Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 mt5KbA>nU
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 lu#LCG-.
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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 2Fz|fW_
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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 "Kc>dJ@W
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分页支持类: ~BDu$
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java代码: DK=cVpN%s
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package com.javaeye.common.util; /;tPNp{!dw
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import java.util.List; vTaJqEE
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publicclass PaginationSupport { fx@j?*Qb
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publicfinalstaticint PAGESIZE = 30; t\RF=BbJJ
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privateint pageSize = PAGESIZE; rz"txN
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privateList items; i~3u>CT
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privateint totalCount; A<6%r7&B'
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privateint[] indexes = newint[0]; yA)(*PFz
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privateint startIndex = 0; P7
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public PaginationSupport(List items, int /
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totalCount){ -tnQCwq#
setPageSize(PAGESIZE); #/NS&_Ge0s
setTotalCount(totalCount); ->h6j
setItems(items); rJa$9B*^
setStartIndex(0); oW^*l#v
} l ^d[EL+
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public PaginationSupport(List items, int `+t.!tv!
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totalCount, int startIndex){ <$N"q
setPageSize(PAGESIZE); t6BHGX{o
setTotalCount(totalCount); (_4;') 9
setItems(items); Y-'78BJk
setStartIndex(startIndex); W5^.-B,(K
} `]LSbS
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public PaginationSupport(List items, int wnTV|^Q
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totalCount, int pageSize, int startIndex){ NxVw!TsR
setPageSize(pageSize); RNPbH.
setTotalCount(totalCount); cpt<WK}
setItems(items); );*YQmdx'
setStartIndex(startIndex); ?:|-Dq,
} R.LL#u};
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publicList getItems(){ U$H@ jJ*
return items; ,Rx{yf]k
} ;f,c't@w
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publicvoid setItems(List items){ bS
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this.items = items; ~^^ NHq
} 9s}Kl($
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publicint getPageSize(){ [TF8'jI0
return pageSize; aZKOY
} q8:{Nk
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publicvoid setPageSize(int pageSize){
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this.pageSize = pageSize; $T<}y_nHl
} VR!-%H\AW
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publicint getTotalCount(){ OzT#1T1'c
return totalCount; hF3&i=;.
} iqhOi|!
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publicvoid setTotalCount(int totalCount){ *?yJkJ"
if(totalCount > 0){ #'OaKt?Z)
this.totalCount = totalCount; 'SLE;_TD
int count = totalCount / w62=06`@
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pageSize; hNXBVIL<&
if(totalCount % pageSize > 0) E3a_8@ZB7
count++; ~#}Dx
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indexes = newint[count]; Ufo>|A6;$
for(int i = 0; i < count; i++){ aFY_:.o2k`
indexes = pageSize * 1\dn1Hh
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} xx*2?i
}else{ rOD1_X-
this.totalCount = 0; SbsouGD,{
} g8ES8SM
} 8 _d-81Dd
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publicint[] getIndexes(){ 6Ggs JU
return indexes; ^TXf sQs
} 92dF`sv
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publicvoid setIndexes(int[] indexes){ {+("C]
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this.indexes = indexes; 5;)*T6Y
} L6
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publicint getStartIndex(){ __p_8P
return startIndex; *! :QdWLq
} H L<s@kEZ
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publicvoid setStartIndex(int startIndex){ <c,~aq#W'
if(totalCount <= 0) XeUC0K[D
this.startIndex = 0; W( *V2<$o
elseif(startIndex >= totalCount) ]_*S~'x
this.startIndex = indexes `GQ{*_-
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[indexes.length - 1]; p4X{"Z\mn
elseif(startIndex < 0) 3$M3Q]z
this.startIndex = 0; }4%/pOi:f
else{ Uhh
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this.startIndex = indexes F=@i6ERi
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[startIndex / pageSize]; c"gsB!xh
} {LE&ylE
} v:ER4
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publicint getNextIndex(){ 0x)dnq\
int nextIndex = getStartIndex() + P-z`c\Rt
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pageSize; 0=U70nKr
if(nextIndex >= totalCount) z
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return getStartIndex(); ~o15#Pfn/
else *07sK1wW
return nextIndex; Yx?aC!5M
} }HZ{(?
