Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 3Viz0I<%
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 mhgvN-? "h
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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 Zs|m_O G
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 'j9x(T1M1
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分页支持类: Y#zHw<<E
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java代码: ?s@=DDB\u
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package com.javaeye.common.util; f~?kx41dq
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import java.util.List; ^4C
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publicclass PaginationSupport { Hyb_>n
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publicfinalstaticint PAGESIZE = 30; @6Z6@Pq(xQ
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privateint pageSize = PAGESIZE; 8'Iei78Ov
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privateList items; kA/yL]m^S
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privateint totalCount; ap<r)<u
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privateint[] indexes = newint[0]; %-L
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privateint startIndex = 0; [ZL<Q
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public PaginationSupport(List items, int 6J <.i
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totalCount){ GO3KKuQ=
setPageSize(PAGESIZE); ))6YOc
setTotalCount(totalCount); \s6VOR/
setItems(items); :)F0~Q
setStartIndex(0); xHe"c<
} p2hPLq
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public PaginationSupport(List items, int -ZoAbp$
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totalCount, int startIndex){ 2>g!+p Ox
setPageSize(PAGESIZE); 23X-h#w
setTotalCount(totalCount); @+sYwlA~
setItems(items); IeAi '
setStartIndex(startIndex); z8j7K'vV1
} [*g'Y;W
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public PaginationSupport(List items, int )BZ6QO`5n
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totalCount, int pageSize, int startIndex){ 5Vr#>W
setPageSize(pageSize); <CWOx&hr
setTotalCount(totalCount); @2sr/gX^
setItems(items); nnTiu,2R
setStartIndex(startIndex); S<g~VK!Tt
} D2f~*!vEnA
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publicList getItems(){ rxOvYF
return items; {6mFI1;q
} f.:0T&%G
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publicvoid setItems(List items){ lt%9Zgr[u
this.items = items; QG5c>Q
} L$?YbQo7
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publicint getPageSize(){ <1<0 odB
return pageSize; 8Rnq
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} wq]vcY9^
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publicvoid setPageSize(int pageSize){ G4%dah 5
this.pageSize = pageSize; L(}/W~En
} 4+Y9":<
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publicint getTotalCount(){ 8aVj@x$'
return totalCount; WyUa3$[gO
} fo e)_
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publicvoid setTotalCount(int totalCount){ 0+k=gO
if(totalCount > 0){ vAtR\Vh
this.totalCount = totalCount; =-!B4G$
int count = totalCount / X3l6b+p
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pageSize; bLO^5` 6
if(totalCount % pageSize > 0) c#a>> V
count++; iThf\
indexes = newint[count]; V5+|H1=
for(int i = 0; i < count; i++){ v>5TTL~?
indexes = pageSize * `rpmh7*WV
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i; US&:UzI.
} |al'_s}I
}else{ B]PG
this.totalCount = 0; E :UJ"6
} pZ 7KWk4
} vH@b
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publicint[] getIndexes(){ SA~oGgk=P
return indexes; 3#idXc
} #^w8Y'{?
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publicvoid setIndexes(int[] indexes){ hmv*IF.
this.indexes = indexes; Sv[+~co<l
} C`\yc_b9Pf
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publicint getStartIndex(){ }KV)F,`
return startIndex; ki]i[cdk
} WISeP\:^
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publicvoid setStartIndex(int startIndex){ 8zpTCae^=7
if(totalCount <= 0) z"Wyf6H0T
this.startIndex = 0; xS_tB)C
elseif(startIndex >= totalCount) 2l +t-
this.startIndex = indexes Su k;##I
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[indexes.length - 1]; rM20Y(|
elseif(startIndex < 0) 't3nh
this.startIndex = 0; h\*I*I8C
else{ kj!mgu#T
this.startIndex = indexes g;!,2,De}
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[startIndex / pageSize]; d'b q#r
}
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} c4L++
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publicint getNextIndex(){ 3!u:*ibt
int nextIndex = getStartIndex() + "@@Z{
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pageSize; IHj9n>c)[
if(nextIndex >= totalCount) PYW>
return getStartIndex(); N"2P]Zr
else Y !AQ7F
return nextIndex; ]f3R;d
} 4 UnN~
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publicint getPreviousIndex(){ d]Mjr2h
int previousIndex = getStartIndex() - F6-U{+KU$!
