Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 dk#k bG;
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 VK\X&Y3l
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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 DZ'P@f)]
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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 y*jp79G
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分页支持类: ,F8 Yn5h
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java代码: ,i?nWlh+
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package com.javaeye.common.util; \R9(x]nZ%
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import java.util.List; wY{-BuXv
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publicclass PaginationSupport { .GPT!lDc
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publicfinalstaticint PAGESIZE = 30; hP%M?MKC
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privateint pageSize = PAGESIZE;
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privateList items; ~OYiq}g
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privateint totalCount; ~|DUt
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privateint[] indexes = newint[0]; Gi|w}j_
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privateint startIndex = 0; K^)Eb(4
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public PaginationSupport(List items, int $D~0~gn~
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totalCount){ u
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setPageSize(PAGESIZE); gS!:+G%
setTotalCount(totalCount); Fj 8z
setItems(items); v|_K/|
setStartIndex(0); q"CVcLi9
} c)6m$5]
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public PaginationSupport(List items, int r..iko]T
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totalCount, int startIndex){ jh?H.;**
setPageSize(PAGESIZE); Y#ap*
setTotalCount(totalCount); :DK {Vg6
setItems(items); bI7Vwyz
setStartIndex(startIndex); z}77Eh<
} .FP$m?
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public PaginationSupport(List items, int R^8o^z['6u
k{R>
totalCount, int pageSize, int startIndex){ ,1.p%UE]>
setPageSize(pageSize); [t m_Mg
setTotalCount(totalCount); !,_u)4
setItems(items); +[6G5cH
setStartIndex(startIndex); "=HA Y
} >mbHy<<
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publicList getItems(){ #ZUI)9My@
return items; gMi0FO'
} l5Ui w2
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publicvoid setItems(List items){ ]#iigPZ7
this.items = items; Fk&c=V;SU
} {LI=:xJJv
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publicint getPageSize(){ E<rp7~#
return pageSize; nUaJzPl
} ^)/0yB
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publicvoid setPageSize(int pageSize){ v4!VrI
this.pageSize = pageSize; zF`0J
} d(ZO6Nr Q
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publicint getTotalCount(){
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return totalCount; etQCzYIhn
} udK%>
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publicvoid setTotalCount(int totalCount){ 1;bh^WMJ
if(totalCount > 0){ dM.f]-g
this.totalCount = totalCount; pHGYQ;:L
int count = totalCount / B B{$&Oh
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pageSize; B&M%I:i
if(totalCount % pageSize > 0) SBu"3ym
count++; $j%'{)gK
indexes = newint[count]; L]|gZ&^
for(int i = 0; i < count; i++){ n1ZbRV
indexes = pageSize * (!u~CZ;
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i; u= *FI
} nAAs{
}else{ .D"m@~j7
this.totalCount = 0; (Bb5?fw
} 6D;Sgc5"
} JJ-( Sl
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publicint[] getIndexes(){ .<0ye_S'y
return indexes; F} yW/
} r.=K~A
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publicvoid setIndexes(int[] indexes){ q4h]o^ +
this.indexes = indexes; &GO}|W
} >{n,L6_t
];$L &5^
publicint getStartIndex(){ s*KhF'fN
return startIndex; ;3coP{
} :wyno#8`-
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publicvoid setStartIndex(int startIndex){ (62"8iD6
if(totalCount <= 0) h|9L5
this.startIndex = 0; ITX a&5D
elseif(startIndex >= totalCount) gnf8l?M
this.startIndex = indexes 1p3z1_wrs
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[indexes.length - 1]; <]t%8GB2V
elseif(startIndex < 0) :as$4|
this.startIndex = 0; .WJYQi
else{ wo{gG?B
this.startIndex = indexes `:fZ)$sY
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[startIndex / pageSize]; ] )\Pqn(
} \~mT]
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} LKB$,pR~1l
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publicint getNextIndex(){ ;u
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int nextIndex = getStartIndex() + 8U"v6S~A%Q
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pageSize; _Kf% \xg
if(nextIndex >= totalCount) !X#OOqPr=
return getStartIndex(); ? pmHFlx
else B)g[3gQ
return nextIndex; `UyG_;
} '3tCH)s
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publicint getPreviousIndex(){ /& {A!.;
int previousIndex = getStartIndex() - 1<@W6@]
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pageSize; ORw,)l
if(previousIndex < 0) S!CC
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return0; AM \'RHL
else cd_yzpL@}J
return previousIndex; :J@gmY:C
} V! A~K
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} b94DJzL1z
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抽象业务类 }@+0/W?\.
java代码: !9r$e99R
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/** 5c0 ZRV#
* Created on 2005-7-12 \ :sUL!
