Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 fW1CFRHH
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 U@)eTHv}6
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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 CXx*_@}MU
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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 '"/=f\)u
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分页支持类: k&vz7Q`T
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java代码: BLf>_bUk
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package com.javaeye.common.util; /cQueUME`
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import java.util.List; +RM SA^
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publicclass PaginationSupport { hPkWCoQpq
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publicfinalstaticint PAGESIZE = 30; ub#a`
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privateint pageSize = PAGESIZE;
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privateList items; li'YDtMKCY
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privateint totalCount; RVA(Q[ ;
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privateint[] indexes = newint[0]; /}fHt^2H
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privateint startIndex = 0; G kl71VX
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public PaginationSupport(List items, int GxI!{oi2
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totalCount){ S.94edQ
setPageSize(PAGESIZE); /hH
setTotalCount(totalCount); lH x^D;m6
setItems(items); 4I
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setStartIndex(0); )@l%
} BB!THj69a6
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public PaginationSupport(List items, int P%:wAYz1^O
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totalCount, int startIndex){ vkx7paY_
setPageSize(PAGESIZE); JHM9
setTotalCount(totalCount); ;!mzyb*
setItems(items); L:pYn_
setStartIndex(startIndex); qYjce]c
} 2W96Zju\
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public PaginationSupport(List items, int JPc+rfF
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totalCount, int pageSize, int startIndex){ ]}-7_n#cC
setPageSize(pageSize); rq/yD,I,
setTotalCount(totalCount); 7{)G_?Q&
setItems(items); L_uVL#To
setStartIndex(startIndex); NMa} {*sQ
} :Ij{s
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publicList getItems(){ D3Ig>gKo?m
return items; J6s`'gFns
} qo90t{|c
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publicvoid setItems(List items){ nQX:T;WL@
this.items = items; uD$u2
} hk(ZM#Bh
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publicint getPageSize(){ B:;pvW]
return pageSize; 8>2.UrC
} j9x<Y]
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publicvoid setPageSize(int pageSize){ _"Dv
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this.pageSize = pageSize; 7a=gH2]&
} */)c?)"
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publicint getTotalCount(){ av}k)ZT_
return totalCount; <
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} SO|NaqWa
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publicvoid setTotalCount(int totalCount){ !N\@'F!
if(totalCount > 0){ '8RsN-w
this.totalCount = totalCount; zU kgG61
int count = totalCount / F#,90F'
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pageSize; UUYSFa%
if(totalCount % pageSize > 0) g|DF[
count++; N=T<_`$5
indexes = newint[count]; p*R;hU
for(int i = 0; i < count; i++){ uB]7G0g:
indexes = pageSize * $<dH?%!7
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} {3>$[bT
}else{ Ga-k
this.totalCount = 0; :j9l"5"
} n71r_S*
} *KZYv=s,u
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publicint[] getIndexes(){ a?I=
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return indexes; v}}F,c(f
} &=@IzmA
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publicvoid setIndexes(int[] indexes){ sQUM~HD\a
this.indexes = indexes; xBThq?N?
} 0rQMLx
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publicint getStartIndex(){ m)ky*"(
return startIndex; Go`vfm"S
} #px+;k5
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publicvoid setStartIndex(int startIndex){ O@T9x$
if(totalCount <= 0) Gvt G(u~
this.startIndex = 0; O%WIf__Q
elseif(startIndex >= totalCount) LiC*@W
this.startIndex = indexes !fV+z%:
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[indexes.length - 1]; |PvPAPy)uu
elseif(startIndex < 0) YquI $PV _
this.startIndex = 0; 9%o32eo,3
else{ 8l>?Pv
this.startIndex = indexes B?eCe}*f;B
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[startIndex / pageSize]; -V*R\,>
} 7cuE7"
} m<<+
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publicint getNextIndex(){ oM
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int nextIndex = getStartIndex() + /7(W?xOe
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pageSize; 6iry6wcHm
if(nextIndex >= totalCount) -vAC"8)S
return getStartIndex(); vz@A;t
else [$ubNk;!z
return nextIndex; &pxg.
