Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 /3j3'~0
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 UId?a}J
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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 $ Gs|Z$(
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改
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分页支持类: ( 9(NP_s
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java代码: [sZ,nB/
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package com.javaeye.common.util; L0>7v
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import java.util.List; Ntlbn&lc;D
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publicclass PaginationSupport { 0?*":o30
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publicfinalstaticint PAGESIZE = 30; OZ4% 6/
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privateint pageSize = PAGESIZE; oT i$@q
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privateList items; ^?S lM
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privateint totalCount; V|)nUsU
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privateint[] indexes = newint[0]; u-R;rf5%k
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privateint startIndex = 0; ~\u~>mtchu
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public PaginationSupport(List items, int G8lTIs4u;
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totalCount){ :'Tq5kE
setPageSize(PAGESIZE); WDF6.i ?
setTotalCount(totalCount); <q:2' 4o
setItems(items); 8TCbEPS@Q
setStartIndex(0); ZM_-g4[H
} 7T?T0x3>
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public PaginationSupport(List items, int ?OC&=}
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totalCount, int startIndex){ a0PClbf2.
setPageSize(PAGESIZE); 8gW$\
setTotalCount(totalCount); JfzfxfM
setItems(items); s]Z++Lh<{
setStartIndex(startIndex); 22R
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} rTzXRMv@o
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public PaginationSupport(List items, int T1c&3
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totalCount, int pageSize, int startIndex){ -#
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setPageSize(pageSize); : 2A\X' @
setTotalCount(totalCount); ~vKDB$2
setItems(items); /;WFRp.
setStartIndex(startIndex); ;-VXp80J
} H(DI /"N
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publicList getItems(){ OySn[4`(i
return items; e?<$H\
} &XB1=b5
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publicvoid setItems(List items){ lh-zE5;
this.items = items; nQ;M@k&9eV
} ZmS
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publicint getPageSize(){ U/jCM?~
return pageSize; JnS@}m
} {;3a^K
; Z2
publicvoid setPageSize(int pageSize){ ;eC8|
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this.pageSize = pageSize; !=]cASPGD
} CJt(c,!z
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publicint getTotalCount(){ ^]9.$$GU\A
return totalCount; JPq' C$
} 7upN:7D-
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publicvoid setTotalCount(int totalCount){ ><{Lh@{
if(totalCount > 0){ Tz{-L%*#
this.totalCount = totalCount; ;M5]XCPk
int count = totalCount / P]H4!}M
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pageSize; E2Ec`o
if(totalCount % pageSize > 0) v dPb-z4
count++; s}?QA cC
indexes = newint[count]; j=Z;M1
for(int i = 0; i < count; i++){ J'*`K>wV
indexes = pageSize * v4r%'bA
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i; i*e'eZ;)
} a>#]d
}else{ _^p\
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this.totalCount = 0; "T.Qb/97@
} EO"G(v
} (#rhD}
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publicint[] getIndexes(){ >uwd3XW5
return indexes; ]f*.C9Y
} 3u4P
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publicvoid setIndexes(int[] indexes){ v|:TYpku3
this.indexes = indexes; nw=:+?
} `FmRoMW9+
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publicint getStartIndex(){ M!
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return startIndex; x*wr8$@J
} .Kssc lSD1
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publicvoid setStartIndex(int startIndex){ #4F0o@Z
if(totalCount <= 0) !gj_9"<
this.startIndex = 0; $`_xP1bUT
elseif(startIndex >= totalCount) #{zF~/Qq
this.startIndex = indexes T26'b .
