Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 by
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 v1}
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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 ,=mn*
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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 gnv4.f:
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分页支持类: 7(jt:V6V
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java代码: w4OVfTlN
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package com.javaeye.common.util; .(sT?M`\J
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import java.util.List; Eb.{M
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publicclass PaginationSupport { 3y@'p(}Az
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publicfinalstaticint PAGESIZE = 30; W?$
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privateint pageSize = PAGESIZE; ]`MRH[{
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privateList items; ;{>z\6N
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privateint totalCount; P"- ,^?6
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privateint[] indexes = newint[0]; p5*i
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privateint startIndex = 0; NE(6`Wq`
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public PaginationSupport(List items, int k -SUp8}g
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totalCount){ fD!O
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setPageSize(PAGESIZE);
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setTotalCount(totalCount); L<E`~\C'
setItems(items); [P[syi#]t
setStartIndex(0); bSmRo
} ?vZ&CB
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public PaginationSupport(List items, int 0n1y$*I4
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totalCount, int startIndex){ Tj.;\a|d
setPageSize(PAGESIZE); BqR8%F
setTotalCount(totalCount); a/?gp>M9
setItems(items); 13B[mp4
setStartIndex(startIndex); iKDGYM
} Q
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public PaginationSupport(List items, int 39u!j|VH
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totalCount, int pageSize, int startIndex){ gP<l
setPageSize(pageSize); QtRKmry{
setTotalCount(totalCount); TIS}'c'C
setItems(items); w{0UA6 +
setStartIndex(startIndex); ;VvqKyUh7`
} H*l8,*M}
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publicList getItems(){ eX}uZR
return items; T9u/|OP
} sB /*gO
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publicvoid setItems(List items){ s7=]!7QGS!
this.items = items; -FJ5N}R
} yaeX-'(Fv[
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publicint getPageSize(){ Wvcj\2'yd
return pageSize; y*P[*/g
} x3)qK6,\
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publicvoid setPageSize(int pageSize){ nE,"3X"
this.pageSize = pageSize; _w(SHWh2
} ]` 3;8,
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publicint getTotalCount(){ h(>4%hF
return totalCount; ^f>+5G
} Y0U:i.)
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publicvoid setTotalCount(int totalCount){ [t,7H
if(totalCount > 0){ W|~Ehg
this.totalCount = totalCount; U{HJNftdpm
int count = totalCount / z )k\p'0"
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pageSize; M7En%sBp
if(totalCount % pageSize > 0) 7Sr7a{
count++; pnDD9u-4;
indexes = newint[count]; {V8v
for(int i = 0; i < count; i++){ ~GMlnA]6
indexes = pageSize * !K_%@|: 7%
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} Ao 1*a%-.
}else{ DaaLRMQ=
this.totalCount = 0; ]Y:|%rvVH
} /)6<`S(
} #m|AQr|
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publicint[] getIndexes(){ Q;SMwCB0M
return indexes; HJM- ;C](
} h@/c76}f6p
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publicvoid setIndexes(int[] indexes){ &rk/ya[
this.indexes = indexes; vxK}f*d
} N}Z"$4
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publicint getStartIndex(){ $5|/X&"O)/
return startIndex; D24@lZ`g~
} YWjw`,EA(
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publicvoid setStartIndex(int startIndex){ :*#I1nb$
if(totalCount <= 0) =((#k DrN
this.startIndex = 0; ABB4(_3E
elseif(startIndex >= totalCount) G^5}T>TV
this.startIndex = indexes z1_\P) M
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[indexes.length - 1]; $
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elseif(startIndex < 0) JT, 8/o
this.startIndex = 0; KE6[ u*\
else{ H/YZwDx,i
this.startIndex = indexes Il>!C\hU
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[startIndex / pageSize]; Tw);`&Ulo
} PO]z'LD
} M+9G^o)u
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publicint getNextIndex(){ 2t*@P"e!
int nextIndex = getStartIndex() + "\U$aaF
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pageSize; O8r9&Nv
if(nextIndex >= totalCount) H5{d;L1[
return getStartIndex(); SX$v&L<
else c{7!:hi`x
return nextIndex; p.n+m[
} {w1sv=$+
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publicint getPreviousIndex(){ Zw`Xg@;xP
int previousIndex = getStartIndex() - a>G|t5w
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pageSize; Ft#d&
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if(previousIndex < 0) <9B\('
return0; hj4Kv
else }L3k pw
return previousIndex; N{ @B@]
} D<]z.33
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} _ ^r KOd
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抽象业务类 ^?VYE26
java代码: U5[xW
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/** pc
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* Created on 2005-7-12 !
