Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 8iaMr278W
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 |Jd8ul:&e
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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 =t-Ud^3
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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 L;")C,CwQ
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分页支持类: \A\
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java代码: h SS9mQ
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package com.javaeye.common.util; A,EG0yb
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import java.util.List; ,0h{RZKw
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publicclass PaginationSupport { Zj]tiN f\"
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publicfinalstaticint PAGESIZE = 30; 8BAe6-*S8
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privateint pageSize = PAGESIZE; 2( GYk
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privateList items; v2]N5
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privateint totalCount; d1g7:s9$0
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privateint[] indexes = newint[0]; <ndY6n3
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privateint startIndex = 0; {f4jE#a>v
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public PaginationSupport(List items, int Xmmj.ZUr
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totalCount){ aj1g9y
setPageSize(PAGESIZE); $ZyOBxI
setTotalCount(totalCount); ux^rF
setItems(items); 3<)][<Ud
setStartIndex(0); Fg
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} RRyD<7s1
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public PaginationSupport(List items, int GKWsJO5 n
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totalCount, int startIndex){ NoF|j57?u'
setPageSize(PAGESIZE); %8DI)n#H
setTotalCount(totalCount); e:MbMj6`
setItems(items); fA1{-JzV<4
setStartIndex(startIndex); //r)dN^
} @!ja/Y^
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public PaginationSupport(List items, int |G/)<1P
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totalCount, int pageSize, int startIndex){ O\=Zo9(NHF
setPageSize(pageSize); C^_m>H3b
setTotalCount(totalCount); [\fwnS_1
setItems(items); F4V) 0)G
setStartIndex(startIndex); G|t0no\f
} XN\rq=
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publicList getItems(){ g&.OJ
return items; TZg1,Z
} >@a7Zzl0H
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publicvoid setItems(List items){ ?djH!
this.items = items; OYmutq
} >s.y1Vg~C
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publicint getPageSize(){ G~_D'o<r
return pageSize; /#t::b+>x
} z'O+B}
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publicvoid setPageSize(int pageSize){ d}|z+D
this.pageSize = pageSize; xd"+ &YT
} BT3yrq9
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publicint getTotalCount(){ E*,nKJu'r
return totalCount; ?h|DeD!s
} J5<16}*
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publicvoid setTotalCount(int totalCount){ SY@;u<Pd
if(totalCount > 0){ E1w8d4P,G
this.totalCount = totalCount; %(K} 1[
int count = totalCount / eZhF<<Y
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pageSize; NweGK
if(totalCount % pageSize > 0) /9Qr1@&v
count++; kaIns
indexes = newint[count]; XVo+ <&
for(int i = 0; i < count; i++){ ,Qo:]Mj
indexes = pageSize * xwHE,ykE
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} O@dK^o
}else{ F|oyrG
this.totalCount = 0; +9yMtR
} (Gapv9R
} [a~@6*=
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publicint[] getIndexes(){ E7w^A
return indexes; ];=|))ky"
} 1>2
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publicvoid setIndexes(int[] indexes){ c]$$ap
this.indexes = indexes; bB*cd!7y
} `/i/AZ{
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publicint getStartIndex(){ /_8nZVu
return startIndex; WqCj;Tj|
} adgd7JjI*
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publicvoid setStartIndex(int startIndex){ t.bM]QU!1
if(totalCount <= 0) zx+}>(U\U
this.startIndex = 0; f3.oc9G
elseif(startIndex >= totalCount) <'hoN/g
this.startIndex = indexes l>(*bb1}b
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[indexes.length - 1]; sP=^5K`g
elseif(startIndex < 0) |;p.!FO
this.startIndex = 0; 8R(l~
else{ mW,b#'hy
this.startIndex = indexes jj 'epbA
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[startIndex / pageSize]; :TV`uUE
} K;w]sN+I
} <R_)[{ 7
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publicint getNextIndex(){ cBZJ
int nextIndex = getStartIndex() + $ma@z0%8}
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pageSize; .O&YdUo
if(nextIndex >= totalCount) #hXvGon$?
return getStartIndex(); "Rtt~["%
else "t-9q
return nextIndex; 8;f5;7Mn
} FNo.#Z5+b
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publicint getPreviousIndex(){ um( xZ6&m
int previousIndex = getStartIndex() - z('t#J!b
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pageSize; ]4K4Nh~
if(previousIndex < 0) 1vJj?Uqc
return0; 2j]uB0
else T&Z*=ShH
return previousIndex; KYz@H#M
} /`y^z"!