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[indexes.length - 1]; uOb}R
elseif(startIndex < 0) Z+
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this.startIndex = 0; =/bC0bb{i
else{ &+df@U6i
this.startIndex = indexes m,r>E%;Cj
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[startIndex / pageSize]; te&p1F
} TchByN6oN<
} |qtZb}"|
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publicint getNextIndex(){ #X*=oG
int nextIndex = getStartIndex() + Rzxkz
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pageSize; 59k-,lyU,
if(nextIndex >= totalCount) TJs ~}&L
return getStartIndex(); tF!-}{c"k
else ZvSEa{
return nextIndex; ,m;G:3}48
} E*83N@i
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publicint getPreviousIndex(){ %=5 m!"F
int previousIndex = getStartIndex() - bqRO-\vO
$#FA/+<&$
pageSize; )gNVJ
if(previousIndex < 0) r_3=+
return0; VX e7b
else qnnP*15`
return previousIndex; P*kC>lvSv
} v.Xmrry
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} [#/@v/`
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抽象业务类 W+#Zmvo
java代码: $rH}2
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/** K(Ak+&[
* Created on 2005-7-12 Yn8aTg[J
*/ !6eF8T
package com.javaeye.common.business; KHoDD=O
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import java.io.Serializable; pGsu#`t
import java.util.List; mh8)yy5\
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import org.hibernate.Criteria; ^Dys#^
import org.hibernate.HibernateException; 6<9gVh<=w
import org.hibernate.Session; yGlOs]>n
import org.hibernate.criterion.DetachedCriteria; e%KCcU
import org.hibernate.criterion.Projections; y-)5d
import 5Pd^Sew
B{ cb'\C
org.springframework.orm.hibernate3.HibernateCallback; 3=IY0Q>/(
import H`NT`BE
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org.springframework.orm.hibernate3.support.HibernateDaoS #)( D_*
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upport; 9^^:Y3j
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import com.javaeye.common.util.PaginationSupport; _hi8mo
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public abstract class AbstractManager extends N6!$V7oT
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HibernateDaoSupport { "SU
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privateboolean cacheQueries = false; VHx:3G
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privateString queryCacheRegion; >?GCH(eW%
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publicvoid setCacheQueries(boolean Dh .<&ri
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cacheQueries){ n!%'%%o2v
this.cacheQueries = cacheQueries; '<&rMn
} p-B
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{
publicvoid setQueryCacheRegion(String .a
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queryCacheRegion){ 3Hkb)Wu
this.queryCacheRegion = _rvO#h
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queryCacheRegion; tQcn%CK
} 3/4r\%1b+
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publicvoid save(finalObject entity){ X5c)T}pyv
getHibernateTemplate().save(entity); 3zo:)N \K
} !Q5NV4gd+
| gP%8nh'C
publicvoid persist(finalObject entity){ +%LR1+/%b
getHibernateTemplate().save(entity); Vi<F@ji
} YF<U'EVU-
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publicvoid update(finalObject entity){ D'oy%
1Q}
getHibernateTemplate().update(entity); ZGQz@H5
} ;7N~d TBQ
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publicvoid delete(finalObject entity){ $;B0x
getHibernateTemplate().delete(entity); !s(s^
} \Culf'iX
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publicObject load(finalClass entity, aYcc2N%C
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finalSerializable id){ Oq*=oz^~1
return getHibernateTemplate().load )cYbE1=u8>
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(entity, id); 3}2a3)
} %q_b\K
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publicObject get(finalClass entity, 6Wc'5t3
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finalSerializable id){ 4>t=r\"4
return getHibernateTemplate().get 31~Rs?~f(
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(entity, id); 4pZ=CB+j
} R![4|FR
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publicList findAll(finalClass entity){ _?a.S8LxJZ
return getHibernateTemplate().find("from
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" + entity.getName()); C}(9SASs%
} Z'o'd_g>I+
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publicList findByNamedQuery(finalString ]TIBy "3
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namedQuery){ =Bb/Y`Q
return getHibernateTemplate L3y`*&e>
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().findByNamedQuery(namedQuery); C^nTLw;K
} ($[)Tcq*~
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publicList findByNamedQuery(finalString query, Y@Ti2bI`v
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finalObject parameter){ }+i~JK
return getHibernateTemplate P%Tffsl
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().findByNamedQuery(query, parameter); Pm!/#PtX
} c<]~q1
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publicList findByNamedQuery(finalString query, =SLCG.
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finalObject[] parameters){ Kld#C51X f
return getHibernateTemplate f/{*v4!
