Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 "|S \J5-%
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 \ qc8;"@
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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 :cmfy6h]
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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 /s>ZT8vaAs
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分页支持类: xQa[bvW
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java代码: !Jw
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package com.javaeye.common.util; ^IuHc_
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import java.util.List; twqjaFA>
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publicclass PaginationSupport { 2Av3.u8%u
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publicfinalstaticint PAGESIZE = 30; '}*5ee](S
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privateint pageSize = PAGESIZE; >De\2gbJ
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privateList items; 12aAO|]/~
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privateint totalCount; 2 As 4}
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privateint[] indexes = newint[0]; ho2o/>Ef3
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privateint startIndex = 0; iLn)Z0<\o
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public PaginationSupport(List items, int fR}|CP
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totalCount){ WS@b3zzN
setPageSize(PAGESIZE); d:O>--$_tw
setTotalCount(totalCount); A?q[C4-BO,
setItems(items); gk~.u
setStartIndex(0); y@'8vOh`
} ,)XT;iGQe
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public PaginationSupport(List items, int C<2vuZD
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totalCount, int startIndex){ <O&L2E @~f
setPageSize(PAGESIZE); F'W{\4
setTotalCount(totalCount); )MLOYX
setItems(items); RyC]4QyC
setStartIndex(startIndex); (1%u`#5n-N
} dl@
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public PaginationSupport(List items, int I 6a{'c(P
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totalCount, int pageSize, int startIndex){ j/{F#auI
setPageSize(pageSize); U^?/nRZ
setTotalCount(totalCount); 3'Q H\t5
setItems(items); .GM&]Hb
setStartIndex(startIndex); NTuS(7m
} Xdsd5 UUM
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publicList getItems(){ @3c5"
return items; `#A&v
} ej4 7'#EY
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publicvoid setItems(List items){ Am%zEt$c
this.items = items; 1bF aQ50t
} Gn#5zx#l
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publicint getPageSize(){ u1/4WYJeJ
return pageSize; LpeQx\
} jn>3(GRGC$
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publicvoid setPageSize(int pageSize){ Mj&G5R~_
this.pageSize = pageSize; rp9?p%
} rjffpU
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publicint getTotalCount(){ rJZR8bo
return totalCount; AH{#RD
} 1rx,qfCq
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publicvoid setTotalCount(int totalCount){ r<$o [,W
if(totalCount > 0){ ?g\emhG
this.totalCount = totalCount; NSa6\.W)
int count = totalCount / #x qiGK
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pageSize; }?\^^v h7
if(totalCount % pageSize > 0) rFUR9O.{E
count++; 9X?RJ."J
indexes = newint[count]; 7u{V1_n1
for(int i = 0; i < count; i++){ #f [}a
indexes = pageSize * ?3lAogB
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} &~Pk*A_:
}else{ ,<N{Y[n]e
this.totalCount = 0; SJ91(K
} %s497'
} uu9IUqEq2
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publicint[] getIndexes(){ ^,0Lr$+
return indexes; #dKy{Q3he
} /ej[oR
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publicvoid setIndexes(int[] indexes){ iciKjXJ:
this.indexes = indexes; >23$_'2
} _RzFh
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publicint getStartIndex(){ ?JG^GD7D
return startIndex; NXQ=8o9,9
} ]J [d8S5
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publicvoid setStartIndex(int startIndex){ ?"*JV1 9
if(totalCount <= 0) Ui!l3_O
this.startIndex = 0; jz`3xFy *]
elseif(startIndex >= totalCount) <}:` Y"
this.startIndex = indexes MT"&|Og
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[indexes.length - 1]; }% f7O
elseif(startIndex < 0) 3<Zp+rD
this.startIndex = 0; a_+?#m
else{ T\n6^@.>
this.startIndex = indexes 8q%y(e
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[startIndex / pageSize]; 5L:-Xr{
} &oMWs]0
} X3a 9-
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publicint getNextIndex(){ }04mJY[
int nextIndex = getStartIndex() + I-Z|FKh_C
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pageSize; G~o!u8^;
if(nextIndex >= totalCount) H)i|?3Ip
return getStartIndex(); GkX Se)#p
else RSe4lw
return nextIndex; n
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} ')!X1A{
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publicint getPreviousIndex(){ y0sce
int previousIndex = getStartIndex() - oR&z,%0wMK
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pageSize; hK{H7Ey*
if(previousIndex < 0) fE+zA)KX
return0; 7Vsp<s9bj
else <M@-|K"Eb
return previousIndex; ^APtV6g
} .Zczya
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} ,JE_aje7
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抽象业务类 <mE`<-$
java代码: v^b4WS+.:
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/** -3R:~z^L
* Created on 2005-7-12 ? +L,
*/ hr}f5Z)^v
package com.javaeye.common.business; Q!;syJBb.
