Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ]_*S~'x
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 w#G2-?aj
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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 Q^eJ4{Ya:
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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 |bZM/U=
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分页支持类: ySdN;d:q
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java代码: d<o.o?Vc
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package com.javaeye.common.util; sLcY,AH
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import java.util.List; v:ER4
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publicclass PaginationSupport { >cOeiK
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publicfinalstaticint PAGESIZE = 30; v%{0 Tyk
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privateint pageSize = PAGESIZE;
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privateList items; &m{'nRU}c
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privateint totalCount; Z/ bB
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privateint[] indexes = newint[0]; V+B71\x<
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privateint startIndex = 0; *FgJ|y6gk
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public PaginationSupport(List items, int Ya4?{2h@+
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totalCount){ mv
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setPageSize(PAGESIZE); ~I_owCVZ
setTotalCount(totalCount); EZr6oO@Nc
setItems(items); 9q4_j
setStartIndex(0); zjM/M
} !G=>ve
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public PaginationSupport(List items, int IS_Su;w>4
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totalCount, int startIndex){ -wr(vE,
setPageSize(PAGESIZE); FRyPeZR
setTotalCount(totalCount); RR25Q.c
setItems(items); ]EL\)xCr
setStartIndex(startIndex); RtF8A5ys
} ]W9B6G_
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public PaginationSupport(List items, int G!-J$@P
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totalCount, int pageSize, int startIndex){ ,ECAan/@
setPageSize(pageSize); .gD km^
setTotalCount(totalCount); Enj_tJs
setItems(items); LM,fwAX
setStartIndex(startIndex); +l\<?
} "n- pl
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publicList getItems(){ !EFBI+?&
return items; y lL8+7W
} |>utWT]S
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publicvoid setItems(List items){ kojG-M
this.items = items; r,'O).7
} /7p>7q9g
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publicint getPageSize(){ <'*4j\*
return pageSize; q Z\L
} @ ^.*$E5
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publicvoid setPageSize(int pageSize){ /t{=8v~
this.pageSize = pageSize; 1X@b?6
} A@ VaaX
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publicint getTotalCount(){ 6"%qv`.Fp
return totalCount; w~-X>~ }
} ( pD7
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publicvoid setTotalCount(int totalCount){ Vipp /WV
if(totalCount > 0){ ~%P3Pp
this.totalCount = totalCount; ;X7i/DQ
int count = totalCount / j.&
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pageSize; SfDQ;1?
if(totalCount % pageSize > 0) VK4/82@5
count++; B)a@fmp"a
indexes = newint[count]; TG]}X\c+V|
for(int i = 0; i < count; i++){ nEVbfNo0
indexes = pageSize * JD&U}dJ
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i; &7][@v
} /co%:}ln
}else{ j`9Nwa
this.totalCount = 0; BTs0o&}e
} FfXZ|o$;
} `vEqj v
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publicint[] getIndexes(){ 1f;or_f#k?
return indexes; UPO^V:.R4
} ,9vJtP+T+!
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publicvoid setIndexes(int[] indexes){ m<FK;
this.indexes = indexes; [d:@1yc
} 4WG=m}X
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publicint getStartIndex(){ =c]a
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return startIndex; H5p5S\g-)
} \\s?B K
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publicvoid setStartIndex(int startIndex){ 9l l|JeNi
if(totalCount <= 0) J0qXtr%h\
this.startIndex = 0; V/&o]b
elseif(startIndex >= totalCount) 8r^j P.V
this.startIndex = indexes r#I>_Utsy
2fP~;\AP
[indexes.length - 1]; 9fCO7AE0#
elseif(startIndex < 0) "OJr*B
this.startIndex = 0; =M7PvH'"
else{ Mk "vvk
this.startIndex = indexes #^;s<YZ`
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[startIndex / pageSize]; `:3&@.{T(
} \CwtX(6.
