Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 5N.-m;s
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Oll,;{<O
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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 f:hsE
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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 ?CU6RC n
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分页支持类: #|R#/Yc@Bv
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java代码: K0xka[x=(
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package com.javaeye.common.util; r=74'g
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import java.util.List; 'ugc=-0pd
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publicclass PaginationSupport { {@YY8SKb9
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publicfinalstaticint PAGESIZE = 30; ;%W]b
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privateint pageSize = PAGESIZE; 7G]v(ay
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privateList items; ewrs
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privateint totalCount; ]/ffA|"U`
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privateint[] indexes = newint[0]; c+A$ [
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privateint startIndex = 0; ]o+5$L,5b
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public PaginationSupport(List items, int Q}6!t$Vk
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totalCount){ ,*MAteD
setPageSize(PAGESIZE); (<KFA,
setTotalCount(totalCount); w 8BSY
setItems(items); W{W8\
setStartIndex(0); !!:mjq<0
} ~;S
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public PaginationSupport(List items, int }huFv*<@'
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totalCount, int startIndex){ K{EDmC
setPageSize(PAGESIZE);
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setTotalCount(totalCount); V]Z!x.x"=y
setItems(items); ``:+*4e9
setStartIndex(startIndex); A}3dx!?7j
} l' mdj!{&
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public PaginationSupport(List items, int ,7h0y
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totalCount, int pageSize, int startIndex){ `~k`m{4.a
setPageSize(pageSize); 6Q*Zy[=
setTotalCount(totalCount); H~:EPFi.(
setItems(items); N5d)&a
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setStartIndex(startIndex); gzd<D}2F~
} $H8B%rT]
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publicList getItems(){ f1w_Cl
return items; f>hA+
} PK).)5sW
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publicvoid setItems(List items){ G0~6A@>
this.items = items; /N9ct4 {^
} W\Df:P {<
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publicint getPageSize(){ c4V%>A
return pageSize; i z%wozf
} cXod43
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publicvoid setPageSize(int pageSize){ 8vqx}2
this.pageSize = pageSize; vdIert?p
} Bw/8-:eb
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publicint getTotalCount(){ u*=8s5Q[
return totalCount; 572{DC&T
} [nASMKK0
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publicvoid setTotalCount(int totalCount){ c> 0R_
if(totalCount > 0){ WCD)yTg:ES
this.totalCount = totalCount; z50P*
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int count = totalCount / ^).
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pageSize; Y*/e;mG.
if(totalCount % pageSize > 0) LU $=j
count++; b.j$Gna>Q
indexes = newint[count]; alH6~
for(int i = 0; i < count; i++){ =&I9d;7
indexes = pageSize * IOT-R!.5V
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} J'C9}7G
}else{ ;-AC}jG
this.totalCount = 0; XR_Gsb%l
} E?-
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} =Hbf()cN)
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publicint[] getIndexes(){ wZfY~
return indexes; Z`<5SHQd
} bH.SUd)
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publicvoid setIndexes(int[] indexes){ 3 <)+)n
this.indexes = indexes; Z 4QL&?U
} R-YNg
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publicint getStartIndex(){ <?>tjCg'
return startIndex; !oa/\p
} Tq?7-_MLC$
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publicvoid setStartIndex(int startIndex){ $5:I~-mx
if(totalCount <= 0) FsLd&$?T&
this.startIndex = 0; GL%)s?
elseif(startIndex >= totalCount) h
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this.startIndex = indexes 2]]}Xvx4#
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[indexes.length - 1]; ot0g@q[3
elseif(startIndex < 0) 5PsjGvm.%
this.startIndex = 0; Ya4yW9*
else{ #mYe@[p@
this.startIndex = indexes =o4gW`\z
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[startIndex / pageSize]; [y~kF?a
} d uP0US
} NvC @
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publicint getNextIndex(){ (&SPMhs_|(
int nextIndex = getStartIndex() + RzU9]e
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pageSize; zZ,"HY=jN
if(nextIndex >= totalCount) ++n_$Qug
return getStartIndex(); xR8y"CpE
else ~ mz X1[
return nextIndex; =h xyR;
} #jJ0Mxg
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publicint getPreviousIndex(){ P?^%i
int previousIndex = getStartIndex() - =ld!=II
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pageSize; 6"?#E[ #[
if(previousIndex < 0) !jf!\Uu[U
return0; ep4?;Qmho
else W[R`],x`
return previousIndex; WcQkeh3n
} Po&'#TC1
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} #&ei
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抽象业务类 EeHghq
java代码: @Ko#nDEq
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/** 5g.w"0MkY
* Created on 2005-7-12 qHgzgS7a
*/ m#ig.z|A
package com.javaeye.common.business; Vju/+
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import java.io.Serializable; zJ$U5r/u
import java.util.List; <,Pl31g^
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import org.hibernate.Criteria; [+8*}03
import org.hibernate.HibernateException; el\xMe^SY
import org.hibernate.Session; ]TJ258P}
import org.hibernate.criterion.DetachedCriteria; 1;PI%++
import org.hibernate.criterion.Projections; 'y5H%I!
