Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 gk8v{'0Er
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 GcO:!b*YMp
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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 2,I]H'}^
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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 n'pJl
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分页支持类: _f>)G3p
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java代码: 751Qi
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package com.javaeye.common.util; ^o q|^O
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import java.util.List; l>i:M#z&
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publicclass PaginationSupport { n?q+:P
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publicfinalstaticint PAGESIZE = 30; rW O#h{
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privateint pageSize = PAGESIZE; kMEXg zl
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privateList items; 3_
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privateint totalCount; ' _K`1U
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privateint[] indexes = newint[0]; 6+s&%io4
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privateint startIndex = 0; Ym
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public PaginationSupport(List items, int Ut1s~b1
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totalCount){ %%wngiz\
setPageSize(PAGESIZE); I%j]p Y4
setTotalCount(totalCount); =''*'a-P
setItems(items); _ qQ
setStartIndex(0); slr>6o%W`
} 4 #lLC-k
@ K2N cb7
public PaginationSupport(List items, int j~;y~Cx?
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totalCount, int startIndex){ mkBQTQGT
setPageSize(PAGESIZE); %md9ou`
setTotalCount(totalCount); &Dp&
setItems(items); 9Y2(.~w6X
setStartIndex(startIndex); B(-F|q\
} ^:O*Sx.CA
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public PaginationSupport(List items, int VF7H0XR/k5
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totalCount, int pageSize, int startIndex){ t#]VR7]
setPageSize(pageSize); 1o
setTotalCount(totalCount); ~ :B/`1[m
setItems(items); TQ {8 ee{
setStartIndex(startIndex); hGUQdTNP
} yN#]Q}4
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publicList getItems(){ 6H|T )
return items; U!nNT==
} p1ER<_fp
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publicvoid setItems(List items){ w;Pe_m7\EO
this.items = items; b0/[+OY
} Z>'hNj)ju
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publicint getPageSize(){ t{ridA}
return pageSize; I?<ibLpX
} v[m1R'
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publicvoid setPageSize(int pageSize){ (L<G=XC
this.pageSize = pageSize; Vf(n
} V Z60
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publicint getTotalCount(){ 1a},(ZcdX
return totalCount; IS!]!s'EI
} vmtmiN8;d
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publicvoid setTotalCount(int totalCount){ xSjs+Y;Mu
if(totalCount > 0){ 072`i46
this.totalCount = totalCount; /9C>{29x!
int count = totalCount / 'KNUPi|
tpKQ$)ed
pageSize; \88IFE
if(totalCount % pageSize > 0) 3],[6%w
count++; N8]d0
indexes = newint[count]; 54&&=NVs|
for(int i = 0; i < count; i++){ a^9}ceu?
indexes = pageSize * 7(5 wP(
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i; Gh{vExH@5(
} 3ry0.
}else{ :B4X/
this.totalCount = 0; If. hA}
} gMZ
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} -M?s<R[&
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publicint[] getIndexes(){ j&=!F3[
return indexes; Aj2yAg
} +P
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publicvoid setIndexes(int[] indexes){ Ha/-v?E
this.indexes = indexes; I =yy
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} B976{;QvXV
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publicint getStartIndex(){ &r!*Y&
return startIndex; @{UtS2L
} *.NVc
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publicvoid setStartIndex(int startIndex){ _n_|skG
if(totalCount <= 0) OX)[?1m8
this.startIndex = 0; |B.tBt^
elseif(startIndex >= totalCount) XQL]I$?
this.startIndex = indexes WMd5Y`y
+}0/ %5 =1
[indexes.length - 1]; keWqL]
elseif(startIndex < 0) VE5M}kDCZ
this.startIndex = 0; %,G0)t
else{ ~!a~ -:#
this.startIndex = indexes
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[startIndex / pageSize]; &'-ze,k}
} x*uQBNf=
} %B'*eBj~fw
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publicint getNextIndex(){ &]Q\@;]Aq
int nextIndex = getStartIndex() + 7 xm>+(
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pageSize; H$i4OQ2
if(nextIndex >= totalCount) "]C$"JR
return getStartIndex(); 48 `k"Uy
else k&PxhDf
return nextIndex; (},TZ+u
} J}cqBk>
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publicint getPreviousIndex(){ O_jf)N\pi
int previousIndex = getStartIndex() - h}o7/p
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pageSize; fQ[ GN}k
if(previousIndex < 0) 'X$2gD3c9
return0; P~y%
else Z;bg;@r|
return previousIndex; +84JvOkWi
} pO.+hy
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} rmOcA
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抽象业务类 .6m%/-whS
java代码: I8C(z1(N
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/** h`0'27\C
* Created on 2005-7-12 hqA6%Y^k
*/ `is."]%f
package com.javaeye.common.business; z+>FKAF
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import java.io.Serializable; I'M,p<B
import java.util.List; ppjS|l*`
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import org.hibernate.Criteria; %B&y^mZv*\
import org.hibernate.HibernateException; ]D@_cxud3
import org.hibernate.Session; A3VXh^y+
import org.hibernate.criterion.DetachedCriteria; $y\\?
