Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 @=_4i&]$
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 O|K-UTWH%
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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 &3gC&b^i
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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 ]2E#P.-!b
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分页支持类: .`p,pt;
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java代码: L a>fvm
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package com.javaeye.common.util; u,RR|/@
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import java.util.List; $8>kk
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publicclass PaginationSupport { f \ E9u}
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publicfinalstaticint PAGESIZE = 30; hY5GNYDh
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privateint pageSize = PAGESIZE; ^4/
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privateList items; )J^5?A
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privateint totalCount; F8H4R7
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privateint[] indexes = newint[0]; G&Fe2&5!w
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privateint startIndex = 0; NF "|*S
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public PaginationSupport(List items, int #| pn,/
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totalCount){
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setPageSize(PAGESIZE); _D 9/,n$
setTotalCount(totalCount); :6gRoMb]
setItems(items); h+rW%`B
setStartIndex(0); 0tKVo]EK
} ~3&*>H^U
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public PaginationSupport(List items, int ^(kmF UV,Z
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totalCount, int startIndex){ ?K\r-J!Y
setPageSize(PAGESIZE); ZH)Jq^^RI
setTotalCount(totalCount); 9dVHh?E
setItems(items); lvAKL>qX
setStartIndex(startIndex); E3LEeXcLS
} .oS[ DTn5S
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public PaginationSupport(List items, int e0<Wed
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totalCount, int pageSize, int startIndex){ F MX^k
setPageSize(pageSize); ,ZI#p6
setTotalCount(totalCount); |A.nP9 hW
setItems(items); redMlHM
setStartIndex(startIndex); Sx:JuK@
} `+h+X9
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publicList getItems(){ d>gQgQ;g
return items; r>#4Sr
} frokl5L@
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publicvoid setItems(List items){ HTLS$o;Q
this.items = items; 0"}=A,o(w
} 1l5'N=hL
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publicint getPageSize(){ l(Ya,/4
return pageSize; (:P#l&f
} A("\m>g$b
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publicvoid setPageSize(int pageSize){ CwM1
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this.pageSize = pageSize; p;qFMzyS9
} wpWZn[j
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publicint getTotalCount(){ `_()|; !y
return totalCount; o)f$ 7.
} tkYPfUvTE
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publicvoid setTotalCount(int totalCount){ e?7y$H-
if(totalCount > 0){ y@@h )P#
this.totalCount = totalCount; ( Sjlm^bca
int count = totalCount / z }Lf]w?
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pageSize; >Hu3Guik]
if(totalCount % pageSize > 0) B)*1[Jf{4
count++; :9DyABK=Cv
indexes = newint[count]; \JC_"gqt
for(int i = 0; i < count; i++){
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indexes = pageSize * Mp QsM-iW
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} O5MV&Zb(
}else{ "574%\#4z
this.totalCount = 0; #qu;{I#W3
} ]SAGh|+xl
} Q4Nut
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publicint[] getIndexes(){ I<Cm$8O?
return indexes; 9n49p?
