Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 P&0o~@`cL
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Ug1n4X3FKn
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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 C_~hX 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 R<GnPN:c
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分页支持类: tB i16=
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java代码: B<p -.tv
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package com.javaeye.common.util;
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import java.util.List; NEb M>1>^
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publicclass PaginationSupport { =KctAR;
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publicfinalstaticint PAGESIZE = 30; 7\?0d!
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privateint pageSize = PAGESIZE; BlrZ<\-/
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privateList items; 6|-V{
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privateint totalCount; )=vQrMyB
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privateint[] indexes = newint[0]; bI_T\Eft
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privateint startIndex = 0; AsOkOS3
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public PaginationSupport(List items, int UHh7x%$n
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totalCount){ ,sqxxq
setPageSize(PAGESIZE); #S*`7MvM
setTotalCount(totalCount); ^DWvzfj
setItems(items); ]?#E5(V@x
setStartIndex(0); % >\v6ea
} >&z=ktB
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public PaginationSupport(List items, int t(RJc
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totalCount, int startIndex){ :~Z-K\
setPageSize(PAGESIZE); }CCTz0[D"
setTotalCount(totalCount); H>qw@JiO!
setItems(items); 'Cv>V"X: `
setStartIndex(startIndex); Uf
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} &I|\AG"X}
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public PaginationSupport(List items, int p!OCF]r
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totalCount, int pageSize, int startIndex){ Fzc8) *w
setPageSize(pageSize); 8`{)1.d5[
setTotalCount(totalCount); 'kC,pN{->
setItems(items); N-9Vx#i
setStartIndex(startIndex); Sl!#!FGI
} Ddr.kXIpo
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publicList getItems(){ Sz_{ #-
return items; y_7lSo8<
} QQPT=_P]
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publicvoid setItems(List items){ |K(2_Wp
this.items = items; |g@n'^]
} vo]!IY
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publicint getPageSize(){ R.(fo:ve>
return pageSize; 0,z3A>C
} Biva{'[m
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publicvoid setPageSize(int pageSize){ S#^2k!(|G
this.pageSize = pageSize; L2,.af6+
} c&mLK1A6
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publicint getTotalCount(){ ZR,"w
return totalCount; <?>1eU%
} [B,w\PLub
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publicvoid setTotalCount(int totalCount){ wqnHaWd*
if(totalCount > 0){ 4m:D8&D_M
this.totalCount = totalCount; @CTSvTt$
int count = totalCount / 6/5Xy69:h
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pageSize; X7g@.Oy`
if(totalCount % pageSize > 0) AL;z's(F?
count++; #B!HPlrv
indexes = newint[count]; 'nMj<:0wlD
for(int i = 0; i < count; i++){ 6L!/#d0
indexes = pageSize * \2c3Nsra
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i; Ov-Y.+L:
} Hh1]\4D,4
}else{ F<+!28&h
this.totalCount = 0; [X%Wg:K
} Z^[
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} s 0To^I
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publicint[] getIndexes(){ BI| TM2oa
return indexes; P{K;vEp
} \GD\N=?~
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publicvoid setIndexes(int[] indexes){ .}c&"L;W
this.indexes = indexes; &Yklf?EZ>Q
} i<b-$9
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publicint getStartIndex(){ L[cP2X]NQ
return startIndex; o}p^q:T*
} rHa*WA;TE
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publicvoid setStartIndex(int startIndex){ 11((b
if(totalCount <= 0) qN"Q3mU^h*
this.startIndex = 0; "OO)m](w
elseif(startIndex >= totalCount) jAcrXB*
this.startIndex = indexes A`:a
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[indexes.length - 1]; =o5|W'>`
elseif(startIndex < 0) `PUGg[Zx^
this.startIndex = 0; S
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else{ "}x%5/(
this.startIndex = indexes &~aS24c
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[startIndex / pageSize]; *6bO2LO"
} 5~[m]
} b]b+PK*h
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publicint getNextIndex(){ h5Ee*De
int nextIndex = getStartIndex() + 6Qk[TL)t
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pageSize; DS1{~_>nFu
if(nextIndex >= totalCount) ]SmN}Iq1
return getStartIndex(); Miz?t*|{[
else ;O7Vl5R
return nextIndex; v{X<6^g
} !$hi:3{U,
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publicint getPreviousIndex(){ ij,Rq`}l
int previousIndex = getStartIndex() - 4l`[,BJ
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pageSize; U,K=(I7OBX
if(previousIndex < 0) zd6F}2*6
return0; #U(kK(uO
else `&9iC 4P
return previousIndex; TM5 Y(Q*
} N%F4ug@i
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} 2){O&8 A
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抽象业务类 ~F^tLi!5
java代码: M1icj~Jr
