndex / pageSize]; ^"
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} mIYKzu_k=
} OhCdBO
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publicint getNextIndex(){ [|eIax xR,
int nextIndex = getStartIndex() + XdV>6<gf{
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pageSize; yLfyLyO L
if(nextIndex >= totalCount) E Zf|>^N
return getStartIndex(); 9D=X3{be#
else |mn} wNUN]
return nextIndex; ri59LY y=
} ">t^jt{
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publicint getPreviousIndex(){ T3
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int previousIndex = getStartIndex() - ,"#nJC
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pageSize; )z74,n7-
if(previousIndex < 0) 4vG-d)"M2
return0; O4oN)
else 'R+^+urq^
return previousIndex; VpHwc!APq
} DGCvH)Q
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} e#h&Xa
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抽象业务类 i_AD3Jrs
java代码: Y96<c" t
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/** AU`z.Isf
* Created on 2005-7-12 E8sM`2z5
*/ I
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package com.javaeye.common.business; T|S-?X,
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import java.io.Serializable; ,#,K_oz
import java.util.List; ?87\_wL/j
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import org.hibernate.Criteria; p7`9
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import org.hibernate.HibernateException; _/>I-\xWA
import org.hibernate.Session; &0Y
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import org.hibernate.criterion.DetachedCriteria; a-,*iK{_u
import org.hibernate.criterion.Projections; -YQS\@?
import ;k#_/c
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org.springframework.orm.hibernate3.HibernateCallback; @Nh}^D >j
import CUpRtE8@[_
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org.springframework.orm.hibernate3.support.HibernateDaoS &XCd2
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upport; U
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import com.javaeye.common.util.PaginationSupport; dba_(I~y
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public abstract class AbstractManager extends 6q>iPK Jt
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HibernateDaoSupport { !*&5O~dfN
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privateboolean cacheQueries = false; |#cqxr "
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privateString queryCacheRegion; g_l-@
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publicvoid setCacheQueries(boolean *:
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cacheQueries){ RXAE
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this.cacheQueries = cacheQueries; Z*q&^/N
} @]~.-(IMh
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publicvoid setQueryCacheRegion(String X!z-J>
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queryCacheRegion){ 3)=ix. wW
this.queryCacheRegion = |-/@3gPO
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queryCacheRegion; )^qXjF
} Z D"*fr
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publicvoid save(finalObject entity){
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getHibernateTemplate().save(entity); @YaI5> ,/
} pd: YR;
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publicvoid persist(finalObject entity){ ol_\ "
getHibernateTemplate().save(entity); !WlL RkwO
} 9$X" D
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publicvoid update(finalObject entity){ Sb2_&5
getHibernateTemplate().update(entity); T^7}Qs9
}
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publicvoid delete(finalObject entity){ .c<U5/
getHibernateTemplate().delete(entity); R1Rk00Ow:
} _/P;`@
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publicObject load(finalClass entity, V[WZ#u-p
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finalSerializable id){ S\I+UeFkf
return getHibernateTemplate().load 4PS|
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(entity, id); 8kU(>' ^_:
} l>
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publicObject get(finalClass entity, n9&fH
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finalSerializable id){ &*O'qOO<2
return getHibernateTemplate().get GcO:!b*YMp
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(entity, id); .7Qqs=Au
} pQ7elv]
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publicList findAll(finalClass entity){ OC,yL Q
return getHibernateTemplate().find("from 4n(w{W>
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" + entity.getName()); 45%D^~2~F
} B!)9
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publicList findByNamedQuery(finalString h'G
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namedQuery){ IR2Qc6+{
return getHibernateTemplate @0H0!9'
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().findByNamedQuery(namedQuery); dQp>z%L)
} vzSjfv
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publicList findByNamedQuery(finalString query, bY,dWNS:
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finalObject parameter){ oTb42a_j{
return getHibernateTemplate _N|AI"sj.