} O1@3V/.Wu
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publicvoid setIndexes(int[] indexes){ K5RgWP
this.indexes = indexes; 6i;q=N$'
} {Hie%2V
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publicint getStartIndex(){ Dm%Q96*VAq
return startIndex; Es- =0gpK
} vmv6y*qU
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publicvoid setStartIndex(int startIndex){ 3&I3ViAH
if(totalCount <= 0) Rh!m1Q(-
this.startIndex = 0; 2Lytk OMf
elseif(startIndex >= totalCount) B8unF=u
this.startIndex = indexes 0dIGX |e
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[indexes.length - 1]; Aj]/A
elseif(startIndex < 0) +f$
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this.startIndex = 0; 1,:QrhC
else{ ,k1ns?i9KH
this.startIndex = indexes 6-~ZOMlV
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[startIndex / pageSize]; <00nu'Ex1v
} R_9M-RP6*
} ]*U+nG
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publicint getNextIndex(){ 62kA(F0e,
int nextIndex = getStartIndex() + XTA:Y7"O
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pageSize; V*r/0|vd
if(nextIndex >= totalCount) }+}Cl T
return getStartIndex(); Ga+Cb2$
else sOVpDtZ]LR
return nextIndex; ;s #I b_
} i1X!G|Awfv
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*,
publicint getPreviousIndex(){ z}iz~WZ
int previousIndex = getStartIndex() - <>( v~a]
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pageSize; y<*\D_J
if(previousIndex < 0) A8QUfg@uK~
return0; k.})3~F-
else nltOX@P-
return previousIndex; Rqbz3h~
} [?=DPE%
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} Y
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抽象业务类 )y6
java代码: }O+S}Hbwy
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/** g6xQQ,q=l
* Created on 2005-7-12 Zl>wWJ3y
*/ {t4':{Y+
package com.javaeye.common.business; ]T(qk
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import java.io.Serializable; <(~Wg{
import java.util.List; ADM!4L(s4}
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import org.hibernate.Criteria; l: kW|
import org.hibernate.HibernateException; B
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import org.hibernate.Session; w11L@t[5W8
import org.hibernate.criterion.DetachedCriteria; O>I%O^
import org.hibernate.criterion.Projections; +3M1^:
import ?v-!`J>EF#
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org.springframework.orm.hibernate3.HibernateCallback; @\:@_}Z`_}
import S;/pm$?/
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org.springframework.orm.hibernate3.support.HibernateDaoS yRDtPK"E-
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upport; OlptO60{ ]
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import com.javaeye.common.util.PaginationSupport; nv(6NV
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public abstract class AbstractManager extends +;)Xu}
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HibernateDaoSupport { WRRR "Q$
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privateboolean cacheQueries = false; D(&Zq7]n
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privateString queryCacheRegion; ug'^$geM
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publicvoid setCacheQueries(boolean |Bv,*7i&
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cacheQueries){ a<]vHC7
this.cacheQueries = cacheQueries; eYn/F~5-
} 3[?;s}61
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publicvoid setQueryCacheRegion(String }jP/XO1f
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queryCacheRegion){ Q'hs,t1<
this.queryCacheRegion =
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queryCacheRegion; ynf!1!4
} &OkPO|
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publicvoid save(finalObject entity){ |VjD. ]I
getHibernateTemplate().save(entity); 5 /T#>l<
} &T ^bv*P
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publicvoid persist(finalObject entity){ *(XGNp[0
getHibernateTemplate().save(entity); bPkz= ^-
} @k# xr
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publicvoid update(finalObject entity){ x8C
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getHibernateTemplate().update(entity); _KBa`lhE
} \/nSRAk
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publicvoid delete(finalObject entity){ cXr_,>k
getHibernateTemplate().delete(entity); TTWiwPo59
} |+JC'b?,
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publicObject load(finalClass entity, bj_/
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finalSerializable id){ /%F,
return getHibernateTemplate().load I>6zX
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(entity, id); W&[-QM8
} gR_Exs'K
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publicObject get(finalClass entity, Uc
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finalSerializable id){ g5x>}@ONq7
return getHibernateTemplate().get 5zyd;y)|'
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(entity, id); x^cJ~e2
} T[ g(S0dz
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publicList findAll(finalClass entity){ \C2HeA\#SW
return getHibernateTemplate().find("from Gv[(0
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" + entity.getName()); P?jI:'u!R.