*/ @o _}g !9=
package com.javaeye.common.business; Ya"a`ozq
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import java.io.Serializable; osAd1<EIC
import java.util.List; *)T^ChD,
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import org.hibernate.Criteria; ,m:.-iy?
import org.hibernate.HibernateException; 7,o7Cf2 z
import org.hibernate.Session; 0R'?~`aTt
import org.hibernate.criterion.DetachedCriteria; +gtbcF@rx
import org.hibernate.criterion.Projections; E
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import d#4**BM
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org.springframework.orm.hibernate3.HibernateCallback; :q%M_
import #rfiD%c
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org.springframework.orm.hibernate3.support.HibernateDaoS kfY}S
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upport; 9IfmW^0
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import com.javaeye.common.util.PaginationSupport; q ^N7I@Y
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public abstract class AbstractManager extends oIzj,v8$
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<?
HibernateDaoSupport { @,7GaK\
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privateboolean cacheQueries = false; ?X<eV1a
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privateString queryCacheRegion; rcG"o\g@+
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publicvoid setCacheQueries(boolean g@!V3V
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cacheQueries){ vw/J8'
this.cacheQueries = cacheQueries; zL0pw'4
} @:vwb\azVD
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publicvoid setQueryCacheRegion(String p%=u#QNi
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queryCacheRegion){ .|fHy
this.queryCacheRegion = \V~eVf;~
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queryCacheRegion; j>" @,B g*
} J<h$
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publicvoid save(finalObject entity){ D'DfJwA
getHibernateTemplate().save(entity); !M1"b;
} 3,qr-g|;jM
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publicvoid persist(finalObject entity){ !?h;wR
getHibernateTemplate().save(entity); >SHhAEF
} iz PDd{[
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publicvoid update(finalObject entity){ S|N_ o
getHibernateTemplate().update(entity); ;h
} N S[l/0F&
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publicvoid delete(finalObject entity){ eru.m+\
getHibernateTemplate().delete(entity); M!^az[[
} SoK
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publicObject load(finalClass entity, tg4pyW<
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finalSerializable id){ /7^4O(iG
return getHibernateTemplate().load yN(%-u"
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(entity, id); Pu$Tk|
} u\;C;I-? '
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publicObject get(finalClass entity, TKmf+ZT*r
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finalSerializable id){ )1`0PJoHE
return getHibernateTemplate().get R$[vm6T?
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(entity, id); 6mxfLlZ
} Z,Dl` w
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publicList findAll(finalClass entity){ VTY 5]|;
return getHibernateTemplate().find("from .Vvx,>>D
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" + entity.getName()); 'e'cb>GnA
} @<EO`L)Z
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publicList findByNamedQuery(finalString v;D~Pa
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namedQuery){ /!XVHkX[
return getHibernateTemplate $}<e|3_
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().findByNamedQuery(namedQuery); F0Yd@Lk$_
} O5T{eBo\
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publicList findByNamedQuery(finalString query, 59;KQ
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finalObject parameter){ TJXT-\Vk
return getHibernateTemplate 07{)?1cod4
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().findByNamedQuery(query, parameter); z 1X` o
} gT6jYQ
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publicList findByNamedQuery(finalString query, ]Gq !`O1
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finalObject[] parameters){ A_q3KB!$=+
return getHibernateTemplate U9MxI%tb
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().findByNamedQuery(query, parameters); AFE~
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} d<P\&!R(
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publicList find(finalString query){ Qj3EXb
return getHibernateTemplate().find 8&b,qQ~
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(query); WOL:IZX%
} L$M9w
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publicList find(finalString query, finalObject Q*ft7$l&
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parameter){ n,WqyNt*
return getHibernateTemplate().find h>m"GpF
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(query, parameter); L)
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} Qh\60f>0
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public PaginationSupport findPageByCriteria [S!/E4>['
