Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 [U\?+@E*
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 =;}W)V|X)S
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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 nK&]8"
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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 ! -gU~0
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分页支持类: 0lw>mxN
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java代码: xad`-vw
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package com.javaeye.common.util; HpwMm^
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import java.util.List; [oWkd_dK
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publicclass PaginationSupport { {]vD@)k
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publicfinalstaticint PAGESIZE = 30; jDzQw>TX
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privateint pageSize = PAGESIZE; ]@q%dsz
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privateList items; Lu.zc='\
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privateint totalCount; >rG>Bz^Pu
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privateint[] indexes = newint[0]; yNu_>!Cp5
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privateint startIndex = 0; 18g_v"6o
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public PaginationSupport(List items, int Cu"Cpt[
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totalCount){ >J"IN I
setPageSize(PAGESIZE); 5/H,UL
setTotalCount(totalCount); ,'#TdLe
setItems(items); kmB!NxF>)F
setStartIndex(0); :qYp%Ub
} b*|~F
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public PaginationSupport(List items, int Z%T Ajm
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totalCount, int startIndex){ g40Hj Y
setPageSize(PAGESIZE); OATdmHW
setTotalCount(totalCount); jm0p%%z
setItems(items); _=v#"l
setStartIndex(startIndex); ]5!3|UYS
} OG\i?N
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public PaginationSupport(List items, int Aq i:h]x
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totalCount, int pageSize, int startIndex){ &$"#hGg
setPageSize(pageSize); Lp`.fn8Ln
setTotalCount(totalCount); cx}Yu8
setItems(items); J8|MK.oD
setStartIndex(startIndex); Daf|.5>(@
} j50vPV8m
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publicList getItems(){ 5'%I4@Qn+
return items; K`*GZ+b|`
} ^@fD{]I
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publicvoid setItems(List items){ hU)t5/h;K
this.items = items; %Ymi,o>
} HB07 n4 |
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publicint getPageSize(){ 1#vy# '
return pageSize; G5ATR<0m
} sqkWQ`Ur
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publicvoid setPageSize(int pageSize){ ;\MWxh,K
this.pageSize = pageSize; XqH@3Ehk
} ^W |YE72Y
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publicint getTotalCount(){ K;K0D@>]HR
return totalCount; M!&Hn,22
} {UNH?2
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publicvoid setTotalCount(int totalCount){ !pU$'1D
if(totalCount > 0){ fI.|QD*$b
this.totalCount = totalCount; Y2|i> 5/|<
int count = totalCount / z4u.bU
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pageSize; jP@ @<dt
if(totalCount % pageSize > 0) 0Tj,TF
count++; o|$D|E
indexes = newint[count]; Q3@ zUjq_Q
for(int i = 0; i < count; i++){ -FeXG#{)
indexes = pageSize * <z Gh}.6v
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i; Y;'<u\^M"
} D
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}else{ p1N}2]e
this.totalCount = 0; *&U~Io"U
} *>fr'jj1$
} +Z`=iia>
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publicint[] getIndexes(){ E@}F^0c
return indexes; KsDS!O
} U}92%W?
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publicvoid setIndexes(int[] indexes){ g 9,"u_
this.indexes = indexes; F^,:p.ihm<
} $]7f1U_e
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publicint getStartIndex(){ ZmK=8iN9J
return startIndex; tE*BZXBlm
} ||+~8z#+,
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publicvoid setStartIndex(int startIndex){ @K;b7@4y
if(totalCount <= 0) `}X3f#eO&
this.startIndex = 0; 5F kdGF
elseif(startIndex >= totalCount) F5)`FM^R
this.startIndex = indexes x&B&lFmo8
}#z1>y!#
[indexes.length - 1]; ?v^NimcZ
elseif(startIndex < 0) M/ S~"iD
this.startIndex = 0; 4o>y9
else{ Vl.,e1)6
this.startIndex = indexes :Cq73:1\B
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[startIndex / pageSize]; Dfs^W{YA
} =VC18yA
} Gxr\a2Z&r%
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publicint getNextIndex(){ :EX>Y<`]
int nextIndex = getStartIndex() + 3W1Lh~Av
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pageSize; NcA
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if(nextIndex >= totalCount) +\!.X_Ij
return getStartIndex(); %=**cvVy
else zlMh^+rMX
return nextIndex; )uqzu%T
}
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publicint getPreviousIndex(){ ]r`;89:s>
int previousIndex = getStartIndex() - -K{R7
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pageSize; H cmW
if(previousIndex < 0) 1>(EvY}Y\
return0; #GM^ :rF
else D
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return previousIndex; 5lsslE+:J
} (MGgr
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} ?
