Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 1G_xP^H!
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 YRu%j4Tx
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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 FP@A;/c
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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 }9FD/
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分页支持类: %)dI2 J^Xf
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java代码: -|$* l
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package com.javaeye.common.util; 3v G
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import java.util.List; K9LEIby
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publicclass PaginationSupport { cnC_#kp
{!g?d<*
publicfinalstaticint PAGESIZE = 30; Xv]*;Bq:SK
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privateint pageSize = PAGESIZE; +%x^ RV}
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privateList items; hxP6C6S
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privateint totalCount; zAu}hVcW
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privateint[] indexes = newint[0]; S{Rh'x\B
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privateint startIndex = 0; 8QPT\~
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public PaginationSupport(List items, int )ZviS.
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totalCount){ Za34/ro/T
setPageSize(PAGESIZE); ?#U0eb5u
setTotalCount(totalCount); 0\QYf0o
setItems(items); |@OJ~5H/{
setStartIndex(0); JPHUmv6
} a{5H33JA
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public PaginationSupport(List items, int q^u6f?B
z{@=_5;
totalCount, int startIndex){ A"`L~|&
setPageSize(PAGESIZE); M3)v-"
setTotalCount(totalCount); kA1f[AL
setItems(items); ,7QBJ_-;QJ
setStartIndex(startIndex); 3s#|Y,{?6R
} @_G` Ok4
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public PaginationSupport(List items, int rrW! X q
2f s9JP{^0
totalCount, int pageSize, int startIndex){ u;$I{b@M]
setPageSize(pageSize); e1:u1(".
setTotalCount(totalCount); a"MTQFm'
setItems(items);
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setStartIndex(startIndex); yIM.j;5:~5
} yl[2et
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publicList getItems(){ >9<_s
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return items; 6R0D3kW
} }3bQ>whF
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publicvoid setItems(List items){ 1VRqz5
this.items = items; [B.W1 GL!
} @2QJm
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publicint getPageSize(){ %{7$\|;J'
return pageSize; QxP` f KC8
} ftDVxKDE?S
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publicvoid setPageSize(int pageSize){ GZ;Z
this.pageSize = pageSize; <m-Ni
} hB?U5J
k?!TjBKm
publicint getTotalCount(){ kO
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return totalCount; H0 {Mlu9
} aY3pvOV
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publicvoid setTotalCount(int totalCount){ `[w}hFl~q
if(totalCount > 0){ 2l]C55p)s
this.totalCount = totalCount; :-W$PIBe
int count = totalCount / clij|?O
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pageSize; zS&7[:IRs'
if(totalCount % pageSize > 0) =>E44v
count++; (or =f`
indexes = newint[count]; qpH j4
for(int i = 0; i < count; i++){ /&y,vkZTT
indexes = pageSize * @^w!% ?J
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i; c80"8r
} 11nO<WH
}else{ C@l +\M(
this.totalCount = 0; Zw3hp,P]
} s|Imz<IE
} {X{01j};8
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publicint[] getIndexes(){ p\4h$."
return indexes; NZC<m$')
} U"jUMOMZ;
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publicvoid setIndexes(int[] indexes){ roK4RYJ7)
this.indexes = indexes; MVu[gB
} /3xFd)|Ds
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publicint getStartIndex(){ BV_a-\Sa=
return startIndex; CNpCe-%&
} A5(kOtgiT
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publicvoid setStartIndex(int startIndex){ O&gy(
if(totalCount <= 0) P,s)2 s'nZ
this.startIndex = 0; 6|>"0[4S
elseif(startIndex >= totalCount) >d1aE)?
this.startIndex = indexes {|t?
/9t*CEu\
[indexes.length - 1]; 7z0;FW3>9
elseif(startIndex < 0) \`p |,j
this.startIndex = 0; S1 R #]
else{ ?w|\7T.?
this.startIndex = indexes URj%
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?CL z@u~
[startIndex / pageSize]; _&8KB1~
} )^QG-IM
} z^SN#v$
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publicint getNextIndex(){ K~9 jin
int nextIndex = getStartIndex() + am)J'i,
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pageSize; jHUz`.8B
if(nextIndex >= totalCount) :Kt mSY
return getStartIndex(); cqU$gKT
else 1bFEx_
return nextIndex; Hf`&&
} k_.j%
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publicint getPreviousIndex(){ n^I|}u\
int previousIndex = getStartIndex() - 'h+4zvI"8
sIQMUC[!