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(final DetachedCriteria detachedCriteria){ 'm
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return findPageByCriteria &&>ekG9@
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 1=Z0w +v{
} ;>7De8v@@
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public PaginationSupport findPageByCriteria ln
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(final DetachedCriteria detachedCriteria, finalint &gx%b*;`L0
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startIndex){ Q hO!Ma]
return findPageByCriteria YT(AUS5n
BLD gt~h#
(detachedCriteria, PaginationSupport.PAGESIZE, A6(/;+n
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startIndex); 9q~s}='"
} +ksVtG,
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public PaginationSupport findPageByCriteria tK\~A,=
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(final DetachedCriteria detachedCriteria, finalint z-)O9PV
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pageSize, #S"nF@
finalint startIndex){ ^k9I(f^c-_
return(PaginationSupport) +QJ#2~pE
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getHibernateTemplate().execute(new HibernateCallback(){ f%}xO+.s
publicObject doInHibernate -nV9:opD
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(Session session)throws HibernateException { Er?&Y,o
Criteria criteria = 1iF1GkLEq
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detachedCriteria.getExecutableCriteria(session); /mzlH
int totalCount = 9XB 8VKu8
f) L
((Integer) criteria.setProjection(Projections.rowCount |&i<bqLw:
aQ@oH#
()).uniqueResult()).intValue(); R (n2A$
criteria.setProjection 13x p_j
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(null); IW] rb/H
List items = ' S/gmn
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criteria.setFirstResult(startIndex).setMaxResults X#^[<5
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(pageSize).list(); 4BpZJ~(p
PaginationSupport ps = "VMz]ybi^
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new PaginationSupport(items, totalCount, pageSize, K[zVa
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startIndex); R.<g3"Lm>
return ps; {E|$8)58i
} (TT}6j
}, true); \ @2R9,9E
} Uw<nxD/+
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public List findAllByCriteria(final \:LW(&[!
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DetachedCriteria detachedCriteria){ +9sQZB# (
return(List) getHibernateTemplate X|]AT9W
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().execute(new HibernateCallback(){ mj7#&r,1l
publicObject doInHibernate 5*u+q2\F
=>~:<X.,
(Session session)throws HibernateException { E|shs=I
Criteria criteria = 8P\Zo8}v
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detachedCriteria.getExecutableCriteria(session); j8:\%|
return criteria.list(); Dk5 1z@
} 'i|YlMFI g
}, true); <t!W5q
} ,f?*{Q2
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public int getCountByCriteria(final ~WF\
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DetachedCriteria detachedCriteria){ s_p!43\J
Integer count = (Integer) ":N9(}9
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getHibernateTemplate().execute(new HibernateCallback(){ <<O$ G7c
publicObject doInHibernate w7&A0M
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(Session session)throws HibernateException { JC}D`h
Criteria criteria = -MBxl`JU
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detachedCriteria.getExecutableCriteria(session); )%fH(ns(
return (S Yln>o
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criteria.setProjection(Projections.rowCount 2y1Sne=<Kb
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()).uniqueResult(); lPAQ3t!,
} SSzIih@u
}, true); E2+`4g@{8<
return count.intValue(); %mgE;~"&
} %iqD5x$OA
} Q22 GIr
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用户在web层构造查询条件detachedCriteria,和可选的 3=V&K-
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 e&>2
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PaginationSupport的实例ps。 i,VMd
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ps.getItems()得到已分页好的结果集 4?01s-Y
ps.getIndexes()得到分页索引的数组 L-&\\{X
ps.getTotalCount()得到总结果数 _,*r_D61S
ps.getStartIndex()当前分页索引 MiX 43Pk]
ps.getNextIndex()下一页索引 4Wp=y
ps.getPreviousIndex()上一页索引 uhq8
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 PQE=D0
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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 2B`JGFcdcB
#lO Mm9
一下代码重构了。 f%8C!W]Dm
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我把原本我的做法也提供出来供大家讨论吧: zKK9r~ M
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首先,为了实现分页查询,我封装了一个Page类: Pc]HP
java代码: y<.5xq5_3
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/*Created on 2005-4-14*/ Rk8P
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package org.flyware.util.page; c+GG\:gM
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/** "uf%iJ:%
* @author Joa _','9|
* {\\Tgs
*/ U%/+B]6jP
publicclass Page { -ze J#B)C
x|29L7i
/** imply if the page has previous page */ CU~PT.
