Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 )/T[Cnx.Nc
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 BzzC|
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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 4Z"}W!A
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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 =RQF::[h
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。 |kYlh5/c d
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分页支持类: b(iF0U>&
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java代码: 'NEl`v*<P
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package com.javaeye.common.util; )6OD@<r{
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import java.util.List; ^3;B4tj[
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publicclass PaginationSupport { {M]_]L{&7
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publicfinalstaticint PAGESIZE = 30; Nd~B$venh
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privateint pageSize = PAGESIZE; 1/.BP
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privateList items; l4bytI{63
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privateint totalCount; 8tj]@GE
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privateint[] indexes = newint[0]; Fc~G*Gz~Z|
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privateint startIndex = 0; -@pjEI
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public PaginationSupport(List items, int )PX VR
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totalCount){ 77P\:xc
setPageSize(PAGESIZE); <J/ =$u/
setTotalCount(totalCount); ma.84~m
setItems(items); i?x gV_q;
setStartIndex(0); mMAN*}`O
} ?Nos;_/
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public PaginationSupport(List items, int q~ H>rC(\
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totalCount, int startIndex){ to={q
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setPageSize(PAGESIZE); "H-s_Y#
setTotalCount(totalCount); dljE.peL
setItems(items); uO%0rKW
setStartIndex(startIndex); 2|nm> 4
} :gVUk\)
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public PaginationSupport(List items, int K d&/9<{>
d)o5JD/
totalCount, int pageSize, int startIndex){ E }L Hp
setPageSize(pageSize); `|dyT6V0I_
setTotalCount(totalCount); mUYRioNj
setItems(items); ZT0\V
]!B
setStartIndex(startIndex); P`Np+E#I
} %B s. XW,
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publicList getItems(){ nV'1 $L#
return items; V=O52?8
} zF1!a
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publicvoid setItems(List items){ 3:J>-MO
this.items = items; AGlBvRX7e
} VD;*UkapZx
^HKXm#vAB
publicint getPageSize(){ .wfydu)3
return pageSize; SE'Im
} $O"ss>8Se
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publicvoid setPageSize(int pageSize){ u47<J?!Q
this.pageSize = pageSize; }w0pi
} r&gvP|W%
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publicint getTotalCount(){ XiUq#84Q
return totalCount; MmF&jd-=
} 70'OS:J=\
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publicvoid setTotalCount(int totalCount){ gq=t7b
if(totalCount > 0){ *1|7%*!8
this.totalCount = totalCount; ACszx\[K3
int count = totalCount / +|A`~\@N
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pageSize; w"hd_8cO
if(totalCount % pageSize > 0) iRQ!J1SGcG
count++; =sJ?]U
indexes = newint[count]; R\j~X@vI
for(int i = 0; i < count; i++){ 8Fn\ycX#"l
indexes = pageSize * M0V<Ay\%O
tsXKhS;/w
i; +
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} tl#sCf!c
}else{ Vk2$b{VdF
this.totalCount = 0; m1$tf
^
} I^NDJdxd
} vFPY|Vzh
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publicint[] getIndexes(){ {6i|"5_j
return indexes; ~?Zib1f)
} [vg&E
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publicvoid setIndexes(int[] indexes){ TnrBHaxbo4
this.indexes = indexes; ;mQj2Bwr
} A5<t> 6Y
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publicint getStartIndex(){ at uqo3
return startIndex; 9&+]YYCS-
} K<S3gb?0
c -w #`
publicvoid setStartIndex(int startIndex){ <BR^Dv07U
if(totalCount <= 0) .. `I<2
this.startIndex = 0; fzsy<Vl",
elseif(startIndex >= totalCount) 9"~ FKMN
this.startIndex = indexes Z#[?~P
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[indexes.length - 1]; -/f$s1
elseif(startIndex < 0) *+M#D^qo
this.startIndex = 0; mLCDN1UO{
else{ U^m#!hp
this.startIndex = indexes [WwoGg*)mn
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[startIndex / pageSize]; a5*r1,
} VAPeMO
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} u`MMK4 %
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publicint getNextIndex(){ pH'_k k
int nextIndex = getStartIndex() + ^<I(
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pageSize; gOF^?M11x
if(nextIndex >= totalCount) p9v:T1?
