Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 |tmD`ndO
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 dM)fr
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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 ){/y-ixH
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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 ~k&b3-A}
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分页支持类: n'&WIf3
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java代码: ^+pmZw90
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package com.javaeye.common.util; ,30&VW##
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import java.util.List; .DT1Jvl
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publicclass PaginationSupport { 6(wpf^br2
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publicfinalstaticint PAGESIZE = 30; 2o,%O91p
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privateint pageSize = PAGESIZE; ^LZU><{';
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privateList items; atYm.qb
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privateint totalCount; ")TI,a`
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privateint[] indexes = newint[0]; s+4G`mq>*
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privateint startIndex = 0; rZ^DiFR
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public PaginationSupport(List items, int 0L|A
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totalCount){ hhwV)Z
setPageSize(PAGESIZE); d6_ CsqV
setTotalCount(totalCount); F3+)bIz
setItems(items); nU/v(lN
setStartIndex(0); ~$+9L2gz
} K2!KMhvQ
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public PaginationSupport(List items, int *.20YruU;j
-O{Af
totalCount, int startIndex){ =3sBWDB[
setPageSize(PAGESIZE); cU+/I>V
setTotalCount(totalCount); #Ez>]`]TB
setItems(items); ms<?BgCSz
setStartIndex(startIndex); ,!c.
} 8K{
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public PaginationSupport(List items, int .F9>|Xx[
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totalCount, int pageSize, int startIndex){ S&9{kt|BI
setPageSize(pageSize); i_V~SC`
setTotalCount(totalCount); ^;N+"oq!y
setItems(items); e1K,4Bq
setStartIndex(startIndex); 8JGt|,
} )Nk^;[
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publicList getItems(){ dqnxhN+&
return items; eEXer>Rm
} Q[S""P.Z|
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publicvoid setItems(List items){ EI]NOG 0
this.items = items; ']>@vo4kK{
} JhIgqW2
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publicint getPageSize(){ [|e7oNT(Q
return pageSize; {p+7QlgK
} Lylw('zZ
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publicvoid setPageSize(int pageSize){ nxCwg>
this.pageSize = pageSize; rk{DrbRx
} <1>\?$)D
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publicint getTotalCount(){ RD<l<+C^~
return totalCount; UuW"
} Ydh]EO0'
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publicvoid setTotalCount(int totalCount){ hQvSh\p
if(totalCount > 0){ l$z\8]x
this.totalCount = totalCount; ggfL
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int count = totalCount / ?u"MsnCXYn
9PIm/10pP^
pageSize; 8NWvi%g
if(totalCount % pageSize > 0) pl%3RVpoc
count++; x)h5W+$
indexes = newint[count]; y#o ,Vg*V
for(int i = 0; i < count; i++){ 6*le(^y`
indexes = pageSize * +-1t]`9k4
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i; 1
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} Y[#i(5w
}else{ H0_hQ:K
this.totalCount = 0; eo4;?z
} 1@im+R?a
} Pl9/1YhD/
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publicint[] getIndexes(){ wz<YflF
return indexes; PSNfh7g
} ]N,n7v+}
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publicvoid setIndexes(int[] indexes){ cK"b0K/M?B
this.indexes = indexes; #/\5a;Elc
} E80C0Q+V
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publicint getStartIndex(){ |]w0ytL>(2
return startIndex; FE,&_J"
} $_%yr
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publicvoid setStartIndex(int startIndex){ /{#1w\
if(totalCount <= 0) "z8L}IC!e5
this.startIndex = 0; POdk0CuX
elseif(startIndex >= totalCount) HeCQF=R
this.startIndex = indexes B0T[[%~3M
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[indexes.length - 1]; -y;SR+
elseif(startIndex < 0) -L}crQl.'c
this.startIndex = 0; 89?$xm _m
else{ *+{umfZy
this.startIndex = indexes aOFF"(]Cl
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[startIndex / pageSize]; Y<0
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} LS}dt?78`V
} /:iO:g1
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publicint getNextIndex(){ ZaBGkDX5
int nextIndex = getStartIndex() + 3iMh)YH5b
sg RY`U.C
pageSize; ZnVi.s~1V
if(nextIndex >= totalCount)
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return getStartIndex(); 5B)Z@-x2
else I@76ABu^
return nextIndex; zc%#7"FM
} &W)Lzpx8c
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publicint getPreviousIndex(){ apPn>\O