} nrbazyKm
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publicint getNextIndex(){ \bRy(Z)
int nextIndex = getStartIndex() + 2YluJ:LN
ex0oAt^
pageSize; &q L<C
if(nextIndex >= totalCount) #'iPDRYy
return getStartIndex(); Q>[Ce3
else X\'E4
return nextIndex; z.j4tc9F/5
} j88=f#<
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publicint getPreviousIndex(){ xfes_v""
int previousIndex = getStartIndex() - Ff&R0v
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pageSize; 8.-S$^hj~6
if(previousIndex < 0) nHVPMi>
return0; h,.fM}=H
else O sB?1;:
return previousIndex; soxfk+
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} 6~3jn+K$1
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} 9PCa*,
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抽象业务类 sU0Stg8&b
java代码: hw|t8 ShW
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/** q>P[n z%
* Created on 2005-7-12 _ Q{T ';
*/ -Sp/fjlq/
package com.javaeye.common.business; !6{Jq]
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import java.io.Serializable; pOX$4$VR<
import java.util.List; eL_^: -
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import org.hibernate.Criteria; )FV6,
import org.hibernate.HibernateException; 1O23"o5=
import org.hibernate.Session; s9G)Bd 8
import org.hibernate.criterion.DetachedCriteria; oFb\TiLu
import org.hibernate.criterion.Projections; K,G,di
import *^ey]),f54
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org.springframework.orm.hibernate3.HibernateCallback; '%);%y@v
import dA|Lufy#
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org.springframework.orm.hibernate3.support.HibernateDaoS Q|Nzbmwh
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upport; ,T/GW,?
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import com.javaeye.common.util.PaginationSupport; T0s35z9
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public abstract class AbstractManager extends {[my"n2
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HibernateDaoSupport { Imke/ =h
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privateboolean cacheQueries = false; :&qC <UD
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privateString queryCacheRegion; u/;_?zI
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publicvoid setCacheQueries(boolean `!<x"xKu
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cacheQueries){ ^4RO
this.cacheQueries = cacheQueries; ~d&'Lp[3
} u"*J[M~
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publicvoid setQueryCacheRegion(String ;,mBT[_ZO
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queryCacheRegion){ !~?W \b\:
this.queryCacheRegion = a^%8QJW
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queryCacheRegion; 23)F-.C}j
} E1^aAlVSD
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publicvoid save(finalObject entity){ )o86lH"z
getHibernateTemplate().save(entity); P_kaIPP
} f%vHx,
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publicvoid persist(finalObject entity){ IES41y<
getHibernateTemplate().save(entity); 0W;q!H[G
} *iPs4Es-
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publicvoid update(finalObject entity){ 6.k^m&-A
getHibernateTemplate().update(entity); -6AOK<kfI
} 9cl{hdP{
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publicvoid delete(finalObject entity){ an-\k*w
getHibernateTemplate().delete(entity); [t {vYo
} _e;N'DZ
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publicObject load(finalClass entity, !1D%-=dWX
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finalSerializable id){ "ugX
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return getHibernateTemplate().load >oVc5}
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(entity, id); M|1eqR%x-?
} 7^n,Tig
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publicObject get(finalClass entity, 5}<.1ab3V
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finalSerializable id){ H?rSP0.
return getHibernateTemplate().get 7yo|ie@S
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(entity, id); e_YW~z=6t
} ]R97n|s_
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publicList findAll(finalClass entity){ \/?
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return getHibernateTemplate().find("from sZ0g99eX
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" + entity.getName()); ]$* $0
} OI)&vQ5k
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publicList findByNamedQuery(finalString k/$Ja;
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namedQuery){ oA(. vr
return getHibernateTemplate ]s1TJw [B
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().findByNamedQuery(namedQuery); ~Da
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} =YS!soO
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publicList findByNamedQuery(finalString query, D<+ bzC
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finalObject parameter){ sV9{4T~#|
return getHibernateTemplate g
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().findByNamedQuery(query, parameter); e_fg s>o`(
} },?-$eyX
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publicList findByNamedQuery(finalString query, 44Seq
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finalObject[] parameters){ 9+WY@du+
return getHibernateTemplate *Y|lO
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().findByNamedQuery(query, parameters); #o(?g-3
} *!-}lc^4
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publicList find(finalString query){ o+)m}'T8
return getHibernateTemplate().find VZ9e~){xA
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(query); ZwY`x')
} m?