} NF-@Q@
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publicList findByNamedQuery(finalString J$T(p%
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namedQuery){ F7]8*[u
return getHibernateTemplate Cy)QS{YX
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().findByNamedQuery(namedQuery); ?iamo.0zN
} 7<K=G2_:
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publicList findByNamedQuery(finalString query, LWN9 D
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finalObject parameter){ xJFcW+
return getHibernateTemplate G
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().findByNamedQuery(query, parameter); ;
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} >66
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publicList findByNamedQuery(finalString query, C}pQFL{B5
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finalObject[] parameters){ ~LP5hL
return getHibernateTemplate %F}d'TPx
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().findByNamedQuery(query, parameters); Um*&S.y
} VCIV*5
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publicList find(finalString query){ C0>L<*C
return getHibernateTemplate().find 23a:q{R
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(query); Mp[2A uf
} TZ}y%iU:mB
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publicList find(finalString query, finalObject A>RK3{7
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parameter){ 6!;D],,"#.
return getHibernateTemplate().find Qv]rj]%
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(query, parameter); QR<<O
} >9yy91H
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public PaginationSupport findPageByCriteria R:f ,g2
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(final DetachedCriteria detachedCriteria){ !HP=Rgh
return findPageByCriteria C<w&mFozL
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ,# %I$
} PR,8c
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public PaginationSupport findPageByCriteria _?eT[!oO8
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(final DetachedCriteria detachedCriteria, finalint kE[R9RS!
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startIndex){ $H&:R&Us
return findPageByCriteria A!}Ps"Z
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(detachedCriteria, PaginationSupport.PAGESIZE, fP$rOJ)P
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startIndex); }'n]C| gZ
} FC]n?1?<(
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public PaginationSupport findPageByCriteria F6>oGmLy
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(final DetachedCriteria detachedCriteria, finalint 9o3?
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pageSize, ySF^^X$J
finalint startIndex){ Y_~otoSoY
return(PaginationSupport) (Ap?ixrR_
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getHibernateTemplate().execute(new HibernateCallback(){ >Pvz5Hf/wW
publicObject doInHibernate ;krIuk-
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(Session session)throws HibernateException { &VG
Criteria criteria = iqN?'8
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detachedCriteria.getExecutableCriteria(session); c:
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int totalCount = #]Jg>
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((Integer) criteria.setProjection(Projections.rowCount %8d]JQ
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()).uniqueResult()).intValue(); }XqC'z
criteria.setProjection dQO5
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(null); gP |>gy#e
List items = aP"!}*
${gO=Z
criteria.setFirstResult(startIndex).setMaxResults ?},RN
n9R0f9:*
(pageSize).list(); 8xkLfN|N=
PaginationSupport ps = $I4Wl:(~}
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new PaginationSupport(items, totalCount, pageSize, KleiX7
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startIndex); io@f5E+?
return ps; *.Z~f"SZy*
} 6qWWfm/6
}, true); ,zxv>8Nt
} \Pe+]4R-Xo
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public List findAllByCriteria(final b/
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DetachedCriteria detachedCriteria){ w6pXF5ur>
return(List) getHibernateTemplate 3e1P!^'\
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().execute(new HibernateCallback(){ LC\U6J't1
publicObject doInHibernate Z9Z\2t
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(Session session)throws HibernateException { G^eXJusOv
Criteria criteria = KKWvV4u
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detachedCriteria.getExecutableCriteria(session); ;V?d;O4u
return criteria.list(); ;WgUhA
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} Kx?8HA[5
}, true); _rmKvSD%
} <y&&{*KW8m
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public int getCountByCriteria(final ;k,@^f8
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DetachedCriteria detachedCriteria){ 2 gR*] ?C*
Integer count = (Integer) 1+YqdDqQ
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getHibernateTemplate().execute(new HibernateCallback(){ `PSjkF(
publicObject doInHibernate Xg*](>/\,
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(Session session)throws HibernateException { qv'w 7T
Criteria criteria = [+!&iN
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detachedCriteria.getExecutableCriteria(session); $g/h=w@
return e+MQmWA'F
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criteria.setProjection(Projections.rowCount vTTXeS-b
<XN=v!2;
()).uniqueResult(); NCl@C$W9q
} d`~~Ww1
}, true); 5}c8v2R:B
return count.intValue(); UM<s#t`\3
} W+$G{XSr5C
} l@ (:Q!Sk
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用户在web层构造查询条件detachedCriteria,和可选的 u8M_2r
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 XUD Ztxa
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PaginationSupport的实例ps。 yxU9W,D v
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ps.getItems()得到已分页好的结果集 #<EYO
ps.getIndexes()得到分页索引的数组
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ps.getTotalCount()得到总结果数 *[|+5LVn
ps.getStartIndex()当前分页索引 }W&9} 9p"
ps.getNextIndex()下一页索引 {8oGWQgrj
ps.getPreviousIndex()上一页索引 F\|4zM
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 1X&jlD?