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().findByNamedQuery(query, parameters); 6tv-PgZ
} \I
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publicList find(finalString query){ A7=k9|
return getHibernateTemplate().find <K
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d{:0R9
(query); 9y( 491"o
} 7V-'><)gI
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publicList find(finalString query, finalObject ZCz#B2Sf8
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parameter){ ;eT+Ly|{
return getHibernateTemplate().find WC`x^HI
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(query, parameter); Tb<}GcwJ
} 52#Ac;Y
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public PaginationSupport findPageByCriteria jC_m0Iwc
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(final DetachedCriteria detachedCriteria){ ^{l$>e]
return findPageByCriteria 3jDAj!_ea
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); !nt[J$.z^
} 40Hm+Ge
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public PaginationSupport findPageByCriteria H?tX^HO:q
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(final DetachedCriteria detachedCriteria, finalint H/N4tWk"
^Rc*X'Iz(!
startIndex){ ~9DD=5\
return findPageByCriteria SCo; Ek
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(detachedCriteria, PaginationSupport.PAGESIZE, EiCEB;*z|d
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startIndex); S0mzDLgE
} ^!sIEL
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public PaginationSupport findPageByCriteria 5Sz}gP('
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(final DetachedCriteria detachedCriteria, finalint gt)wk93d>
$ uqB.f$
pageSize, 'o%6TWl9s
finalint startIndex){ 67T=ku
return(PaginationSupport) YG
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getHibernateTemplate().execute(new HibernateCallback(){ Am"e%|:
publicObject doInHibernate <db>~@;X!
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(Session session)throws HibernateException { osZ]R
Criteria criteria = Q%n$IQr4gM
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detachedCriteria.getExecutableCriteria(session); `/JuItL-
int totalCount = V2LvE.Kj
}0idFotck
((Integer) criteria.setProjection(Projections.rowCount }) Zcw1g
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()).uniqueResult()).intValue(); Js/QL=,
criteria.setProjection R(p3*t&n
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(null); O#?@'1
List items =
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{
criteria.setFirstResult(startIndex).setMaxResults z4{:X Da
5]~451
(pageSize).list(); 4}F~h
PaginationSupport ps = yZkS
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new PaginationSupport(items, totalCount, pageSize,
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'^%k TNn
startIndex); cV:Ak~PKl
return ps; |&U{
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} 2B"&WKk
}, true); ~}RfepM
} y-N]{!
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public List findAllByCriteria(final -Pc6W9$
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DetachedCriteria detachedCriteria){ _)[UartKx
return(List) getHibernateTemplate ZaF9Q%
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().execute(new HibernateCallback(){ <h%I-e6
publicObject doInHibernate 0t7vg#v|
p} {H%L
(Session session)throws HibernateException { f"SK3hI$p
Criteria criteria = <.hutU*1
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detachedCriteria.getExecutableCriteria(session); CaR-Yk
return criteria.list(); 8p_6RvG
} 9J$-E4G.M
}, true); +
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} kxmc2RH>nB
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public int getCountByCriteria(final `#"xgOSP>
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DetachedCriteria detachedCriteria){ xSq{pxX
Integer count = (Integer) Z): Nd9
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getHibernateTemplate().execute(new HibernateCallback(){ g
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publicObject doInHibernate qKTzigjj
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(Session session)throws HibernateException { 0ZJj5<U
Criteria criteria = **JBZ \'
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detachedCriteria.getExecutableCriteria(session); f$ 7C 5
