Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 G_(ct5:_"!
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 q+%!<]7X
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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 b1)\Zi
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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 7d9Z/J@>
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分页支持类: !NA`g7'
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java代码: .vaJ Avg
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package com.javaeye.common.util; C P&o%Uc*
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import java.util.List; 9b%j.Q-W
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publicclass PaginationSupport { A:)sg!Lt
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publicfinalstaticint PAGESIZE = 30; JMePI%#8
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privateint pageSize = PAGESIZE; e^WqJ7j
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privateList items; ' &N20w
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privateint totalCount; KBj@V6Q
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privateint[] indexes = newint[0]; |*1xrM:v~
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privateint startIndex = 0; >#?iO]).
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public PaginationSupport(List items, int niAZ$w
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totalCount){ #G~wE*VR$
setPageSize(PAGESIZE); RNe9h lr
setTotalCount(totalCount); vX 1W@s
setItems(items); Ys%'#f
setStartIndex(0); t%HI1eO7h
} FE}s#n_Pd
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public PaginationSupport(List items, int !mae^A1
]_\AHnJ
totalCount, int startIndex){ q|Fjm]AF
setPageSize(PAGESIZE); L6xB`E9
setTotalCount(totalCount); AoU_;B\b%
setItems(items); J@gm@ jLc
setStartIndex(startIndex); K4Y'B
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} $E @ouX?
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public PaginationSupport(List items, int (gDQ\t@3-
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totalCount, int pageSize, int startIndex){
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setPageSize(pageSize); r;'i<t{P
setTotalCount(totalCount); 6"%@L{UQ
setItems(items); Z,SY
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setStartIndex(startIndex); (H2ylMpQt
} GI?PGAT
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publicList getItems(){ LS{bg.e
return items; 0W_mCV
} X*)?LxTj
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publicvoid setItems(List items){ {=qEBbM
this.items = items; [bsXF#
} wePI*."]
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publicint getPageSize(){ |SxMN%M!
return pageSize; %fBP:5%K
} ]d^k4 d
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publicvoid setPageSize(int pageSize){ G LoiH#R
this.pageSize = pageSize; {wHvE4F2
} 2+o! o
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publicint getTotalCount(){ {N"*olx
return totalCount; B_!wutV@
} 9QC< E|
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publicvoid setTotalCount(int totalCount){ x
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if(totalCount > 0){ =pyVn_dg
this.totalCount = totalCount; CX]RtV!
int count = totalCount / *!i,?vn
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pageSize;
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if(totalCount % pageSize > 0) 4`$5
_}
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count++; O/(3 87= U
indexes = newint[count]; k{_1r;
for(int i = 0; i < count; i++){ 0u>yT?jP
indexes = pageSize * +)?, {eE|
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i; Qg[heND
} b$dBV}0 L
}else{ 8>ESD}(
this.totalCount = 0; xC'mPcU8
} q)vK`\Y
} ::v;)VdX+*
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publicint[] getIndexes(){ uW )
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return indexes; ijE<spG
} akMJ4EF/
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publicvoid setIndexes(int[] indexes){ x!OWJ/O
this.indexes = indexes; EG%I1F%
} ,tau9>!
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publicint getStartIndex(){ 33*^($bE&
return startIndex; XMomFW_@
} KuIkul9^%
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publicvoid setStartIndex(int startIndex){ GI}4,!^N
if(totalCount <= 0) Sw yaYK
this.startIndex = 0; K*TnUQ
elseif(startIndex >= totalCount) L^6"'#
this.startIndex = indexes "pOqd8>]
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[indexes.length - 1]; zMbfV%b
elseif(startIndex < 0) UP}feN
this.startIndex = 0; JvKO $^
else{ *@CVYJ'<
this.startIndex = indexes $K`_
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[startIndex / pageSize]; dUI3erO
} Rk}\)r\
} ]gb _Nv
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publicint getNextIndex(){ }*0,>w>
int nextIndex = getStartIndex() + x6"/z
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pageSize; ThjUiuWe
if(nextIndex >= totalCount) @mvIt
return getStartIndex(); zB;'_[8M
else joxS+P5#
return nextIndex; Tnf&pu#5
} MKV=m8G=
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publicint getPreviousIndex(){ cR,'o'V/
int previousIndex = getStartIndex() - $Vo/CZW7
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pageSize; ^!q 08`0
if(previousIndex < 0) r5D jCV"
return0; :uOZjEZi
else SL6mNn9c
return previousIndex; 0PYvey }[
} G%xb0%oi]%
p^T&jE8])#
} eLCdAr
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抽象业务类 uCY(:;[<
java代码: jn.R.}TT
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/** 2b; rr
* Created on 2005-7-12 CW.&Y?>Tv
*/ ,Y`'myL8W
package com.javaeye.common.business; aeEw#
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import java.io.Serializable; &mX5&e