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pageSize; Bc51
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if(previousIndex < 0) <84d
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return0; 1#^r5E4
else n }4L q^$
return previousIndex; _u8d`7$*%
} "9!CsloWhz
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} %ysfFE
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抽象业务类 3Uni{Z]Q)
java代码: fnudu0k
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/** hOIk6}r4X
* Created on 2005-7-12 )n1 7}Qm`V
*/ 7|q _JdKoU
package com.javaeye.common.business; O@? *5
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import java.io.Serializable; qn~:B7f
import java.util.List; =bB7$#al
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import org.hibernate.Criteria; I xE}v%&
import org.hibernate.HibernateException; g=x1}nm
import org.hibernate.Session; LkIbvJCV
import org.hibernate.criterion.DetachedCriteria; t+Hx&_pMj
import org.hibernate.criterion.Projections; ?FwjbG<
import S*?x|&a
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org.springframework.orm.hibernate3.HibernateCallback; :]^FTnO
import [49Ae2W`
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org.springframework.orm.hibernate3.support.HibernateDaoS $(eqZ<y
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upport; HVK./yqy
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import com.javaeye.common.util.PaginationSupport; 9!|+GIjn
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public abstract class AbstractManager extends )m[dfeqd +
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HibernateDaoSupport { ?br 4 wl
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privateboolean cacheQueries = false; j9/Ev]im|F
'ai!6[|SD
privateString queryCacheRegion; {Qr0pjE7R
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publicvoid setCacheQueries(boolean 2rJeON
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cacheQueries){ *oU-V#
this.cacheQueries = cacheQueries; JypXQC}~
} ?sm@lDZ\
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publicvoid setQueryCacheRegion(String .WT^L2l%
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queryCacheRegion){ !wZ9P
this.queryCacheRegion = sCE2 F_xjL
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queryCacheRegion; %1jApCJ
} F_&bE@k
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publicvoid save(finalObject entity){ j}$Up7pW
getHibernateTemplate().save(entity); duk:: |{F
} e=%6\&q
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publicvoid persist(finalObject entity){ X ?l F,p
getHibernateTemplate().save(entity); J%n{R60b
} 8${Yu
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publicvoid update(finalObject entity){ }th^l*g
getHibernateTemplate().update(entity); [M{EO)
} ?dcR!-3
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publicvoid delete(finalObject entity){ bn$}U.m$-
getHibernateTemplate().delete(entity); :&oUI&(o
} Lv{xwHnE
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publicObject load(finalClass entity, ^3:DeZf!u
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finalSerializable id){ ax)j$
return getHibernateTemplate().load +#d}3^_]
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(entity, id); /-W-MP=Wd
} KZxA\,Y'5
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publicObject get(finalClass entity, 2iM8V
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finalSerializable id){ khW9n*
return getHibernateTemplate().get H~P"uYKIZ
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(entity, id); qWzzUM1=
} k<M~co;L
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publicList findAll(finalClass entity){ XFg.Z+ #
return getHibernateTemplate().find("from XT|!XC!|
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" + entity.getName()); %YaUc{.%
} '%m0@5|hCD
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publicList findByNamedQuery(finalString G D$jP?
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namedQuery){ i~IQlyGr.
return getHibernateTemplate ;
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().findByNamedQuery(namedQuery); ')9%eBaeK
} G=8w9-Ww
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publicList findByNamedQuery(finalString query, h]94\XQ>$
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finalObject parameter){ RTSR-<{z
return getHibernateTemplate LC/w".oq?