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} 3'SN0VL
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抽象业务类 &78lep
java代码: l?L s=J*
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/** 8u1?\SYnb
* Created on 2005-7-12 TnQW~_:
*/ 3|EAOoWnK
package com.javaeye.common.business; 2~V"[26t
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import java.io.Serializable; -*kZ2grLt
import java.util.List; 5FsfJpw
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import org.hibernate.Criteria; 1Cw$^jd
import org.hibernate.HibernateException; HLL=.: P
import org.hibernate.Session; k$kxw_N5d
import org.hibernate.criterion.DetachedCriteria; }
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import org.hibernate.criterion.Projections; IfY?P(P
import SQMtR2
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org.springframework.orm.hibernate3.HibernateCallback; Rv.IHSQUo
import ?>gr9w\
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org.springframework.orm.hibernate3.support.HibernateDaoS *uKYrs [
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upport; sN) xNz
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import com.javaeye.common.util.PaginationSupport; |Nadk(}
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public abstract class AbstractManager extends *_H]?&
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HibernateDaoSupport { `P$X`;SwE
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privateboolean cacheQueries = false; 0WyOORuK
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privateString queryCacheRegion; 1qp"D_h
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publicvoid setCacheQueries(boolean }FX:sa?5
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cacheQueries){ ;*d?Qe:
this.cacheQueries = cacheQueries; d ]#`?}
} kjt(OFh'Y+
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publicvoid setQueryCacheRegion(String E?VOst&
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queryCacheRegion){ /2Ok;!.
this.queryCacheRegion = 7ZUS
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queryCacheRegion; RcZ&/MY
} <oSx'_dc
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publicvoid save(finalObject entity){ ll?Qg%V[t
getHibernateTemplate().save(entity); H|'n|\{lt
} `3z6y&dmx
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publicvoid persist(finalObject entity){ NL'(/|)
getHibernateTemplate().save(entity); _T;Kn'Gz(&
} }*vE/W
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publicvoid update(finalObject entity){ "
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getHibernateTemplate().update(entity); H8m[:K]_H
} hE'>8 {
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publicvoid delete(finalObject entity){ U}l=1B
getHibernateTemplate().delete(entity);
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} zXkq2\GHA
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publicObject load(finalClass entity, Q@*9|6-
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finalSerializable id){ []?*}o5&>T
return getHibernateTemplate().load Dw,LB>Eq,
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(entity, id); g``S SU
} 8<J3Xe
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publicObject get(finalClass entity, gRZ!=z[&
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finalSerializable id){ /sqfw,h@
return getHibernateTemplate().get OJ.oHf=K!
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(entity, id); M"$g*j
} $MM[`^~
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publicList findAll(finalClass entity){ iL~(BnsF
return getHibernateTemplate().find("from N1U.1~U
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" + entity.getName()); Qh]k)]+*|
} ?DY6V;&F@f
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publicList findByNamedQuery(finalString sBNqg~HwB?
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namedQuery){ \JP9lJ3<
return getHibernateTemplate T`c:16I
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().findByNamedQuery(namedQuery); CYM>4C~>JW
} Jt)J1CAYo
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publicList findByNamedQuery(finalString query,
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finalObject parameter){ Q{
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return getHibernateTemplate "M,Hm!j
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().findByNamedQuery(query, parameter); VI.Cmw~S
} P|a|4Bb+fW
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publicList findByNamedQuery(finalString query, *#GX~3A
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finalObject[] parameters){ zXe]P(p<
return getHibernateTemplate WGUd@lC~
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().findByNamedQuery(query, parameters); }G"bD8+
} UAC"jy1D
Seq
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publicList find(finalString query){ mw83 pU6
return getHibernateTemplate().find D$`$4mX@hP
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(query); t*-_MG
} O`;o"\P<
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publicList find(finalString query, finalObject w(Q{;RNM;
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parameter){ r4]hcoU
return getHibernateTemplate().find -r[O_[g w
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(query, parameter); HUel
} P R_|
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public PaginationSupport findPageByCriteria "_\77cqpTh
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(final DetachedCriteria detachedCriteria){ ] B>.}
return findPageByCriteria 4v`;D,dIu
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); v\5`n@}4
} F*y7 4j,
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public PaginationSupport findPageByCriteria _ujhD
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(final DetachedCriteria detachedCriteria, finalint |gfG\fL3V
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startIndex){ $8Gj9mw4e'
return findPageByCriteria )t$-/8
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(detachedCriteria, PaginationSupport.PAGESIZE, +y 48.5
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startIndex); 2rM/kF >g
} *tl; 0<n
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public PaginationSupport findPageByCriteria <4-g2.\
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(final DetachedCriteria detachedCriteria, finalint WFvVu3
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pageSize, $kxu-
finalint startIndex){ tSVS ogGd
return(PaginationSupport) z#6(PZC}
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getHibernateTemplate().execute(new HibernateCallback(){ ZSLvr-,D
publicObject doInHibernate 4@M`BH`
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(Session session)throws HibernateException { <9S 5
Criteria criteria = 3s#/d,+
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detachedCriteria.getExecutableCriteria(session); 8k^1:gt^
int totalCount = AH^ud*3F
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((Integer) criteria.setProjection(Projections.rowCount -(zw80@&
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()).uniqueResult()).intValue(); 5dL! e<<
criteria.setProjection hcR^?