return getStartIndex(); +nYFLe
else d$!Q6ux;
return nextIndex; g=Xf&}&=x
} ?sN{U\
DDE-$)lf>
publicint getPreviousIndex(){ 4 m:h&^`N
int previousIndex = getStartIndex() - X[B P0:`t
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pageSize; 0|&@)`
if(previousIndex < 0) $1f2'_`8~
return0; BgQEd@cN
else k:0j;\Sx
return previousIndex; zWY988fX0
} E&U_1D9=L<
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} :i.@d?
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抽象业务类 u\\t~<8
java代码: Hw \of
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/** 2<D| {
* Created on 2005-7-12 X^\D"fmE.
*/ \n<!
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package com.javaeye.common.business; UtQj<18<
)/RG-L
import java.io.Serializable; b\P:a_vq
import java.util.List; q
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import org.hibernate.Criteria; U5Hi9fe
import org.hibernate.HibernateException; ]]j^
import org.hibernate.Session; yE}\4_0I/
import org.hibernate.criterion.DetachedCriteria; YR?Y:?(
import org.hibernate.criterion.Projections; z; GQnAG@
import g=Z52y`N<
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org.springframework.orm.hibernate3.HibernateCallback; RpJ7.
import !se1W5ke#
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org.springframework.orm.hibernate3.support.HibernateDaoS ;cMQ0e
Oeh A3$|#
upport; O= S[n
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import com.javaeye.common.util.PaginationSupport; MK1\
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public abstract class AbstractManager extends :nx+(xgw
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HibernateDaoSupport { OZ&/&?!XE
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privateboolean cacheQueries = false; u8-6s+
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privateString queryCacheRegion; b A+_/1C
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publicvoid setCacheQueries(boolean 7zu\tCWb
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cacheQueries){ `~XksyT
this.cacheQueries = cacheQueries; ~F"S]
} j
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publicvoid setQueryCacheRegion(String 3](hMk,}
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queryCacheRegion){ ?+zFa2J
this.queryCacheRegion = &5W;E+Pub
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queryCacheRegion; 3x~7N
} Wga2).j6
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publicvoid save(finalObject entity){ p:08q
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getHibernateTemplate().save(entity); <K CI@
} .W{CJh
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publicvoid persist(finalObject entity){ DzVCEhf
getHibernateTemplate().save(entity); VrIN.x
} sxT&T=7
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publicvoid update(finalObject entity){ '{
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getHibernateTemplate().update(entity); Q.N!b7r7
} 4R'CLN
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publicvoid delete(finalObject entity){ 1KZigeHXI
getHibernateTemplate().delete(entity); ?UsCSJ1V
} z~t0l
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publicObject load(finalClass entity, z/\OtYz
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finalSerializable id){ URb8[~dR:
return getHibernateTemplate().load G_+/ e]P
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(entity, id); '8 .JnCg
} 2Mx\D
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publicObject get(finalClass entity, J _rrc;F
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finalSerializable id){ }H
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return getHibernateTemplate().get j|KDgI<0
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(entity, id); )0/9
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} /9br &s$B
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publicList findAll(finalClass entity){ m!ZY]:)$
return getHibernateTemplate().find("from bMKX9`*o
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" + entity.getName()); 7qqzL_d>
} }uma<b
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publicList findByNamedQuery(finalString .Y6v#VI
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namedQuery){ )K[\j?
return getHibernateTemplate v~SM"ky#
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().findByNamedQuery(namedQuery); #scZP
} 4aArxJ
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publicList findByNamedQuery(finalString query, '~Y@HRVL@|
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finalObject parameter){ kWW2N0~$
return getHibernateTemplate rR6}
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().findByNamedQuery(query, parameter); 26p[x'W
} !7DDPJ~
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publicList findByNamedQuery(finalString query, .2&L.