int previousIndex = getStartIndex() - [Dni>2@0
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pageSize;
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if(previousIndex < 0) }%Dsy2:y
return0; BuII|j
else Nz %{T
return previousIndex; ~ x-
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} ;& ny< gQ
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} z-<U5-'
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抽象业务类 ~vgm;O
java代码: &>y[5#qOl
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/** k \rzvo=U
* Created on 2005-7-12 /X>Fn9mM
*/ Pi7vuOJr8
package com.javaeye.common.business; pVbgjJI
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import java.io.Serializable; cD5c&+,&I
import java.util.List; (lBgWz
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import org.hibernate.Criteria; :d\ne
import org.hibernate.HibernateException; 1D159 NLB
import org.hibernate.Session; 3}V`]B#a
import org.hibernate.criterion.DetachedCriteria; X;25G
import org.hibernate.criterion.Projections; MW*@fl<@?M
import +c$]Q-(
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org.springframework.orm.hibernate3.HibernateCallback; No#1Ik w
import ,5J-C!C
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org.springframework.orm.hibernate3.support.HibernateDaoS (:v|(Gn/
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upport; BBnW0vAZ*
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import com.javaeye.common.util.PaginationSupport; zG)XB*c
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public abstract class AbstractManager extends *[K\_F?^h
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HibernateDaoSupport { 8G@I e
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privateboolean cacheQueries = false; #'m&<g,
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privateString queryCacheRegion; ?`T<
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publicvoid setCacheQueries(boolean r;m_@*]
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cacheQueries){
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this.cacheQueries = cacheQueries; I{#&!h>]U
} y\Su!?4!
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publicvoid setQueryCacheRegion(String MR:GH.uM:
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queryCacheRegion){ *9V;;bY#
this.queryCacheRegion = ~gU.z6us
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queryCacheRegion; )9LlM2+y
} c|?0iN
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publicvoid save(finalObject entity){ $qOV#,@
getHibernateTemplate().save(entity); IoUQ~JviA
} C/AqAW1
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publicvoid persist(finalObject entity){ rz/^_dV
getHibernateTemplate().save(entity); A0Z<1|6r*
} &+F|v(|r
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publicvoid update(finalObject entity){ F-K=Otj
getHibernateTemplate().update(entity); ;:(kVdb
} my+y<C-o`
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publicvoid delete(finalObject entity){ ia=eFWt.
getHibernateTemplate().delete(entity); i$MYR @
} Th1/Bxb:
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publicObject load(finalClass entity, l"9.zPvT<
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finalSerializable id){ 4-lG{I_S:
return getHibernateTemplate().load 8w,U[aJm
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(entity, id); *]uo/g
} LObS
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publicObject get(finalClass entity, rzmd`)g
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finalSerializable id){ UG)J4ZX
return getHibernateTemplate().get zQY|=4NP
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(entity, id); % H"A%
} 1O" Mo
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publicList findAll(finalClass entity){ -"*UICd
return getHibernateTemplate().find("from YbS$D
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" + entity.getName()); \;w$"@9
} #'"zyidu
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publicList findByNamedQuery(finalString :5kgJu
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namedQuery){ eK]g FXk
return getHibernateTemplate 4yLC
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().findByNamedQuery(namedQuery); BI9~%dm
} 77y_?di^I
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publicList findByNamedQuery(finalString query, w[g(8#*
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finalObject parameter){ m~KGB"
return getHibernateTemplate wPhN_XV
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().findByNamedQuery(query, parameter); G/Ll4
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} B+e$S%HV
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publicList findByNamedQuery(finalString query, Vp3r
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finalObject[] parameters){ vfb~S~|U6g
return getHibernateTemplate ?$rSbw
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().findByNamedQuery(query, parameters); %<^B\|d'?