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} I {SjlN}d
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publicint getPreviousIndex(){ \,'m</o~,
int previousIndex = getStartIndex() - u%GEqruo[
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pageSize; [CTnXb
if(previousIndex < 0) mtpeRVcF
return0; ^L,K& Jd
else +i6GHBn~J
return previousIndex; ~V:\ _{mE
} \:P>le'1
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} _f7 9wx\B
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抽象业务类 p
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java代码: 3RUy,s
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/** `](e:be}
* Created on 2005-7-12 5f rX
*/ i}(LqcYU
package com.javaeye.common.business; :S]\0;8]
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import java.io.Serializable; M+oHtX$
import java.util.List; E[OJ+ ;c
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import org.hibernate.Criteria; 9FF0%*tGo
import org.hibernate.HibernateException; |o7[|3:M
import org.hibernate.Session; [=C6U_vU
import org.hibernate.criterion.DetachedCriteria; r[e##M
import org.hibernate.criterion.Projections; y-Fo=y
import 6dHOf,zjm
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org.springframework.orm.hibernate3.HibernateCallback; pt?bWyKG
import 3s*mbk[J
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org.springframework.orm.hibernate3.support.HibernateDaoS @?ebuj5{e
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upport; rV.}PtcFY
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import com.javaeye.common.util.PaginationSupport; 1> ?M>vK
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public abstract class AbstractManager extends VCYwzB
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HibernateDaoSupport { Fk7?xc
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privateboolean cacheQueries = false; 8H[<X_/ke
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privateString queryCacheRegion; 3F"lXguS
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publicvoid setCacheQueries(boolean D'>_I.
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cacheQueries){ '$Dn
this.cacheQueries = cacheQueries; l03B=$
} rE7G{WII
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publicvoid setQueryCacheRegion(String h#I>M`|
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queryCacheRegion){ fy1|$d{'
this.queryCacheRegion = #!B4 u?"m
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queryCacheRegion; c?Y*Y
} F~ty!(c
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publicvoid save(finalObject entity){ Vsr.=Nd=
getHibernateTemplate().save(entity); D_ 2:k'4
} -]Bq|qTH[(
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publicvoid persist(finalObject entity){ J`Q>3]wL
getHibernateTemplate().save(entity); (y'hyJo
} PN%zIkbo
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publicvoid update(finalObject entity){ UBKu/@[f@
getHibernateTemplate().update(entity); \<h0Q,e
} },?kk1vIT{
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publicvoid delete(finalObject entity){ Oxnp0 s
getHibernateTemplate().delete(entity); J-:.FKf\5l
} R+:yVi[F]U
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publicObject load(finalClass entity, m,28u3@r
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finalSerializable id){ 'c&Ed
return getHibernateTemplate().load OdbEq?3S/?
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(entity, id); OnziG+ak
} ;a!S!%.h
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publicObject get(finalClass entity, @s>Czm5
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finalSerializable id){ Z#jZRNU%ox
return getHibernateTemplate().get pQ" >UL*
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(entity, id); LP^$AAy
} z
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publicList findAll(finalClass entity){ )}R0Y=e
return getHibernateTemplate().find("from ~NgA
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" + entity.getName()); BZ#(
} Y Uc+0
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publicList findByNamedQuery(finalString %Xg4b6<9
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namedQuery){ #Pau\|e_
return getHibernateTemplate uc{Ihw
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().findByNamedQuery(namedQuery); 5~U/
} 2W(s(-hD
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publicList findByNamedQuery(finalString query, 8%mu8l
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finalObject parameter){ P5V}#;v
return getHibernateTemplate \7eUw,~Q>
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().findByNamedQuery(query, parameter); c):/!Q
} #zy:a%
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publicList findByNamedQuery(finalString query, &B;~
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finalObject[] parameters){ *R,5h2;
return getHibernateTemplate `hm-.@f,9
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().findByNamedQuery(query, parameters); bs&43Ae
} zk+9'r`-D
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publicList find(finalString query){ ,Vax&n+J
return getHibernateTemplate().find }#+^{P3 ;
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(query); I,DS@SK
} QL/(72K
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publicList find(finalString query, finalObject cZ*@$%_
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parameter){ T Z@]:e:"b
return getHibernateTemplate().find 7z,C}-q
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(query, parameter); `[yKFa
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} #z%fx
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public PaginationSupport findPageByCriteria RBd7YWo\|j
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(final DetachedCriteria detachedCriteria){ I][*j
return findPageByCriteria 1.hyCTnI
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); hfB%`x#akQ
} }v{LRRi
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public PaginationSupport findPageByCriteria 7EEl+;wK
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(final DetachedCriteria detachedCriteria, finalint G!##X: 6'
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startIndex){ VQ@
return findPageByCriteria e%M;?0j
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(detachedCriteria, PaginationSupport.PAGESIZE, {S\{Ii6
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startIndex); {YC@T(
} ]/6z;
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public PaginationSupport findPageByCriteria 1GRCV8"Z^
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(final DetachedCriteria detachedCriteria, finalint J)>c9w
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pageSize, q
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finalint startIndex){ (WJRi:NP?