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().findByNamedQuery(query, parameter); afEp4(X~
} I_yIVw;
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publicList findByNamedQuery(finalString query, \ooqa<_
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finalObject[] parameters){ V=|^r?
return getHibernateTemplate lxK_+fj
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().findByNamedQuery(query, parameters); !dLz ?0
} ;f-|rC_"
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publicList find(finalString query){ <LW|m7
return getHibernateTemplate().find R7KQ-+Zb
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(query); L\og`L)5\
} z1+rz%
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publicList find(finalString query, finalObject ~,e!t.339
#|XEBOmsQ
parameter){ 3i(k6)H$4
return getHibernateTemplate().find MatC2-aV1
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(query, parameter); (?\ZN+V)
} gE=~.P[ZX
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public PaginationSupport findPageByCriteria vP}K(' (
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(final DetachedCriteria detachedCriteria){ /^[)JbgB
return findPageByCriteria H>XbqIkL@
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); gSj-~kP
} CHpDzG>]4
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public PaginationSupport findPageByCriteria t=\V&,
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(final DetachedCriteria detachedCriteria, finalint
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Vd<=
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startIndex){ vB4cdW
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return findPageByCriteria \S7OC
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(detachedCriteria, PaginationSupport.PAGESIZE, CJKH"'u3^
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startIndex); JNp`@`0V
} 4}LF>_+=
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public PaginationSupport findPageByCriteria <Z8] W1)
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(final DetachedCriteria detachedCriteria, finalint ^LU[{HZV
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pageSize, 6$6NVq
finalint startIndex){ ONjc},_
return(PaginationSupport) dY-a,ch"8p
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getHibernateTemplate().execute(new HibernateCallback(){ ABHZ)OM
publicObject doInHibernate |%V.Lae
;%Da {
(Session session)throws HibernateException { ,xh9,EpBk
Criteria criteria = 2@&|hd=-
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detachedCriteria.getExecutableCriteria(session); D1Sl+NOV
int totalCount = UUU^YT \
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((Integer) criteria.setProjection(Projections.rowCount _uu:)%
$Tur"_`I;
()).uniqueResult()).intValue(); #]
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criteria.setProjection a,4g`?
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(null); 2>!ykUw^O
List items = kxmS
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criteria.setFirstResult(startIndex).setMaxResults 8
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(pageSize).list(); $~YuS_sYg
PaginationSupport ps = tQ~B!j]
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new PaginationSupport(items, totalCount, pageSize, i`SF<)M(
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startIndex); _Nn!SE
return ps; u
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} 7asq]Y}<
}, true); XJzXxhk2
} ".)_kt[
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public List findAllByCriteria(final H+;wnI>@
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DetachedCriteria detachedCriteria){ ^8m+*t
return(List) getHibernateTemplate V"p<A
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().execute(new HibernateCallback(){ qj6`nbZ{va
publicObject doInHibernate t4IJ%#22
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(Session session)throws HibernateException { '/H(,TM
Criteria criteria = AVr!e
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detachedCriteria.getExecutableCriteria(session); K*Jtyy}r
return criteria.list(); K|G$s
} ja;5:=8A5
}, true); Vi#im`@
} x3s^u~C)(w
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public int getCountByCriteria(final