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/** !QpOrg
* Created on 2005-7-12 c'>_JlG~
*/ J&iSS9c
package com.javaeye.common.business; J 5(^VKj
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import java.io.Serializable; "x vizvR
import java.util.List; /J(vqYK"
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import org.hibernate.Criteria; d
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import org.hibernate.HibernateException; !S%0#d2
import org.hibernate.Session; 1F_$[iIX]
import org.hibernate.criterion.DetachedCriteria; ('{aOiSH
import org.hibernate.criterion.Projections; _, E/HAX
import Cs(sar:7
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org.springframework.orm.hibernate3.HibernateCallback; ?;y-skh
import >C19Kie72
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org.springframework.orm.hibernate3.support.HibernateDaoS *7E#=xb
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upport; K iEmvC
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import com.javaeye.common.util.PaginationSupport; Wb>;L@jB7
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public abstract class AbstractManager extends 14"+ctq
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HibernateDaoSupport { i)'tt9f$
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privateboolean cacheQueries = false; J?dLI_{<
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privateString queryCacheRegion; e_|Z&
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publicvoid setCacheQueries(boolean ~8yh,U
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cacheQueries){ 51`&%V{daL
this.cacheQueries = cacheQueries; }h=PW'M{
} T9I$6HAi
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publicvoid setQueryCacheRegion(String t>AOF\
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queryCacheRegion){ 9|lLce$
this.queryCacheRegion = -pIz-*
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queryCacheRegion; ggL/7I(
} ,l6,k<
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publicvoid save(finalObject entity){ 2Kf/I d1
getHibernateTemplate().save(entity); .1q}mw
} hHhDs>tB
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publicvoid persist(finalObject entity){ 'Y#'ozSQv
getHibernateTemplate().save(entity); m$_b\^we
} @lF?+/=$
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publicvoid update(finalObject entity){ *V%"q|L8
getHibernateTemplate().update(entity); (jA5`4>u
} L2,2Sn*4i
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publicvoid delete(finalObject entity){ o0]YDX@T
getHibernateTemplate().delete(entity); nj'5iiV`]
} 5XUm} D$
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publicObject load(finalClass entity, l)vC=V6MG
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finalSerializable id){ L?j0t*do
return getHibernateTemplate().load N.vWZ7l8
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(entity, id); fJ[ ^_,O
} m~5 unB9
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publicObject get(finalClass entity, h/t;ZLUAZP
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finalSerializable id){ XZb=;tYo
return getHibernateTemplate().get o6px1C:
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(entity, id); y\Aa;pL)RQ
} Tc/^h4xH
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publicList findAll(finalClass entity){ -0d9,,c
return getHibernateTemplate().find("from eO <N/?t
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" + entity.getName()); |E7J5ha
} \Q|-Npw
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publicList findByNamedQuery(finalString ]JjS$VMauX
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namedQuery){ J)>DsQ+Cj
return getHibernateTemplate SjB"#E)
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().findByNamedQuery(namedQuery); 1H-Y3G>jN
} a]u.Uqyx2w
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publicList findByNamedQuery(finalString query, <E4(KE
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finalObject parameter){ GIM/ T4!)
return getHibernateTemplate q$:7j5E
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().findByNamedQuery(query, parameter); =G:Krc8w@
} `/PBZnj
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publicList findByNamedQuery(finalString query, ?.SGn[
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finalObject[] parameters){ fWmc$r5n](
return getHibernateTemplate x#EE_i/W
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().findByNamedQuery(query, parameters); ._G,uP$
} ~a([e\~
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publicList find(finalString query){ B?z2@,
return getHibernateTemplate().find >[;W~*
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(query); Mp`$1Ksn
} 4=^_VDlpd
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publicList find(finalString query, finalObject SUc%dpXZa
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parameter){ W#F9Qw
return getHibernateTemplate().find =~+ WJN
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(query, parameter); \jiE:Qt
} !zX()V
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public PaginationSupport findPageByCriteria INN}xZ
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(final DetachedCriteria detachedCriteria){ u}iuf_
return findPageByCriteria 5bLNQz\WJ
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); IEhD5?