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*/ eR4%4gW)
package com.javaeye.common.business; }PTYNidlR
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import java.io.Serializable; ML^c-xY(
import java.util.List; TXWi5f[
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import org.hibernate.Criteria; uhz:G~x!
import org.hibernate.HibernateException; Y.$'<1
import org.hibernate.Session; FY|.eY_7 {
import org.hibernate.criterion.DetachedCriteria; g@BQ!}_#5
import org.hibernate.criterion.Projections; J*vy-[w
import =X'i^Q
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org.springframework.orm.hibernate3.HibernateCallback; !ZPaU11
import |[7xTD
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org.springframework.orm.hibernate3.support.HibernateDaoS >gtKyn]
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upport; 2;VggPpT
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import com.javaeye.common.util.PaginationSupport; SQ9s
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public abstract class AbstractManager extends !~u;CMR
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HibernateDaoSupport { Iww.Nd2
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privateboolean cacheQueries = false; (p08jR
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privateString queryCacheRegion; u=JI 1
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{
publicvoid setCacheQueries(boolean FIG3P))
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cacheQueries){ Av:5v3%
this.cacheQueries = cacheQueries; z=J%-Hq>
} =\GuIH2
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publicvoid setQueryCacheRegion(String [4KW64%l
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queryCacheRegion){ tt2`N3Eu\
this.queryCacheRegion = { K'QE0'x
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queryCacheRegion; lS&$86Jo(
} &^KmfT5C
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publicvoid save(finalObject entity){ 2iYf)MC
getHibernateTemplate().save(entity); gswp:82e2
} tkx1iBW=
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publicvoid persist(finalObject entity){ P#m/b<
getHibernateTemplate().save(entity); qPY
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} f<bc8Lp
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publicvoid update(finalObject entity){ E$"( :%'v
getHibernateTemplate().update(entity); l=G=J( G
} =X6WK7^0
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publicvoid delete(finalObject entity){ u;rK.3o
getHibernateTemplate().delete(entity); `@eo <6
} Y>LgpO.
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publicObject load(finalClass entity, c|OIUc
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finalSerializable id){ @|! 9~F
return getHibernateTemplate().load FjYih>
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(entity, id); 7714}%Z
} Ta^l1]9.*
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publicObject get(finalClass entity, Cg[]y1Ne
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finalSerializable id){ ""Nu["|E
return getHibernateTemplate().get b<o Uy
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(entity, id); 9Ps[i)-
} ihivJZ
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publicList findAll(finalClass entity){ #
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return getHibernateTemplate().find("from HH
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" + entity.getName()); 'wB6-
} 7A'd55I4
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publicList findByNamedQuery(finalString 04>dxw)8
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namedQuery){ Bwv@D4bii
return getHibernateTemplate V9qZa
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().findByNamedQuery(namedQuery); Gu}
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} Ln/6]CMl
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publicList findByNamedQuery(finalString query, ."9t<<!