} \SB~rz"A
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publicList find(finalString query){ ce/Z[B+d
return getHibernateTemplate().find f-at@C1L%L
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(query); g? 7%
} 7MX nt5qUh
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publicList find(finalString query, finalObject (e>.hfrs
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parameter){ NZUQ
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return getHibernateTemplate().find P( z#Wk
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(query, parameter); {+Rf?'JZH
} YS$?Wz
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public PaginationSupport findPageByCriteria O0`k6$=6r
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(final DetachedCriteria detachedCriteria){ I]S8:w![
return findPageByCriteria [3Qu @;"&
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); Bq}p]R3X
} l}|KkW\y
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public PaginationSupport findPageByCriteria VUfV=&D-*g
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(final DetachedCriteria detachedCriteria, finalint oBVYgv)
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startIndex){ vIk;x
return findPageByCriteria ,^dyS]!d$
& <{=
(detachedCriteria, PaginationSupport.PAGESIZE, YuO-a$BP
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startIndex); SG6@Rn*^
} A]VcQ_e
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public PaginationSupport findPageByCriteria E1,Sr?'
~=W|I:@
(final DetachedCriteria detachedCriteria, finalint ym,UJs&
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pageSize, idL6 *%M
finalint startIndex){ ~b}@*fq
return(PaginationSupport) W/dl`UDY
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getHibernateTemplate().execute(new HibernateCallback(){ }m6zu'CV
publicObject doInHibernate {fsU(Jj\
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(Session session)throws HibernateException { >BC?%|l
Criteria criteria = oH/6
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detachedCriteria.getExecutableCriteria(session); + V:P-D
int totalCount = E;l|I
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((Integer) criteria.setProjection(Projections.rowCount ~T<yp
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()).uniqueResult()).intValue(); kj(Ko{
criteria.setProjection ,3^gB,ka
0>#or$:6E
(null); "tuBfA+f
List items = 11Kbj`sRZ
*&VH!K#@{
criteria.setFirstResult(startIndex).setMaxResults u(ep$>[F#_
]lj,GD)c
(pageSize).list(); -eKi}e
PaginationSupport ps = FI,>v`
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new PaginationSupport(items, totalCount, pageSize, E|u#W3-:
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startIndex); $ t' .
return ps; L%,tc~)A
} klC;fm2C
}, true); #NZ\UmA
} "eWN52
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public List findAllByCriteria(final ; z_ZZ(W
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DetachedCriteria detachedCriteria){ Y,O)"6ev
return(List) getHibernateTemplate R:+2}kS5e{
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().execute(new HibernateCallback(){ ]d#Lfgo
publicObject doInHibernate G([8Q8B4+
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(Session session)throws HibernateException { w9D<^(_}/
Criteria criteria = vywd&7gK
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detachedCriteria.getExecutableCriteria(session); "bFt+N
return criteria.list(); HJl$v#]#+
} T(@y#09
}, true); (P;z*
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} =ogzq.+|
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public int getCountByCriteria(final <b74L
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DetachedCriteria detachedCriteria){ A|sTnhp~
Integer count = (Integer) i_OoR"J%
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getHibernateTemplate().execute(new HibernateCallback(){ %1Gat6V<'
publicObject doInHibernate wN,DTmtD
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(Session session)throws HibernateException { ..yuEA
Criteria criteria = V"n0"\k,
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detachedCriteria.getExecutableCriteria(session); 41luFtE9
return @DgJxY|
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criteria.setProjection(Projections.rowCount [; M31b3