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publicList find(finalString query, finalObject DzX6U[=
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parameter){ 20SF<V
return getHibernateTemplate().find D@/9+]-,
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(query, parameter); LH?gJ8`
} oT9XJwqnv
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public PaginationSupport findPageByCriteria +oxqS&$L
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(final DetachedCriteria detachedCriteria){ z9OMC$,V
return findPageByCriteria K-g=td/@
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); A;/Xt
} ;iwD/=Y
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public PaginationSupport findPageByCriteria }RC.Q`b
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(final DetachedCriteria detachedCriteria, finalint (o6A?37i
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startIndex){ -7C=- \]
return findPageByCriteria (AyRs7Dkn
(
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(detachedCriteria, PaginationSupport.PAGESIZE, X:zyzEhS
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startIndex); ul5::
} A_X^k|)T
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public PaginationSupport findPageByCriteria (>)+;$Dr,\
8&`T<ECq>
(final DetachedCriteria detachedCriteria, finalint v]d?6g
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pageSize, 7@e[:>e
finalint startIndex){ U3VsMV*Y
return(PaginationSupport) j3V"d 3)
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getHibernateTemplate().execute(new HibernateCallback(){ %Pt[3>
publicObject doInHibernate unbcz{&Hb[
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(Session session)throws HibernateException { HeAc(_=C
Criteria criteria = `siy!R
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detachedCriteria.getExecutableCriteria(session); :#"OCXr
int totalCount = l#J>It\
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((Integer) criteria.setProjection(Projections.rowCount *(XgUJq+
@/ovdf{
()).uniqueResult()).intValue(); [3bwbfHhi
criteria.setProjection ~k:>Xo[|O
,M9hb<:m
(null); ,_4KyLfBF
List items = +$pO
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criteria.setFirstResult(startIndex).setMaxResults [))2u:tbS\
z;@S_0M,Z
(pageSize).list(); %Tm'aY"
PaginationSupport ps = X~/9Vd g
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new PaginationSupport(items, totalCount, pageSize, iR4,$Nn>
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startIndex); m SvTnd8
return ps; nG(|7x
} Xb07 l3UG
}, true); s$=B~l
} m<VL19o>R
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public List findAllByCriteria(final l<+,(E=
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DetachedCriteria detachedCriteria){ _ZvX" {y~
return(List) getHibernateTemplate EWvid4QEi
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().execute(new HibernateCallback(){ 7C6BZ$(
publicObject doInHibernate }e;p8)]Wl
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(Session session)throws HibernateException { 70 DQ/b
Criteria criteria = j(2tbWg9-
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detachedCriteria.getExecutableCriteria(session); 8i+jFSZ$
return criteria.list(); C ^ k3* N
} v(WL 3[y;
}, true); u>-uRz<)t
} rBL_]\$7}
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public int getCountByCriteria(final I[YfF
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DetachedCriteria detachedCriteria){ ?(XX
Integer count = (Integer) UW~tS
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getHibernateTemplate().execute(new HibernateCallback(){ U1@P/
publicObject doInHibernate d`rDEa
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(Session session)throws HibernateException { m:o$|7r
Criteria criteria = aG&kl O>m
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detachedCriteria.getExecutableCriteria(session); @eD2<e
return W71#NjM2Z
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criteria.setProjection(Projections.rowCount u=?P*Y/|W
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()).uniqueResult(); vzQmijr-
} Lw78v@dY
}, true); dYttse'
return count.intValue(); 1 bx^Pt)
} dXr
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} $[9V'K
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用户在web层构造查询条件detachedCriteria,和可选的 pl? J<48
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 O#ajoE
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PaginationSupport的实例ps。 *xX0]{49q
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ps.getItems()得到已分页好的结果集 /t2<OU9
ps.getIndexes()得到分页索引的数组 4rCqN.J
ps.getTotalCount()得到总结果数 e2H'uMy;&
ps.getStartIndex()当前分页索引 XT;IEZQZ
ps.getNextIndex()下一页索引 7UnO/K7oB.