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finalObject parameter){ Zo`Ku+RL2'
return getHibernateTemplate JRQ{Q"`)
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().findByNamedQuery(query, parameter); Fr/3Qp@S
} O9y4.`a"
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publicList findByNamedQuery(finalString query, \7M+0Ul1
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finalObject[] parameters){ Qx{k_ye`
return getHibernateTemplate $%~-p[)<(P
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().findByNamedQuery(query, parameters); %Ci`OhT
} Z^? 1MJ:`
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publicList find(finalString query){ wcz|Zy
return getHibernateTemplate().find pm$ZKM
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(query); 9+<%74|,
} $B6CLWB
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publicList find(finalString query, finalObject A$*#n8,
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parameter){ h'Tn&2r6
return getHibernateTemplate().find Q|40
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(query, parameter); Fe8JsB-
} l(X8 cHAi
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public PaginationSupport findPageByCriteria z"/Mva3|
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(final DetachedCriteria detachedCriteria){ #sl_
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return findPageByCriteria 8vFt<k}G
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); |<nS<x
} I,4t;4;Zk
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public PaginationSupport findPageByCriteria e1Kxqw7
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(final DetachedCriteria detachedCriteria, finalint ::13$g=T9s
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startIndex){ :|hFpLt
return findPageByCriteria +B^(,qKMN
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(detachedCriteria, PaginationSupport.PAGESIZE, @oC# k<
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startIndex); ?v-Y1j
} jG($:>3a@
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public PaginationSupport findPageByCriteria _isqk~ ul
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(final DetachedCriteria detachedCriteria, finalint Nxk3uF^
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pageSize, >:W7f2%8`
finalint startIndex){ a[TR_uR
return(PaginationSupport) IT,d(UV_
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getHibernateTemplate().execute(new HibernateCallback(){ 3f'dBn5
publicObject doInHibernate 3$Ecq|4J:
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(Session session)throws HibernateException { Wxjv=#3
Criteria criteria = en\shc{R]`
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detachedCriteria.getExecutableCriteria(session); rBBA`Ut@F
int totalCount = y!6+jrI
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((Integer) criteria.setProjection(Projections.rowCount 4%l
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()).uniqueResult()).intValue(); rNzsc|a:
criteria.setProjection 1rhsmcE
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(null); @8zp(1.
List items = .54E*V1
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criteria.setFirstResult(startIndex).setMaxResults jO'+r'2B9
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(pageSize).list(); x+~IXi>Ig
PaginationSupport ps = |12Cg>;j*n
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new PaginationSupport(items, totalCount, pageSize, ">b~k;M?
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startIndex); C N9lK29F)
return ps; m9*Lo[EXO
} NwQexYm1_
}, true); q/w U7P\%
} ucm3'j
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public List findAllByCriteria(final tT7< V{i4
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DetachedCriteria detachedCriteria){ 2u9^ )6/
return(List) getHibernateTemplate jYwv+EXg
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().execute(new HibernateCallback(){ 4Q0@\dR9
publicObject doInHibernate $YDZtS&h
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(Session session)throws HibernateException { S@suPkQ<>
Criteria criteria = JyPsRpi\
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detachedCriteria.getExecutableCriteria(session); W":is"
return criteria.list(); COS(pfC
} mT
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}, true); >:l;W4j
} 5ug?'TOj'
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public int getCountByCriteria(final |_l\.
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DetachedCriteria detachedCriteria){ }g WSV
Integer count = (Integer)
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getHibernateTemplate().execute(new HibernateCallback(){ HgG-r&r!2
publicObject doInHibernate &fBLPF% 6
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(Session session)throws HibernateException { %
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Criteria criteria = !O$ */7
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detachedCriteria.getExecutableCriteria(session); 66\0JsT?3
return #8;|_RU
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criteria.setProjection(Projections.rowCount s{q)m@
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()).uniqueResult(); 4)=LOGW
}
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}, true); oRM EC7!A0
return count.intValue(); od>DSn3T
} y:!MWZ
} =YX/]g|9K
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用户在web层构造查询条件detachedCriteria,和可选的 S~vbISl
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ?uUK9*N
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PaginationSupport的实例ps。 kr7f<;rmJ
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ps.getItems()得到已分页好的结果集 5YIiO7@4
ps.getIndexes()得到分页索引的数组 ogv86d
ps.getTotalCount()得到总结果数 J'.:l} g!1
ps.getStartIndex()当前分页索引 ]s jFj
ps.getNextIndex()下一页索引
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ps.getPreviousIndex()上一页索引 uF>I0J#z?
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 daBu<0\
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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 CogLo&.
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一下代码重构了。 j' -akXo<
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我把原本我的做法也提供出来供大家讨论吧: .LafP}%
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首先,为了实现分页查询,我封装了一个Page类: ?PWD[mQE\
java代码: Ze~ a+%Sb
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/*Created on 2005-4-14*/ K&"Yv~h
package org.flyware.util.page; `Oys&]vb
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/** T4T_32`XR
* @author Joa Rs)tf|`/
* xZFha=#
*/ AW6]S*rh
publicclass Page { v:CYf_
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/** imply if the page has previous page */ cl2@p@av
privateboolean hasPrePage; 6+IOJtj
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/** imply if the page has next page */ p<'mc|hGq
privateboolean hasNextPage; N##T1 Qm)
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/** the number of every page */ HhNH"b&