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 >[;=c0(
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一下代码重构了。 C,GZ
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我把原本我的做法也提供出来供大家讨论吧: 8ZLHN',
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首先,为了实现分页查询,我封装了一个Page类: 7D4tuXUq2
java代码: NzTF2ve(
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/*Created on 2005-4-14*/ y@It#!u0
package org.flyware.util.page; o]<9wc:FZ
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/** Jazg n5
* @author Joa A.dbb'^
* :tI
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*/ R&a$w8
publicclass Page { {]Hv*{ ]
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/** imply if the page has previous page */ ai-rF^ehC
privateboolean hasPrePage; Bc[~'gn
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/** imply if the page has next page */ "H<us?r{
privateboolean hasNextPage; k)|.<
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/** the number of every page */ Z7RBJK7|.
privateint everyPage; :GO"bsjL
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/** the total page number */ %W)pZN}
privateint totalPage; F=
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/** the number of current page */ `fTM/"
privateint currentPage; Y)+q[MZ R
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/** the begin index of the records by the current c38XM]Jeq
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query */ 'A3skznX{
privateint beginIndex; H(r D*R[
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/** The default constructor */ !hhL",
public Page(){ ~rJG4U
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} [nP s
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/** construct the page by everyPage n2hV}t9O
* @param everyPage G0Qw&
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* */ Vm>E F~ r
public Page(int everyPage){ >MYDwH
this.everyPage = everyPage; 9;?u%
} ~"CGur P
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/** The whole constructor */ _gI1rXI
public Page(boolean hasPrePage, boolean hasNextPage, C5,fX-2Q
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int everyPage, int totalPage, G9 O6Fi
int currentPage, int beginIndex){ ow.!4kx{ d
this.hasPrePage = hasPrePage; wz*iwd-
this.hasNextPage = hasNextPage; mV$ebFco0
this.everyPage = everyPage; ABX%oZ7[|o
this.totalPage = totalPage; Es%f@$0uy
this.currentPage = currentPage; qul#)HI
this.beginIndex = beginIndex; .t5.(0Xk[A
} ;54NQB3L
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/** ,_I
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* @return <\u3p3"[4
* Returns the beginIndex. IrqM_OjC
*/ oDz|%N2s|
publicint getBeginIndex(){ E)gD"^rex
return beginIndex; R=lw}jH [Z
} 7MLLx#U
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/** _>Raw
* @param beginIndex h<`aL;.g
* The beginIndex to set. Y(.e e%;,
*/ {;c'@U
publicvoid setBeginIndex(int beginIndex){ N8{jvat
this.beginIndex = beginIndex; 7GYf#} N
} :^v Q4/,
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/** %+N]$Q
* @return Pc`d]*BYi
* Returns the currentPage. )Y7H@e\1
*/ t?4H9~iH
publicint getCurrentPage(){ ApXf<MAy
return currentPage; 'z(Y9%+a
} f
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/** <46&R[17M
* @param currentPage FklR!*oL,)
* The currentPage to set. i}sAF/
*/ G`Nw]_
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publicvoid setCurrentPage(int currentPage){ m9DFnk<D