} |8k1Bap`z
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public PaginationSupport findPageByCriteria 0SI@`C*1o
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(final DetachedCriteria detachedCriteria, finalint PR@6=[|d
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startIndex){ Iq+N0G<j
return findPageByCriteria Pf[E..HF*d
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(detachedCriteria, PaginationSupport.PAGESIZE, CPOHqK`k
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startIndex); zV&l^.
} \V>5)Rn
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public PaginationSupport findPageByCriteria B]X8KzLu
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(final DetachedCriteria detachedCriteria, finalint w5%Yi{
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pageSize, %zcA|SefP
finalint startIndex){ e(t}$Q=
return(PaginationSupport) 8FuxN2
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getHibernateTemplate().execute(new HibernateCallback(){ %hVR|K|J
publicObject doInHibernate 1[!:|=
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(Session session)throws HibernateException { /.SG? 5t4
Criteria criteria = MKBDWLCB
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detachedCriteria.getExecutableCriteria(session); JXc.?{LL
int totalCount = (GC]=
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((Integer) criteria.setProjection(Projections.rowCount @"7S$@cO
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()).uniqueResult()).intValue(); ?\o~P
criteria.setProjection Xq 135/d
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(null); dbby.%
List items = IXy6Yn9l
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criteria.setFirstResult(startIndex).setMaxResults EOB8|:*
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(pageSize).list(); \|,| )
PaginationSupport ps = yx]9rD1cz
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new PaginationSupport(items, totalCount, pageSize, jYp!?%!
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startIndex); L8`v
return ps; "Vp
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} 0/GBs~P
}, true); 2VN].t:
} hZJ~zx~
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public List findAllByCriteria(final -#ZLu.
*`H*@2
DetachedCriteria detachedCriteria){ pAy4%|(
return(List) getHibernateTemplate @ VWED
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().execute(new HibernateCallback(){ 7P<VtS
publicObject doInHibernate h&'|^;FM
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(Session session)throws HibernateException { Pe@#6N`
Criteria criteria = Y9^l|,bm5
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detachedCriteria.getExecutableCriteria(session); zH]oAu=H
return criteria.list(); e0P[,e*0
} q/b+V)V
}, true); IhNX~Jg'^
} K%J?'-
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public int getCountByCriteria(final vD#U+
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DetachedCriteria detachedCriteria){ l eC!Yj
Integer count = (Integer) R/~!km
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getHibernateTemplate().execute(new HibernateCallback(){ ~[Tcl
publicObject doInHibernate CP7Fe{P
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(Session session)throws HibernateException { 30sJ"hF9
Criteria criteria = QD@O!};
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detachedCriteria.getExecutableCriteria(session); w
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return M{jXo%C
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criteria.setProjection(Projections.rowCount rDWAZ<;;
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()).uniqueResult(); E+ /Nicn=
} tc'iKJ5)
}, true); )V1xL_hx/
return count.intValue(); .
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} @[;'b$T$
} $\u\4n
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用户在web层构造查询条件detachedCriteria,和可选的 zQ=b|p]|W
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 21v--wZ
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PaginationSupport的实例ps。 ?,$:~O*w
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ps.getItems()得到已分页好的结果集 ;KQU%
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ps.getIndexes()得到分页索引的数组 rnK]3Ust
ps.getTotalCount()得到总结果数 Wr[LC&
ps.getStartIndex()当前分页索引 x Q"uC!Gu4
ps.getNextIndex()下一页索引 q1VKoKb6\:
ps.getPreviousIndex()上一页索引 T~xVHk1
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ) f~;P+
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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 OL\-SQ&
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一下代码重构了。 T:Cq}4k<
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我把原本我的做法也提供出来供大家讨论吧: )x!q;^Js9A
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首先,为了实现分页查询,我封装了一个Page类: `/WxEu3
java代码: j/TnKO
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/*Created on 2005-4-14*/ oZ2:%
package org.flyware.util.page; NV./p`k
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/** (3N/DY1/
* @author Joa 5J`w8[;
* %X_A# 9
*/ '
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publicclass Page { zYaFbNi
Qb^{`
/** imply if the page has previous page */
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privateboolean hasPrePage; m@<,bZkl
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/** imply if the page has next page */ yq.@-]ytZ
privateboolean hasNextPage; K["rr/
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/** the number of every page */ )L&y@dy)
privateint everyPage; w
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/** the total page number */ 4]1/{</B|
privateint totalPage; 6?,qysm06
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/** the number of current page */ |4DN2P
privateint currentPage; N@PuC>
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/** the begin index of the records by the current FtJaX])b
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query */ D<v<
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privateint beginIndex; :'r*
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/** The default constructor */ iJOoO"Ai
public Page(){ l8E))oz1T
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} %rB,Gl:)g
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/** construct the page by everyPage r~=+>,
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* @param everyPage 4(,.<#
* */ GQg
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public Page(int everyPage){ DvhFCA}z
this.everyPage = everyPage; 1[OY -G
} MVMJl ">
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/** The whole constructor */ +m
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public Page(boolean hasPrePage, boolean hasNextPage,
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int everyPage, int totalPage, MNU7OX<
int currentPage, int beginIndex){ pej-W/R&
this.hasPrePage = hasPrePage; (f"Qz~R|6_
this.hasNextPage = hasNextPage; !l dE9 .