return qHnX)
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criteria.setProjection(Projections.rowCount #mkf2Z=t-
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()).uniqueResult(); :0Z\-7iK
}
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}, true); Kr;;aT0P
return count.intValue();
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} +QNsI2t;r
} V!/9GeIF
*/2nh%>$
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用户在web层构造查询条件detachedCriteria,和可选的 -e"A)Bpl(
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 OrwVRqW-z
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PaginationSupport的实例ps。
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ps.getItems()得到已分页好的结果集 DLuaM?7
ps.getIndexes()得到分页索引的数组 dz!m8D0
ps.getTotalCount()得到总结果数 W4UK?#S+
ps.getStartIndex()当前分页索引 SP/'4m
ps.getNextIndex()下一页索引 `aTw!QBfG
ps.getPreviousIndex()上一页索引 Lv#0-+]$Bt
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错
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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 qsQ{`E0
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一下代码重构了。 ea]qX6)UZ
7Mk>`4D'c
我把原本我的做法也提供出来供大家讨论吧: #ID
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首先,为了实现分页查询,我封装了一个Page类: @T:J<,
java代码: i&?\Pp;5-j
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/*Created on 2005-4-14*/ rVP{ ^Jdo
package org.flyware.util.page; 'v9M``
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/** M\-[C!h,
* @author Joa D, Gv nfY
* 8d_J9Ho
*/ 7F2 RH 8 )
publicclass Page { ` Nf
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/** imply if the page has previous page */ *CPp U|
privateboolean hasPrePage; 8|^&~Rl4
qoOwR[NDcq
/** imply if the page has next page */ qYJ<I'Ux O
privateboolean hasNextPage; ]YtN6Rq/
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/** the number of every page */ OGIv".~s4
privateint everyPage; *5.wwV
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/** the total page number */ 3&CV!+z
privateint totalPage; :;eQ*{ `\
WMC\J(@.
/** the number of current page */ T0Xm}i
privateint currentPage; ;i\N!T{>
qajZ~oB{
/** the begin index of the records by the current #/o~h|g
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query */ ')0@J`
privateint beginIndex; l5.k2{'
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/** The default constructor */ x"g)pGsT
public Page(){ S3l^h4
wU>Fz*
} AH :uG#
e4,SR(O>
/** construct the page by everyPage f;Oh"Yt
* @param everyPage "[!b5f3!I
* */ &l3(+4Sh
public Page(int everyPage){ ?_d6;
this.everyPage = everyPage; r{^43g?
} CgmAxcK
D =mmBo
/** The whole constructor */ pZ}B/j
public Page(boolean hasPrePage, boolean hasNextPage, n1{[CCee@
i@.Tv.NZ
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int everyPage, int totalPage, mvK^')
int currentPage, int beginIndex){ y: x<`E=
this.hasPrePage = hasPrePage; W#~7X
this.hasNextPage = hasNextPage; kl]MP}wc
this.everyPage = everyPage; h x&"f e
this.totalPage = totalPage; |T@SlNi]
this.currentPage = currentPage; \*=wm$p&*
this.beginIndex = beginIndex; 9?MzIt
} J@2wPKh?Yp
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/** `MCiybl,&P
* @return Lc5zu7ncg
* Returns the beginIndex. IH dA2d?.]
*/ ,|s*g'u
publicint getBeginIndex(){ A5J41yH
return beginIndex; v}N\z2A
} |(Mxbprz
#Zw:&'
QB
/** Bh'fkW3
* @param beginIndex @,GL&$Y:W
* The beginIndex to set. \Q(a`6U
*/ Lv]%P.=[G
publicvoid setBeginIndex(int beginIndex){ "A"YgD#t
this.beginIndex = beginIndex; Qy0w'L/@
} 'mbLK#q
hdCd:6
/** O*GF/ R8B
* @return !IdVg $7
* Returns the currentPage. _wK.n.,S~
*/ On}1&!{1]
publicint getCurrentPage(){ $QwpoVp`~
return currentPage; oG1zPspL
} c>K]$;}
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/** #jW -&a
* @param currentPage I2WP/
* The currentPage to set. cJaA*sg
*/ k:Y\i]#yP
publicvoid setCurrentPage(int currentPage){ O^`EuaL
this.currentPage = currentPage; 0S$k;q
} (&Rk#i U
2
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/** =Q40]>bpx
* @return M%`CzCL
u
* Returns the everyPage. /HLI9
*/ sFz0:SqhE
publicint getEveryPage(){ 3?a`@C&x
return everyPage; HTT&T9]
} dhob]8b
Hvm}@3F|
/** W&Fm;m@M
* @param everyPage 9GH5
* The everyPage to set. 8#yu.\N.xt
*/ yiQ ?p:DM
publicvoid setEveryPage(int everyPage){ N'VTdf?
