Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 hiP^*5h
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 b.ow0WYe
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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 <=jE,6_|
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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 $!KV]]
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分页支持类: Kw-E%7gh4c
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java代码: W@pVP4F0xM
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package com.javaeye.common.util; 4-cnkv\~
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import java.util.List; M;3uG/E\
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publicclass PaginationSupport { J. {[>
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publicfinalstaticint PAGESIZE = 30; v*]|1q%/
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privateint pageSize = PAGESIZE; Ibpk\a?A{
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privateList items; pBmacFP
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privateint totalCount; \zgRzO'N
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privateint[] indexes = newint[0]; ot-!_w<
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privateint startIndex = 0; VA2%2g2n{
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public PaginationSupport(List items, int "C}nS=]8m
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totalCount){ 7nIg3s%
setPageSize(PAGESIZE); h}+,]^
setTotalCount(totalCount); 37M7bB0
setItems(items); ^qV*W1|0
setStartIndex(0); d [K56wbpx
} ;:"~utL7
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public PaginationSupport(List items, int d \0K3=h
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totalCount, int startIndex){ S>cT(q_&
setPageSize(PAGESIZE); Rn-L:o@?
setTotalCount(totalCount); fN t
setItems(items); rmWG9&coW
setStartIndex(startIndex); 8]2S'mxE
} #M{}Grg
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public PaginationSupport(List items, int ,n&Dg58K
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totalCount, int pageSize, int startIndex){ }$g5:k!
setPageSize(pageSize); ?^,GaZ^V
setTotalCount(totalCount); Hhfqb"2on
setItems(items); 80:na7$)#
setStartIndex(startIndex); Q"QrbU
} 5#WZXhlc}
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publicList getItems(){ )+\e+Ad}H
return items; MO/l(wO
} ^#gGA_H
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publicvoid setItems(List items){ =\oNu&Q^
this.items = items; KDHR}`
} e2/[`k=7-
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publicint getPageSize(){ @8V8gV?zm
return pageSize; 9J l9\y9
} I /> .P
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publicvoid setPageSize(int pageSize){ F+c*v#T
this.pageSize = pageSize; {e>}.R
} V{c
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publicint getTotalCount(){ Lo9+#ITyx
return totalCount; bYowEzieF
} 'nW:2(J
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publicvoid setTotalCount(int totalCount){ Eepy%-\
if(totalCount > 0){ ;QW)tv.y
this.totalCount = totalCount; ^\Jg
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int count = totalCount / |A0kbC.
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pageSize; /Xn I>
if(totalCount % pageSize > 0) njvmf*A?S
count++; LH0\SmhU
indexes = newint[count]; 5RZAs63t
for(int i = 0; i < count; i++){ ?XW+&!ar
indexes = pageSize * tXPS@4F
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} I,t 0X)
}else{ rd. "mG.
this.totalCount = 0; CDR^xo5
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} N[r@Y{
} !4-NbtT
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publicint[] getIndexes(){ TC J\@|yw
return indexes; .6
} ,!bOzth2>K
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publicvoid setIndexes(int[] indexes){ =:9n+7~$
this.indexes = indexes; ;jI\MZ~l\
} 5.5dB2w
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publicint getStartIndex(){ &X +@,!
return startIndex; sOVaQ&+y
} #N,\c@Gy
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publicvoid setStartIndex(int startIndex){ x$6-7<p
if(totalCount <= 0) X9zTz2 Fy
this.startIndex = 0; >8jDW "Ua
elseif(startIndex >= totalCount) 5M*q{kX)
this.startIndex = indexes ZhM-F0;`
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[indexes.length - 1]; dI'C[.zp[
elseif(startIndex < 0) e`8z1r
this.startIndex = 0; /`2VJw
else{ tHhY1[A8m
this.startIndex = indexes I8`.eqV
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[startIndex / pageSize]; L'z?M]
} WV?iYX!
} }{E//o:Ta
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publicint getNextIndex(){ s7T=/SC54
int nextIndex = getStartIndex() + <%) :'0q&
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pageSize; c3oI\lU
if(nextIndex >= totalCount) qY#*zx
return getStartIndex(); c|ZZ+2IYd
else _VR4|)1g
return nextIndex; x{Gih1
} zM[WbB+"m
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publicint getPreviousIndex(){ ^k u~m5v
int previousIndex = getStartIndex() - hFQC%N.'
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pageSize; | %6B#uy
if(previousIndex < 0) w&C SE
return0; =fG(K!AQ
else :UFf6T?
return previousIndex; w_A-:S
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} o)1wF
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} 1\zI#"b ^
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抽象业务类 n>Zkx+jLj<
java代码: =U|J{^ >I
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/** )Q7;)iPY#
* Created on 2005-7-12 Hk3HzN3
*/ 9chiu%20
package com.javaeye.common.business; AS4m227
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import java.io.Serializable; :gQc@)jZ(*
import java.util.List; kl2]#G(
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import org.hibernate.Criteria; ?e&CbVc4
import org.hibernate.HibernateException; P\SD_8
import org.hibernate.Session; QC ?8
import org.hibernate.criterion.DetachedCriteria; t@)~{W
{
import org.hibernate.criterion.Projections; =X+DC&]%!
import B[b'OtH
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org.springframework.orm.hibernate3.HibernateCallback; 7"8HlOHA
import }yB@?