pageSize; )2*|WHO
if(previousIndex < 0) 0(.R?1*:Rf
return0; .5$V7t.t$\
else 9h)P8B.>M
return previousIndex; C$EFh4
} !Dhfr{
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} iI/'!85
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抽象业务类 ,m_&eF
java代码: &Funao>
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/** Lu u-c<*M
* Created on 2005-7-12 wMR[*I/
*/ R?FtncL%D
package com.javaeye.common.business; xDAA`G
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import java.io.Serializable; EJ[iOYx
import java.util.List; :EmMia-)J
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import org.hibernate.Criteria; kK_>*iCMo
import org.hibernate.HibernateException; 374_G?t&
import org.hibernate.Session; o::ymAj
import org.hibernate.criterion.DetachedCriteria; z8rh*Rfxd
import org.hibernate.criterion.Projections; \ {E;u'F
import gJ}'O4*b
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org.springframework.orm.hibernate3.HibernateCallback; 62KW
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import >G -?e!
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org.springframework.orm.hibernate3.support.HibernateDaoS Ij,?G*
9dhFQWz"
upport; YfYL?G
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import com.javaeye.common.util.PaginationSupport; ZYp-dlEXq
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public abstract class AbstractManager extends .<|4PG
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HibernateDaoSupport { 7H@Cy}a
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privateboolean cacheQueries = false; -V)5Tr=
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privateString queryCacheRegion; (]#
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publicvoid setCacheQueries(boolean mZ.6Njb
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cacheQueries){ z 4OR
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this.cacheQueries = cacheQueries; -
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} MLDg).5
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publicvoid setQueryCacheRegion(String d~oWu [F*
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queryCacheRegion){ bJ5z??
this.queryCacheRegion = FWx*&y~$
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queryCacheRegion; #esu@kMU`
} Xf/<.5A
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publicvoid save(finalObject entity){ [,V92-s;N
getHibernateTemplate().save(entity); $/sZYsN~T
} Q\th8/ /
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publicvoid persist(finalObject entity){ ?
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getHibernateTemplate().save(entity); _O71r}4
} 29E@e]Y,`
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publicvoid update(finalObject entity){ p[+me o
getHibernateTemplate().update(entity); G6g=F+X2
} "I1M$^8n
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publicvoid delete(finalObject entity){ At_Y$N:
getHibernateTemplate().delete(entity); s)ajy^6'M
} RwLdV+2\R`
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publicObject load(finalClass entity, ,lG wW8$R
?;kc%Rz
finalSerializable id){ =kkA
return getHibernateTemplate().load Z["nY&.sI
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(entity, id); D&lXi~Z%.
} ,Onm!LI=
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publicObject get(finalClass entity, wtick~)
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finalSerializable id){ ,oVBgCf
return getHibernateTemplate().get ?;QKe0I^
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(entity, id); 5/VB'N#7s
} :jp$X|
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publicList findAll(finalClass entity){ @ dU3d\!}
return getHibernateTemplate().find("from 4'e8VI0
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" + entity.getName()); @g5]w&o_
} 2\W<EWJ@
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publicList findByNamedQuery(finalString cB'4{R@e
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namedQuery){ by3kfY]4s
return getHibernateTemplate x \{jWR%
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().findByNamedQuery(namedQuery); e?fjX-
} KFrmH
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publicList findByNamedQuery(finalString query, nff ]Y$FB
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finalObject parameter){ B{u.Yc:
return getHibernateTemplate +:8YMM#9V
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().findByNamedQuery(query, parameter); 1j-i nj`
} h$h`XBVZe;
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publicList findByNamedQuery(finalString query, *wx^mB9
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finalObject[] parameters){ E8 )*HOT_T
return getHibernateTemplate ^^(ZK 6 d
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().findByNamedQuery(query, parameters); akoKx)(<
} Zdz GJ[$
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publicList find(finalString query){ mTbPzZ4
return getHibernateTemplate().find LKG|S<s
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(query); RH 0a\RC!G
} +N!{(R:"v}
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publicList find(finalString query, finalObject Ct33S+y
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parameter){ bHG>SW\]`?