import -?l`LbD
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org.springframework.orm.hibernate3.HibernateCallback; M2;6Cz>,P
import ]"^p}:
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org.springframework.orm.hibernate3.support.HibernateDaoS R#i`H(N
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upport; W7;RQ
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import com.javaeye.common.util.PaginationSupport; YI;MS:Qj
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public abstract class AbstractManager extends jcjl q-x
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HibernateDaoSupport { C4GkFD
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privateboolean cacheQueries = false; Ms5R7<O.7
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privateString queryCacheRegion; ?o`:V|<v
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publicvoid setCacheQueries(boolean }#2(WHf=<
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cacheQueries){ 11k}Ly
this.cacheQueries = cacheQueries; HGDiwA
} G*,7pc
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publicvoid setQueryCacheRegion(String M`8c|*G
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queryCacheRegion){ 4CtWEq
this.queryCacheRegion = yu@Pd3
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queryCacheRegion; |WpJen*?Y
} \j-:5M#m
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publicvoid save(finalObject entity){ o?cNH
getHibernateTemplate().save(entity); vR>GE?s6
} lauq(aD_C
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publicvoid persist(finalObject entity){ <>Ha<4A
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getHibernateTemplate().save(entity); 6!USSipn
} gzy|K%K
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publicvoid update(finalObject entity){ $pt~?ZZ3-
getHibernateTemplate().update(entity); mB6%. "
} Gd'_X D
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publicvoid delete(finalObject entity){ V6h8+|hK
getHibernateTemplate().delete(entity); ks
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} r:Q=6j,
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publicObject load(finalClass entity, d(@ ov^e-
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finalSerializable id){ _3NH"o
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return getHibernateTemplate().load 1~},}S]id
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(entity, id); yjq|8.L[
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} 7Ka4?@bQ
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publicObject get(finalClass entity, H<;~u:;8Q
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finalSerializable id){ .6I'V3:Kg
return getHibernateTemplate().get :h/v"2uDN
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(entity, id); ITEf Q@#jU
} =fdW H4
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publicList findAll(finalClass entity){ @?;)x&<8?3
return getHibernateTemplate().find("from JoZzX{eu"
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" + entity.getName()); ^<uQ9p^B
} V]"pM]>3X
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publicList findByNamedQuery(finalString HD1/1?y!@q
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namedQuery){ U.b|3E/^
return getHibernateTemplate ts("(zI1E
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().findByNamedQuery(namedQuery); 2$VSH&
} feeHXKD|
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publicList findByNamedQuery(finalString query, QUfF>,[sv
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finalObject parameter){ &3xda1H
return getHibernateTemplate Q`Q"p
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().findByNamedQuery(query, parameter); #l.s>B4
} @v!#_%J
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publicList findByNamedQuery(finalString query, 4x?I,cAN
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finalObject[] parameters){ y\[* mgl:
return getHibernateTemplate fF=tT C
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().findByNamedQuery(query, parameters); ?YDMl
} 1CM8P3
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publicList find(finalString query){ P"t Dq&
return getHibernateTemplate().find Dkh=(+> <
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(query); '<*%<J{(
} :_nGh]%
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publicList find(finalString query, finalObject IG2z3(j
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parameter){ %da-/[
return getHibernateTemplate().find zwP*7u$CH
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(query, parameter); a40>_;}:x
} gQ%mVJB{(
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public PaginationSupport findPageByCriteria Ge=\IAj
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(final DetachedCriteria detachedCriteria){ b^()[4M;
return findPageByCriteria {a9.0N :4
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); Cy B4apJ
} ,OP\^
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public PaginationSupport findPageByCriteria Z@$'fX?~9
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(final DetachedCriteria detachedCriteria, finalint ,9ew75Jl
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startIndex){ * kUb[
return findPageByCriteria 5lM 3In@
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(detachedCriteria, PaginationSupport.PAGESIZE, /[Rp~YzW
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startIndex); H`Zg-j`
} Bsd~_y}8
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public PaginationSupport findPageByCriteria ]@}hyM[D;
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(final DetachedCriteria detachedCriteria, finalint !1]jk(Z
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pageSize, [D<(xr&N%
finalint startIndex){ &zVXd
return(PaginationSupport) m6 Y0,9
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getHibernateTemplate().execute(new HibernateCallback(){ EaH/Gg3
publicObject doInHibernate [D?d~pB
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(Session session)throws HibernateException { Zw%:mZN
Criteria criteria = +UTBiB R
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detachedCriteria.getExecutableCriteria(session); f}ch1u>
int totalCount = fjuPGg~
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((Integer) criteria.setProjection(Projections.rowCount wsc=6/#u
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()).uniqueResult()).intValue(); m")p]B&i=
criteria.setProjection 0Jd>V
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(null); l2wu>Ar7.