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DetachedCriteria detachedCriteria){ psC7IE<v
Integer count = (Integer) aHC;p=RQ\A
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getHibernateTemplate().execute(new HibernateCallback(){ v)yimIHzo
publicObject doInHibernate :6?&FzD`
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(Session session)throws HibernateException { pU ]{Z(
Criteria criteria = `5-#M/J
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detachedCriteria.getExecutableCriteria(session); udGGDH
return UWp8I)p!\O
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criteria.setProjection(Projections.rowCount LH#LBjOZk
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()).uniqueResult(); f#kevf9zc
} LDEt.,6i
}, true); #>jH[Q
return count.intValue(); P$/A! r
} wmE,k1G
} &PuJV + y
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用户在web层构造查询条件detachedCriteria,和可选的 @Q\$dneY
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 $a*Q).^
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PaginationSupport的实例ps。 ?VZXJO{^
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ps.getItems()得到已分页好的结果集 ]a!; `m$
ps.getIndexes()得到分页索引的数组 L+rySP
ps.getTotalCount()得到总结果数 5m USh3
ps.getStartIndex()当前分页索引 +.#S[G
ps.getNextIndex()下一页索引 "8iiRzt#
ps.getPreviousIndex()上一页索引 VgsCwJ9w
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 R c:cVK
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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 JeTrMa 2
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一下代码重构了。 -~ O;tJF2
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我把原本我的做法也提供出来供大家讨论吧: `-K)K<
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首先,为了实现分页查询,我封装了一个Page类: v(@+6#&
java代码: h/0-Mrk;e
lmtQr5U
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/*Created on 2005-4-14*/ 7{+Io
package org.flyware.util.page; .)^3t~
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/** Y6<0%
* @author Joa sx( l
* W`/jz/
*/ ghobu}wuF
publicclass Page { oY2?W
kL PO+lg+
/** imply if the page has previous page */ 8~s-t
privateboolean hasPrePage; dy6F+V\DG
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/** imply if the page has next page */ M ,_^hm7
privateboolean hasNextPage; j^$3vj5E[
JM+sHHs
/** the number of every page */ xH`j7qK.
privateint everyPage; $~G0#JL
ttbQergS
/** the total page number */ M~z(a3@[V
privateint totalPage; }lC64;yo
g"Q}h
/** the number of current page */ 3h[:0W!C]
privateint currentPage; 'x45E.wYw
U8WHE=Kk\h
/** the begin index of the records by the current ndKvJH 4
M89-*1
query */ C?/r}ly<\
privateint beginIndex; C;)Xwm>e
8!&ds~?
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/** The default constructor */ qtdxMX]iR
public Page(){ J]|6l/i
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} ]cLEuE^&
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/** construct the page by everyPage {?
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* @param everyPage D,GPn%Wqi
* */ <r7qq$
public Page(int everyPage){ e"o6C\c
this.everyPage = everyPage;
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} @wEKCn|}o
_
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/** The whole constructor */ n&YW".iG
public Page(boolean hasPrePage, boolean hasNextPage, 0$f_or9T
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int everyPage, int totalPage, 9N*S-Po=
int currentPage, int beginIndex){ >p]WCb'PH
this.hasPrePage = hasPrePage; x
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this.hasNextPage = hasNextPage; I!F}`d
this.everyPage = everyPage; e}](6"t`5
this.totalPage = totalPage; c#\ah}]Vo
this.currentPage = currentPage; @Hspg^
this.beginIndex = beginIndex; 8u:v:>D.'
} |c06ix;).
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/** .-('C> @
* @return /`4v"f0V
* Returns the beginIndex. t`<}UWAH+
*/ $tDCS
publicint getBeginIndex(){ gJ FR1
return beginIndex; Nl=m'4@`
} 3r~>~ueZ
gtaV6sD
/** Qm35{^p+
* @param beginIndex G|QUujl
* The beginIndex to set. Tsm)&$JI8
*/ Wz6]*P`qv
publicvoid setBeginIndex(int beginIndex){ xecieC
this.beginIndex = beginIndex; m0xJ05Zx
} _KSfP7VU
eD*?q7
/** w|!YoMk+o
* @return MO));M)
* Returns the currentPage. LPq*ZZK
*/ 86;+r'3p.
publicint getCurrentPage(){ u"`5
return currentPage; KXoL,)Hl
} b lRY7
!p]T6_t]Q
/** %|: ;Ti
* @param currentPage ;=5@h!@R
* The currentPage to set. Qa,NGP.