import org.hibernate.criterion.Projections; cg-\|H1
import Z9MT,
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org.springframework.orm.hibernate3.HibernateCallback; 2cy: l03
import .]_
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org.springframework.orm.hibernate3.support.HibernateDaoS SL9]$M mJn
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upport; nwOT%@nw
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import com.javaeye.common.util.PaginationSupport; U8+5{,$\.
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public abstract class AbstractManager extends o&
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HibernateDaoSupport { WJp9io[GM
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privateboolean cacheQueries = false; MCBZq\c
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privateString queryCacheRegion; Q Q3a&
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publicvoid setCacheQueries(boolean >l & N
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cacheQueries){ t u)kWDk
this.cacheQueries = cacheQueries; #bz#&vt$
} D<-MbK^S
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publicvoid setQueryCacheRegion(String cO]_5@#f'8
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queryCacheRegion){ jea{BhdUr
this.queryCacheRegion = sp=;i8Y 3
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queryCacheRegion; F}/tV7m
} rHzwSR@}1
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publicvoid save(finalObject entity){ : MfY8P)
getHibernateTemplate().save(entity); Ev
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} 7+!4pf
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publicvoid persist(finalObject entity){ (!^i6z0Sp
getHibernateTemplate().save(entity); - '<K_e;
} v}vwk8
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publicvoid update(finalObject entity){ 4 f)B@A-
getHibernateTemplate().update(entity); ULqFJ*nla
} `7v"(
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publicvoid delete(finalObject entity){ JDp"!x{O
getHibernateTemplate().delete(entity); |"j{!Ei
} V 6DWYs>
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publicObject load(finalClass entity, ,~z*V;y)
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finalSerializable id){ Yo 0wufbfV
return getHibernateTemplate().load 0|a ,bwZ
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(entity, id); 2=\} 0
} MmI[:
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publicObject get(finalClass entity, ]~YY#I":
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finalSerializable id){ |Ok@:Au
return getHibernateTemplate().get @%aU)YDwi
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(entity, id); DlMT<ld
} WQJnWe
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publicList findAll(finalClass entity){ zwLJ|>
return getHibernateTemplate().find("from >8v4fk
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" + entity.getName()); sz"N,-<Ig
} d~0k}|>
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publicList findByNamedQuery(finalString n'5LY9"
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namedQuery){ Ie z`g<r
return getHibernateTemplate ij=_h_nA
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().findByNamedQuery(namedQuery); (9]8r2|.
} cF2!By3M
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publicList findByNamedQuery(finalString query, F|wT']1Y
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finalObject parameter){ aVE/qXB
return getHibernateTemplate N6>ert1
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().findByNamedQuery(query, parameter); -4;$NiB?
} X21k7 Ls
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publicList findByNamedQuery(finalString query, wni^qs.i@3
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finalObject[] parameters){ 83i;:cn
return getHibernateTemplate kgv29j?k;
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().findByNamedQuery(query, parameters); .rcXxV@f
} ?!Wh ^su-
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publicList find(finalString query){ * YR>u@
return getHibernateTemplate().find B>kVJK`X
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(query); G'<Ie@$6l
} qydRmi
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publicList find(finalString query, finalObject 8o SL3
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parameter){ x,fX mgE
return getHibernateTemplate().find (R|_ 6[zy
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(query, parameter); 5L 0w!q'W
} ']:>Ww.S
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public PaginationSupport findPageByCriteria *K'#$`2
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(final DetachedCriteria detachedCriteria){ E5X#9;U8E"
return findPageByCriteria 1Xkl.FcFw
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); n.b_fkZNr
} vPSY1NC5
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public PaginationSupport findPageByCriteria
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(final DetachedCriteria detachedCriteria, finalint ,c&%/"i:w
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startIndex){ ] ]lN[J
return findPageByCriteria 7Ml OBPh
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(detachedCriteria, PaginationSupport.PAGESIZE, ayZWt| iHA
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startIndex); Vif)e4{Pn
} ZRP[N)Ld$
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public PaginationSupport findPageByCriteria
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(final DetachedCriteria detachedCriteria, finalint
, D}
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pageSize, V`_)H
finalint startIndex){ 2Xqa?ay0>
return(PaginationSupport) V5!mV_EoR@
*@fVog r^
getHibernateTemplate().execute(new HibernateCallback(){ om1D} irKT
publicObject doInHibernate W0LJXp-v
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(Session session)throws HibernateException { `##^@N<P
Criteria criteria = |HQFqa<
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detachedCriteria.getExecutableCriteria(session); X8 x:/]/0
int totalCount = vPET'Bf(YV
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((Integer) criteria.setProjection(Projections.rowCount W744hq@P%
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()).uniqueResult()).intValue(); Bi`m +ob
criteria.setProjection K j6@=
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(null); 7D=gAMPvJ
List items = kp8kp`S7
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criteria.setFirstResult(startIndex).setMaxResults r~; TId} #
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(pageSize).list(); F>"B7:P1:Q
PaginationSupport ps = Vee;&
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new PaginationSupport(items, totalCount, pageSize, dRXdV7-!