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(null); )Dyyb1\)
List items = 88l{M[B2
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criteria.setFirstResult(startIndex).setMaxResults {]O.?Yru?
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(pageSize).list(); Xvxrz{
PaginationSupport ps = )IKqO:@
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new PaginationSupport(items, totalCount, pageSize, b6@0?_n
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startIndex); $v=(`=
return ps; sc z8`%
} 1/A|$t[
}, true); jOL=vG
} b[MKo7
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public List findAllByCriteria(final xN6}4JB
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DetachedCriteria detachedCriteria){ R xc
return(List) getHibernateTemplate DK|/|C}6
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().execute(new HibernateCallback(){ g>{t>B%v^K
publicObject doInHibernate h@Ix9!?+
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(Session session)throws HibernateException { b2~5 LZ
Criteria criteria = bUc++M
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detachedCriteria.getExecutableCriteria(session); Iz&<rL;s
return criteria.list(); ;ih;8
} y 48zsm{
}, true); vyT-!mC
} y4Nam87;/?
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public int getCountByCriteria(final 1:4u]$@E
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DetachedCriteria detachedCriteria){ $^W|@et{
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Integer count = (Integer) aQV? }
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getHibernateTemplate().execute(new HibernateCallback(){ %
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publicObject doInHibernate 5E2T*EXSh
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(Session session)throws HibernateException { TU9$5l/;g
Criteria criteria = *?o 'sTH
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detachedCriteria.getExecutableCriteria(session); && WEBQ
return <M\#7.](
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criteria.setProjection(Projections.rowCount "}:SXAZ5`
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()).uniqueResult(); ]MB6++.e
} //yz$d>JN
}, true); 7 M$cIWe$
return count.intValue(); YH&0Vy#c$
} \sS0@gnDI
} H)5" <=]
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用户在web层构造查询条件detachedCriteria,和可选的 [f=Y*=u9,
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 &,$N|$yK}|
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PaginationSupport的实例ps。 p-,Bq!aG$
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ps.getItems()得到已分页好的结果集 l_P90zm39!
ps.getIndexes()得到分页索引的数组 Nu+DVIM
ps.getTotalCount()得到总结果数 "1rT>
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ps.getStartIndex()当前分页索引 (dHjf;
ps.getNextIndex()下一页索引 euET)Ccq
ps.getPreviousIndex()上一页索引 X5=I{eY}
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错
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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 0KjCM4t
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一下代码重构了。 m1M6N`f
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我把原本我的做法也提供出来供大家讨论吧: 0+AMN-
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首先,为了实现分页查询,我封装了一个Page类: GF*uDJ Kp
java代码: ul!q)cPb{
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/*Created on 2005-4-14*/ SUD~@]N1
package org.flyware.util.page; N3wy][bo
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/** #It!D5A
* @author Joa sY?sQ'E2]
* N[N4!k )!$
*/ IH.EvierJ
publicclass Page { t;_1 /mt
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/** imply if the page has previous page */ \p!m/2
privateboolean hasPrePage; ..=lM:13|
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/** imply if the page has next page */ i*mI-l
privateboolean hasNextPage; =nlj|S ~3
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/** the number of every page */ X7?j90tH
privateint everyPage; Ii>#9>!F
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/** the total page number */ qJR8fQ
privateint totalPage; rw?wlBEG%
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/** the number of current page */ &LQfs4}a,
privateint currentPage; (@S9>z4s
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/** the begin index of the records by the current 1+Vei<H$
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query */ o%K1!'
privateint beginIndex; a&[>kO
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/** The default constructor */ #*3 vE& p
public Page(){ `R*!GHro
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} 01IfvK
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/** construct the page by everyPage T;i+az{N:V
* @param everyPage w<Iq:3
* */ 4ZB]n,pfT
public Page(int everyPage){ \3)U~[O>:
this.everyPage = everyPage; z!^3%kJJ>
} 9>d~g!u=
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/** The whole constructor */ cA`X(Am6]g
public Page(boolean hasPrePage, boolean hasNextPage, $PTl{
}do=lm?/
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int everyPage, int totalPage, HE3x0H}o>
int currentPage, int beginIndex){ 5Veybchy "
this.hasPrePage = hasPrePage; k7bfgb{
this.hasNextPage = hasNextPage; SY+$8^
this.everyPage = everyPage; Fh ^Ax3P(
this.totalPage = totalPage; 9K#U<Q0b'
this.currentPage = currentPage; 1Gk'f?dw
this.beginIndex = beginIndex; m[&