this.everyPage = everyPage; ?-<lIFFh
} __'4Qt
uL^; i""
/** xj;:B( i
* @return K<*6E@+i
* Returns the hasNextPage. aE5-b ub c
*/ kZz'&xdv'.
publicboolean getHasNextPage(){ {WrEe7dLy
return hasNextPage; 0fXMY-$I
} NUYKMo1ze
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/** W+!UVUpW
* @param hasNextPage AE}cHBwZE
* The hasNextPage to set. isL
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*/ q7Hf7^a
publicvoid setHasNextPage(boolean hasNextPage){ _x<NGIz
this.hasNextPage = hasNextPage; g77M5(ME
} sQ#e 2
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/** S4_/%~?
* @return Pj
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* Returns the hasPrePage. d j\Z}[
*/ XYzaSp=bb
publicboolean getHasPrePage(){ lf7bx}P*
return hasPrePage; F)hj\aHm k
} \t7yH]:>@
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/** b!@PS$BTxq
* @param hasPrePage ^7spXfSAd
* The hasPrePage to set. h5'hP>b#
*/ ^1.*NG8
publicvoid setHasPrePage(boolean hasPrePage){ m}wn+R
this.hasPrePage = hasPrePage; T06(Q[)
} Q
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/** pz
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* @return Returns the totalPage. 7?=^0?a
* XG.[C>
*/ R7Y_ 7@p
publicint getTotalPage(){ x8rg/y
return totalPage; =:s`C,l.4
} hi[nUG(OI
?z9!=A%<V~
/** Pz2 b
* @param totalPage wu.l-VmGp)
* The totalPage to set. [j0[c9.p[
*/ +=8wZ]
publicvoid setTotalPage(int totalPage){ e%JIqKS
this.totalPage = totalPage; eT".psRiC
} K|Sq_/#+U
$CE dJ+0z
} cb9-~*1
?.VKVTX^
4[$:KGh3
_U^[h !
~9+01UU^
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 d^}p#7mB\
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个PageUtil,负责对Page对象进行构造: (kLaXayn
java代码: @-)?uYw:r
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/*Created on 2005-4-14*/ T/'z,,Y
package org.flyware.util.page; Gw<D'b)!
^Lgvey%
import org.apache.commons.logging.Log; e-ta 7R4
import org.apache.commons.logging.LogFactory; -"I$$C
c#N4XsG,
/** lr>NG,N
* @author Joa "#O9ij
* d&NnpjH}c
*/ ynIC (t
publicclass PageUtil { Q ]CMm2L^f
@njNP^'Kx
privatestaticfinal Log logger = LogFactory.getLog :8)Jnh\5
'v]0;~\mp>
(PageUtil.class); $NVVurXa
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/** .|O T#"LP
* Use the origin page to create a new page /q IQE&V-
* @param page |_TiF;^
* @param totalRecords >
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* @return eC!=4_lx)
*/ q%4X1 W
publicstatic Page createPage(Page page, int S oeoUI]m
k9x[(
#
totalRecords){ RTc@`m3 M
return createPage(page.getEveryPage(), @
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page.getCurrentPage(), totalRecords); z{W Cw
} q2EDrZ
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/** w6V/Xp][U
* the basic page utils not including exception ;|Mfq`s
WA(x]""
handler 0 %~~IT}U
* @param everyPage jB?SX
* @param currentPage w.x&3aG
* @param totalRecords n2mO-ZXud
* @return page H4y9\
-
*/ ^N/d`IAjv
publicstatic Page createPage(int everyPage, int r ]7: ?ir
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currentPage, int totalRecords){ O^MI073Q>t
everyPage = getEveryPage(everyPage); \t!~s^ Oox
currentPage = getCurrentPage(currentPage); ,JZ>)(@)
int beginIndex = getBeginIndex(everyPage, 8 MO-QO
+F)-n2Bi
currentPage); ./F:]/Mt
int totalPage = getTotalPage(everyPage, /2?