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抽象业务类 L0w6K0J4
java代码: 1UP
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/** St5;X&Q
* Created on 2005-7-12 wFMH\a
*/ @CNJpQ ujn
package com.javaeye.common.business; pg{VKrT`
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import java.io.Serializable; pRQ7rT',v
import java.util.List; TV{GHB!p"
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import org.hibernate.Criteria; 99yWUC,
import org.hibernate.HibernateException; BU -;P
import org.hibernate.Session; bEcs(Mc~
import org.hibernate.criterion.DetachedCriteria; |[],z 8
import org.hibernate.criterion.Projections; s;A7:_z#7
import a1pp=3Pd?~
8Lgt
org.springframework.orm.hibernate3.HibernateCallback; UPtj@gtcY
import ~z^?+MgZ2
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org.springframework.orm.hibernate3.support.HibernateDaoS 21TR_0g&<
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upport; L{/%
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import com.javaeye.common.util.PaginationSupport; eT
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public abstract class AbstractManager extends E&9<JS
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HibernateDaoSupport { WK|5:V8E
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privateboolean cacheQueries = false; IiE6i43
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privateString queryCacheRegion; $;5Q
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publicvoid setCacheQueries(boolean |r~ u7U\
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cacheQueries){ |_?e.}K
this.cacheQueries = cacheQueries; HOx4FXPs
} oq7G=8gTp
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publicvoid setQueryCacheRegion(String <::lfPP
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queryCacheRegion){ jPSVVOG
this.queryCacheRegion = \2@J^O1,
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queryCacheRegion; [IAUJ09>I
} `cp\UH@
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publicvoid save(finalObject entity){ _?-oPb
getHibernateTemplate().save(entity); (MLcA\LJ
} 6Vnq|;W3Zv
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publicvoid persist(finalObject entity){ .B]l@E-u
getHibernateTemplate().save(entity); "t^v;?4
} W>#yXg9
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publicvoid update(finalObject entity){ L-+g`
getHibernateTemplate().update(entity); a``|sn9
}
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publicvoid delete(finalObject entity){ SIp)&
getHibernateTemplate().delete(entity); #*bmwb*i
} y#'hOSR2
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publicObject load(finalClass entity, 1AAyzAP9`
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finalSerializable id){ l cl|o3yQ
return getHibernateTemplate().load hDxq9EF
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(entity, id); H,} &=SCk
} W6<oy
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publicObject get(finalClass entity, Db"mq'vT
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finalSerializable id){ t@!n?j
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return getHibernateTemplate().get ?%5VaxWJ
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(entity, id); e|Ri
} ;M?)-dpZ
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publicList findAll(finalClass entity){ u1/>)_U
return getHibernateTemplate().find("from b,Wm]N
G(t:s5:
" + entity.getName()); Q]9$dr=Kk0
} r *K
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publicList findByNamedQuery(finalString )R7Sh51P
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namedQuery){ h'"m,(a
return getHibernateTemplate Na91K4r#
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().findByNamedQuery(namedQuery); dk&e EDvfd
} z>N[veX%
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publicList findByNamedQuery(finalString query, CY o
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finalObject parameter){ (H_dZL
return getHibernateTemplate '?C6P5fm
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().findByNamedQuery(query, parameter); MhN;GMH
} -,")GA+[7
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publicList findByNamedQuery(finalString query, D1rVgM
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finalObject[] parameters){ {JfQQP&FV
return getHibernateTemplate |<Ls;:5.
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().findByNamedQuery(query, parameters); 1gHe$dzXk
} yV.p=8:
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publicList find(finalString query){ m[}P
return getHibernateTemplate().find v_XN).f;
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(query); v +4v
} 2W+~{3[#
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publicList find(finalString query, finalObject DvH-M3
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parameter){ y`RzcXblIZ
return getHibernateTemplate().find dgP eH8_
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(query, parameter); rMwa6ZO'm;
} jf3Zy:*K
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public PaginationSupport findPageByCriteria 4K^cj2X
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(final DetachedCriteria detachedCriteria){ 4vg3F(
return findPageByCriteria :$D*ab^^P
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); r(r(&NU
} 7 z
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public PaginationSupport findPageByCriteria UPH#~D!