*/ r.^0!(d
publicvoid setCurrentPage(int currentPage){ PtQQZ"ept
this.currentPage = currentPage; k%EWkM)?
} 2gQY8h8
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/** 8 *4@-3Sx
* @return _-4n~(
* Returns the everyPage. CTh1+&Pa
*/ ]^iFqQe
publicint getEveryPage(){ |_l<JQvf`E
return everyPage; 0OleO9Ua
} A5CdLwk
i&A{L}eCr:
/** 3+CSQb8
* @param everyPage 8fJR{jD(s
* The everyPage to set. ~/^y.SsWM
*/ mV6#!_"
publicvoid setEveryPage(int everyPage){ a(PjcQ4dY
this.everyPage = everyPage; ePV-yy
} #5'c\\?Q
jo 7Hyw!g
/** aqcFY8b
'
* @return lTa1pp
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* Returns the hasNextPage. ljNzYg~-
*/ *0=fT}&!
publicboolean getHasNextPage(){ Nc
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return hasNextPage; KotPV
} +90u!r^v
AkxH
/** 2-B6IPeI
* @param hasNextPage 3x04JE3!
* The hasNextPage to set. e(?:g@]-r
*/ 6?53q e
publicvoid setHasNextPage(boolean hasNextPage){ GLo\q:5A
this.hasNextPage = hasNextPage; 0L!er%GM
} y<O@rD8iA
z[WC7hvU
/** mZ`1JO9
* @return ]WTf< W<
* Returns the hasPrePage. TFBYY{Y
*/ k%{ l4
publicboolean getHasPrePage(){ \9046An
return hasPrePage; !nec 7
} zl0;84:H
mG0L !5
/** *6NO-T; -
* @param hasPrePage +2-
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* The hasPrePage to set. 6kP7
*/ &foD&
publicvoid setHasPrePage(boolean hasPrePage){ MinbE13?U
this.hasPrePage = hasPrePage; IeO-O'^&`
} =Nw2;TkB[
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/** uQ{=o]sy
* @return Returns the totalPage. 0('OyH)
* aL88E
*/ \s,Iz[0Vfz
publicint getTotalPage(){ 7@FDBjq
return totalPage; Kp8fh-4_
} )V=0IZi
V{43HA10b
/** xC<R:"Mn
* @param totalPage |a%B|CX
* The totalPage to set. 5i|s>pD4z1
*/ ):/,w!1
publicvoid setTotalPage(int totalPage){
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this.totalPage = totalPage; PoJmW^:}
} `tX@8|
Nfr:`$k
} P=c?QYF
L{!ihJr
$+7 ci~gs
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M!(
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 o1e4.-xI
FH4u$g+
个PageUtil,负责对Page对象进行构造: {nTG~d
java代码: :=y0'f
V(@
l`DtiJ?$$0
Y=9qJ`q
/*Created on 2005-4-14*/ F@<O;b#Ip
package org.flyware.util.page; ZOp^`c9~
oL#xDG
import org.apache.commons.logging.Log; +a #lofhv
import org.apache.commons.logging.LogFactory; Gv;;!sZ
Jff 79)f
/** Bw6 L;Vu
* @author Joa ;xhOj<:
* y">fN0{<
*/ `n6/ A)
publicclass PageUtil { 'm[6v}
f?Z|>3.2
privatestaticfinal Log logger = LogFactory.getLog `N$!s7M
Tj&'KF8?L
(PageUtil.class); #$FY+`
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/** CldDr<k3
* Use the origin page to create a new page Mxo6fn6-46
* @param page h!v/s=8c
* @param totalRecords o_sQQF
* @return l^ARW
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*/ Ey'J]KVW
publicstatic Page createPage(Page page, int ~> PgJ^G
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totalRecords){ 3I]Fdp)'
return createPage(page.getEveryPage(), wDMjk2YN
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page.getCurrentPage(), totalRecords); +tIz[+u
} *o!l/>4g
@7fm1b
/** :\mRtVH
* the basic page utils not including exception k}HQq_Y(<
vu<#wW*9
handler _|X7
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* @param everyPage zi
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* @param currentPage )%qtE34`
* @param totalRecords Ge^Qar
* @return page @ ICbKg:
*/ 0Qp[\ia
publicstatic Page createPage(int everyPage, int |0kXCq
Y87XLvig}
currentPage, int totalRecords){ p-,Iio+
everyPage = getEveryPage(everyPage); ck$M(^)l
currentPage = getCurrentPage(currentPage); w.uK?A>W,
int beginIndex = getBeginIndex(everyPage, _f|/*.