return getHibernateTemplate().find ?':'zT
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(query, parameter); ~Q]M_,`M
} cK/odOi
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public PaginationSupport findPageByCriteria $~\qoW<
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(final DetachedCriteria detachedCriteria){ 6lFs N2
return findPageByCriteria K 6Ua~N^
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); [K QZHIe
} .U
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public PaginationSupport findPageByCriteria &"0[7zgYQz
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(final DetachedCriteria detachedCriteria, finalint Q)8t;Kx
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startIndex){ wAPdu y[
return findPageByCriteria s2kynQ#a
MeS$+9jV(
(detachedCriteria, PaginationSupport.PAGESIZE, zvg&o)/[
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startIndex); ttRH[[E(
} zW.sXV,
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public PaginationSupport findPageByCriteria ;I'["k%
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(final DetachedCriteria detachedCriteria, finalint D.f=!rT7E7
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pageSize, 0^^i=iE-u
finalint startIndex){ YO61 pZY
return(PaginationSupport) J ASn\z
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getHibernateTemplate().execute(new HibernateCallback(){ Czn7,KE8X
publicObject doInHibernate 4v$AM8/o
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(Session session)throws HibernateException { :r=_\?
Criteria criteria = Pl>t\`1:|A
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detachedCriteria.getExecutableCriteria(session); -OxHQ
int totalCount = a#=-Aj-
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((Integer) criteria.setProjection(Projections.rowCount QJ?!_2Ax
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()).uniqueResult()).intValue(); tp&iOP6O
criteria.setProjection 4dAhJjhgD
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(null); f|)t[,c
List items = rG6/h'!|
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criteria.setFirstResult(startIndex).setMaxResults /|f]L9)2<
b iD7(AK
(pageSize).list(); f
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PaginationSupport ps = RCr:2
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new PaginationSupport(items, totalCount, pageSize, wr(?L7
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startIndex); n66_#X
return ps; =G :H)i
} T~Cd=s(T"
}, true); '
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} WDq3K/7\
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public List findAllByCriteria(final e^QOn
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DetachedCriteria detachedCriteria){ TrW3@@}j
return(List) getHibernateTemplate Ns_d10rZ.
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().execute(new HibernateCallback(){ HN+z7 Q8hH
publicObject doInHibernate G 2##M8:U0
@U5o;X!qU
(Session session)throws HibernateException { &[uGfm+@
Criteria criteria = CDhk!O..
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detachedCriteria.getExecutableCriteria(session); S6
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return criteria.list(); .67W\p
} >8so'7(
}, true); YuZnuI@m9
} )C[8#Q-:
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public int getCountByCriteria(final QG.FW;/L,
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DetachedCriteria detachedCriteria){ 9viC3bj. o
Integer count = (Integer) 2#!D" F
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getHibernateTemplate().execute(new HibernateCallback(){ Z)<>d.
publicObject doInHibernate
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(Session session)throws HibernateException { (iFhn*/
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Criteria criteria = _wMz+<7bY
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detachedCriteria.getExecutableCriteria(session); Y]PZ| G)
return d{&z^
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criteria.setProjection(Projections.rowCount ;FUd.vg{
(DU{o\=
()).uniqueResult(); _
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} :
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}, true); w[iQndu
return count.intValue(); WG,{:|!E
} 5o?bF3
} .gB*Y!c7
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用户在web层构造查询条件detachedCriteria,和可选的 GZ"O%:d
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 No?pv"
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PaginationSupport的实例ps。 M1:m"#=
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ps.getItems()得到已分页好的结果集 BN=,>-O%
ps.getIndexes()得到分页索引的数组 iH2|w
ps.getTotalCount()得到总结果数 {pqm&PB04
ps.getStartIndex()当前分页索引 u}$?r\H'(
ps.getNextIndex()下一页索引 C..O_Zn{g
ps.getPreviousIndex()上一页索引 yR&E6o.$z
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 rei<{woX
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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 a}yJ$6xi
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一下代码重构了。 _+GCd8d
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我把原本我的做法也提供出来供大家讨论吧: W];4P=/
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首先,为了实现分页查询,我封装了一个Page类: G 2mv6xK'
java代码: a 3HS!/
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/*Created on 2005-4-14*/ [p(Y|~
package org.flyware.util.page; )Aj~ xA
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/** RtSk;U1
* @author Joa rHMsA|xz6
* t{$t3>p-t
*/ hHdC/mR
publicclass Page { yCwQ0|
|
#,b1|af
/** imply if the page has previous page */ +!X^E9ra
privateboolean hasPrePage; sGV%O=9?2
GDk/85cv0$
/** imply if the page has next page */ X{)M}WO+r
privateboolean hasNextPage; 2D
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/** the number of every page */ [;c#LJ/y
privateint everyPage; [Ga9^e$Zv
_9<Ko.GVq
/** the total page number */ 3]wV`mD
privateint totalPage; Od!j+.OY<
;yH/GN#O
/** the number of current page */ K]RkKMT,
privateint currentPage; >J4_/p>Qs
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/** the begin index of the records by the current UlyX$f%2
$Cte$jg{;
query */ `74A'(u_
privateint beginIndex; (HY|0Bgr
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/** The default constructor */ yHCBf)N7\
public Page(){ /7*u!CNm
Tmq:,.^}
} )4j#gHN\
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/** construct the page by everyPage 98x(2fCvF(
* @param everyPage WFtxEIrl3j
* */ GX\/2P7CZ
public Page(int everyPage){ " 4s,a
this.everyPage = everyPage; (d_{+O"
} _,5(HETE2
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/** The whole constructor */ #\w~(Nm-
public Page(boolean hasPrePage, boolean hasNextPage, Rf7py )
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int everyPage, int totalPage, vQztD_bX%
int currentPage, int beginIndex){ `6UW?1_Z5
this.hasPrePage = hasPrePage; 9hcZbM]
this.hasNextPage = hasNextPage; \s[Uq
this.everyPage = everyPage; F`f#gpQ
this.totalPage = totalPage; R7+k=DI
this.currentPage = currentPage; !