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(final DetachedCriteria detachedCriteria, finalint OQumAj
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startIndex){ Aits<0
return findPageByCriteria &%fcGNzJQ
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(detachedCriteria, PaginationSupport.PAGESIZE, llZU: bs
{($bzT7c
startIndex); {L;sF=d
} [+o{0o>
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public PaginationSupport findPageByCriteria -H%v6E%yh
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(final DetachedCriteria detachedCriteria, finalint (}b~}X9
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pageSize, ~IZ-:?+S^
finalint startIndex){ I<2`wL=
return(PaginationSupport) ?J2{6,}O*.
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getHibernateTemplate().execute(new HibernateCallback(){ c=u+X`
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publicObject doInHibernate 4$R!)
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(Session session)throws HibernateException { |*?N#0s5h
Criteria criteria = W5u5!L/
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detachedCriteria.getExecutableCriteria(session); jgE{JK\n4
int totalCount = [R4#bl
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((Integer) criteria.setProjection(Projections.rowCount NAo.79
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()).uniqueResult()).intValue(); PzPNvV/o
criteria.setProjection 437Wy+Q|e
+ nR("Il
(null); eP2Q2C8g
List items = dSwfea_
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criteria.setFirstResult(startIndex).setMaxResults P8c_GEna
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(pageSize).list(); Z0&^(Fb
PaginationSupport ps = FJ84'T\~
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new PaginationSupport(items, totalCount, pageSize, JM;bNW8
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startIndex); |va@&;#wf
return ps; )#AYb
} jN+`V)p
}, true); ).kU7;0
} x[t?hl=:
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public List findAllByCriteria(final Gxd/t#;
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DetachedCriteria detachedCriteria){ v.W!
return(List) getHibernateTemplate "5eD
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().execute(new HibernateCallback(){ oI-Fr0!
publicObject doInHibernate &m5^
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(Session session)throws HibernateException { W,~*pyLdO
Criteria criteria = ++~
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detachedCriteria.getExecutableCriteria(session); d*+}_EV)Y3
return criteria.list(); "dCIg{j
} HVvm3qu4
}, true); <uIPv
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} v
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public int getCountByCriteria(final sA6Hk B.
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DetachedCriteria detachedCriteria){ SsX$l<t*
Integer count = (Integer) _,^f,WO~
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getHibernateTemplate().execute(new HibernateCallback(){ xLIyh7$t
publicObject doInHibernate _LF'0s*
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(Session session)throws HibernateException { V.3#O^S
Criteria criteria = DQhHU1
,;6%s>Cvd(
detachedCriteria.getExecutableCriteria(session); I&|8
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return fp||<B
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criteria.setProjection(Projections.rowCount M}jl\{
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()).uniqueResult(); 7h9oY<W
} T2-x 1Sw_
}, true); 6iQqOAG
return count.intValue(); Yaq0mef0
} _x5-!gK
} 2^s@n3t
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用户在web层构造查询条件detachedCriteria,和可选的 bY`Chb.
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 L\Oxyi<{
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PaginationSupport的实例ps。 F4(;O7j9
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ps.getItems()得到已分页好的结果集 &>B|?d
ps.getIndexes()得到分页索引的数组 qjfv9sU
ps.getTotalCount()得到总结果数 Iy5W/QK6
ps.getStartIndex()当前分页索引 W(ZEqH2
ps.getNextIndex()下一页索引 jM*wm~4>@
ps.getPreviousIndex()上一页索引 IAd^$9
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 BvlY\^
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 /x-tl)(s=
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一下代码重构了。 FlS)m`
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我把原本我的做法也提供出来供大家讨论吧: ziW[qH {
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首先,为了实现分页查询,我封装了一个Page类: TuMZHB7h;
java代码: yyR@kOGga
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/*Created on 2005-4-14*/ !/&~Feb
package org.flyware.util.page; tORDtMM9+
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/** t[%=[pJHW
* @author Joa QL(}k)dB
* `).;W
*/ 0txSF^x
publicclass Page { lSId<v?C>
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/** imply if the page has previous page */ '.&,.E&{$
privateboolean hasPrePage; y(#F&^|
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{
/** imply if the page has next page */ `.6Jgfu
privateboolean hasNextPage; ,/L_9wV-\
1 _W5@)
/** the number of every page */ (aCl*vV1
privateint everyPage; J! eVw\6
nfvs"B;
/** the total page number */ I^A01\p
privateint totalPage; ;rta#pRn
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/** the number of current page */ QQjMC'
privateint currentPage; 6ud<B
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/** the begin index of the records by the current ;Wr,VU]
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query */ r3 {o_w
privateint beginIndex; w_J`29uc
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/** The default constructor */ NU/~E"^I.