privateboolean hasPrePage; MUwMb!Z.s
onV>.7sG
/** imply if the page has next page */ |&4/n6;P$0
privateboolean hasNextPage; MfkN]\Jyw
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/** the number of every page */ %SUQ9\SEs
privateint everyPage; V G~Vs@c(
Zgb!E]V[
/** the total page number */ ^/k*h J{
privateint totalPage; A_UjC`
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/** the number of current page */ wS3'?PRX
privateint currentPage; U`s{Jm
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/** the begin index of the records by the current %N_%JK\{@
x$(f7?s] 1
query */ 7>*vI7O0l
privateint beginIndex; 6d~'$<5on
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/** The default constructor */ 7IM@i>p%
public Page(){ yaV|AB$v
lk80#( :Z
} Jfl!#UAD|n
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/** construct the page by everyPage <=C?e<Y
* @param everyPage j_7mNIr
* */ t.C5+^+%
public Page(int everyPage){ ;xn0;V'=
this.everyPage = everyPage; FXU8[j0P_G
} T&7qC=E#5
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/** The whole constructor */ I1&aM}y{G
public Page(boolean hasPrePage, boolean hasNextPage, MnW+25=N
{BU;$
B#1;r-^P<
int everyPage, int totalPage, IEvdV6{K
int currentPage, int beginIndex){ .6 ?U@2
this.hasPrePage = hasPrePage; LjHVJSC
this.hasNextPage = hasNextPage; vY`s'%WV
this.everyPage = everyPage; Ny)X+2Ae
this.totalPage = totalPage; C+&l<
fM&
this.currentPage = currentPage; ]')RMg zM*
this.beginIndex = beginIndex; [z9Z5sLO
} lU8Hd|@-
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/** ,~W|]/b<q
* @return %ULr8)R;
* Returns the beginIndex. _v]MsT-q
*/ \xoP)Ub>
publicint getBeginIndex(){ 0#^v{DC
return beginIndex; <1M-Ro?5k
} Aq7osU1B
@7n"yp*"
/** j"Pv0tehw
* @param beginIndex h@@=M
* The beginIndex to set. qJUK_6|3
*/ y:l\$pGC%
publicvoid setBeginIndex(int beginIndex){ {.mngRQF
this.beginIndex = beginIndex; BIL Lq8)
} ~W]TD@w
K",N!koj
/** .#pU=v#/[
* @return iOO)Q\
* Returns the currentPage. v|2T%y_
u
*/ R{T$[$6S
publicint getCurrentPage(){ du^J2m{f
return currentPage; *CHX
} *4Y Vv
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/** [!OxZ!
* @param currentPage |ZBI *
* The currentPage to set. 5`: Yye
*/ #>+ HlT
publicvoid setCurrentPage(int currentPage){ Y:a]00&)#Y
this.currentPage = currentPage; f&
'
} N87B8rDl
HyWCMK6b
/** u;c?d!E
* @return J-hbh
* Returns the everyPage. 0lR5<^B
*/ TRq6NB
publicint getEveryPage(){ R~$qo)v
return everyPage; n?Nt6U
} 92KRb;c
}`~+]9<
/** |
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* @param everyPage XOS[No~
* The everyPage to set. @MCg%Afw
*/ g}',(tPMZ
publicvoid setEveryPage(int everyPage){ K(Bf2Mfq
this.everyPage = everyPage; "#\;H$+
} n6a`;0f[R
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/** ]?[fsdAQW
* @return *!7O~yQ
* Returns the hasNextPage. S|`o]?nc>
*/ )P|),S,;Z
publicboolean getHasNextPage(){ 6,{$J
return hasNextPage; Npy:!
} ^.NU|NQi'
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/** <GaS36ZW
* @param hasNextPage
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* The hasNextPage to set. O@C@eW#
*/ E=!\z%4
publicvoid setHasNextPage(boolean hasNextPage){ .OY`Z)SS%
this.hasNextPage = hasNextPage; @6T/Tdz
} pcWPH.
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/** wDe& 1(T^
* @return z ~/` 1
* Returns the hasPrePage. :&9s,l
*/ 81
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publicboolean getHasPrePage(){ |_@>*Vmg
return hasPrePage; jZkcBIK2
} [uN?
~lp\%
q01wbO3-"
/** fW1CFRHH
* @param hasPrePage J$w<$5UY
* The hasPrePage to set. 4-y:/8
*/ `*N[jm"
publicvoid setHasPrePage(boolean hasPrePage){ Ed df2;-.
this.hasPrePage = hasPrePage; 6@F9G4<Z
} 17"uf.G
' ;FnIZ
/** E`usknf>l
* @return Returns the totalPage. /cQueUME`
* =M[bnq*\
*/ SaAFz&WRl
publicint getTotalPage(){ }"P|`"WW
return totalPage; &4x}ppX
} *:LK8U
IT7wT+
/** :tB1D@Cb6
* @param totalPage {14fA)`%
* The totalPage to set. v,{
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*/ Y^;ovH~ ve
publicvoid setTotalPage(int totalPage){ l\!fj#
this.totalPage = totalPage; /hH
} I7vz+>Jr
t?-n*9,#S
} n&;85IF1
~"&|W'he[
i$:*Pb3mV
%G_B^p4
]7F=u!/`<C
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 vrhT<+q
gx8ouOh
个PageUtil,负责对Page对象进行构造: +\c5]`
java代码: DJXmGt]
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.