ps.getPreviousIndex()上一页索引 Kh_>V m/
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 i_9/!D
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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 [75e\=wK
XsCbJ[Z_?q
一下代码重构了。 ;R>42
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我把原本我的做法也提供出来供大家讨论吧: !)1Zp*
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首先,为了实现分页查询,我封装了一个Page类: 1+[|pXT}
java代码: M>l+[U
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/*Created on 2005-4-14*/ PbC>v
package org.flyware.util.page; $zH0$aOx
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/** `e:RZ
* @author Joa UmMYe4LQR
* |UiykQ
*/ z+`)|c4-
publicclass Page { ymJw{&^am
B~?Q. <M
/** imply if the page has previous page */ Yl3PZ*#@ Q
privateboolean hasPrePage; C F 0IP
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/** imply if the page has next page */ "PP0PL^5F
privateboolean hasNextPage; hndRgCo
bGLp0\0[
/** the number of every page */ >.sN?5}y
privateint everyPage; ?v*7!2;
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/** the total page number */ Z4tq&^ :c=
privateint totalPage; Q/SC7R&"t
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/** the number of current page */ YuuG:Kk
privateint currentPage; "+C\f)
8-#2?=
/** the begin index of the records by the current *y$r y]
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query */ SQ.Wj?W)
privateint beginIndex; \Xp"I5
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/** The default constructor */ s: .XF|e{
public Page(){ |1 6v4 R
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} (M?Q9\X
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/** construct the page by everyPage \d`Sz
*
* @param everyPage =1?yS3
* */ '.v^seU
public Page(int everyPage){ *g}&&$b0
this.everyPage = everyPage; XsMphZnK
} Lu5.$b
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/** The whole constructor */ -w0>4JDs
public Page(boolean hasPrePage, boolean hasNextPage, y`dzo`f
(NlEb'~+
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int everyPage, int totalPage, a-hGpYJJG
int currentPage, int beginIndex){ -L3RzX
this.hasPrePage = hasPrePage; ^@> Qiy
this.hasNextPage = hasNextPage; +Ea XS
this.everyPage = everyPage; H2KY$;X[
this.totalPage = totalPage; 2$UR"P
this.currentPage = currentPage; q{(&:~M
this.beginIndex = beginIndex; !Z)^c&
} b
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/** I(S6DkU
* @return N#ObxOE6T"
* Returns the beginIndex. \mGM#E
*/ 2geC3v% 0o
publicint getBeginIndex(){ DgP%Q
return beginIndex; vGDo?X~#o
} 9^olAfX`dB
xb;mm9H
/** f ebh1rUX
* @param beginIndex uwzT? C A6
* The beginIndex to set. K>6p5*&
*/ SW,Po>Y
publicvoid setBeginIndex(int beginIndex){ a"4 6_>
this.beginIndex = beginIndex; hgltD8,
} 1i2w<VG1
h!]A(T\J
/** K@hUif|([
* @return &9{BuBO[
* Returns the currentPage. ,:{+
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*/ EC/R|\d?Un
publicint getCurrentPage(){ %W+Fe,]
return currentPage; CB1u_E_
} &o.SmkJI
z w9r0bG
/** m8'1@1d|
* @param currentPage 7F~+z7(h
* The currentPage to set. h#nQd=H<g#
*/ _%B`Y ?I`
publicvoid setCurrentPage(int currentPage){ ]^<~[QK_C
this.currentPage = currentPage; W@=ilW3RD
} tT:yvU@a
U @|_5[nl
/** A@r,A?(
* @return ^Quy64M
* Returns the everyPage. '~0&m]N
*/ a/fYD2uNo
publicint getEveryPage(){ _{%H*PxTn=
return everyPage; 8E{>czF"
} PMcyQ2R->
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/** \9^@,kfP
* @param everyPage lla96\R
* The everyPage to set. "
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*/ <ZEA&:p
publicvoid setEveryPage(int everyPage){ |zKcL3*
this.everyPage = everyPage; W{d/m;<@N
} <5%We(3
Viw3 /K
/** u!W00;`L
* @return 3OlY Ml
* Returns the hasNextPage. I4'j_X
t
*/ \\JXY*DA:+
publicboolean getHasNextPage(){ T~>:8i
return hasNextPage; ?a@l.ZM*
} *VB*/^6A
4y]*"(sQ;
/** tP-c>|cz
* @param hasNextPage =_Rd0,
* The hasNextPage to set. e<K=Q$U.
*/ ;]!
publicvoid setHasNextPage(boolean hasNextPage){ _NFJm(X.
this.hasNextPage = hasNextPage; Pif1sL6'
} +8M{y D9#
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/** c/RG1w
* @return LJD"N#c
* Returns the hasPrePage. f&'md
*/ -5K/ cK
publicboolean getHasPrePage(){ , utFCZW
return hasPrePage; 4p.O<f;A8
} tN~{Mt$-W
"2J;~
/** szHUHW~;J
* @param hasPrePage 4~4Hst#^
* The hasPrePage to set. S5JnJkNn
*/ K9R[
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publicvoid setHasPrePage(boolean hasPrePage){ bu-
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this.hasPrePage = hasPrePage; .@'Vz;&mQ
} 5|Qr"c$p
xlAaIo)T
/** `F#KXk
* @return Returns the totalPage. H@zpw1fH+
* U!4 ^;
*/ ) =[Tgh
publicint getTotalPage(){ 0U'r ia:$
return totalPage; <,{v>vlw
} R[QE:#hT
C;` fOCz^
/** jolCR-FDu
* @param totalPage <Vim\
* The totalPage to set. ]+AI:
*/ DWAU8>c+
publicvoid setTotalPage(int totalPage){ @,]v'l!u
this.totalPage = totalPage; <IYt*vlm
} 4.8,&{w<m
0^=S:~G
} 7Do)++t
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lk80)sTZ
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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 yAOC<d9 E
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个PageUtil,负责对Page对象进行构造: x{m)I<.:
java代码: 4[?Q*f!