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import java.io.Serializable; );h(D!D,
import java.util.List; >MHlrSH2
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import org.hibernate.Criteria; :J`@@H
import org.hibernate.HibernateException; H\Ra*EO~j
import org.hibernate.Session; g0tnt)]
import org.hibernate.criterion.DetachedCriteria; b$,Hlh,^
import org.hibernate.criterion.Projections; '\I(n|\
import r%?-MGc
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org.springframework.orm.hibernate3.HibernateCallback; I "AjYv4R
import y("WnVI
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org.springframework.orm.hibernate3.support.HibernateDaoS f1MRmp-f'
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upport; NS[eQ_rT
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import com.javaeye.common.util.PaginationSupport; hy*{{f;
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public abstract class AbstractManager extends ep"[;$Eb
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HibernateDaoSupport { f8]sjeY
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privateboolean cacheQueries = false; x%}D+2ro-t
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privateString queryCacheRegion; ^3$l!>me
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publicvoid setCacheQueries(boolean :(n<c
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cacheQueries){ 9(N
this.cacheQueries = cacheQueries; j>\c >U
} !g|O.mt
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publicvoid setQueryCacheRegion(String jSY[Y:6md
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queryCacheRegion){ +`
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this.queryCacheRegion = rwF$aR>9
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queryCacheRegion; T#&1q]P1F
} uNf'Zeo
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publicvoid save(finalObject entity){ B~o3Z
getHibernateTemplate().save(entity); ^aaj=p:cV
} -t_&H\_T
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publicvoid persist(finalObject entity){ eHx {[J?
getHibernateTemplate().save(entity); @G&oUhS
} 3B#fnj
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publicvoid update(finalObject entity){ bP:u`!p
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getHibernateTemplate().update(entity); hbXm Ist
} #cR5k@
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publicvoid delete(finalObject entity){ S*r }oX0
getHibernateTemplate().delete(entity); tT`S"
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} .WglLUJ:Z
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publicObject load(finalClass entity, W&A^.% 2l
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finalSerializable id){ p7},ymQ|YQ
return getHibernateTemplate().load |$8N*7UD
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(entity, id); #E4oq9{0*W
} <MxA;A
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publicObject get(finalClass entity, s]vsD77&
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finalSerializable id){ |}l/6WHB
return getHibernateTemplate().get MDpx@.A,
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(entity, id); @$b7
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} (>Sy,
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publicList findAll(finalClass entity){ JWt@vf~
return getHibernateTemplate().find("from g6q[
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" + entity.getName()); @
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} %AMF6l[
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publicList findByNamedQuery(finalString <95*z @
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namedQuery){ V" 5rIk
return getHibernateTemplate qE^u{S4Z@
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().findByNamedQuery(namedQuery); 17rg!'+
} voN, u>U
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publicList findByNamedQuery(finalString query, : 2L-Nf
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finalObject parameter){ "jq F
return getHibernateTemplate o`jV d,aj
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().findByNamedQuery(query, parameter); )q+;+J`>
} c5Hm94,p
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publicList findByNamedQuery(finalString query, ;;17 #T2
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finalObject[] parameters){ X{5(i3?S
return getHibernateTemplate oFJx8XU
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().findByNamedQuery(query, parameters); {NIE:MXX
} Ut"F b
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publicList find(finalString query){ 5,V3_p:)VI
return getHibernateTemplate().find k5Df97\s
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(query); ;x=0+0JD
} A3e83g~L
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publicList find(finalString query, finalObject n ^C"v6X
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parameter){ `oH6'+fT`;
return getHibernateTemplate().find p?sC</R
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(query, parameter); z/S}z4o/
} 6SD9lgF*-
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public PaginationSupport findPageByCriteria /4-6V
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(final DetachedCriteria detachedCriteria){ 1O;q|p'9
return findPageByCriteria d#3E'8
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ~Wj.