this.currentPage = currentPage; }kqh[`:
} 3ic /xy;}
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/** ahg:mlaob
* @return A'DFY {
* Returns the everyPage. I)Xf4FS@
*/ E1eGZ&&Gd
publicint getEveryPage(){ CO='[1"_5
return everyPage; gEd A
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} e0zP LU}
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/** u
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* @param everyPage &Q883A
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* The everyPage to set. i/x |c!E
*/ )4L2&e`k)(
publicvoid setEveryPage(int everyPage){ ^ `y7JXI:
this.everyPage = everyPage; CUu
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} uL`#@nI
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/** pCs3-&rI3
* @return FvpU]
* Returns the hasNextPage. t0m;tb bg
*/ q? '4&
publicboolean getHasNextPage(){ "GO!^ZG]
return hasNextPage; da7"Q{f+
} mqZH<.mn
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/** /iU<\+ H
* @param hasNextPage TTz=*t+D
* The hasNextPage to set. k83K2>]
*/ HAxLYun(3w
publicvoid setHasNextPage(boolean hasNextPage){ mr\,"S-`
this.hasNextPage = hasNextPage; (p-q>@m
} (,U|H`
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/** 2/&=:,"t,B
* @return pl`4&y%Me
* Returns the hasPrePage. &n6{wtBP
*/ 4=L >
publicboolean getHasPrePage(){ 4X+xh|R:U
return hasPrePage; TEz;:* ,CG
} atTR6%!6
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/** W{F)YyR{.
* @param hasPrePage z9aR/:W}
* The hasPrePage to set. |]?f6^|4
*/ F1#{(uW
publicvoid setHasPrePage(boolean hasPrePage){ q`*.F#/4c
this.hasPrePage = hasPrePage; J4T"O<i$58
} >3!~U.AA'x
o[ZjXLJzV
/** _J1\c~ke"
* @return Returns the totalPage. tvI<Why\p
* .-Lrrk)R+
*/ >v+1v
publicint getTotalPage(){ a
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return totalPage; 0/R;g~q@
} f .O^R~,
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/** ;ElCWs->\
* @param totalPage W=+n|1
* The totalPage to set. hVzyvpw
*/ @_ %RQO_X
publicvoid setTotalPage(int totalPage){ TKB8%/_p
this.totalPage = totalPage; n
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} d{S'6*`D
Tb i?AJa}
} wN[lC|1c
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pP| @Z{7d`
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 oco,sxT
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个PageUtil,负责对Page对象进行构造: mw"FQ?bJ
java代码: pJHdY)Cz
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/*Created on 2005-4-14*/ |T<aWZb^=
package org.flyware.util.page; :h(HKMSk1
?X|)0o
import org.apache.commons.logging.Log; [MIgQ.n
import org.apache.commons.logging.LogFactory; ~B;}jI]d[
PuNL%D
/** X:W\EeH
* @author Joa ; J W]b]
* )E9!m
*/ 2.v{W-D[
publicclass PageUtil { AU9C#;JD
jEBn"]\D
privatestaticfinal Log logger = LogFactory.getLog oMbd1uus
: s
*
(PageUtil.class); |5~Oh`w
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/** T?1BcY
* Use the origin page to create a new page c(Dp`f,
* @param page n#X~"|U`
* @param totalRecords wkp2A18n
* @return eo]nkyYDP
*/ A%D'Z85
-
publicstatic Page createPage(Page page, int !aT:0m$:9c
"@G[:(BoB<
totalRecords){ {)qr3-EM#
return createPage(page.getEveryPage(), 2y`h'z
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page.getCurrentPage(), totalRecords); _[6sr7H!
} 3 yx[*'e$
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/** sC3Vj(d!i
* the basic page utils not including exception fu!T4{2
w9|x{B
handler c+FTt(\8.