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this.beginIndex = beginIndex; e%"L79Of6)
} ceAK;v
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/** d!!5'/tmS
* @return u"tv6Qp
* Returns the beginIndex. A2]N :=
*/ |Zz3X
publicint getBeginIndex(){ .I[uXd
return beginIndex; 7x`uGmp1
} 'H:lR1(,
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/** pkhZW8O
* @param beginIndex Aqq%HgY:t
* The beginIndex to set. \S3C"P%w
*/ IeE+h-3p
publicvoid setBeginIndex(int beginIndex){ 8xlj:5;(w
this.beginIndex = beginIndex; 0/;T\9
} .hnGHX
8\/E/o3
/** ^KmyB6Yg
* @return bc%7-%
* Returns the currentPage. $f_Brc:n {
*/ ACc.&,!IZ
publicint getCurrentPage(){ >AV?g8B;
return currentPage; -49OE*uF
} anHP5gD
bNj| GIf
/** tvZpm@1
* @param currentPage az\;D\\
* The currentPage to set. &!a[rvtZ+
*/ Jt@7y"<
publicvoid setCurrentPage(int currentPage){ gQ h;4v
this.currentPage = currentPage; [[ HXOPaV
} \%f4)Qb
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/** S-g`rTx
* @return sLPFeibof5
* Returns the everyPage. gtJUQu p2
*/ 4,
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publicint getEveryPage(){ mbU[fHyV
return everyPage; &$|k<{j[<f
} Cj,fP[p#7
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/** USfOc
* @param everyPage Z'hW;^e%_z
* The everyPage to set. BB>3Kj:|
*/ e=QnGT*b5
publicvoid setEveryPage(int everyPage){ /\(0@To
this.everyPage = everyPage; {C[<7ruF
} mS6L6)] S
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/** #P<v[O/rA
* @return JEGcZeq)
* Returns the hasNextPage. Wl?*AlFlk
*/ @?f3(Gh,
publicboolean getHasNextPage(){ [?yOJU%`
return hasNextPage; Xq1n1_Z
} vH9/}w2
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/** [-=PK\ B
* @param hasNextPage Rq<T2}K
* The hasNextPage to set. eZk
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*/ 7?dB&m6W
publicvoid setHasNextPage(boolean hasNextPage){ n@Y`g{{e~
this.hasNextPage = hasNextPage; JY~s-jxa
} /)e&4.6
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/** &S]\)&Yt
* @return ;a[56W
* Returns the hasPrePage. 2(Vm0E
*/ fYl$$.
publicboolean getHasPrePage(){ A!x_R {,yH
return hasPrePage; NyFa2Ihd
} Jr==AfxyT
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/** TY],H=
* @param hasPrePage Nj@k|_1
* The hasPrePage to set. (G*--+Gn
*/ gQCkoQi:j
publicvoid setHasPrePage(boolean hasPrePage){ h1:uTrtA
this.hasPrePage = hasPrePage; <U (gjX
} +MIDq{B
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/** 0bVtku K;G
* @return Returns the totalPage. FDkRfh K
* nxA Y]Q
*/ 1.4]T, `
publicint getTotalPage(){ b,cA mZ
return totalPage; 'RC(ss1G
} =;9Wh!{
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/** Nc,"wA
* @param totalPage 2kp.Ljt@
* The totalPage to set. kVCSFF*
*/ |[)t4A"}
publicvoid setTotalPage(int totalPage){ =hH>]$J[
this.totalPage = totalPage; k9vr6We'
} I QS|
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} ={o>g'
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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 Zm>Q-7r9
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个PageUtil,负责对Page对象进行构造: ><mZOTn e;
java代码: TxoMCN?7c
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/*Created on 2005-4-14*/ $6Lgaz
package org.flyware.util.page; &.y:QVR,!