[u[`!L=
()).uniqueResult(); mG[S"?C
} j I
}, true); tjZ.p.IlG
return count.intValue(); %)[m bb
} %MyA;{-F6
} T.kmoLlH
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用户在web层构造查询条件detachedCriteria,和可选的 JpN]j`
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 %V-\ |cw
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PaginationSupport的实例ps。 D$g|f[l
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ps.getItems()得到已分页好的结果集 iTgGf
ps.getIndexes()得到分页索引的数组 -|^}~yOx0=
ps.getTotalCount()得到总结果数 X%W_cb2
ps.getStartIndex()当前分页索引 O@[c*3]e
ps.getNextIndex()下一页索引 |fdr\t#'~
ps.getPreviousIndex()上一页索引 fII;t-(x
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ~S}>|q$
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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 %&KJtKe
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一下代码重构了。 $Z)Dvy|
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我把原本我的做法也提供出来供大家讨论吧: $Gb] K{e
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首先,为了实现分页查询,我封装了一个Page类: @AUx%:}0Y:
java代码: )c=R)=N
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/*Created on 2005-4-14*/ wsp&U
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package org.flyware.util.page; xN
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/** !}wJ+R ^2
* @author Joa 0S@O]k)
* d;&'uiS
*/ g~_cYy
publicclass Page { evf){XhT;n
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/** imply if the page has previous page */ <mlQn?u
privateboolean hasPrePage; ]bO{001y,
+7?p&-r)x
/** imply if the page has next page */ mfOr+
privateboolean hasNextPage; (gBP`*2
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/** the number of every page */ X}'3N'cbkU
privateint everyPage; @O+yxGA
}h<\qvCcU
/** the total page number */ )#[?pYd
privateint totalPage; ]xQPSs_
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/** the number of current page */ :$d3}TjsA+
privateint currentPage; R`ajll1
=O~1L m;
/** the begin index of the records by the current 2%0zPflT
v :]y#y
query */ 7uJy<O
privateint beginIndex; kXS_:f;M
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/** The default constructor */ Z!=/[,b
public Page(){ P\;lH"9
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} [dFxW6n
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/** construct the page by everyPage P8!Vcy938
* @param everyPage CYrVP%xRA
* */ r AMnM>`
public Page(int everyPage){ jPYed@[+
this.everyPage = everyPage; E^L
} |Hg )!5EJ
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/** The whole constructor */ #6'oor X
public Page(boolean hasPrePage, boolean hasNextPage, Vnuz!
6.
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int everyPage, int totalPage, QQPbKok>
int currentPage, int beginIndex){ !%J;dOcU
this.hasPrePage = hasPrePage; SQ5SvYH
this.hasNextPage = hasNextPage; / _v5B>
this.everyPage = everyPage; x3>K{
this.totalPage = totalPage; CF9a~^+%
this.currentPage = currentPage; b!SGQv(^M
this.beginIndex = beginIndex; 6NJ"ty9Bp
} qa#Fa)g*
6FG h=~{3,
/** +Y(cs&V*
* @return t3u"2B7oG
* Returns the beginIndex. kCxmC<34
*/ 'p-jMD}O
publicint getBeginIndex(){ dgpo4'c}
return beginIndex; s `xp6\$
} (:2:_FL
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/** ;%2/
* @param beginIndex m8$6FN
* The beginIndex to set.
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*/ sR,]eo<p&
publicvoid setBeginIndex(int beginIndex){ !y$Hr[v
this.beginIndex = beginIndex; ??12
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} eS fT+UL
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/** 4>>{}c!nf
* @return -[i9a:eRM
* Returns the currentPage. VJBVk8P
*/ ]B=B@UO@.
publicint getCurrentPage(){ 67%eAS
return currentPage; K@U"^
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} r4dG83qg
'IBs/9=ZC
/** im9 B=D
* @param currentPage ^ $Q',
* The currentPage to set. 6=A2Y:8
*/ x68J [; jm
publicvoid setCurrentPage(int currentPage){ [Ua4{3#
this.currentPage = currentPage; ESiNW&u2
} 1QtT*{zm$F
En8-Hc#NC
/** #Bj{
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* @return l@Ma{*s6=5
* Returns the everyPage. ,=B
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*/ W*;~(hDz
publicint getEveryPage(){ <8 Nh dCO6
return everyPage; )XMSQ ="m
} HKv:)h{?