List items = 300[2}Y]
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criteria.setFirstResult(startIndex).setMaxResults /c4$m3?]
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(pageSize).list(); ou]jm=4[
PaginationSupport ps = 1}p:]/;
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new PaginationSupport(items, totalCount, pageSize, rsw=a_S
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startIndex); oJ#;X R
return ps; kK0zb{
} /;u=#qu(E-
}, true); hQvI}
} 1,we:rwX
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public List findAllByCriteria(final 3#\C!T0y
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DetachedCriteria detachedCriteria){ ld5+/"$
return(List) getHibernateTemplate 60D6UW
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().execute(new HibernateCallback(){ mT;
publicObject doInHibernate zU4*FXt
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(Session session)throws HibernateException { U><$p{)
Criteria criteria = gzlRK^5
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detachedCriteria.getExecutableCriteria(session); $H/: -v
return criteria.list(); Tl?jq]
} ,.;{J|4P
}, true); 5B3sRF}
} :SZi4:4-J8
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public int getCountByCriteria(final 0a,B&o1
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DetachedCriteria detachedCriteria){ hxw6^EA
Integer count = (Integer) %xp 69
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getHibernateTemplate().execute(new HibernateCallback(){ ;:Tb_4Hr
publicObject doInHibernate SWT)M1O2
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(Session session)throws HibernateException { f>Tn#OW
Criteria criteria = VmXXj6l&
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detachedCriteria.getExecutableCriteria(session); BXytAz3
return 5UG"i_TC
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criteria.setProjection(Projections.rowCount 6.|[;>Km
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()).uniqueResult(); NZ+TTMv
} v9#F\ F/
}, true); RS2uk7MB
return count.intValue(); bY~V?yNgKM
} DD[<J:6
} I-Am9\
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用户在web层构造查询条件detachedCriteria,和可选的 3,Iu!KB
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 xlc2,L;i
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PaginationSupport的实例ps。 \GK]6VW
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ps.getItems()得到已分页好的结果集 }z2[w@M
ps.getIndexes()得到分页索引的数组 VLfKN)g
ps.getTotalCount()得到总结果数 o Z%oP V:
ps.getStartIndex()当前分页索引 Pa?C-Xn^
ps.getNextIndex()下一页索引 MaF4lFmS
ps.getPreviousIndex()上一页索引 CWb*bw0
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 o,/w E
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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 Kv ajk~
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一下代码重构了。 :xY9eq=
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我把原本我的做法也提供出来供大家讨论吧: (Dx p
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首先,为了实现分页查询,我封装了一个Page类: f`[E^zj
java代码: iAt&927
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/*Created on 2005-4-14*/ U[Lr+nKo\
package org.flyware.util.page; _KZTY`/*
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/** lnK#q.]
* @author Joa 5!Ovd
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* ss`Sl$
*/ vb9C
publicclass Page { B'b OK`p
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/** imply if the page has previous page */ _s}`ohKvD
privateboolean hasPrePage; O<MO2U+^x
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/** imply if the page has next page */ zu
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privateboolean hasNextPage; f*Os~@K
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/** the number of every page */ q
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privateint everyPage; U&#`5u6'j
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/** the total page number */ yl0;Jx?
privateint totalPage; =VV><^uzdY
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/** the number of current page */ /Zxq-9
privateint currentPage; Q^X}7Z|T
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/** the begin index of the records by the current d-z[=1m
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query */ beNy5~M$
privateint beginIndex; ~y,m7%L
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