Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 !^yH]v
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 =JkPE2mU
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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 Wbq0K6X
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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 uc<JF=
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分页支持类: 5}3#l/
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java代码: 4'+g/i1S
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package com.javaeye.common.util; W? F Q
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import java.util.List; ]
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publicclass PaginationSupport { qkM)zOZ^
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publicfinalstaticint PAGESIZE = 30; E0*KKo%
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privateint pageSize = PAGESIZE; :`>$B?x+
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privateList items; f7SMO-3a
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privateint totalCount; :R{pV7<O
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privateint[] indexes = newint[0]; /h7uE
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privateint startIndex = 0; 0H+!v
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public PaginationSupport(List items, int q^DQ9B
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totalCount){ &z]x\4#,
setPageSize(PAGESIZE); #z1/VZ
setTotalCount(totalCount); k\TP3*fD
setItems(items); 4J1_rMfh
setStartIndex(0); S\SYFXUl
} F%:74.]Y
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public PaginationSupport(List items, int bZ>dr{%%e
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totalCount, int startIndex){ T)I\?hqTB
setPageSize(PAGESIZE); 2lCgUe)N
setTotalCount(totalCount); GJ{XlH
setItems(items); 3L CT-rp
setStartIndex(startIndex); 8:;]tt
} ?Rk[P
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public PaginationSupport(List items, int OQIr"
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totalCount, int pageSize, int startIndex){ Q Hr'r/0
setPageSize(pageSize); zM(-f|wVI)
setTotalCount(totalCount); 4wN5 x[vp
setItems(items); vGnFX0?h
setStartIndex(startIndex);
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} gZ|!'
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publicList getItems(){ 6V"uovN2
return items; !' 0PM[
} N^M6*,F,J
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publicvoid setItems(List items){ njZJp|y6
this.items = items; }H<Z`3_U%
} ))dw[Xa
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publicint getPageSize(){ ORM3oucP
return pageSize; )Ii`/I^
} 4TI`
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publicvoid setPageSize(int pageSize){ _#1EbvO*l
this.pageSize = pageSize; kl[(!"p
} PhPe7^
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publicint getTotalCount(){ ?lfyC/
return totalCount; kBLFK3i
} sv&^sARN
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publicvoid setTotalCount(int totalCount){ s)fahc(@E
if(totalCount > 0){ -L4G)%L\
this.totalCount = totalCount; Lyf5Yf([-
int count = totalCount / yMu G? x+
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pageSize; m+(g.mvK>
if(totalCount % pageSize > 0) 1Jdx#K
count++; :nR80]
indexes = newint[count]; +$#<gp"
for(int i = 0; i < count; i++){ 5|~nX8>
indexes = pageSize * &ds+9A
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} $U.|
}else{ t)Cf]]dV
this.totalCount = 0; VKZP\]$XG
} N UvVhy]{
} F\&{ >&
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publicint[] getIndexes(){ 9r+'DX?>
return indexes; & !ds#-
} Sgv_YoD?-
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publicvoid setIndexes(int[] indexes){ }:{9!RMO
this.indexes = indexes; [*5]NNB
} dt@c,McN|Q
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publicint getStartIndex(){ ZfX$q\7
return startIndex; akNqSZwj
} LEeA ,Y
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publicvoid setStartIndex(int startIndex){ j`"!G*Vh
if(totalCount <= 0) hrq% { !Z
this.startIndex = 0; De^:9<{jc
elseif(startIndex >= totalCount) vG'#5%,|
this.startIndex = indexes Q.$Rhjb
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[indexes.length - 1]; =f
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elseif(startIndex < 0) lya},_WCq
this.startIndex = 0; `7w-_o
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else{ 2aCf?l(
this.startIndex = indexes d,^ZH
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[startIndex / pageSize]; 1s@QsZ3
} RC[Sa wA
} #@OPi6.#!<
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publicint getNextIndex(){ aIFlNS,y
int nextIndex = getStartIndex() + J_Tz\bZ3)
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pageSize; /P@%{y
if(nextIndex >= totalCount) z,ERq,g+L
return getStartIndex(); 7~QI4'e
else tF}^
return nextIndex; :=;{w~D
} |xcI~ X7Q
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publicint getPreviousIndex(){ aH{)|?