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().findByNamedQuery(query, parameter); 8?<J,zu@AV
} zJ1M$U
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publicList findByNamedQuery(finalString query, D2o|.e<r
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finalObject[] parameters){ ]-X\n
return getHibernateTemplate 5\JV }
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().findByNamedQuery(query, parameters); "k"+qR`fH
} /s(PFN8#Y
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publicList find(finalString query){ d= vD Pf
return getHibernateTemplate().find v=dN$B5y3
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(query); K'"s9b8
} Mjl,/-0 w
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publicList find(finalString query, finalObject =7: }/&
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parameter){ %Y|AXxR
return getHibernateTemplate().find ~% ]V,-4
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(query, parameter); j[$+DCO#|m
} b=W kRj
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public PaginationSupport findPageByCriteria Ew{N2
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(final DetachedCriteria detachedCriteria){ +Ezl.O@z
return findPageByCriteria I%j]p Y4
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); v=uQ8_0~N
} X^m@*,[s
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public PaginationSupport findPageByCriteria L5&,sJz
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(final DetachedCriteria detachedCriteria, finalint .OW5R*
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startIndex){ Mj19;nc0I
return findPageByCriteria #:MoZw`rlw
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(detachedCriteria, PaginationSupport.PAGESIZE, iztF
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startIndex); m<MN.R7
} b3GTsX\2|
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public PaginationSupport findPageByCriteria ^b.fci{1m
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(final DetachedCriteria detachedCriteria, finalint 9(Kff nE^
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pageSize, <P Vmr2Jp"
finalint startIndex){ q}g0-Da
return(PaginationSupport) VF7H0XR/k5
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getHibernateTemplate().execute(new HibernateCallback(){ `"iPJw14
publicObject doInHibernate qX[C%
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(Session session)throws HibernateException { jM'Fb.>~
Criteria criteria = D2:ShyYAS
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detachedCriteria.getExecutableCriteria(session); 3VQmo\li
int totalCount = oye/tEMG
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((Integer) criteria.setProjection(Projections.rowCount Z\)P|#L$
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()).uniqueResult()).intValue(); _B}QS"A
criteria.setProjection oJ=u
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(null); GL&rT&
List items = p1ER<_fp
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criteria.setFirstResult(startIndex).setMaxResults "KY]2v.
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(pageSize).list(); <&t[E0mU
PaginationSupport ps = bXHtw}n
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new PaginationSupport(items, totalCount, pageSize, 1<M~#
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startIndex); z7*mT}Q
return ps; \]L ha
} ,#.^2O9-^
}, true); 3ZYrNul"
} rN {5^+w
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public List findAllByCriteria(final :\1vy5 _
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DetachedCriteria detachedCriteria){ -r{]9v2j
return(List) getHibernateTemplate lWU? R
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().execute(new HibernateCallback(){ \FyHIs
publicObject doInHibernate 3\P/4GK)
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(Session session)throws HibernateException { ".fnx8v,
Criteria criteria = C2
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detachedCriteria.getExecutableCriteria(session); -n$hm+S
return criteria.list(); 7q^a@5f BG
} xSjs+Y;Mu
}, true); sQY0Xys<4
} Bq\WG=Fd
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public int getCountByCriteria(final jATN):8W
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DetachedCriteria detachedCriteria){ s3 gT6
Integer count = (Integer) MXY!N/
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getHibernateTemplate().execute(new HibernateCallback(){ )$FwB6^
publicObject doInHibernate a^9}ceu?
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(Session session)throws HibernateException { 5CM]-qbf@
Criteria criteria = *IC9))PGJ
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detachedCriteria.getExecutableCriteria(session); eZRu{`AF*
return ]P(_
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criteria.setProjection(Projections.rowCount =)XC"kUp
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()).uniqueResult(); e%&/K7I "?
}
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}, true); km!jxs
return count.intValue(); XiUae{j`
} Y!nE65
} ?bK^IHh
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用户在web层构造查询条件detachedCriteria,和可选的 Yf,U2A\
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ]W 6!Xw)[
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PaginationSupport的实例ps。 L(eLxw e%
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ps.getItems()得到已分页好的结果集 go$zi5{h#
ps.getIndexes()得到分页索引的数组 keWqL]
ps.getTotalCount()得到总结果数 6N'v`p8
ps.getStartIndex()当前分页索引 '\.fG\xD
ps.getNextIndex()下一页索引 ,XNz.+Ov
ps.getPreviousIndex()上一页索引 ey>V^Fj
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ^X/[x]UOT@
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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 'm,3znX!c
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一下代码重构了。 6{p]cr
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我把原本我的做法也提供出来供大家讨论吧: Jx8?x#}
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首先,为了实现分页查询,我封装了一个Page类: }&OgI