* @param everyPage ai<qK3!O
* @param currentPage HYdM1s6vo
* @param totalRecords sQgz}0_=)
* @return page zH1;h
*/ X_78;T)uA
publicstatic Page createPage(int everyPage, int J1w[gf]J
g
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currentPage, int totalRecords){ KdoI
everyPage = getEveryPage(everyPage); a>v *
currentPage = getCurrentPage(currentPage); m"!SyN}&9?
int beginIndex = getBeginIndex(everyPage, d|R-K7 ~~
x;?8Zr
currentPage); y.Z_\@
int totalPage = getTotalPage(everyPage, R'gd/.[e
if&bp ,
totalRecords); +?)7l
boolean hasNextPage = hasNextPage(currentPage, F3bTFFt
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totalPage); )c11_1;
boolean hasPrePage = hasPrePage(currentPage); daSe0:daJ
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returnnew Page(hasPrePage, hasNextPage, 7T/BzXr,B
everyPage, totalPage, \c\~k0u
currentPage, iy~h|YK;
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beginIndex); KS*,'hvY
} yEWm.;&3=
}#7l-@{<
privatestaticint getEveryPage(int everyPage){ ]Za[]E8MD
return everyPage == 0 ? 10 : everyPage; 3jZGO9ttnS
} Rw'}>?k]
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privatestaticint getCurrentPage(int currentPage){ 3k'Bje?9~
return currentPage == 0 ? 1 : currentPage; sywuS
} y`oj\
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privatestaticint getBeginIndex(int everyPage, int z|Y54o3
=w3A{h"^
currentPage){ ^iONC&r
return(currentPage - 1) * everyPage; 6/<Hx@r (
} 0d+n[Go+S
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privatestaticint getTotalPage(int everyPage, int O[d#-0s
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totalRecords){ i
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int totalPage = 0; /phMrL=
! ;>s .]
if(totalRecords % everyPage == 0) O+W<l:|$
totalPage = totalRecords / everyPage; 4 bk`i*-O
else [RXLR#
totalPage = totalRecords / everyPage + 1 ; Fv]6an.
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return totalPage; o}Grb/LJ
} 8y27O
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privatestaticboolean hasPrePage(int currentPage){ aV$kxzEc
return currentPage == 1 ? false : true; mo^E8t.
} ,ciX *F"
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privatestaticboolean hasNextPage(int currentPage, s~{rC{9X
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int totalPage){ bse`Xfg
return currentPage == totalPage || totalPage == [;wJM|Z J0
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0 ? false : true; jSpj6:@B
} l,J>[Q`<
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} %%K3J<5
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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。 ND1hZ3(^
x\'3UKQP+^
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 RNc:qV<H
g?80>-!bF
做法如下: D _dv8
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ,a&,R*r@&
+(=-95qZ
的信息,和一个结果集List: ZP~H!
java代码: (d#&m+
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/*Created on 2005-6-13*/ no8\Oees
package com.adt.bo; d 0B`5#4
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import java.util.List; /Pextj<
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import org.flyware.util.page.Page; Ug+ K:YUq
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/** DY#195H
* @author Joa w4P;Z-Cd
*/ }Hb0@
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publicclass Result { #M~yt`R~
f_)#
private Page page; el2Wk@*
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private List content; Y-bTKSn
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/** VLV]e_D6s
* The default constructor pnuo;r s
*/ ~qZ6I)?
public Result(){ $e+4Kt
,
super(); uD(C jHM>
} .nZKy't
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/** ^.:&ZsqV
* The constructor using fields >>$L
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* &jY|
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* @param page PESvx>:
* @param content Je|:\Qk
*/ ?GH/W#{o)
public Result(Page page, List content){ 1qR$ Yr\
this.page = page; v)np.j0V7
this.content = content; E
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} &OJ?Za@p@)
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/** vLxaZWr
* @return Returns the content. 5/Qu5/
*/ +F q_w
publicList getContent(){ ;`/a. /bc
return content;
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} sSfP.R
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/** f/c&Ya(D~
* @return Returns the page. C$0u-Nx8
*/ bM"?^\a&Q