int previousIndex = getStartIndex() - ^@AyC"K
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pageSize; O7VEyQqf5
if(previousIndex < 0) W6i{yneW
return0; 9D1WUUa
else ]<f(@]R/d
return previousIndex; $\h-F8|JMX
} o=($'(1
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} I_v}}h{
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抽象业务类 `T[@ -
java代码: IB[$~sGe
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/** 4G(7V:
* Created on 2005-7-12 X n!mdR
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package com.javaeye.common.business; (~^fx\-S
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import java.io.Serializable; P{n#^4
import java.util.List; >Dr(%z6CN
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import org.hibernate.Criteria; vNGE]+QX
import org.hibernate.HibernateException; <@-O06
import org.hibernate.Session; .
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import org.hibernate.criterion.DetachedCriteria; ,\\ba_*z
import org.hibernate.criterion.Projections; Dd5
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import ^b+>r
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org.springframework.orm.hibernate3.HibernateCallback; LOx+?4|y
import BUBx}dbCM
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org.springframework.orm.hibernate3.support.HibernateDaoS W%g*sc*+
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upport; }~I!'J#)
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import com.javaeye.common.util.PaginationSupport; pD$4nH4KST
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public abstract class AbstractManager extends !'jq.RawP
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HibernateDaoSupport { 'V:Q :
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privateboolean cacheQueries = false; dM-cQo:
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privateString queryCacheRegion; l/X_CM8y~
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publicvoid setCacheQueries(boolean S 5S\zTPIf
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cacheQueries){ EMmgX*iu@
this.cacheQueries = cacheQueries; IK2da@V
} qk (Eyp
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publicvoid setQueryCacheRegion(String `>:5[Y
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queryCacheRegion){ 9jkz83/+<
this.queryCacheRegion = ZLkl:'E_
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queryCacheRegion; (u,)v_Oo]a
} 4mX(.6
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publicvoid save(finalObject entity){ @Po5AK3cy
getHibernateTemplate().save(entity); Lzh8-d=HQ
} ]at$ohS
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publicvoid persist(finalObject entity){ d6luksO*9
getHibernateTemplate().save(entity); cI=6zMB
} H%wB8Y
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publicvoid update(finalObject entity){ Ds`e-X)O;\
getHibernateTemplate().update(entity); G]K1X"W?
} hg)Xr5>
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publicvoid delete(finalObject entity){ E'AR.!
getHibernateTemplate().delete(entity); U4 !bW
} h[
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publicObject load(finalClass entity, n1-p/a.
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finalSerializable id){ y~9wxK
return getHibernateTemplate().load ? x%s
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(entity, id); TDh)}Ms
} MP%#)O6
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publicObject get(finalClass entity, N1 t4o~
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finalSerializable id){ "#d$$ 8
return getHibernateTemplate().get 9[eiN
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(entity, id);
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} UTA|Ps$
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publicList findAll(finalClass entity){ W{,fpm
return getHibernateTemplate().find("from 9jal D
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" + entity.getName()); i$Y#7^l%k
} l)u%`Hcn
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publicList findByNamedQuery(finalString RD`|Z~:q:K
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namedQuery){ HhbBt'fH
return getHibernateTemplate a*M|_&MH*
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().findByNamedQuery(namedQuery); Jz8P':6[
} (Jq m9
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publicList findByNamedQuery(finalString query, Y>$5j}K
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finalObject parameter){ Xu{y5N
return getHibernateTemplate %Wtf24'o;v
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().findByNamedQuery(query, parameter); 4 H 6t" X
} O"\4[HE^
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publicList findByNamedQuery(finalString query, XT^=v6^H
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finalObject[] parameters){ %|jS`kj
return getHibernateTemplate HNkOPz+d&8
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().findByNamedQuery(query, parameters); H{cOkuy
} bdrE2m
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publicList find(finalString query){ l0&Fm:))k
return getHibernateTemplate().find `0upm%A
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(query); BB}WfA
} 0A}XhX
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publicList find(finalString query, finalObject SU%O \4Ty
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parameter){ bB@=J~l4
return getHibernateTemplate().find TTG=7x:3
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(query, parameter); q}i#XQU
} V@0T&#
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public PaginationSupport findPageByCriteria .H|Z3d!Jj
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(final DetachedCriteria detachedCriteria){ z,;XWv?