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/** T
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* @param everyPage d~C
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* The everyPage to set. l*HONl&j
*/ Qc\JUm]
publicvoid setEveryPage(int everyPage){ K8Gc5#OF
this.everyPage = everyPage; `j0T[Pi
} 1lfkb1BM
k6ERGQ9|I
/** Z/sB72K1
* @return P[ n`X
* Returns the hasNextPage. 3m#v|52oj
*/ Z66akr
publicboolean getHasNextPage(){ @cAv8iK
return hasNextPage; );}k@w
fw)
} mj[PKEdkB
+c/am``
/** )b"H]"
* @param hasNextPage r^ S4 I&
* The hasNextPage to set. gQ.yNe
*/ CY)/1 # J
publicvoid setHasNextPage(boolean hasNextPage){ If\u^c
this.hasNextPage = hasNextPage; qW6a|s0}
} 9@./=5N~3
HC*=E.J
/** Kpz>si?CL
* @return )I 4d_]&
* Returns the hasPrePage. N6cf`xye
*/ &BqRyUM$F
publicboolean getHasPrePage(){ ,IA0n79
return hasPrePage; ~;aSX1
} '{\VOU
A`Z!=og=
/** ]7O)iq%
* @param hasPrePage ^)rX27!G
* The hasPrePage to set. <?&GBCe
*/ Tc,Bv7:
publicvoid setHasPrePage(boolean hasPrePage){ l^:m!SA_
this.hasPrePage = hasPrePage; LVq3R 8A
} :HYqm*v;W
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/** vI{JBWE,S
* @return Returns the totalPage. W tnZF]1:u
* .UakO,"z
*/ SWD
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publicint getTotalPage(){ @R9zLL6#7
return totalPage; ^HLi1w|
} Z6!MX_ep
UA!h[+Z
/** D5\$xdlJy
* @param totalPage dD1`[%
* The totalPage to set. %Xh/16X${
*/ chQt8Ar3
publicvoid setTotalPage(int totalPage){ S6h=}
V)
this.totalPage = totalPage; e-,U@_B
} xM9EO(u
F}DdErd!f
} Zd1+ZH
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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 }.3F|H
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个PageUtil,负责对Page对象进行构造: L=iaL[zdJ
java代码: +)^F9LPl
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/*Created on 2005-4-14*/ CCDoiTu!4
package org.flyware.util.page; 7fLLV2
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import org.apache.commons.logging.Log; K%Mm'$fTw
import org.apache.commons.logging.LogFactory; WiH%URFB
m( C7Fa
/** S]KcAz( fX
* @author Joa @BbZ(cZ*
* i@6MO'y
*/ xQ>c.}J/i
publicclass PageUtil { iJ~5A'?6
[3nhf<O
privatestaticfinal Log logger = LogFactory.getLog ;o,t*
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(PageUtil.class); $)mq
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/** r) T^ Td1
* Use the origin page to create a new page <GF)5QB
* @param page <^UB@'lCm
* @param totalRecords 9U>ID{
* @return LG [2u
*/ ;9q3FuR
publicstatic Page createPage(Page page, int YPDc
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totalRecords){ 3P6pQm'.f
return createPage(page.getEveryPage(), F
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page.getCurrentPage(), totalRecords); p>Ju)o
} 9r
fR
};+ '
/** >Gk<[0U
* the basic page utils not including exception +Q_X,gZ
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handler [@"H2#CQ
* @param everyPage ?;0=>3p*0
* @param currentPage g:q+.6va"
* @param totalRecords n>Y3hY
* @return page RsIEY5Q
*/ 2xZg, \
publicstatic Page createPage(int everyPage, int &O#a==F!(
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currentPage, int totalRecords){ 7$z")JB
everyPage = getEveryPage(everyPage); V,<,;d fR
currentPage = getCurrentPage(currentPage); `=^29LC#
int beginIndex = getBeginIndex(everyPage, /SY40;k:
-DlKFN
currentPage); NS#qein~i
int totalPage = getTotalPage(everyPage, %;!@\5$
xp7,0'(;
totalRecords); [zm&}$nnN
boolean hasNextPage = hasNextPage(currentPage, %/oOM\}++
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totalPage); m`g%\o^6i
boolean hasPrePage = hasPrePage(currentPage); #KXaz Zu"
6]\F_Z41
returnnew Page(hasPrePage, hasNextPage, nR6~oB{-
everyPage, totalPage, .i"v([eQ
currentPage, % rdW:
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beginIndex);
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} vYL{5,t {1
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privatestaticint getEveryPage(int everyPage){ oZ& ns!#
return everyPage == 0 ? 10 : everyPage; J@oGAa%3)
} @@*->
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privatestaticint getCurrentPage(int currentPage){ 6^wg'u]c
return currentPage == 0 ? 1 : currentPage; la8se=^
} Vvm6T@b M8
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privatestaticint getBeginIndex(int everyPage, int _R1UEE3M
t+qLQY}=
currentPage){ `V w9j,G
return(currentPage - 1) * everyPage; "@gJ[BL#
} dg4"4\c*P
hAOXOj1
privatestaticint getTotalPage(int everyPage, int V(L~t=k$
NSOWn]E
totalRecords){ KA`1IW;
int totalPage = 0; ,4NvD2Y
ba%[!