import java.util.List; Is4%}J!8
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import org.hibernate.Criteria; b{Z^)u2X
import org.hibernate.HibernateException; AQE
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import org.hibernate.Session; Y'tq m&}
import org.hibernate.criterion.DetachedCriteria; 6"BtfQ")
import org.hibernate.criterion.Projections; |Dl*w/n
import }@3Ud'
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org.springframework.orm.hibernate3.HibernateCallback; 5x:Ift
*
import p>2||
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org.springframework.orm.hibernate3.support.HibernateDaoS sxC{\iLY%
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upport; 3$kv%uf{
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import com.javaeye.common.util.PaginationSupport; *Y^Y
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public abstract class AbstractManager extends PU@U@
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HibernateDaoSupport { j_ywG{Jk
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privateboolean cacheQueries = false; I8-&.RE
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privateString queryCacheRegion; *> &N
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publicvoid setCacheQueries(boolean 0R%uVJG
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cacheQueries){ S}xDB
this.cacheQueries = cacheQueries; um0}`Xq ^
} 1o6J9kCq^3
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publicvoid setQueryCacheRegion(String Kz*AzB
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queryCacheRegion){ HU'`kimWb
this.queryCacheRegion = [%)B%h`XGf
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queryCacheRegion; -Bwu$$0
} e,j ?_p
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publicvoid save(finalObject entity){ G/RheH
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getHibernateTemplate().save(entity); <GFB'`L
} Bdk{.oh6
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publicvoid persist(finalObject entity){ tgF(=a]o
getHibernateTemplate().save(entity); @Ozf}}#
} yV]-Oa$*s0
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publicvoid update(finalObject entity){ '`goy%Wd
getHibernateTemplate().update(entity); ##+8GLQM
} WbD C
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publicvoid delete(finalObject entity){ $d??(
getHibernateTemplate().delete(entity); )i6U$,]
} kq.R(z+
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publicObject load(finalClass entity, ks`
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finalSerializable id){ W-ND<=:Up
return getHibernateTemplate().load MPEBinE?
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(entity, id); ThQEQ6y
} 1oW]O@R
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publicObject get(finalClass entity, ?KuJs9SM
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finalSerializable id){ +MoxvW6
return getHibernateTemplate().get +fQ$~vr{'
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(entity, id); KZ
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} tIy/QN_42
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publicList findAll(finalClass entity){ bg3jo1J
return getHibernateTemplate().find("from H><mcah
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" + entity.getName()); ]A<u eM
} AQNx%
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publicList findByNamedQuery(finalString tlxjs]{0E
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namedQuery){ e=Tc(Mwn
return getHibernateTemplate pYvF}8
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().findByNamedQuery(namedQuery); mE@o27
} /g-X=|?F
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publicList findByNamedQuery(finalString query, 3\l9Sf=M|
]~ 8N
finalObject parameter){ {kO:HhUg
return getHibernateTemplate J2k'Ke97o
<W|{)U?p
().findByNamedQuery(query, parameter); kX .1#%Ex
} "=TTsxyM6P
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publicList findByNamedQuery(finalString query, @DKl<F
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finalObject[] parameters){ jJQfCOD$
return getHibernateTemplate p~;z"Z
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().findByNamedQuery(query, parameters); ~map5@Kd
} nPX'E`ut-V
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publicList find(finalString query){ EBE>&{%$^
return getHibernateTemplate().find <@ex})su
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(query); b020U>)v
} 7
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publicList find(finalString query, finalObject jN{xpd
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parameter){ ;HwJw\fo
return getHibernateTemplate().find T
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(query, parameter); X_S]8Aa
} F7u%oLjr
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public PaginationSupport findPageByCriteria %z_b/yG
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(final DetachedCriteria detachedCriteria){ bN%MT#X
return findPageByCriteria )
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p.Yg-CA
(detachedCriteria, PaginationSupport.PAGESIZE, 0); _BaS\U%1(
} f5XcBW9E
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public PaginationSupport findPageByCriteria BqA wo
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(final DetachedCriteria detachedCriteria, finalint bGnJ4R3J
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startIndex){ |}Z"|-Z
return findPageByCriteria QN5N hs
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(detachedCriteria, PaginationSupport.PAGESIZE, v"TH[}C9D
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startIndex); .5 r0%
} T1
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public PaginationSupport findPageByCriteria `erQp0fBM