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publicint getPreviousIndex(){ A| x:UQlu
int previousIndex = getStartIndex() - ahIE;Y\j'
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pageSize; 3(lVmfk
if(previousIndex < 0) !Rw&DFU
return0; Q .RO
else iQ`]ms+
return previousIndex; -@bp4Z=
} v|+5:jFOqb
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} H7IW"UkBR
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抽象业务类 Lx+`<<_dJ
java代码: eK_*q-
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/** pieT'mA
* Created on 2005-7-12 Cd~LsdKE5
*/ h[U7!aM
package com.javaeye.common.business; #EwK"S~
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import java.io.Serializable; @ ^.*$E5
import java.util.List; :EB,{|m
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import org.hibernate.Criteria; `jW4H$D
import org.hibernate.HibernateException; 6"%qv`.Fp
import org.hibernate.Session; +i)AS0?d
import org.hibernate.criterion.DetachedCriteria; .Ty,_3+{#p
import org.hibernate.criterion.Projections; ^
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import ;X7i/DQ
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org.springframework.orm.hibernate3.HibernateCallback; w6U
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import OOLe[P3J3
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org.springframework.orm.hibernate3.support.HibernateDaoS _;G=G5r
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upport; )0|):g
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import com.javaeye.common.util.PaginationSupport; 3H'*?|Y(#
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public abstract class AbstractManager extends DB8s
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HibernateDaoSupport { eBvW#Hzp
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privateboolean cacheQueries = false; u\5g3BH
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privateString queryCacheRegion; Z:^3Fm->+
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publicvoid setCacheQueries(boolean *H*\gaSh
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cacheQueries){ bX&e_Pd
this.cacheQueries = cacheQueries; %yhI;M^
} 2fP~;\AP
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publicvoid setQueryCacheRegion(String =M7PvH'"
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queryCacheRegion){ MLeX;He
this.queryCacheRegion = TU-c9"7M~
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queryCacheRegion; 2:~cJk{
} 5%'S
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publicvoid save(finalObject entity){ N6BNzN}-P
getHibernateTemplate().save(entity); Z fqQ{_
} c.-cpFk^L&
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publicvoid persist(finalObject entity){ j88=f#<
getHibernateTemplate().save(entity); PS/W
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} c
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publicvoid update(finalObject entity){ w Oj88J)
getHibernateTemplate().update(entity); uDI}R]8~
}
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publicvoid delete(finalObject entity){ <L2GUX36#
getHibernateTemplate().delete(entity); 5Abz5-^KH
} b_ZNI0Hp@
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publicObject load(finalClass entity, ]'6'<S
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finalSerializable id){ Vp\80D&
return getHibernateTemplate().load MyqiBGTb
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(entity, id); *F|i&2
} !6{Jq]
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publicObject get(finalClass entity, InP[yFV-z
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finalSerializable id){ s9G)Bd 8
return getHibernateTemplate().get Vv2{^!aZ
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(entity, id); A3<^ U
} !2#\| NJk
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publicList findAll(finalClass entity){ R/Tj^lM
return getHibernateTemplate().find("from T0s35z9
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" + entity.getName()); Oe/73|
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} i]LU4y%'
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publicList findByNamedQuery(finalString gO9'q='5l
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namedQuery){ 7KeXWW/ d
return getHibernateTemplate bG"6pU
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().findByNamedQuery(namedQuery); 0
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} ?U}sQ;c$
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publicList findByNamedQuery(finalString query, ;A
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finalObject parameter){ =.VepX|?D
return getHibernateTemplate >c}:
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().findByNamedQuery(query, parameter); '_k >*trV
} p
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publicList findByNamedQuery(finalString query, 9qnuR'BDu
*iPs4Es-
finalObject[] parameters){ mgk64}K [n
return getHibernateTemplate L-`(!j
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().findByNamedQuery(query, parameters); ( P
} f:n] Exsy
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publicList find(finalString query){ Lr K9F^c
return getHibernateTemplate().find yBr$ 0$
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(query); =%Q\*xaR.W
} I/u'bDq
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publicList find(finalString query, finalObject qPp1:a"
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parameter){ cjCE3V9X
return getHibernateTemplate().find hVQ7'@
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(query, parameter); sZ0g99eX
} tpN]evp|
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public PaginationSupport findPageByCriteria P}ehNt*($
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(final DetachedCriteria detachedCriteria){ k/$Ja;
return findPageByCriteria (2\l i{$e
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ~Da
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} wJ;9),fL
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public PaginationSupport findPageByCriteria 4v rm&k
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(final DetachedCriteria detachedCriteria, finalint &.|;yt%v
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startIndex){ >WGX|"!"
return findPageByCriteria @\x,;!N@
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(detachedCriteria, PaginationSupport.PAGESIZE, 8cYuzt]..