]@ruizb8
finalObject[] parameters){ 1^|#QMT
return getHibernateTemplate Hs)Cf)8u
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().findByNamedQuery(query, parameters); /3M8;>@u
} 5n?P}kca)
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publicList find(finalString query){ rfk{$g
return getHibernateTemplate().find Qyw@ r
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(query); sT;wHtU
} glLVT
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publicList find(finalString query, finalObject i.^ytbH
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parameter){ loIb}8
return getHibernateTemplate().find vCP[7KhGj
qb[hKp5K6
(query, parameter); L2>e@p\>
} |Y
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public PaginationSupport findPageByCriteria %T]$kF++&
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(final DetachedCriteria detachedCriteria){ 1_t+lJI9j
return findPageByCriteria pl).U#7`
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ^i|R6oO_5
} %W~w\mT
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public PaginationSupport findPageByCriteria Oa/zEH
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(final DetachedCriteria detachedCriteria, finalint ~vA{I%z5~
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startIndex){ ?#w} S%
return findPageByCriteria ktrIi5B
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(detachedCriteria, PaginationSupport.PAGESIZE, LWCFCkx%
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startIndex); p{5m5x
} .=;IdLO,Bf
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public PaginationSupport findPageByCriteria _Z(t**Zh6y
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(final DetachedCriteria detachedCriteria, finalint RiQ]AsTtl
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pageSize, HaVhdv3L
finalint startIndex){ 5TJd9:\Af
return(PaginationSupport) bY#BK_8 :
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getHibernateTemplate().execute(new HibernateCallback(){ N" L&Z4Z
publicObject doInHibernate l$&~(YE f
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(Session session)throws HibernateException { b=r 3WkB6
Criteria criteria = X8ulaa
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detachedCriteria.getExecutableCriteria(session); !hq2AY&H)
int totalCount = r>(,)rs(l
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((Integer) criteria.setProjection(Projections.rowCount 0{b} 1D
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()).uniqueResult()).intValue(); $6Q^ur:
criteria.setProjection V~/G,3:0y%
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(null); G$f%]A1
List items = ],SQD3~9
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criteria.setFirstResult(startIndex).setMaxResults CFh9@Nx
jh oA6I
(pageSize).list(); #VrIU8Q7'
PaginationSupport ps =
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new PaginationSupport(items, totalCount, pageSize, t}eyfflZ
] :;x,$k
startIndex); K ~mUO
return ps; !Q[v"6?
} y2I7Zd .
}, true); 5csh8i'V
} O?X[&t
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public List findAllByCriteria(final mi] WZlg$
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DetachedCriteria detachedCriteria){ Wu{=QjgY
return(List) getHibernateTemplate o*H U^
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().execute(new HibernateCallback(){ 1*=ev,Z
publicObject doInHibernate tq59w
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(Session session)throws HibernateException { 1x|3|snz)
Criteria criteria = &MSU<S?1
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detachedCriteria.getExecutableCriteria(session);
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return criteria.list(); ]$ "eGHX
} 8NHm#Z3Ol
}, true); 6|NH*#s
} @N4~|`?U
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public int getCountByCriteria(final (j'\h/
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DetachedCriteria detachedCriteria){ n- 2X?<_Z
Integer count = (Integer) >IIq_6Z#
OL
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getHibernateTemplate().execute(new HibernateCallback(){ fF)Q;~_VA
publicObject doInHibernate 8vVE
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(Session session)throws HibernateException { w1G(s$;C
Criteria criteria = Lyhuyb)k5^
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detachedCriteria.getExecutableCriteria(session); -UkK$wP5
return c;kU|_
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criteria.setProjection(Projections.rowCount `0NU
c)`
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()).uniqueResult(); *Y(59J2
} Y ]([K.I=
}, true); 1w=.vj<d8
return count.intValue(); 7z$Z=cs
} 2{h2]F
} Hi09?AX
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fi
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用户在web层构造查询条件detachedCriteria,和可选的 (C.