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L>B0%TP^
/*Created on 2005-4-14*/ GCrN:+E0FJ
package org.flyware.util.page; N`M5`=.
xK/`XY
import org.apache.commons.logging.Log; wgrYZ^]
import org.apache.commons.logging.LogFactory; rO
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cMj<k8.{
/** x\*5A,w{c]
* @author Joa O1z>A
* =c|Bu^(Ctw
*/ =xgW$c/yB
publicclass PageUtil { I
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privatestaticfinal Log logger = LogFactory.getLog ;BqX=X+#
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(PageUtil.class); +wmfl:\^{H
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/** 7
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* Use the origin page to create a new page }5~;jN=k
* @param page X@arUs7
* @param totalRecords L2 I/h`n"
* @return 7Qo*u;fr
*/ ]SQ_*$`
publicstatic Page createPage(Page page, int @t_<oOI2
kz#DBh!&
totalRecords){ *
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return createPage(page.getEveryPage(), /F\7_
p'H5yg3h
page.getCurrentPage(), totalRecords); 8w{V[@QLn
} xe5>)\18-
dWI\VS 9
/** w(vf>L6(
* the basic page utils not including exception 9`xq3EL2T
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handler `p!.K9r7
* @param everyPage 4o%hH
* @param currentPage toF@@%
* @param totalRecords (vY10W{
* @return page L9x,G!
*/ Iv{}U\ u
publicstatic Page createPage(int everyPage, int a@%FwfIu
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currentPage, int totalRecords){ V@$B>HeK
everyPage = getEveryPage(everyPage); 7B'0(70
currentPage = getCurrentPage(currentPage); Cnn,$R=/s
int beginIndex = getBeginIndex(everyPage, 9Vp$A$7M
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currentPage); Q[}mH: w
int totalPage = getTotalPage(everyPage, UPbG_ #"wZ
2+|[e_
totalRecords); 6ds&n#n
boolean hasNextPage = hasNextPage(currentPage, V482V#BP
jildiT[s
totalPage); 5bgx;z9
boolean hasPrePage = hasPrePage(currentPage); l!`m}$
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returnnew Page(hasPrePage, hasNextPage, uz%rWN`{
everyPage, totalPage, &)rmv
currentPage, 3 iY`kf
c^m}ep\F5L
beginIndex); /ZAEvdO*P
} " I:j a7
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privatestaticint getEveryPage(int everyPage){ ,\Cy'TSz
return everyPage == 0 ? 10 : everyPage; C<{k[!N%zm
} &ed.%:
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privatestaticint getCurrentPage(int currentPage){ }APf^Ry
return currentPage == 0 ? 1 : currentPage; f9;M"Pd
} $[IuEdc/
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privatestaticint getBeginIndex(int everyPage, int +|^rz#X
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currentPage){ ^G5_d"Gr
return(currentPage - 1) * everyPage; [~$9n_O94
} 42Z2Mjtk
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privatestaticint getTotalPage(int everyPage, int htIV`_<Ro
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totalRecords){ U#YM)8;Iz
int totalPage = 0; ni9/7
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if(totalRecords % everyPage == 0) N'TL &]
totalPage = totalRecords / everyPage; 2LXy$[)7
else ny{|{a
totalPage = totalRecords / everyPage + 1 ; qRTy}FU1
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return totalPage; iQ:]1H s
} f\1)BZ'I
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privatestaticboolean hasPrePage(int currentPage){ z~Gi/Ln
return currentPage == 1 ? false : true; zxXm9zrLo
} "`16-g97
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privatestaticboolean hasNextPage(int currentPage, Rs7=v2>I
&d=j_9
int totalPage){ YMC*<wXN
return currentPage == totalPage || totalPage == |]^OX$d
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0 ? false : true; waldLb>7D
} qY0p)`3!%
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} LC/6'4}_
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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|v{[>tr
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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 ~gmj/PQ0
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做法如下: u1(`^^Ml
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 y?;&(Tcbt8
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的信息,和一个结果集List: an=8['X
java代码: ~[t%g9
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+,f|Y6L<