this.everyPage = everyPage; ~98q1HgS]D
this.totalPage = totalPage; #U0| j?!D
this.currentPage = currentPage; T.De1Q|
this.beginIndex = beginIndex; ~7aD#`amU
} ;nh_L(
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/** 4+qo=i
* @return &K!0yR
* Returns the beginIndex. .+2:~%v6
*/ 4grV2xtX
publicint getBeginIndex(){ <O)
if^
return beginIndex; L]=mQo
} s
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/** Wv3p!zW3I
* @param beginIndex n<EIu
* The beginIndex to set. Af]BR_-
*/ l
publicvoid setBeginIndex(int beginIndex){ FM3.z)>
this.beginIndex = beginIndex; 0<A*I{,4L
} fC"?r6d
<> HI(6\@Z
/** D0\*WK$
* @return 7.{+8#~nV
* Returns the currentPage. zKk=R6w
*/ @0:Eg 1-
publicint getCurrentPage(){ Gf7r!Ur;g
return currentPage; cgcU2N6y;
} q%s<y+
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/** `j2|aX
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* @param currentPage 9u^za!pE
* The currentPage to set. % T$!I (L&
*/ )fuAdG
publicvoid setCurrentPage(int currentPage){ 4,`t9f^:
this.currentPage = currentPage; j0cB#M44
} +IGSOWL
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/** (=%0x"'
* @return s7`2ky()kz
* Returns the everyPage. _B&;z $
*/ n Fwg pT
publicint getEveryPage(){ @gx]3t*]I
return everyPage; UZJs!#P
} m2%
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/** gf;B&MM6
* @param everyPage pmUC4=&e
* The everyPage to set. ],<pZ1V;
*/ {- &wV
publicvoid setEveryPage(int everyPage){ 93)1
this.everyPage = everyPage; VyIM ,glu
} /z1-4:^`A[
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/** KWVl7Kw#e
* @return -<\hcV`&
* Returns the hasNextPage. LqQ&4I
*/ V'N]u(^
publicboolean getHasNextPage(){ \ 0F
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return hasNextPage; MR":aT
} [r1\FF@v,
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/** EzU=q
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* @param hasNextPage {us#(4O
* The hasNextPage to set. N,ihQB5
*/ Xj6?,J
publicvoid setHasNextPage(boolean hasNextPage){ b9l%5a
this.hasNextPage = hasNextPage; G{'`L)~3N
} NW*$+u%/R
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/** h],l`lT1\
* @return F`f8q\Fc
* Returns the hasPrePage. rV/! VJ6x
*/ %\!3tN
publicboolean getHasPrePage(){ 4:s!mHcz
return hasPrePage; w2]]##J
} Kb#Z(C9
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/** O1z3(
* @param hasPrePage $gcC}tX
* The hasPrePage to set. d/I*$UC
*/ lDtl6r/
publicvoid setHasPrePage(boolean hasPrePage){ k
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this.hasPrePage = hasPrePage; X_J(P?
} R` >z>!)
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/** II}3w#r4
* @return Returns the totalPage. ujoJ6UOG
* F@@6D0\X?