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(final DetachedCriteria detachedCriteria, finalint 4nXS9RiF2
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pageSize, MNE)<vw>
finalint startIndex){ jl29~^@}1i
return(PaginationSupport) D)$k{v#~
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getHibernateTemplate().execute(new HibernateCallback(){ Q%d[U4@
publicObject doInHibernate 9:5NX3"p
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(Session session)throws HibernateException { Z4sjH1W
Criteria criteria = g{{SY5qDj
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detachedCriteria.getExecutableCriteria(session); pMrfi}esx
int totalCount = ~u1JR`y
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((Integer) criteria.setProjection(Projections.rowCount ds[~Cp
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_*
()).uniqueResult()).intValue(); pDN,(Ip
criteria.setProjection #>NZN1
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(null); GUZi }a|=
List items = ?E+XD'~
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criteria.setFirstResult(startIndex).setMaxResults !9Xex?et
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(pageSize).list(); Qp Vm
PaginationSupport ps = Kwau:_B
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new PaginationSupport(items, totalCount, pageSize, (acRYv(
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startIndex); t')I c6.?i
return ps; Stx-(Kfn4
} .6(i5K
}, true); l,8|E
} #r}c<?>Vw
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public List findAllByCriteria(final }RK9Onh3G
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DetachedCriteria detachedCriteria){ J#nEGl|a
return(List) getHibernateTemplate SjU6+|l
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().execute(new HibernateCallback(){ 1 crjRbi
publicObject doInHibernate Xb;`WE gC
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(Session session)throws HibernateException { ?!vW&KJZx
Criteria criteria = .=D6<4#t
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detachedCriteria.getExecutableCriteria(session); 1Pc'wfj
return criteria.list(); 7%WI
} O;tn5
}, true); ?+_"2XY
} (ZJ_&8C#
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public int getCountByCriteria(final m 9Q{)?J7
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DetachedCriteria detachedCriteria){ 8i"fhN3?Y
Integer count = (Integer) Rh^$0Q*2
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getHibernateTemplate().execute(new HibernateCallback(){ ]e9kf$'
publicObject doInHibernate I}{eYXh
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(Session session)throws HibernateException { }%|OnEk"
Criteria criteria = <9vkiEo
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detachedCriteria.getExecutableCriteria(session); C<ljBz`,t
return ~a Rq\fx{
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criteria.setProjection(Projections.rowCount X*&r/=
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()).uniqueResult(); Pd?YS!+S
} =X):Zi
}, true); %0'f`P6
return count.intValue(); oKiu6=
} +ZO*~.zZ
} t@v8>J%K
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用户在web层构造查询条件detachedCriteria,和可选的 }W J`q`g
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 eX/$[SL[
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PaginationSupport的实例ps。 ~Hf,MLMdTf
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ps.getItems()得到已分页好的结果集 L K$hV"SYb
ps.getIndexes()得到分页索引的数组 J/ ~]A1fP6
ps.getTotalCount()得到总结果数 }I0^nv1
ps.getStartIndex()当前分页索引 6W o7q\ "
ps.getNextIndex()下一页索引 ubw ]}sfM#
ps.getPreviousIndex()上一页索引 MmB-SR[>P
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 rv[\2@}
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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 -$rfu
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一下代码重构了。 &+sN=J.x
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我把原本我的做法也提供出来供大家讨论吧: _nt%&f
!E8JpE|z#
首先,为了实现分页查询,我封装了一个Page类: ,$Mw/fA
java代码: :d;5Q\C`
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/*Created on 2005-4-14*/
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package org.flyware.util.page; &nss[w$%C
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/** 0qv)'[O
* @author Joa oT'XcMn
* Lv"83$^S9
*/ W~qo
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publicclass Page { uE2Yn`Ha
ME(!xI//JZ
/** imply if the page has previous page */ fHiCuF
privateboolean hasPrePage; VmW_,
b({2|R
/** imply if the page has next page */ BdTj0{S1u
privateboolean hasNextPage; j8b:+io
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/** the number of every page */ [O3R(`<e5
privateint everyPage; F^f]*MhT"
z)0F k
/** the total page number */ LImD]e`
privateint totalPage; sdY6_HtE
!dGgLU_
/** the number of current page */ 9D
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privateint currentPage; 6\`,blkX
c:bB4ch}
/** the begin index of the records by the current (?Yz#Yf
AxeWj%w@
query */ >/>a++19
privateint beginIndex; hN.#ui5 $
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,/KHKLY7
/** The default constructor */ =F`h2 A;a
public Page(){ _^B+Xo@E-
_R]1J0
} FR&RIFy
REw3>/=
/** construct the page by everyPage >TE&myZ?*
* @param everyPage [x&&N*>N
* */ 1Dbe0u
public Page(int everyPage){ t :_7O7
this.everyPage = everyPage; `yhL11]~
} .C1^QY-wL
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/** The whole constructor */ *6h.#$\
public Page(boolean hasPrePage, boolean hasNextPage, </fnbyGR
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int everyPage, int totalPage, BdceINI
int currentPage, int beginIndex){ $6_J`7
this.hasPrePage = hasPrePage; \6N\6=t!A
this.hasNextPage = hasNextPage; YC$pT
this.everyPage = everyPage; 6O"0?wG+
this.totalPage = totalPage; &^}w|J?