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startIndex); JA
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return ps; \)+s)&JLb
} Z]k+dJ[-
}, true); ($s%B
} 0T<DHPQ1
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public List findAllByCriteria(final 4 moVS1
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DetachedCriteria detachedCriteria){ +KHk`2{y~
return(List) getHibernateTemplate NqZR*/BOz
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().execute(new HibernateCallback(){ ziG]BZ
publicObject doInHibernate fXB64MNo
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(Session session)throws HibernateException { [p 8fg!|
Criteria criteria = W=?s-*F[~
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detachedCriteria.getExecutableCriteria(session); }OLBEhGs
return criteria.list(); @+^5ze\
} m|k:wuzqK
}, true); Tsl0$(2W
} !_LRuqQ?"
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public int getCountByCriteria(final 5wGc"JHm
= ms
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DetachedCriteria detachedCriteria){ q@&.)sLPgO
Integer count = (Integer) he1OLk
w@ \quy:
getHibernateTemplate().execute(new HibernateCallback(){ zoO9N oUHW
publicObject doInHibernate 7s'r3}B`
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(Session session)throws HibernateException { '3V?M;3|K
Criteria criteria = 7d'gG[Z^^
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detachedCriteria.getExecutableCriteria(session); , K[}Bz
return _+x&[^gjP
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criteria.setProjection(Projections.rowCount E/N*n!sV
bx8|_K*^
()).uniqueResult(); c!}f\ ]D
} YF(TG]?6
}, true); 7K}Sk
return count.intValue(); Bi|XdS$G
} F3V_rE<
} J#tY$PE
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用户在web层构造查询条件detachedCriteria,和可选的 nkvkHh
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 @fwk
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PaginationSupport的实例ps。 k4ijWo{:0
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ps.getItems()得到已分页好的结果集 _N-JRM m<
ps.getIndexes()得到分页索引的数组 (`pd>
ps.getTotalCount()得到总结果数 (e$/@3*
ps.getStartIndex()当前分页索引 ntT~_Ba8;u
ps.getNextIndex()下一页索引 |p7k2wzN
ps.getPreviousIndex()上一页索引 A&~<qgBTp
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 8 O5@FU
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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 =_/,C
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一下代码重构了。 pWwB<F
ages-Z_X
我把原本我的做法也提供出来供大家讨论吧: E"P5rT
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首先,为了实现分页查询,我封装了一个Page类: dU~DlaEy(
java代码: j`9+pI
jJmg9&^R
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/*Created on 2005-4-14*/ /{~cUB,Um
package org.flyware.util.page; (HUGgX"=
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/** n?QpVROo\
* @author Joa cQaEh1n
* ]qJ6#sAw75
*/ 79>8tOuo
publicclass Page { ?V}AwLX}
G([!(8&2Y
/** imply if the page has previous page */ myj^c>1Iz
privateboolean hasPrePage; ;rj=hc
m*h, <,}-+
/** imply if the page has next page */ #]yb;L
privateboolean hasNextPage; A@wRP8<GKj
Xj\SJ*
/** the number of every page */ #0HF7C3
privateint everyPage; XMM@EN
TT429
/** the total page number */ "Iy @PR?>
privateint totalPage; =%:mZ@x'
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/** the number of current page */ U+!H/R)(
privateint currentPage; kMS[
x0])&':!