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 m ~&
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PaginationSupport的实例ps。 FFqK tj's
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ps.getItems()得到已分页好的结果集 .h W>#
ps.getIndexes()得到分页索引的数组 XN<!.RCw
ps.getTotalCount()得到总结果数 h*VDd3[#
ps.getStartIndex()当前分页索引 j~N*T XkC
ps.getNextIndex()下一页索引 H=BI%Z
ps.getPreviousIndex()上一页索引 s^zlBvr|.
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Sl8+A+
BHY-fb@R]H
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 MZ"V\6T]
Z+k) N
一下代码重构了。 h A ){>B<;
h-PJC/>
我把原本我的做法也提供出来供大家讨论吧: MUl`0H"tR
B[ZQn]y
首先,为了实现分页查询,我封装了一个Page类: &^$@LH3
java代码: PaSwfjOnqr
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/*Created on 2005-4-14*/ Doc zQc-U+
package org.flyware.util.page; }K) AjZ
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/** f$>_>E
* @author Joa
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* {LiJ=Ebt
*/ c6F?#@?
publicclass Page { =u2~=t=LV
|>(Vo@
/** imply if the page has previous page */ 9\Gk)0
privateboolean hasPrePage; h^(U:M=A
T)e2IXGN
/** imply if the page has next page */ fc~fjtqwvz
privateboolean hasNextPage; (/uN+
H}r]j\
/** the number of every page */ h>bjG
privateint everyPage; &Z~_BT
d[?RL&hJO
/** the total page number */ 4vL\t
uoz
privateint totalPage; O + aK#eF
rS>.!DiYr,
/** the number of current page */ 1#N`elm
privateint currentPage; ^!B]V>L-
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/** the begin index of the records by the current <*J"6x
@rT$}O1?`
query */ F2zo
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privateint beginIndex; [,Ul
K-]) RIM
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/** The default constructor */ QyA^9@iVs
public Page(){ #Tc`W_-
yreH/$Ou8
} 0 @#Jz#?
oPs asa
/** construct the page by everyPage OD}Uc+;K
* @param everyPage f=91
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* */ ,$!fyi[;C
public Page(int everyPage){ =A5i84y.2u
this.everyPage = everyPage; gA=Pz[i)p
} $zOV*O2
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/** The whole constructor */ qf K
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public Page(boolean hasPrePage, boolean hasNextPage, dUB;ZB7
=eY
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int everyPage, int totalPage, 8o:h/F
int currentPage, int beginIndex){ (;g/wb:
this.hasPrePage = hasPrePage; n5"i'o{w
this.hasNextPage = hasNextPage; hD#Mhy5h
this.everyPage = everyPage; ~<u\YIJ
this.totalPage = totalPage; c@,1?q1bv
this.currentPage = currentPage; roZn{+f
this.beginIndex = beginIndex; F$i50s
} WS&a9!3;
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/** y=9fuGL6
* @return 9+(6/<
* Returns the beginIndex. KOR*y(* 8
*/ EiD41N
publicint getBeginIndex(){ 0<uL0FOT
return beginIndex; KYkS^v
} rk%pA-P2
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/** 1WaQWZ:=
* @param beginIndex q !}~c
* The beginIndex to set. UK'8cz9
*/ (Qw >P42J
publicvoid setBeginIndex(int beginIndex){ ,I|^d.[2
this.beginIndex = beginIndex; jKcl{',
} }`Wo(E}O
>G1]#'6;
/** <b~~X`Z
* @return 'xuxMav6m
* Returns the currentPage. w?_'sP{pd
*/ fvta<
publicint getCurrentPage(){ }x6)}sz7
return currentPage; "w 4^i!\
} LTx,oa:ma
@}^VA9ULK
/** ~d<&OL
* @param currentPage tHqa%
* The currentPage to set. nCV7(ldmH
*/ B{`K?e0
publicvoid setCurrentPage(int currentPage){ ?!"pzDg
this.currentPage = currentPage; "8)%XSb
} [fwk[qFa
K
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/** ~"bBwPI
* @return LCXWpUj~
* Returns the everyPage. qz)KCEs
*/ HXh:83