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/*Created on 2005-4-14*/ rb2S7k0{
package org.flyware.util.page; GmeQ`;9,
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import org.apache.commons.logging.Log; qo90t{|c
import org.apache.commons.logging.LogFactory; 1R{!]uh
q77;ZPfs8
/** F3v!AvA|
* @author Joa Qcq`libK
* (cAIvgI
*/ _"Dv
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publicclass PageUtil { j^j1
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privatestaticfinal Log logger = LogFactory.getLog ]Yn D
w(*vj
(PageUtil.class); (lBCO?`fx
"/*\1v9
/** 53;}Nt#R
* Use the origin page to create a new page q1$N>;&
* @param page t9k zw*U9
* @param totalRecords |C;=-|
* @return -[4T
*/ fnjPSts0
publicstatic Page createPage(Page page, int zH?!
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totalRecords){ #l\=}#\1Wb
return createPage(page.getEveryPage(), a?I=
!js
q 6:dy
page.getCurrentPage(), totalRecords); ajbA\/\G;
} EA@.,7F
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/** fa
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* the basic page utils not including exception rKe2/4>0X
#vz7y(v
handler .LPV#&
* @param everyPage /wQy17g
* @param currentPage d\&U*=
* @param totalRecords X[-xowE-
* @return page lK?uXr7^
*/ .9/hHCp
publicstatic Page createPage(int everyPage, int rT=rrvV3g
m4[ ;(1
currentPage, int totalRecords){ g+8OekzB5
everyPage = getEveryPage(everyPage); -P(efYk
currentPage = getCurrentPage(currentPage); Q,,e+exbb5
int beginIndex = getBeginIndex(everyPage, B?eCe}*f;B
1jmjg~W
currentPage); @+&LYy72
int totalPage = getTotalPage(everyPage, afCW(zHp
5N#aXG^9
totalRecords); JinUV6cr
boolean hasNextPage = hasNextPage(currentPage, a
kk NI3
N~nziY*C,*
totalPage); 3H'sHuK"X
boolean hasPrePage = hasPrePage(currentPage); _>o:R$ %}
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returnnew Page(hasPrePage, hasNextPage, u4*BX&
everyPage, totalPage, f%A;`4`q
currentPage, lne|5{h
$H2u.U<ip
beginIndex); 3p$?,0ELH
} /`Ug9,*
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privatestaticint getEveryPage(int everyPage){ [CTnXb
return everyPage == 0 ? 10 : everyPage; M:=J^0
} H-!,yte
[>vLf2OID
privatestaticint getCurrentPage(int currentPage){ dUD[e,?
return currentPage == 0 ? 1 : currentPage; zF@/K`
} Q8$}@iA[
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privatestaticint getBeginIndex(int everyPage, int w$>u b@=
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currentPage){ #]-SJWf3
return(currentPage - 1) * everyPage; f'F?MINJP
} !@5 9)
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privatestaticint getTotalPage(int everyPage, int ~kV/!=
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totalRecords){ `T1
int totalPage = 0; M+oHtX$
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if(totalRecords % everyPage == 0) &L3M]
totalPage = totalRecords / everyPage; "BAK !N$9
else &Hrj3E
totalPage = totalRecords / everyPage + 1 ; )J=! L\
//B&k`u
return totalPage; g%o(+d
} pt?bWyKG
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privatestaticboolean hasPrePage(int currentPage){ 'z8pzMmT
return currentPage == 1 ? false : true; ]IaMp788
} SV4E0c>
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privatestaticboolean hasNextPage(int currentPage, O}gV`q;
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int totalPage){ :x3QRF
return currentPage == totalPage || totalPage == 0^ _uV9r
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0 ? false : true; XE RUo
} v4<nI;Ux
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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。 [>3./YH`
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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 c?Y*Y
:]K4KFM
做法如下: 3ZuZ/=
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 D_ 2:k'4
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的信息,和一个结果集List: AF{\6<m
java代码: (y'hyJo
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/*Created on 2005-6-13*/ wSL}`C gU
package com.adt.bo; `cn#B
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import java.util.List; Ufj`euY
.~db4d]
import org.flyware.util.page.Page; <V'@ks%
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/** _{O>v\u
* @author Joa @n/\L<