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} Ut^ {4_EC
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public PaginationSupport findPageByCriteria h}jE=T5Hc
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(final DetachedCriteria detachedCriteria, finalint m&8'O\$
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startIndex){ /q >1X!Z
return findPageByCriteria $4&e{fLt|v
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(detachedCriteria, PaginationSupport.PAGESIZE,
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startIndex); .+ g8zbD4
} DF!*S{)
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public PaginationSupport findPageByCriteria jUCrj'
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(final DetachedCriteria detachedCriteria, finalint f+Ht
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pageSize, ;4ETqi9
finalint startIndex){ GY,HEe]2r
return(PaginationSupport) fTg^~XmJ
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getHibernateTemplate().execute(new HibernateCallback(){ ^9*kZV<K
publicObject doInHibernate <*55d2
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(Session session)throws HibernateException { G :JQ_w
Criteria criteria = TO~Z6NA0
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detachedCriteria.getExecutableCriteria(session); 9(
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int totalCount = U sS"WflB
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((Integer) criteria.setProjection(Projections.rowCount TcM;6h`
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()).uniqueResult()).intValue(); DYFfq
criteria.setProjection ?(d<n
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(null); Yw_^]:~
List items = >Xv
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criteria.setFirstResult(startIndex).setMaxResults F9PXQD(
V
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(pageSize).list(); eWWtMnq
PaginationSupport ps = i_<GSUTTr/
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new PaginationSupport(items, totalCount, pageSize, MlH0
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startIndex); Lh
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return ps; -4!S?rHwd+
} Zv&<r+<g
}, true); '"M9`@Y3^
} w6&p4Jw/H?
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public List findAllByCriteria(final |B~^7RHXo
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DetachedCriteria detachedCriteria){ q:ah%x[
return(List) getHibernateTemplate >1S39n5z.
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().execute(new HibernateCallback(){ -a\[`JHi
publicObject doInHibernate |kK_B
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(Session session)throws HibernateException { (d*~Qpi{7
Criteria criteria = 3XcFBFE
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detachedCriteria.getExecutableCriteria(session); TpRI+*\
return criteria.list(); zbAyYMtEk
} V6kJoSyde
}, true); j2s{rQQ
} ,'%*z
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public int getCountByCriteria(final j7yUya&
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DetachedCriteria detachedCriteria){ N)
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Integer count = (Integer) NX8.
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getHibernateTemplate().execute(new HibernateCallback(){ 1s-=zs
publicObject doInHibernate l,ic-Y1
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(Session session)throws HibernateException { Oid;s!-S 6
Criteria criteria = %afz{a5
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detachedCriteria.getExecutableCriteria(session); |?\2F
return /X;!
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criteria.setProjection(Projections.rowCount x,Z:12H0
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()).uniqueResult(); VLC=>w\,
} Q+p9^_r
}, true); $d
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return count.intValue(); @+hO,WXN
} Z9zsvg
} H,;9' *84
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用户在web层构造查询条件detachedCriteria,和可选的 @Uqcym.
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 yH(%*-S
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PaginationSupport的实例ps。 {i)FDdDGD
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ps.getItems()得到已分页好的结果集 xpWY4Q
ps.getIndexes()得到分页索引的数组 BP=<TRp.
ps.getTotalCount()得到总结果数 i}~U/.P
ps.getStartIndex()当前分页索引 v(l:N@L
ps.getNextIndex()下一页索引 g3c,x kaO
ps.getPreviousIndex()上一页索引 P]H4!}M
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 c> ":g~w
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 U)D}J_Zi(
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一下代码重构了。 Z+
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我把原本我的做法也提供出来供大家讨论吧: YRU#/TP
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首先,为了实现分页查询,我封装了一个Page类: 3 H`ES_JL
java代码: 6eW9+5oL
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/*Created on 2005-4-14*/ ZvSEa{
package org.flyware.util.page; Q`BB@E
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/** >H,PST
* @author Joa TlJ'pG 4^
* j4E`O%@^
*/ |L~RC
publicclass Page { P*kC>lvSv
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/** imply if the page has previous page */ ig4mj47wJ
privateboolean hasPrePage; 8:jakOeT
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/** imply if the page has next page */ "\"sM{x
privateboolean hasNextPage; IvM>z03
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/** the number of every page */ >0I\w$L
privateint everyPage; DaqpveKa
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/** the total page number */ M$2lK^2L
privateint totalPage; idNg&'
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/** the number of current page */ 5Pd^Sew
privateint currentPage; _+.
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/** the begin index of the records by the current m]/sR3yF
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query */ I|)U>bV
privateint beginIndex; >\Ml\CyL
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/** The default constructor */ +D|E8sz8
public Page(){ =Y-mc#{8
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} "ac$S9@~
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/** construct the page by everyPage E,7b=t
* @param everyPage Vnnl~|Xx
* */ 8o!LgT5
public Page(int everyPage){ xoN?[
this.everyPage = everyPage; [,ZHn$\
} iU?xw@WR
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/** The whole constructor */ Oi\,clR^[o
public Page(boolean hasPrePage, boolean hasNextPage, l&uBEYx
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int everyPage, int totalPage, L'<.#(|
int currentPage, int beginIndex){ %lS jC%Z'd
this.hasPrePage = hasPrePage; `*--vSi
this.hasNextPage = hasNextPage; vABUUAo!Jr
this.everyPage = everyPage; nx@h
this.totalPage = totalPage; tz/NR/[
this.currentPage = currentPage; &