this.currentPage = currentPage; '?d[ ip
this.beginIndex = beginIndex; &,\S<B2.
} U;^{uQJ+,
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/** {>i'Pb0mG|
* @return l6O2B/2j
* Returns the beginIndex. 71~V*
*/ wxoBq{r;
publicint getBeginIndex(){ DCNuvrZ
return beginIndex; U{ Y)\hR-
} A_2ppEG
i,~{{XS<
/** (<f[$ |%
* @param beginIndex +"C0de |-
* The beginIndex to set. t+&WsCN
*/ !:>y.^O
publicvoid setBeginIndex(int beginIndex){ 6 2LZ}yn_"
this.beginIndex = beginIndex; 0]Li"Wb
} }/=VnCfU
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/** ur'A ;B
* @return "];19]x6q
* Returns the currentPage. |OC6yN *P)
*/ wk3yz6V2
publicint getCurrentPage(){ )qKfTtN`
return currentPage; 6L2.88 i
} ^v,^.>P
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/** dkXK0k
* @param currentPage EZ$m4:{e
* The currentPage to set. eX=W+&lj
*/ 4Fnr8 r8W
publicvoid setCurrentPage(int currentPage){ ^@N@gB
this.currentPage = currentPage; fQv^=DI#
} 4WNWn#M
<5nz:B/
/** O=yUAAD$
* @return Ly^r8I
* Returns the everyPage. 0iwx$u7[
*/ iR_X,&p
publicint getEveryPage(){ !7_Q_h',
return everyPage; 5T,`j=\
} l9-(ofY*J
d`Wd"LJ=
/** #"TTI
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* @param everyPage En[cg
* The everyPage to set. *t~(_j
*/ E*CY/F I_
publicvoid setEveryPage(int everyPage){ [Y5B$7|s<
this.everyPage = everyPage; D@!#79:)
} P[D^*}
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/** 2?HLEiI1
* @return .i&]VGv
* Returns the hasNextPage. "6.kZ$`%
*/ @o_-UsUX
publicboolean getHasNextPage(){ R7vO,kZ6Q
return hasNextPage; )4DF9 JpD
} xvb5-tK
-
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/** A9[l5E
* @param hasNextPage 32dR`qb
* The hasNextPage to set. 3]V"9+
*/ Uc6P@O*,
publicvoid setHasNextPage(boolean hasNextPage){ <zrGPwk
this.hasNextPage = hasNextPage; UE*M\r<
} hH%@8'1v
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/** JEj.D=@[
* @return zU]95I
* Returns the hasPrePage. ?&"-y)FG
*/ Td?a=yu:J
publicboolean getHasPrePage(){ \= i>}Sg
return hasPrePage; O9jqeF`L=
} 4R.rSsAH
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/** 10t9Qv/
* @param hasPrePage /JJU-A(
* The hasPrePage to set. (oxe'\
*/ =lA*?'kd
publicvoid setHasPrePage(boolean hasPrePage){ H:2#/1Oz>
this.hasPrePage = hasPrePage; GXf"a3
} Eufw1vDa
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/** R{u/r%
* @return Returns the totalPage. jo/-'Lf{?
* u m,Zt
*/ e0qU2
publicint getTotalPage(){ !5&%
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return totalPage; hj s[$,1
} fpu^
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/** r+ k5Bk'
* @param totalPage i#=s_v8
* The totalPage to set. O6 bB CF;
*/ %,1bh
publicvoid setTotalPage(int totalPage){ =UT*1-yhR
this.totalPage = totalPage; d%8hWlffz
} 0escp~\Z
)BmK'H+l
} +<7`Gn(n3
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 )w=ehjV^m
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个PageUtil,负责对Page对象进行构造: Y?ouB
java代码: *;5P65:u$>
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/*Created on 2005-4-14*/ rzsAnLxo
package org.flyware.util.page; *#\da]"{
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import org.apache.commons.logging.Log; {d|e@`"T
import org.apache.commons.logging.LogFactory; 2guWWFS
%L, mj
/** L/t'|<m
* @author Joa iK%%
* $t}t'uJ
*/ __O@w.