public Page(){ 1[`l`Truz
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} s.dn~|a
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/** construct the page by everyPage a( {`<F
* @param everyPage &<i>)Ss
* */ U7fE6&g
public Page(int everyPage){ g?o$:>c
this.everyPage = everyPage; W%Zyt:H`
} Zk;;~ESOU
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/** The whole constructor */ XKU=VOY
public Page(boolean hasPrePage, boolean hasNextPage, lR^dT4
z8"=W,2
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int everyPage, int totalPage, *&2#;mf3
int currentPage, int beginIndex){ 9'8oOBqm3%
this.hasPrePage = hasPrePage; f&cG;Y
this.hasNextPage = hasNextPage; 3yD5u
this.everyPage = everyPage; |-aj$u%~
this.totalPage = totalPage; 1aMBCh<}JN
this.currentPage = currentPage; |QgXSe7
this.beginIndex = beginIndex; ;%z0iZmg
} 0Rk'sEX,
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/** @%cJjZ5y
* @return "RX?"pB
* Returns the beginIndex. {}^ELw
*/ LA@}{hU
publicint getBeginIndex(){ x}>tX
return beginIndex; u!`C:C'
} ]R>k0X.V
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/** YL=k&QG
* @param beginIndex gS|xicq!
* The beginIndex to set. 246lFxG.
*/ =<_5gR
publicvoid setBeginIndex(int beginIndex){ 1k%ko?
this.beginIndex = beginIndex; Yh%wf3
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} 0j/81Y}p
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/** G =4 y!y
* @return B# H
* Returns the currentPage. IFTW,9hh
*/ YXg
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publicint getCurrentPage(){ M2EN(Y_k0
return currentPage; ?Ru`ma\;
} ^{K8uN7
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/** (Mm{"J3uv
* @param currentPage A7RX2
* The currentPage to set. #f~a\}$I
*/ +l/j6)O`(m
publicvoid setCurrentPage(int currentPage){ S'JeA>L
this.currentPage = currentPage; KE&}*Nf[
} qtH&]Suu,
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/** yl 8v&e{
* @return 4F4u1r+
* Returns the everyPage. Y#Vy:x[
*/ G\p;
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publicint getEveryPage(){ |O9=C`G_
return everyPage; #
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} 8W[]#~77b
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/** bv4cw#5z$9
* @param everyPage zB$6e!fc
* The everyPage to set. 7Mv$.Z(
*/ .nH
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publicvoid setEveryPage(int everyPage){ kZ.3\
this.everyPage = everyPage; ) IhY&?jk?
} '> Q$5R1
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/** S+y2eP G
* @return =5M>\vt]
* Returns the hasNextPage. dJ^`9W
*/ G0Eq}MyF
publicboolean getHasNextPage(){ /a|NGh%
return hasNextPage; 7 f*_
} e`Yns$x
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/** ZO1J";>u
* @param hasNextPage 5l}h8So4
* The hasNextPage to set. *n'xS L
*/ Madaxx
publicvoid setHasNextPage(boolean hasNextPage){ ksaC[G;}:
this.hasNextPage = hasNextPage; \-0` %k"&
} rw2|1_AF
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/** JrAc]=
* @return @#tSx
* Returns the hasPrePage. T_Y }1n|7[
*/ {@$3bQ
publicboolean getHasPrePage(){ 6<Wr
8u,
return hasPrePage; R4(8]oUW
} /6c10}f
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/** P.B'Gh#^
* @param hasPrePage /,UkT*+>!
* The hasPrePage to set. B,Brmn
*/ ;#i$0~lRl
publicvoid setHasPrePage(boolean hasPrePage){ @GtZK
this.hasPrePage = hasPrePage; (d#Z-w-
} SXz([Z{)
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/** m_ m@>}ud
* @return Returns the totalPage. OP}p;(
* \AzcW;03g[
*/ AyO|9!F@A
publicint getTotalPage(){ )x &@j4,
return totalPage; OF/)-}!
} q)b?X
^
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/** [9_ (+E[}
* @param totalPage Gnt!!1_8L
* The totalPage to set. +:%FJCOT
*/ K>6k@okO
publicvoid setTotalPage(int totalPage){ s*~o%emw
this.totalPage = totalPage; DZ.trtK
}
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} QJM!Wx+
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 b_Jq=Gk`
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个PageUtil,负责对Page对象进行构造: ld}$Tsy0
java代码: A i){,nh`0
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/*Created on 2005-4-14*/ _i@eOqoC
package org.flyware.util.page; B~zg"
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import org.apache.commons.logging.Log; /'fDXSdP
import org.apache.commons.logging.LogFactory; _j\=FJz[
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/** XuoEAu8]
* @author Joa S} Cp&}G{P
* $YY)g$
*/ CN~NyJL H
publicclass PageUtil { -Dxhq&
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privatestaticfinal Log logger = LogFactory.getLog tlLn
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(PageUtil.class); {a8^6dm*E
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/** uE#,c\[8
* Use the origin page to create a new page g)?g7{&?>?