if(totalRecords % everyPage == 0) L:`|lc=^
totalPage = totalRecords / everyPage; U#-&%|b$
else 394u']M
totalPage = totalRecords / everyPage + 1 ; ?fXg_?+{'g
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return totalPage; nOkX:5
} zr&K0a{hc
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privatestaticboolean hasPrePage(int currentPage){ iEr|?,
return currentPage == 1 ? false : true; 7_S+/2}U*
} $P^=QN5Bb
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privatestaticboolean hasNextPage(int currentPage, N ]}Re$5
eoR@5OA&
int totalPage){ C]WVH\Pp
return currentPage == totalPage || totalPage == (*/P~$xIj
s$C;31k
0 ? false : true; {Xwin$C
} 1;fs`k0p
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} :B$=Pp1
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 >%qGK-_
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 ;1NZY.pyc
ppR_y
做法如下: r4J4|&ym
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 #E^ %h
pP{b!1
的信息,和一个结果集List: m]Z+u e
java代码: &'WgBjP
*#N%3:@T
U^VFHIm
/*Created on 2005-6-13*/ uji])e MN~
package com.adt.bo; /#
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5;`([oX|_
import java.util.List; ?TMo6SU
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import org.flyware.util.page.Page; IhM-a
Y
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/** S&_ZQLiQ$
* @author Joa _]j=[|q 9
*/ cn<9!2a
publicclass Result { `WWf?g
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private Page page; HZ[&ZNTa
twf;{lZ(
private List content; @*is]d+Ya
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/** ;f?OT7>kN
* The default constructor d^ipf*aLC
*/ ovm*,La)g
public Result(){ |1J "r.K
super(); d>@{!c-
} .a;-7|x
I #1_
/** 0Yfk/}5
* The constructor using fields xqP0Z),Ow
* BAzc'x&<
* @param page Gg5vf]VFo
* @param content &Radpb2p6
*/ FE M_7M
public Result(Page page, List content){ QHP^1W`
this.page = page;
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this.content = content; `'0opoQRe
} Y)BKRS~
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/** t,k9:p
* @return Returns the content. D@DK9?#
*/ _qE2r^o"B
publicList getContent(){ <u->hT
return content; )I1LBvfQ
} Y]Su<tgX?
p7.@ez ;
/** Q>TaaGc
* @return Returns the page. <@F4{*
*/ u:g(x+u4:
public Page getPage(){ "Hgn2o.;5
return page; Bw{@YDO{
} iW*0V3
FuEHO 6nx
/** cTRCQ+W6:
* @param content pC5-,Z;8
* The content to set. `q$DNOrS
*/ w\$b(HC
public void setContent(List content){ \sp7[}Sw
this.content = content; #Sn&Wo
} <6v7_
7-^df0
/** Ta9;;B?$
* @param page *D4H; P#
* The page to set. >4h4t/G
*/ `kekc.*-[@
publicvoid setPage(Page page){ fK4laDBTO
this.page = page; 8 ehC^Cg
} Xk7zXah
} zoUW}O
TuaT-Z~U{
zYls>fbp,
Bm~>w`1wK
;uba
2. 编写业务逻辑接口,并实现它(UserManager, !Y\hF|[z
HnOF_Twq
UserManagerImpl) /Zm@.%.
java代码: <a$cB+t
Kl+*Sp!
HF47Lc*c
/*Created on 2005-7-15*/ 3P#1fI(c
package com.adt.service; z,2m7C
$1Xg[>1g5
import net.sf.hibernate.HibernateException; b[*di{?-
veK
import org.flyware.util.page.Page; vP,WV9Q1u
F},JP'\X
import com.adt.bo.Result; RKjA`cJ
@XmMD6{<