*/ @O&; %IZMY
publicint getTotalPage(){ MryY<s
return totalPage; 5tu 4uYp;
} !L55S03
ty)~]!tA
/** ]n&Eb88
* @param totalPage ,g bQqoLV
* The totalPage to set. Q\GSX RP
*/ lZhd^69y
publicvoid setTotalPage(int totalPage){ A}(Q^|6
this.totalPage = totalPage; \9jvQV/y
} uY$BZEuAZ
rTYMN
} ^yVKW5x
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8\_ YP3
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 ~e<h2/Xc
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个PageUtil,负责对Page对象进行构造: QMWDII&t
java代码: 4A~1Z,"%v(
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LHgEb9\Q
/*Created on 2005-4-14*/ nv2p&-e+
package org.flyware.util.page; Y.v. EZ
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import org.apache.commons.logging.Log; .l ufE
import org.apache.commons.logging.LogFactory; e"ur+7
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/** ;UDd4@3`S"
* @author Joa KMogwulG
* ?CUGJT
*/ Tn 3<cO7v
publicclass PageUtil { 4ROuy+Ms'
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privatestaticfinal Log logger = LogFactory.getLog f"g-Hbl5
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(PageUtil.class); DE _<LN
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/** KO5! (vi@
* Use the origin page to create a new page
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* @param page Dt\rMSjZ9
* @param totalRecords &3%V%_
* @return Ym5ji$!2
*/ cfA)Ui
publicstatic Page createPage(Page page, int /D&7 \3}
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totalRecords){ s\A4y "
return createPage(page.getEveryPage(), |?/,ED+|>D
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page.getCurrentPage(), totalRecords); 0mD=Rjb*a
} N9=1<{Z
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/** X|Z2"*;b`
* the basic page utils not including exception q7ubRak
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handler , UiA?7k
* @param everyPage 0s'H(qE,_
* @param currentPage ( !=^ (Nd
* @param totalRecords yEB1gYJB
* @return page rwSmdJ~
*/ hk.Zn.6A'
publicstatic Page createPage(int everyPage, int Ir :y#
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currentPage, int totalRecords){ T?Y/0znB*
everyPage = getEveryPage(everyPage); 95%QF;h
currentPage = getCurrentPage(currentPage); }{(J*T
int beginIndex = getBeginIndex(everyPage, +JrbC/&
(n0h#%
currentPage); ;;? Zd
int totalPage = getTotalPage(everyPage, .*W_;F o
S@[B?sNj
totalRecords); 6
r}R%{
boolean hasNextPage = hasNextPage(currentPage, \4 5%K|
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totalPage); )CM3vL {
boolean hasPrePage = hasPrePage(currentPage); 5`H.{4@
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returnnew Page(hasPrePage, hasNextPage, bIP%xl
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everyPage, totalPage, $:D-dUr1
currentPage, rI.CCPY~s
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beginIndex); 0JS#{EDh+
} Gbrc!3K2
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privatestaticint getEveryPage(int everyPage){ E\lel4ai
return everyPage == 0 ? 10 : everyPage; b]cnTR2E
} Z/~7N9?m(
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privatestaticint getCurrentPage(int currentPage){ 7;x}W-`iF
return currentPage == 0 ? 1 : currentPage; w_h}c$;GK
} CPt62j8
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privatestaticint getBeginIndex(int everyPage, int $zv&MD!&h
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currentPage){ 0AWOdd>.
return(currentPage - 1) * everyPage; rIJv(&l
} :j}4F
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privatestaticint getTotalPage(int everyPage, int czu?]9;^
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totalRecords){
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int totalPage = 0; #$;i 4a
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if(totalRecords % everyPage == 0)
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totalPage = totalRecords / everyPage; CS|al(?~
else %|\Af>o4d
totalPage = totalRecords / everyPage + 1 ; `<x((@#
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return totalPage; $9}jU#Z|hd
} {sb2r%U!+
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privatestaticboolean hasPrePage(int currentPage){ 7x5wT ?2W
return currentPage == 1 ? false : true; JNk6:j&Pf
} *iwVB^^$
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privatestaticboolean hasNextPage(int currentPage,
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int totalPage){ tS:/:0HnA)
return currentPage == totalPage || totalPage == ,!7\?=G6}v
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0 ? false : true; +pG[
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} v_L2>Pa.
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} 3<R8_p
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 |zCT~#
4157!w'\y
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 U *K6FWqiB
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做法如下: >Sc/E}3
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 AJ"a
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的信息,和一个结果集List: 7GG:1:2+>
java代码: Xdl7'~k
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/*Created on 2005-6-13*/ rJKac"{
package com.adt.bo; *VV#o/Qp
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import java.util.List; #ni:Bwtl{
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import org.flyware.util.page.Page; ] =*G[
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/** U!O"f
* @author Joa K'\Jnn
*/ R>T9 H0
publicclass Result { CAa&,ZR
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