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currentPage); Xu6K%]i^
int totalPage = getTotalPage(everyPage, 036[96t,F
t8/%Dgu
totalRecords); yj
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boolean hasNextPage = hasNextPage(currentPage, ~RInN+N#
@VK6JjIq
totalPage); kYlg4 .~M
boolean hasPrePage = hasPrePage(currentPage); .,M;huRg
`%=<R-/#7S
returnnew Page(hasPrePage, hasNextPage, n=o_1M|
everyPage, totalPage, Za%LAyT_s
currentPage, 6,+nRiZ
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beginIndex); }Eh*xOta
} ne*#+Q{E
#wjH4DT
privatestaticint getEveryPage(int everyPage){ u-szt ? O|
return everyPage == 0 ? 10 : everyPage; :u/mTZDi
} 41yOXy ;~l
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privatestaticint getCurrentPage(int currentPage){ 7@l<?
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return currentPage == 0 ? 1 : currentPage; ="'- &
} DP*@dFU"
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privatestaticint getBeginIndex(int everyPage, int [zh"x#AyI
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currentPage){ J +q|$K6
return(currentPage - 1) * everyPage; YeyGN
} bX2"89{
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privatestaticint getTotalPage(int everyPage, int LT_iS^&1
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totalRecords){ 3sbK7,4
int totalPage = 0; {G*OR,HN
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if(totalRecords % everyPage == 0) !` 26\@1
totalPage = totalRecords / everyPage; y@;%Uv&
else O('Nn]wo~9
totalPage = totalRecords / everyPage + 1 ;
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return totalPage; 9$RIH\*
} $iPP|Rw
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privatestaticboolean hasPrePage(int currentPage){ eW50s`bKY
return currentPage == 1 ? false : true; <n^3uXzD
} .~mCXz<x
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privatestaticboolean hasNextPage(int currentPage, nIBFk?)6
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int totalPage){ F8=nhn
return currentPage == totalPage || totalPage == Wi$dZOcSJ
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0 ? false : true; Fo}7hab
} _Y!sVJ){,c
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} ST;t,
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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。 M_|> kp
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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 f /y`
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做法如下: n:4uA`Vg
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Z
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的信息,和一个结果集List: T3 pdx~66
java代码: |B^G:7c
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/*Created on 2005-6-13*/ ln<]-)&C
package com.adt.bo; 6rX_-Mm6w
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import java.util.List; T):SGW
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import org.flyware.util.page.Page; H%}IuHhN)
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/** 0LL c 1t>}
* @author Joa c/aup
*/ '{[),*nC n
publicclass Result { 2Z/K(J"&J
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private Page page; JTW)*q9a
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private List content; a07=tD
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/** M1!pQC_9
* The default constructor G>z,#Xt
*/ ,Em$ !n
public Result(){ .}`hCt08
super(); ig_2={Q@
} :i*JnlvZ
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/** `<fh+*
* The constructor using fields 9|WV~
* ga0'zo9K
* @param page Ph,-sR
* @param content cQUC.TZ_
*/ f3tv3>p
public Result(Page page, List content){ *fc-gAj
this.page = page; c&'JmKV>&
this.content = content; %fjuG
} z#Nl@NO&
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/** ]v 29 Rx
* @return Returns the content. Vpp&