* @param page zZ"U9!T
* @param totalRecords )]c3bMVE-
* @return s[2ZxCrCw
*/ Evq Ai/(g
publicstatic Page createPage(Page page, int )QCM2
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totalRecords){ "=\_++
return createPage(page.getEveryPage(), 6mpg&'>
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page.getCurrentPage(), totalRecords); _c
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} 66@3$P%1p
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/** h<'5q&y
* the basic page utils not including exception Oqpl2Y"/
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handler 14n="-9
* @param everyPage -N8cjr4l
* @param currentPage O< tnM<"(
* @param totalRecords B5,QJ W*
* @return page k)usUP'
*/ koEX4q
publicstatic Page createPage(int everyPage, int UcLNMn|
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currentPage, int totalRecords){ ]ZKt1@4AY
everyPage = getEveryPage(everyPage); zP(=,)d
currentPage = getCurrentPage(currentPage); g2{H^YUN$_
int beginIndex = getBeginIndex(everyPage, }{wTlR.]
p=_XMh`;
currentPage); Vx6?@R
int totalPage = getTotalPage(everyPage, 2iPmCG
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totalRecords); (ND5CKCR^
boolean hasNextPage = hasNextPage(currentPage, r3H}*Wpf
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totalPage); 1 73<x){
boolean hasPrePage = hasPrePage(currentPage); ,d>X/kd|o
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returnnew Page(hasPrePage, hasNextPage, of'ZNQ/
everyPage, totalPage, !q$&JZY
currentPage, -e{)v' C)
oa &z/`@
beginIndex); 9U=fJrj'u
} 12tJrS*Z
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privatestaticint getEveryPage(int everyPage){ Uc&6=5~Ys\
return everyPage == 0 ? 10 : everyPage; D,dHP-v
} +-aU+7tu
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privatestaticint getCurrentPage(int currentPage){ 833%H`jQc
return currentPage == 0 ? 1 : currentPage; uojh%@.4
} !
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privatestaticint getBeginIndex(int everyPage, int d2A
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currentPage){ Foe>}6~{?
return(currentPage - 1) * everyPage; dgco*TIGO
} v;fJM5PA
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privatestaticint getTotalPage(int everyPage, int ~[zFQ)([
-OrY{^F
totalRecords){ 0\cnc^Z
int totalPage = 0; 1c)\
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if(totalRecords % everyPage == 0) %wt2F-u
totalPage = totalRecords / everyPage; i5
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else Hz]4A S
totalPage = totalRecords / everyPage + 1 ; *bCi2mbm@
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return totalPage; VelB-vy&
} jcEs10y
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privatestaticboolean hasPrePage(int currentPage){ \-Iny=$
return currentPage == 1 ? false : true; 0~+NB-L}
} iY
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privatestaticboolean hasNextPage(int currentPage, |oe!P}u
?{
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int totalPage){ TsaW5ho<p
return currentPage == totalPage || totalPage == g> ~cs_N@
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0 ? false : true; 9Hf*cQ
} 83KfM!w
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} X~v4"|a
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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。 `E3:;|
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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 X,RT<GNNb
(TEo_BW|+
做法如下: 87^:<\pp
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 \npz.g^c_
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的信息,和一个结果集List: !}>eo2$r^
java代码: F2IC$:e
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/*Created on 2005-6-13*/ g!1I21M1~
package com.adt.bo; Mn]}s:v
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import java.util.List; ?SC3Vzr
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import org.flyware.util.page.Page; m_Mwg
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/** O6yP
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* @author Joa $d'CBsu|<
*/ W1xf2=z`)T
publicclass Result { 2Sge
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private Page page; R{*_1cyW
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private List content; S?*^>Y-e;
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/** !xkj30O(G
* The default constructor EVR! @6@
*/ sf Dg/ a
public Result(){ &&;ex9
super(); P?^JPbfV
} mT96]V\
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/** XjX 2[*l
* The constructor using fields +.w[6
* @. "q
* @param page gf+o1\5t@
* @param content F?7u~b|@{
*/ Q"A_bdg5
public Result(Page page, List content){ :I2H&,JT
this.page = page; YMi/uy
this.content = content; 8{oZi]ob
} F4Rr26M
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/** Q}=fVY
* @return Returns the content. 4 GUA&