/** the begin index of the records by the current %NbhR(
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query */ ~%4#R4&
privateint beginIndex; ^ ,Bxq^'D
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/** The default constructor */ *R*Tmo"
public Page(){ <!\J([NM8
B
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} 7oPBe1P,K+
V*U7-{ *a
/** construct the page by everyPage H~c+L'=
* @param everyPage FU0&EO
* */ .cA[b
public Page(int everyPage){ P
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this.everyPage = everyPage; Aa&3x~3+
} '}c0:,5
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/** The whole constructor */ I\sCH
public Page(boolean hasPrePage, boolean hasNextPage, ZYBNS~Q
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int everyPage, int totalPage, l[^bo/
int currentPage, int beginIndex){ Nuk\8C
this.hasPrePage = hasPrePage; MB\vgKY
this.hasNextPage = hasNextPage; H BmjB=
this.everyPage = everyPage; ^HHJ.QR
this.totalPage = totalPage; io:?JnQSA
this.currentPage = currentPage; Zx<s-J4o=w
this.beginIndex = beginIndex; knypSgk_
} 8k+Ctk
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/** mxjY-Kq
* @return 3Nw9o6` U
* Returns the beginIndex. A]BD2
*/ W"|89\p}
publicint getBeginIndex(){ D?]aYCT
return beginIndex; A1\;6W:
} XLFJ?$)Tro
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/**
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* @param beginIndex %Q}#x
* The beginIndex to set. O>w$
*/ TA}gCXE
e
publicvoid setBeginIndex(int beginIndex){ g9I2SdaJ
this.beginIndex = beginIndex; xgJ2W_
} w0moC9#$?
tA@#SIw
/** \0j|~/6
* @return )0PUK9
* Returns the currentPage. Ik=KEOz
*/ )R{4"&&2
publicint getCurrentPage(){ ^']xkS
return currentPage; L3X>v3CZ5
} MsX`TOyO!
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/** e|AJxn]
* @param currentPage )e9(&y*o
* The currentPage to set. ,/:#=TuYm
*/ z7{b>oub('
publicvoid setCurrentPage(int currentPage){ ;{BELv-4
this.currentPage = currentPage; Y4!v1
} lh~!cOm\=E
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/** vYmRW-1Zxq
* @return O>|Q Zd
* Returns the everyPage. hRxR2
*/ kP6g0,\|a|
publicint getEveryPage(){ 8K6yqc H
return everyPage; %dO'kU /-
} #=7~.Y
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/** bNY_V;7Kw`
* @param everyPage IR(JBB|xNQ
* The everyPage to set. /S\P=lcb
*/ LurBqr
publicvoid setEveryPage(int everyPage){ 8_8R$=V
this.everyPage = everyPage; &`pd&U{S*
} E7oL{gU
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/** #s)6u?N
* @return !95ZK.UT
* Returns the hasNextPage. E]6;nY?
*/ gI'4g ZH
publicboolean getHasNextPage(){ aJOhji<b#L
return hasNextPage; @lDoMm,m'
} wC`])z}bT
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/** _rY,=h{+
* @param hasNextPage w2YfFtgD,
* The hasNextPage to set. ,g6w2y7 ]
*/ j1Q G-Rs&
publicvoid setHasNextPage(boolean hasNextPage){ K82pWpR
this.hasNextPage = hasNextPage; O9dIobu4
} JN$v=Ox{
|94"bDL3~
/** iaLsIy#h
* @return k3}|^/bHJ
* Returns the hasPrePage. /al(=zf
*/ xCEEv5(5
publicboolean getHasPrePage(){ O!\P]W4r$
return hasPrePage; iLws;3UX;x
} )d2 <;c
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/** m@u!frE,
* @param hasPrePage &Op, ?\
* The hasPrePage to set. B<I%:SkF@
*/ /![S 3Ol
publicvoid setHasPrePage(boolean hasPrePage){ SirjWYap
this.hasPrePage = hasPrePage; 8&IsZPq%l
} ]Vln5U
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/** qb]n{b2
* @return Returns the totalPage. 4askQV &hj
* hJ (Q^Z
*/ S1E=E5
publicint getTotalPage(){ lQ<2Vw#Yl
return totalPage; _[<R<&jG
} C},;M@xV
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/** m$ )yd~
* @param totalPage o+4/L)h
* The totalPage to set. .0:BgM
*/ GvF8S MO[x
publicvoid setTotalPage(int totalPage){ Kyt.[" p
this.totalPage = totalPage; yM}}mypS
} jrbEJ.
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} `MAee8u'
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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 :3^b>(W.
|NJe4lw+?