publicclass PageUtil { w7+3?'L
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privatestaticfinal Log logger = LogFactory.getLog AU0pJB'
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(PageUtil.class); @|BaZq,g
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/** > yk2
* Use the origin page to create a new page Y- esD'MD
* @param page VB=$D|Ll
* @param totalRecords #6* j+SX^
* @return %PW_v~sg
*/ 2)cq!Zv
publicstatic Page createPage(Page page, int bh
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}M*yE]LL;Z
totalRecords){ ZgarxV*
return createPage(page.getEveryPage(), 3V2dN)\
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page.getCurrentPage(), totalRecords); M ^S <G
} :rR)rj'
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/** AYb-BaIc
* the basic page utils not including exception ~?E.U,R
Q#M@!&
handler Pr|BhX
* @param everyPage $z[FL=h)?+
* @param currentPage kMd1)6%6A
* @param totalRecords Ww\M3Q`h
* @return page bYt[/K,
*/ 0[E}[{t`
publicstatic Page createPage(int everyPage, int K;)(fc
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currentPage, int totalRecords){ 0Ez(;4]3
everyPage = getEveryPage(everyPage); +xYU$e6Z
currentPage = getCurrentPage(currentPage); {Qv Whf
int beginIndex = getBeginIndex(everyPage, pg0Sq9qCN
*,az`U
currentPage); Wl?0|{W
int totalPage = getTotalPage(everyPage, T%q@jv{c
{/ef`MxV
}
totalRecords); we?#
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boolean hasNextPage = hasNextPage(currentPage, ,v\^efc:%
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totalPage); 1xBgb/+
boolean hasPrePage = hasPrePage(currentPage); GoSdo
f
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returnnew Page(hasPrePage, hasNextPage, rD_\NgVAs
everyPage, totalPage, 3:wN^!A}ve
currentPage, C6` Tck!
UmEc")3
beginIndex); b;xn0sDn#
} s]X0}"cz
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privatestaticint getEveryPage(int everyPage){ C!X"0]@FA
return everyPage == 0 ? 10 : everyPage; ~$PY6s
} 8@rddk
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privatestaticint getCurrentPage(int currentPage){ JiN>sEAM
return currentPage == 0 ? 1 : currentPage; W*.j=?)\[
} >a%C'H.A9
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privatestaticint getBeginIndex(int everyPage, int +%sMd]$,n
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currentPage){ nY M2Vxi0+
return(currentPage - 1) * everyPage; ){}1u ?
} lD9QS ;
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privatestaticint getTotalPage(int everyPage, int SB
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totalRecords){ (pv6V2i
int totalPage = 0; ,::f?
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if(totalRecords % everyPage == 0) e|1.-P@
totalPage = totalRecords / everyPage; Ah:d2*SR4
else [ikW3 '99,
totalPage = totalRecords / everyPage + 1 ; yt+d
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return totalPage; 5do49H_
} $Cnv]1%
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privatestaticboolean hasPrePage(int currentPage){ >S}^0vNZX
return currentPage == 1 ? false : true; +d!"Zy2|B
} `=%mU/v
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privatestaticboolean hasNextPage(int currentPage, ]iezwz`'
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int totalPage){ Gr&YzbSX
return currentPage == totalPage || totalPage == c9O0YQ3&8
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0 ? false : true; .dPy<6E
} XlJA}^e
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} X+KQ%Efo
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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。 nnZM{<!hF
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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 H: rrY
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做法如下: wA< Fw
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1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 BTnrgs#[
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的信息,和一个结果集List: 3)*Twqt
java代码: 3[Z7bhpV
}. t8Cy9G
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/*Created on 2005-6-13*/ UFPSQ
package com.adt.bo; Z/oP?2/Afh
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import java.util.List; |2!cPf^8
*\# ?)q
import org.flyware.util.page.Page;
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/** m{?uR.O
* @author Joa U2CCjAgRs
*/ St|B9V?eEB
publicclass Result { qr'P0+|~5
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private Page page; 5Y#~+Im=[@
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private List content; Oi4y~C_Xd
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/** i p;
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* The default constructor -F&*>?I
*/ lG R6S
public Result(){ chszP{-@X
super(); D:#e;K
} ' }T6dS
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/** cr>"LAi
* The constructor using fields R4AKp1Y
* &O\$=&, h
* @param page JW9U&Bj{
* @param content &Xp