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startIndex); ` 4s#5g
} A"P\4
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public PaginationSupport findPageByCriteria m)tI
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(final DetachedCriteria detachedCriteria, finalint {[(W4NAlH
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pageSize, hr/xpQW
finalint startIndex){ ~m,mvRS
return(PaginationSupport) Mt7X<?GZm
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getHibernateTemplate().execute(new HibernateCallback(){ yKX:Z4I/
publicObject doInHibernate $=;bccIob
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(Session session)throws HibernateException { tA;ZW2$#
Criteria criteria = ;&7qw69k
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detachedCriteria.getExecutableCriteria(session); ;I0yQlx|U
int totalCount = Aw_R
$
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((Integer) criteria.setProjection(Projections.rowCount qB`0^V
0*]<RM
()).uniqueResult()).intValue(); !'6J;Fb#
criteria.setProjection _3FMQY(
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(null); 6w .iEb
List items = q(${jz4w
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criteria.setFirstResult(startIndex).setMaxResults .[eSKtbc)
:#"OCXr
(pageSize).list(); <)0LwkFtB
PaginationSupport ps = 1nX68fS.9
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new PaginationSupport(items, totalCount, pageSize, @Z1?t%1
37<GG)
startIndex); O+3D
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return ps; JqH.QnKcv
} z;@S_0M,Z
}, true); _oyL*Cb
} hGaYQgGq
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public List findAllByCriteria(final 5"Xo R)
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DetachedCriteria detachedCriteria){ s$=B~l
return(List) getHibernateTemplate
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().execute(new HibernateCallback(){ <P
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publicObject doInHibernate :fMM-?s]
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(Session session)throws HibernateException { %%-Tjw o
Criteria criteria = uma9yIk
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detachedCriteria.getExecutableCriteria(session); D\i8rqU/l
return criteria.list(); E<.{
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} ZBh@%A
}, true); ?\ i,JJO
} :O2v0Kx
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public int getCountByCriteria(final J5r
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DetachedCriteria detachedCriteria){ N6 Cc%,
Integer count = (Integer) m0K2 p~
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getHibernateTemplate().execute(new HibernateCallback(){ ]&%X(jWyn
publicObject doInHibernate YJ;a{)e
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(Session session)throws HibernateException { yyYbB ]D
Criteria criteria = L``mF(R^
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detachedCriteria.getExecutableCriteria(session); P<w>1
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return 4iB)oR
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criteria.setProjection(Projections.rowCount )fcpE,g'
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()).uniqueResult(); ^*T{-U'
} y#SD-#I-
}, true); LHGK!zI
return count.intValue(); (]uoN4
} "gVH;<&]
} n@8{FoF
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用户在web层构造查询条件detachedCriteria,和可选的 k-p7Y@`+a
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ~V)VGGOL$v
9n2%7dLQ*
PaginationSupport的实例ps。 8YkH
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ps.getItems()得到已分页好的结果集 >@\?\!Go
ps.getIndexes()得到分页索引的数组 Y
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ps.getTotalCount()得到总结果数 *fyEw\`a
ps.getStartIndex()当前分页索引 &Fr68HNmj
ps.getNextIndex()下一页索引 FKTP0e7=9
ps.getPreviousIndex()上一页索引 U\plt%2m>
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ?DTP-#5Ba
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 JHOBg{Wg
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一下代码重构了。 i(#c
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我把原本我的做法也提供出来供大家讨论吧: }Bg<Fm
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首先,为了实现分页查询,我封装了一个Page类: 8?R_O}U
java代码: vWga>IGM
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/*Created on 2005-4-14*/ s: .XF|e{
package org.flyware.util.page; Q(Y,p`>
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/** tOVm~C,R
* @author Joa a#j^gu$m
* 3Q"+
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*/ TniKH(w/
publicclass Page { :cz]8~i\
*XR~fs?/*W
/** imply if the page has previous page */ O/~^}8TLL
privateboolean hasPrePage; [Y~ s
>gl <$LQ?X
/** imply if the page has next page */ VAzJclB
privateboolean hasNextPage; )SLs
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/** the number of every page */ (LPc\\Vv
privateint everyPage; H!=BjU1Pmg
(`*wiu+i
/** the total page number */ md
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privateint totalPage; |`/uS;O
EF~PM
/** the number of current page */ N$b;8F
privateint currentPage; Xqw7lj;K
dkC / ?R
/** the begin index of the records by the current bS6Yi)p
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query */ M] *pBc(o0
privateint beginIndex; c^k.