return findPageByCriteria >V.?XZ nt
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); <.`i,|?MHS
} 9@1n:X
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public PaginationSupport findPageByCriteria E+y_te^+b
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(final DetachedCriteria detachedCriteria, finalint |X{j^JP5
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startIndex){ 6$#,$a O
return findPageByCriteria Kmx4bp4
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(detachedCriteria, PaginationSupport.PAGESIZE, G5hRx@vfrL
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startIndex); 39^+;Mev
} )EMlGM'2q
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public PaginationSupport findPageByCriteria `U0XvWPr[
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(final DetachedCriteria detachedCriteria, finalint IV~)BW leT
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pageSize, f)vnm*&-
finalint startIndex){ xS,F
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return(PaginationSupport) #Q2s3"X[
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getHibernateTemplate().execute(new HibernateCallback(){ i:Y5aZc/Ds
publicObject doInHibernate t7-r YY(
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(Session session)throws HibernateException { ?uCL[
Criteria criteria = fFEB#l!oUb
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detachedCriteria.getExecutableCriteria(session); bV:<%l]
int totalCount = i^WY/ OhL
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((Integer) criteria.setProjection(Projections.rowCount L0VZ>!*o
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()).uniqueResult()).intValue(); ['>ZC3?"h
criteria.setProjection b1^wK"#
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(null); = ~s+<9c]
List items = 3LyNi$`f
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criteria.setFirstResult(startIndex).setMaxResults #6~KO7}
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(pageSize).list(); _{): w~zi
PaginationSupport ps = x+~!M:fAc9
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new PaginationSupport(items, totalCount, pageSize, 6RIbsy
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startIndex); 6yYjZ<
return ps; mUl0D0#
} C@;e<
}, true); [$K8y&\L
} FaJK
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public List findAllByCriteria(final Zs|Ga,T
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DetachedCriteria detachedCriteria){ 4cy,'B
return(List) getHibernateTemplate byP< !p*
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().execute(new HibernateCallback(){ D
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publicObject doInHibernate -Sh&x
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(Session session)throws HibernateException { Y>C05?>
Criteria criteria = &2%|?f|
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detachedCriteria.getExecutableCriteria(session); zqt%x?l
return criteria.list(); J:'_S `J
} 0datzEns`
}, true); o R8'^G0<
} ,j{tGj_
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public int getCountByCriteria(final ^AI02`c.
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DetachedCriteria detachedCriteria){ &2.DZ),L
Integer count = (Integer) I.Catm2
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getHibernateTemplate().execute(new HibernateCallback(){ bxwwYSS
publicObject doInHibernate (#6Fg|f4Y
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(Session session)throws HibernateException { "uL~D5!f
Criteria criteria = <L*`WO]\l
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detachedCriteria.getExecutableCriteria(session); Odw'Ua
return dPpJDY0
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criteria.setProjection(Projections.rowCount 0#=xUk#LP`
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()).uniqueResult(); \}4*}Lr
} 6&;GC<].(y
}, true); S"?fa)~
return count.intValue(); ?[.8A/:5
} m3o -p
} J2
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用户在web层构造查询条件detachedCriteria,和可选的 U/AiI;Ne
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 mj9sX^$dE
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PaginationSupport的实例ps。 ![Gn0X?]
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ps.getItems()得到已分页好的结果集 o9sPyY$aQ
ps.getIndexes()得到分页索引的数组 P%Vq#5
ps.getTotalCount()得到总结果数 f@hM ^%
ps.getStartIndex()当前分页索引 g"|>^90
ps.getNextIndex()下一页索引 "@hd\w{.
ps.getPreviousIndex()上一页索引 eCsk\f`
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 qF`6l(
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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 u<cnz%@
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一下代码重构了。 `vOL3`P
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我把原本我的做法也提供出来供大家讨论吧: 'n-y*f
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首先,为了实现分页查询,我封装了一个Page类: ]7K2S{/o{
java代码: hPNMp@Nm6
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/*Created on 2005-4-14*/ 3Y2~HuM
package org.flyware.util.page; <C(o0u&/
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/** B T"R"w
* @author Joa /A-WI x
* :(X3?%
*/ "EMW'>&m