publicint getEveryPage(){ I=Y_EjZD
return everyPage; 7<:o4\q?m
} |U'` Sc
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/** modem6#x'
* @param everyPage ',Z]w;D!G
* The everyPage to set. Z @DDuVr
*/ }] 1C=~lC
publicvoid setEveryPage(int everyPage){ `)8SIx
this.everyPage = everyPage; 3 %BI+1&T_
} F1}d@^K
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/** m+dQBsz\
* @return u>] )q7s
* Returns the hasNextPage. oG hMO
*/ s,mt%^x[
publicboolean getHasNextPage(){ 5%K|dYv^^
return hasNextPage;
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} 3:w_49~:~
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/** I(3YXv
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* @param hasNextPage ]"O*&
* The hasNextPage to set. ~md06"AYJ
*/ h8k\~/iJ
publicvoid setHasNextPage(boolean hasNextPage){ h0x'QiCc
this.hasNextPage = hasNextPage; Jz0AYiCq
} _/ 5
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/** <h|&7
* @return %"#ydOy
* Returns the hasPrePage. Y#P!<Q>}
*/ P=P']\`p+
publicboolean getHasPrePage(){ =~,2E;#X
return hasPrePage; ',D%,N}J
} h*hkl#
h`v T[u~l
/** @ I&k|\
* @param hasPrePage gLFSZ
* The hasPrePage to set. D#,A_GA{A
*/ `PLax@]2
publicvoid setHasPrePage(boolean hasPrePage){ XE0b9q954
this.hasPrePage = hasPrePage; &\ad.O/Q
} U.Z5;E0:
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/** ;B }4pv}
* @return Returns the totalPage. lN"@5(5%
* -`X`Ff
*/ hq&9S{Ep
publicint getTotalPage(){ A*|\E:fo
return totalPage; 3 l
j^I
} Rb^G~82d?
B<.ZW}#v
/** EZp >Cf7
* @param totalPage ; Ob^@OM
* The totalPage to set. ]W`M
<hEI
*/ 8F$]@0v`%
publicvoid setTotalPage(int totalPage){ BEAY}P(y3
this.totalPage = totalPage; dtG>iJ
} gL@]p
O"X7 DgbC
} [1Qg *
+'w6=qI
!4z vkJO
[_KOU2
zDxJK
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 y34 <B)Wy
5]kv1nQ
个PageUtil,负责对Page对象进行构造: }dU!PZ9N)
java代码: SY}"4=M?l
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/*Created on 2005-4-14*/ qjg Z
package org.flyware.util.page; Qip@L WvT
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import org.apache.commons.logging.Log; XrXW6s;Z
import org.apache.commons.logging.LogFactory; |v#rSVx
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/** F{
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s#
* @author Joa [CAFh:o
* xNRMI!yv
*/ `O%O[
publicclass PageUtil { Z;;A#h'%e
4)XB3$<
privatestaticfinal Log logger = LogFactory.getLog T}"[f/:N/
}P\6}cK
(PageUtil.class); 3".#nN
d\c)cgh%
/** q}z`Z/`/
* Use the origin page to create a new page rzvKvGd#N
* @param page 0q]0+o*%
* @param totalRecords G2sj<F=AV
* @return z$ {[Z=
*/ wIWO?w2
publicstatic Page createPage(Page page, int Vkf{dHjW
niyxZ<Z
totalRecords){ 0<f.r~
return createPage(page.getEveryPage(), 00r7trZW^
=<K6gC27
page.getCurrentPage(), totalRecords); : Hu{MN\
} i{Du6j^j
4#t-?5"
/** ttBqp|.?S
* the basic page utils not including exception U?5G%o(q
.F$cR^i5u
handler bFH`wLW
* @param everyPage (Y^tky$9
* @param currentPage f)r6F JLU
* @param totalRecords 50T^V`6
* @return page ##alzC
*/ v}IhO~`uEq
publicstatic Page createPage(int everyPage, int Otf{)f
& Yx12B\
currentPage, int totalRecords){ }iUpBn
everyPage = getEveryPage(everyPage); fILvEf4b
currentPage = getCurrentPage(currentPage); Zdfh*MHMg
int beginIndex = getBeginIndex(everyPage, B;piO-hH
=NNxe"Kd;U
currentPage); &zP>pQr`#
int totalPage = getTotalPage(everyPage, (I+e@UUiL
}EJ/H3<
totalRecords); i;29*"
boolean hasNextPage = hasNextPage(currentPage, ^oW{N
zW)Wt.svP
totalPage); RU>qj
*e
boolean hasPrePage = hasPrePage(currentPage); @Q;s[Kg{!