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/** The default constructor */ WGK::?
public Page(){ ?8/h3xV;
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} tsD^8~
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/** construct the page by everyPage h#nQd=H<g#
* @param everyPage zBfBYhS-
* */ 0rUf'S
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public Page(int everyPage){ +3CMfYsr8
this.everyPage = everyPage; h='=uj8o5
} !HYqM(|{.
7a net
/** The whole constructor */ E
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public Page(boolean hasPrePage, boolean hasNextPage, K(2s%
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x
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int everyPage, int totalPage, 9~yuyv4$
int currentPage, int beginIndex){ R#M).2::
this.hasPrePage = hasPrePage; .VT,,0
this.hasNextPage = hasNextPage; L8Q!6oO=<
this.everyPage = everyPage; EK_^#b
this.totalPage = totalPage; Z%R^;8 !~
this.currentPage = currentPage; iqeGy&F-
this.beginIndex = beginIndex; I5]zOKlVR
} +fN0>@s
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/** *VB*/^6A
* @return jC%I]#!n
* Returns the beginIndex. b8&9pLl
*/ Tx_LH"8
publicint getBeginIndex(){ }: e9\r)
return beginIndex; g,nE iL
} ojri~erJE?
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/** q`hg@uwA{`
* @param beginIndex ^E^: =Q?'_
* The beginIndex to set. ||f4f3R'
*/ c@`P{6
publicvoid setBeginIndex(int beginIndex){ ?AE%N.rnsi
this.beginIndex = beginIndex; 9}N*(PI
} >\ W" 3.
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/** K4"as9oFP
* @return novZ<?7 5;
* Returns the currentPage. aH_&=/-Tz
*/ l}x{.q7Ul
publicint getCurrentPage(){ Iu8=[F>
return currentPage; 43Q&<r$[T
} H UjmJu6f{
y3#\mBiw
/** {<@~;iq
* @param currentPage SDkN
* The currentPage to set. 1K>4i. X
*/ vjpe'zx
publicvoid setCurrentPage(int currentPage){ qF?S[Z;
this.currentPage = currentPage; &N EzKf
} dn Xc- <
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/** @azS)4L
* @return X^ovP'c2
* Returns the everyPage. E]
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*/ ,Gfnf%H\8>
publicint getEveryPage(){ UxW~yk
return everyPage; m#Cp.|>kP4
} v [x`I;
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/** B~^\jRd"
* @param everyPage rP'oUV_
* The everyPage to set. f*Kipgp
*/ o}T]f(>}
publicvoid setEveryPage(int everyPage){ 0t) IWD
this.everyPage = everyPage; n}l Z
} -$7Jc=:>
"783F:mPh
/** [-l^,,E
* @return |k8;[+
* Returns the hasNextPage. eu#| |
*/ ^C(AMT
publicboolean getHasNextPage(){ 4ngiad6bR
return hasNextPage; oR+Fn}mG
} 3yTBkFI!
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/** U}UIbJD*=
* @param hasNextPage ,yB-jk?
* The hasNextPage to set. Qwb@3{
*/ f~]5A%=cZ
publicvoid setHasNextPage(boolean hasNextPage){ 8'zwyd3
this.hasNextPage = hasNextPage; B$\5=[U
} (vQShe\
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/** @gZ%>qe
* @return Cnn,$R=/s
* Returns the hasPrePage. R)#"Ab Z'
*/ "DUL} "5T
publicboolean getHasPrePage(){ `aCcTs7~]p
return hasPrePage; &oT]ycz%
} KVK@Snn
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/** [\I\).