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import org.apache.commons.logging.Log; 0m(/hK
import org.apache.commons.logging.LogFactory; rUvqAfE&+
Xp[[ xV|
/** eu@-v"=w
* @author Joa O5CIK}A
* d+[yW7%J
*/ Cg?D<l4
publicclass PageUtil { #'^!@+)
tV<}!~0,*
privatestaticfinal Log logger = LogFactory.getLog KwndY,QD
gYn1-/Z>I
(PageUtil.class); Ol`/r@s
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/** 2asA]sY
* Use the origin page to create a new page Ok/~E
* @param page m\(4y Gj
* @param totalRecords B$1e AwT9
* @return S$HzuK\f
*/ [
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publicstatic Page createPage(Page page, int s#/JMvQ#
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totalRecords){ ,A[40SZA
return createPage(page.getEveryPage(), (C={/waJ
.]6_
page.getCurrentPage(), totalRecords); TRL4r_
} `C%,Nj
: ~"^st_[!
/** =QHW>v
* the basic page utils not including exception <W2}^q7F^
*91iFeKj=
handler >"q0"zrN,
* @param everyPage ^hv
* @param currentPage odMjxWY
* @param totalRecords ^W5rL@h_
* @return page bo '
*/ a,b;H(em
publicstatic Page createPage(int everyPage, int i[`nu#n/
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currentPage, int totalRecords){ y44FejH(v
everyPage = getEveryPage(everyPage); RIJ+]uir4
currentPage = getCurrentPage(currentPage); $v#Q'?jE
int beginIndex = getBeginIndex(everyPage, JR|yg=E
:~3sW< PR
currentPage); I&l 1b>
int totalPage = getTotalPage(everyPage, 2+M(!FHfy
-l+&Bkf
totalRecords); R/R[r> 1)6
boolean hasNextPage = hasNextPage(currentPage, \[Op:^S
i;;CU9`E2q
totalPage); dE!{=u(!i
boolean hasPrePage = hasPrePage(currentPage); B(wk $2
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returnnew Page(hasPrePage, hasNextPage, #Z;ziM:
everyPage, totalPage, M8X*fYn
currentPage, / tM<ois*
$9Hod-Z1
beginIndex); .\= GfF'
} 9:4PJ%R9
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privatestaticint getEveryPage(int everyPage){ ^)<>5.%1''
return everyPage == 0 ? 10 : everyPage; &&4av*\I
} zYO+;;*@
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privatestaticint getCurrentPage(int currentPage){ B;XFPQ#b
return currentPage == 0 ? 1 : currentPage; x.qn$?3V]
} rpu9
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privatestaticint getBeginIndex(int everyPage, int LbOjKM^-
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currentPage){ `Jhu&MWg
return(currentPage - 1) * everyPage; ~z#Faed=a
} Zy,U'Dv
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privatestaticint getTotalPage(int everyPage, int !;.i#c_u
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totalRecords){ S1(. AI~
int totalPage = 0; ]b4*`}\
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if(totalRecords % everyPage == 0) vNlYk
totalPage = totalRecords / everyPage; Iz,a
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else $]|fjB#D
totalPage = totalRecords / everyPage + 1 ; !31v@v:)
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return totalPage; 7\@[e, ^9
} hu%rp{m^,
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privatestaticboolean hasPrePage(int currentPage){ oNY;z-QK
return currentPage == 1 ? false : true; mj=$[y(
} |UZPn>F~
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privatestaticboolean hasNextPage(int currentPage, B;9X{"
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int totalPage){ o7S,W?;=5
return currentPage == totalPage || totalPage == <^6|ZgR
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0 ? false : true; YQe9g>G&
} ^]o]'
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} S~0 mY}
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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。 G/>upnA{w
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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 _Z z"`
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做法如下: w^EAk(77
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 XBe!9/'k>
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的信息,和一个结果集List: }D/0&