个PageUtil,负责对Page对象进行构造: nfJ|&'T
java代码: zlF*F8>m
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/*Created on 2005-4-14*/ e^&QT
package org.flyware.util.page; 1t_$pDF}
uSLO"\zysX
import org.apache.commons.logging.Log; XSyCT0f08
import org.apache.commons.logging.LogFactory; `zGK$,[%
xphw0Es
/** ` wuA}v3!
* @author Joa QWH1xId
* {_0Efc=7
*/ IMIZ#/
publicclass PageUtil { S(9Xbw)T
;ZHKTOoK
privatestaticfinal Log logger = LogFactory.getLog ?BT\)@h
U_v{Vs
(PageUtil.class); E1IRb':
4!p~Mr[E
/** C9E l {f
* Use the origin page to create a new page !8yw!hA
* @param page +Mc kR
* @param totalRecords iDt^4=`
* @return A`v (hBM
*/ TC[_Ip&
publicstatic Page createPage(Page page, int Pk9s~}X
T=35?
totalRecords){ 0L"CM?C
return createPage(page.getEveryPage(), aehGT|
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page.getCurrentPage(), totalRecords); ^wPKqu)^
} #gq4%;
#mlTN3
/** j2# nCU54Z
* the basic page utils not including exception 'c<vj
jIg
^prseO?A
handler hYMIe]kJ
* @param everyPage +N5#EpW
* @param currentPage Y$b4Ga9j
* @param totalRecords UZ0fw@R M
* @return page LWHP31{R
*/ j89|hG)2
publicstatic Page createPage(int everyPage, int [Av#Z)R
Hy5_iYP5
currentPage, int totalRecords){ ^0"NcOzzxl
everyPage = getEveryPage(everyPage); O&l(`*P
currentPage = getCurrentPage(currentPage); TJ[C,ic=D
int beginIndex = getBeginIndex(everyPage, t5mI)u
9 +"D8J7
currentPage); {MdxIp[
int totalPage = getTotalPage(everyPage, [tsi8r=T
RR!(,j^M
totalRecords); -QjdL9\[c7
boolean hasNextPage = hasNextPage(currentPage, 6eE%x?#
KY
H*5
totalPage); A`<#}~A
boolean hasPrePage = hasPrePage(currentPage); *F* c
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returnnew Page(hasPrePage, hasNextPage, qKt8sxg
everyPage, totalPage, au7%K5
currentPage, B!GpD@U
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beginIndex); \o !
} u8qL?Aj^
R 5 47
privatestaticint getEveryPage(int everyPage){ %])-+T
return everyPage == 0 ? 10 : everyPage; 21D4O,yCe
} _ _cJ+%e
HmKvu"3
privatestaticint getCurrentPage(int currentPage){ \eF5* {9
return currentPage == 0 ? 1 : currentPage; =Xze ).g
} :khl}|
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privatestaticint getBeginIndex(int everyPage, int `GOxFDB.
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currentPage){ jb1OcI%
return(currentPage - 1) * everyPage; L>+g;GJ
} J XKps#,(#
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privatestaticint getTotalPage(int everyPage, int 9UTWq7KJ
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totalRecords){ QwXM<qG*
int totalPage = 0; !+Z"7e
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if(totalRecords % everyPage == 0) MV6%~T
totalPage = totalRecords / everyPage; ^4(CO[|c~
else @+~=h{jv<
totalPage = totalRecords / everyPage + 1 ; VaC#9Tp2X
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return totalPage; BF8n: }9U
} HRIf)n&~f
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privatestaticboolean hasPrePage(int currentPage){ u_.V]Rjc
return currentPage == 1 ? false : true; t+}@J}b
} YS=|y}Q|7d
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privatestaticboolean hasNextPage(int currentPage, GDw4=0u-
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int totalPage){ {YZ)IaqZ
return currentPage == totalPage || totalPage == }<7Dyn,
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0 ? false : true; Fp4?/-]
} AbUU#C7
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} % \N.m/5
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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。 Iu|G*~\
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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 I@cKiB
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做法如下: ;Fcdjy
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 9bgKu6-X
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的信息,和一个结果集List: efMv1>{
java代码: -qfd)A6]
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/*Created on 2005-6-13*/ o"[P++qd
package com.adt.bo; 6v GcM3M
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import java.util.List; o]n5pZ\\W<
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import org.flyware.util.page.Page; Bx
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/** =N<Hc:<t4
* @author Joa ig; ~
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*/ +>z/54R
publicclass Result { \yb^%$hZ0
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private Page page; [HF)d#A
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private List content; fouy??
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/** tt|U,o
* The default constructor #`z!f0
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*/ _<