* @param hasPrePage Ngg (<ZN
* The hasPrePage to set. le*pd+> j
*/ F.JE$)B2EX
publicvoid setHasPrePage(boolean hasPrePage){ f5'+F-`N
this.hasPrePage = hasPrePage; ]+J]}C]\d
} akaQ6DIdG
~V (WD;Mk
/** HIF.;ImG^
* @return Returns the totalPage. ]E,
* Wt_@ vs@.O
*/ 3uN;*f
publicint getTotalPage(){ W4Zi?@L>'
return totalPage; (;!&RZ
} lx%<oC+M
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/** RF qbwPX
* @param totalPage b8>rUGA{
* The totalPage to set. [7$.)}Q-
*/ S_C+1e
publicvoid setTotalPage(int totalPage){ $LKniK
this.totalPage = totalPage; y+@7k3"
} FLi)EgZXt
9^ )=N=wV
} $l Y
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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 c_+}`
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个PageUtil,负责对Page对象进行构造: g;vG6!;E\
java代码: HjLY\.S
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<!R~G-D#_T
/*Created on 2005-4-14*/ 6!O~:\`DJ
package org.flyware.util.page; _z~|*7@
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import org.apache.commons.logging.Log; 9tWu>keu
import org.apache.commons.logging.LogFactory; Wfz&:J#
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/** dFK/
* @author Joa ?(4=:o
* Fep#Pw1
*/ NO8)XJ3s
publicclass PageUtil { V~ %!-7?
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privatestaticfinal Log logger = LogFactory.getLog hxGZ}zq*S
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(PageUtil.class);
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=Z2Cg{z
/** a)/!ifJ;
* Use the origin page to create a new page C0Z
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* @param page ~sx?aiO
* @param totalRecords s,)Z8H
* @return qlNK }
*/ R#DnV[!\
publicstatic Page createPage(Page page, int ?I6 !m~
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totalRecords){ N^jQ\|A<
return createPage(page.getEveryPage(), _ ?]bd-E
l03{
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page.getCurrentPage(), totalRecords); gi#bU
} h(l4\)
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xB
/** #(=8
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* the basic page utils not including exception 7j| ^ZuI+
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handler F<39eDNpz
* @param everyPage ^{lcj
* @param currentPage F !g>fIg
* @param totalRecords ;89 `!V O
* @return page uxLT*,
*/ nLicog)!I
publicstatic Page createPage(int everyPage, int =bgzl=A`
z3x/Y/X$S
currentPage, int totalRecords){ P'MfuTtT&
everyPage = getEveryPage(everyPage); ova4
currentPage = getCurrentPage(currentPage); iq*]CF
int beginIndex = getBeginIndex(everyPage, jkTC/9AE|
EIQ`?8KSR
currentPage); cuzU*QW"g
int totalPage = getTotalPage(everyPage, X?whyD)vE@
+L(|?|i8
totalRecords); q(xr5iuP_
boolean hasNextPage = hasNextPage(currentPage, !1(*D*31
Wg{ 9X#|
totalPage); GWd71ZtFO
boolean hasPrePage = hasPrePage(currentPage); m' HAt~
C)Ep}eHjf_
returnnew Page(hasPrePage, hasNextPage, t@r>GHO
everyPage, totalPage, !y_4.&C{
currentPage, 6.5E
d-
^IW5c>;|
beginIndex); +;,65j+n
} BV;dV6`z
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privatestaticint getEveryPage(int everyPage){ k4T`{s}e
return everyPage == 0 ? 10 : everyPage; vo(riHH
} "xWrYq'"
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privatestaticint getCurrentPage(int currentPage){ (>]frlEU~
return currentPage == 0 ? 1 : currentPage; yK+1C68A
} -A]-o
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privatestaticint getBeginIndex(int everyPage, int ;*(i}'
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currentPage){ *RYok{w
return(currentPage - 1) * everyPage; 3ch<a0
} ~cv322N
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privatestaticint getTotalPage(int everyPage, int x3AAn,m8
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totalRecords){ Kj53"eW
int totalPage = 0; s,CN<`/>x
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if(totalRecords % everyPage == 0) :_8Nf1B+T
totalPage = totalRecords / everyPage; i2P:I A|@
else E]O/'-
totalPage = totalRecords / everyPage + 1 ; pJdR`A-k|
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return totalPage; 9 1.gE*D
} K>2M*bGcp
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privatestaticboolean hasPrePage(int currentPage){ ^]5^p9Jt"e
return currentPage == 1 ? false : true; C;3
} ^>/~MCyM.
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privatestaticboolean hasNextPage(int currentPage, %63s( ekU
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int totalPage){ sTS/]"l
return currentPage == totalPage || totalPage == lFtH;h,==v
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0 ? false : true; O70#lvsM;
} 8S`
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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。 JU#m?4g
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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 *C);IdhK%y
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做法如下: R`J.vMT
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 |~o0-: 'C
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的信息,和一个结果集List: j&u/T
java代码: a/</P
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