return(PaginationSupport) v1JzP#
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getHibernateTemplate().execute(new HibernateCallback(){ h#*dI`>l-
publicObject doInHibernate S hWJ72c
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(Session session)throws HibernateException { f~[7t:WD*
Criteria criteria = t@;p
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detachedCriteria.getExecutableCriteria(session); Z{d^-
int totalCount = ajT*/L!0_
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((Integer) criteria.setProjection(Projections.rowCount @mBQ?;qlK
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()).uniqueResult()).intValue(); D_7,m%Z:
criteria.setProjection T-L||yE,h
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(null); u=s p`%?
List items = l)\! .X
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criteria.setFirstResult(startIndex).setMaxResults 3"e,qY
#{6/ (X
(pageSize).list(); xo&_bMO
PaginationSupport ps = mJnIwdW*
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new PaginationSupport(items, totalCount, pageSize, ;'K5J9k
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startIndex); &z3o7rif$
return ps; @. l@\4m
} T -2t.Xs
}, true); aXYY:;
} 6gE7e|+
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public List findAllByCriteria(final RqrdAkg
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DetachedCriteria detachedCriteria){ reWot&;
return(List) getHibernateTemplate 59A}}.@?m
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().execute(new HibernateCallback(){ t:Q*gWRh
publicObject doInHibernate fr3d
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(Session session)throws HibernateException { "8MF_Gu):
Criteria criteria = 7$=InK
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detachedCriteria.getExecutableCriteria(session); vE?G7%,
return criteria.list(); u6agoK|^9
} n>YKa)|W`
}, true); NLqzi%s
} ?a5! H*,
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public int getCountByCriteria(final 4[eXe$
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DetachedCriteria detachedCriteria){ `;C V=,M
Integer count = (Integer) 5;EvNu
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getHibernateTemplate().execute(new HibernateCallback(){ =,M5KDk`
publicObject doInHibernate *]X'( /b_
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(Session session)throws HibernateException { :F?C)F
Criteria criteria = 4B.*g-L
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detachedCriteria.getExecutableCriteria(session); ga +dt
return y)@wjH{6
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criteria.setProjection(Projections.rowCount !|(NgzDP/
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()).uniqueResult(); 1+s;FJ2}
} g-
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}, true); "to;\9lP
return count.intValue(); ]a`$LW}
} 0 H:X3y+
} WsB ?C&>x
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用户在web层构造查询条件detachedCriteria,和可选的 $UwCMPs X
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 9.#<b|g
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PaginationSupport的实例ps。 z{QqY.Gu{G
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ps.getItems()得到已分页好的结果集 ?J0y|
ps.getIndexes()得到分页索引的数组 z24q3 3O
ps.getTotalCount()得到总结果数 2?Vd 5xkt
ps.getStartIndex()当前分页索引 'g\4O3&_
ps.getNextIndex()下一页索引 L4W5EO$
ps.getPreviousIndex()上一页索引 R|(a@sL
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ccxNbU
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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 i%?* @uj
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一下代码重构了。 }GM'.yutX
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我把原本我的做法也提供出来供大家讨论吧: z1a7*)8P
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首先,为了实现分页查询,我封装了一个Page类: ;_=&-mz
java代码: o mx=
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/*Created on 2005-4-14*/ V7/Rby Q
package org.flyware.util.page; h";L
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/** DlJo^|5
* @author Joa *T1_;4i
* {!`6zBsP
*/ #vlgwA
publicclass Page { lOp`m8_=
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/** imply if the page has previous page */ Fr-SvsNFB
privateboolean hasPrePage; 7tp36 TE
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/** imply if the page has next page */ P+}h$_x
privateboolean hasNextPage; j~MI<I+l[
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/** the number of every page */ rJB}qYD
privateint everyPage; Z_NCD`i;
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/** the total page number */ ,esmV-
privateint totalPage; ar,7S&s