CB\
[on_=N{W[
totalRecords); V5K/)\#
boolean hasNextPage = hasNextPage(currentPage, t%Jk3W/f
kGV:=h
totalPage); X}Oe 'y
boolean hasPrePage = hasPrePage(currentPage); B.; qvuM~
H'k}/<%Q
returnnew Page(hasPrePage, hasNextPage, `<nxXsLe
everyPage, totalPage, ,\6Vb*G|E>
currentPage, 712nD ?>
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beginIndex); I}_}VSG(
} BY~Tc5
vIRT$W' O}
privatestaticint getEveryPage(int everyPage){
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return everyPage == 0 ? 10 : everyPage; tB4mhX|\
} $P{`-Y }a
"-=fi
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privatestaticint getCurrentPage(int currentPage){ J%CCUl2
return currentPage == 0 ? 1 : currentPage; g!XC5*}
} INA3^p'w
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privatestaticint getBeginIndex(int everyPage, int fbh,V%t7
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currentPage){ =^KgNQ
return(currentPage - 1) * everyPage; Nm"P8/-09
} NBPP?\1
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privatestaticint getTotalPage(int everyPage, int $9`#p/V
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totalRecords){ W0f^!}f(
int totalPage = 0; PLkS-B
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if(totalRecords % everyPage == 0) JdS,s5Z>
totalPage = totalRecords / everyPage; +4:eb)e
else e#*3X4<\K
totalPage = totalRecords / everyPage + 1 ; (xb2H~WrN
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return totalPage; lEHx/#qt9
} UH MJ(.Wa-
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privatestaticboolean hasPrePage(int currentPage){ 8._uwA<[
return currentPage == 1 ? false : true; -$:;en?
} (,h2qP-;ud
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privatestaticboolean hasNextPage(int currentPage, zP44
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int totalPage){ ]Kt@F0U<o
return currentPage == totalPage || totalPage == 86=W}eV1r
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0 ? false : true; GTR*3,rw
} d^=)n-!T
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} #^L&H
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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。 4gen,^ Ij
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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 {IgH0+z
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做法如下: ;M.Q=#;E
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 0OM^,5%8
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的信息,和一个结果集List: 4 eLZ
java代码: 1b3 a(^^E
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/*Created on 2005-6-13*/ g[(@@TiG
package com.adt.bo; .aT@'a{F
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import java.util.List; Onq^|r's&
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import org.flyware.util.page.Page; KVOV<uDCj
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/** a]r+np]vTy
* @author Joa t)&U'^
*/ 3Z";a
publicclass Result { ?+Gt?-! 5q
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private Page page; vQ}ZfP
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private List content; 5[4wN(
)
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/** -*k2:i`
* The default constructor &za
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*/ <J<"`xKL
public Result(){ K80f_iT5
super(); +KbkdYZ
} b,^ "-r
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;
/** yn\c;Z
* The constructor using fields Ss%Cf6qdWL
* g)#?$OhP"
* @param page dM;\)jm
* @param content @MOQk
*/ *F1TZ_GS
public Result(Page page, List content){ \}Am]Y/ w
this.page = page; OWibmX
this.content = content; ms0V1`
} }*(_JR4G
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/** Aars\
* @return Returns the content. ',R%Q0Q
*/ |J!mM<*K
publicList getContent(){ $sY'=S
return content; h\[@J rDa
} `o{ Z;-OF
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/** >UCg3uFj
* @return Returns the page. #//xOL3J
*/ &9flNoNR9
public Page getPage(){ th73eC'
return page; ^W$R{`
} x6,ozun
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/** |~5cNm
* @param content >
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* The content to set. ];k!*lR)
*/ )zxb]Pg+
public void setContent(List content){ L(yUS)O
this.content = content; u9 &$`N_G
} 1Of(O!
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/** , ~
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* @param page O5r8Ghf)
* The page to set. q%x i>H.:{
*/ 'etA1]<N
publicvoid setPage(Page page){
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this.page = page; vSHPN|*
} d3q%[[@
} xmnBG4,f
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