!*?9n^PaF
returnnew Page(hasPrePage, hasNextPage, @tJic|)x
everyPage, totalPage, O,NVhU7,
currentPage, >Ml5QO$*.q
OF-VVIS
beginIndex); {:Kr't<XzF
} ?|\wJrM ]
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privatestaticint getEveryPage(int everyPage){ 0y+i?y
9
return everyPage == 0 ? 10 : everyPage; 2n-kJl`: O
} h[<l2fy
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privatestaticint getCurrentPage(int currentPage){ H4sc7-
return currentPage == 0 ? 1 : currentPage; 1<*U:W
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} H(y Gh
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privatestaticint getBeginIndex(int everyPage, int ojA !!Ru
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currentPage){ )%lPKp4]
return(currentPage - 1) * everyPage; {2i8]Sp1d/
} 33&\E- Q>
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privatestaticint getTotalPage(int everyPage, int 4:/^ .:
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totalRecords){ |f.,fVVV;
int totalPage = 0; Q7tvpU
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if(totalRecords % everyPage == 0) /{W6]6^
totalPage = totalRecords / everyPage; ibG>|hV
else aeAx0yE[p
totalPage = totalRecords / everyPage + 1 ; >[~7fxjK-
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return totalPage; yO*
} 5OX[)Li
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privatestaticboolean hasPrePage(int currentPage){ %&q}5Y4!
return currentPage == 1 ? false : true; nb6Y/`G
} KeXt"U
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privatestaticboolean hasNextPage(int currentPage, tCar:p4$
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int totalPage){ kQQDaZ8
return currentPage == totalPage || totalPage == *v?kp>O
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0 ? false : true; 5}Xi`'g,
} NSH4 @x
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} 4??LK/s*
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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。 Vo6g /h?`
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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 9\/oL{
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做法如下: %O<8H7e)V
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 PL3hrI 5
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的信息,和一个结果集List: ^H{YLO
java代码: =Vazxt@[
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/*Created on 2005-6-13*/
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package com.adt.bo; P8ZmrtQm
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import java.util.List; <gfRAeXA
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import org.flyware.util.page.Page; {IaDZ/XS6
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/** Pz\K3-
* @author Joa n;Q8Gg2U
*/ cC NRv$IO\
publicclass Result { Ym!e}`A\F
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private Page page; BenyA:W"
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private List content; g.vE%zKL
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/** i. (Af$
* The default constructor 5b*knN>
*/ Zj'%c2U_
public Result(){ 0\X<vrW
super(); 85;bJfY
} SgehOu
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/** jlFlhj:/I
* The constructor using fields di0@E<@1:
* 6N5(DD
* @param page 1 <+aF,
* @param content +}a(jO
*/ '%XYJr:H[
public Result(Page page, List content){ "J=Cy@SSa
this.page = page; isQOt *
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this.content = content; lG%697P
} OE9,D:tv
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/** \=bKuP(it
* @return Returns the content. lw.[qP
*/ 19#>\9*
publicList getContent(){ >eQ.y-
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return content; N&