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org.springframework.orm.hibernate3.support.HibernateDaoS j:{<
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upport; n=hz7tjaz
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import com.javaeye.common.util.PaginationSupport; |#!25qAT
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public abstract class AbstractManager extends :5@7z9 >
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HibernateDaoSupport { VFG)|Z
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privateboolean cacheQueries = false;
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privateString queryCacheRegion; RZ?>>Ll6
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publicvoid setCacheQueries(boolean _>3GNvS
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cacheQueries){ FVF:1DT
this.cacheQueries = cacheQueries; 2hU4g
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} zxwpS
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publicvoid setQueryCacheRegion(String XV+BSW7}
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queryCacheRegion){ X
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this.queryCacheRegion = _$Z46wHmB
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queryCacheRegion;
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} Q^0K8>G^
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publicvoid save(finalObject entity){ ;{HxY98Q
getHibernateTemplate().save(entity); mP:mzmUw
} 5HOhk"
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publicvoid persist(finalObject entity){ Of:e6N
getHibernateTemplate().save(entity); #2u-L~n
} Zvr(c|Q
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publicvoid update(finalObject entity){ A.z~wu%(
getHibernateTemplate().update(entity); [~jhOv^
} tK8\Ib J
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publicvoid delete(finalObject entity){ Xwx;m/
getHibernateTemplate().delete(entity); hi.{
} ;B1}so1]
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publicObject load(finalClass entity, M_*w)<
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finalSerializable id){ yChC&kX
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return getHibernateTemplate().load 7a@V2cr@
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(entity, id); S6]D;c8GE
} xFyMg&
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publicObject get(finalClass entity, &s]
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finalSerializable id){ QjZ}*p
return getHibernateTemplate().get NWoZDsu
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(entity, id); ;gW~+hW ^
} -R&h?ec
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publicList findAll(finalClass entity){ v,>q]!
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return getHibernateTemplate().find("from br'~SXl
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" + entity.getName()); e3(0L I
} n,AN&BZ
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publicList findByNamedQuery(finalString u2Rmp4]
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namedQuery){ zIdQ^vm8Q
return getHibernateTemplate *>\RGL;]8
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().findByNamedQuery(namedQuery); yM#W,@
}
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publicList findByNamedQuery(finalString query, lgnF\)
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finalObject parameter){ rylllJz|L:
return getHibernateTemplate Gg-<3z
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().findByNamedQuery(query, parameter); +<3tv&"
} ]B5\S
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publicList findByNamedQuery(finalString query, HP?e?3.T
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finalObject[] parameters){ VQ}=7oe%q
return getHibernateTemplate ,'ndQ{\9
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().findByNamedQuery(query, parameters); ?G8 D6
} kdoE)C
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publicList find(finalString query){ <-lz_
return getHibernateTemplate().find `ZNjA},.
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(query); g5T~%t5lo
} u 6%56 %^f
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publicList find(finalString query, finalObject c)$/Uu
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parameter){ qv,|7yw{
return getHibernateTemplate().find OZISh?
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(query, parameter); w5&UG/z%l
} q.g!WLiI
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public PaginationSupport findPageByCriteria *XNvb ^<
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(final DetachedCriteria detachedCriteria){ bAW;2
NB
return findPageByCriteria H=wmN0s{<
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); g8vN^nQf[
} gzC\6ca
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public PaginationSupport findPageByCriteria xDVzHgbf
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(final DetachedCriteria detachedCriteria, finalint @AyC0}
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startIndex){ ZNuyGo;
return findPageByCriteria 7p~@S4
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(detachedCriteria, PaginationSupport.PAGESIZE, sN;U,{
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startIndex);
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} !UgJ^v
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public PaginationSupport findPageByCriteria }}Q|O]e
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(final DetachedCriteria detachedCriteria, finalint 1nvs51?H
6*]Kow?
pageSize, $?'z%a{
finalint startIndex){ ^ S%4R'
return(PaginationSupport) p?dMa_g
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getHibernateTemplate().execute(new HibernateCallback(){ Fd ]! 7
publicObject doInHibernate g0ug:- R
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(Session session)throws HibernateException { GLk7#Y
Criteria criteria = 3S.rIai+
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detachedCriteria.getExecutableCriteria(session); A70_hhP
int totalCount = (xxJ^u>QC
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((Integer) criteria.setProjection(Projections.rowCount hL8QA!
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()).uniqueResult()).intValue(); ^ ]`<nO
criteria.setProjection qdcCX:Z<
d/* [t!
(null); w0
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List items = m&;
t;
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criteria.setFirstResult(startIndex).setMaxResults 1{u;-pg
qOk4qbl[
(pageSize).list(); 2{&|%1Jg
PaginationSupport ps = IG#=}q
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new PaginationSupport(items, totalCount, pageSize, x.45!8Zb
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startIndex); 5M*ZZ+YX
return ps; RtF_p
{s
} b@5bN\"x$
}, true); a+J :1'
} V{a 7@_y
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public List findAllByCriteria(final Ebp8})P/~
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DetachedCriteria detachedCriteria){ hDz_BvE
return(List) getHibernateTemplate m2 N
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}3vB_0[r
().execute(new HibernateCallback(){ &jg,8
publicObject doInHibernate JU"!qXQr
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(Session session)throws HibernateException { HeF[H\a<
Criteria criteria = W_M]fjL.
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detachedCriteria.getExecutableCriteria(session); mu:Q2t^
return criteria.list(); hbN*_[
} ;qzCoe
}, true); # Dy;x\a
} }*?e w
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public int getCountByCriteria(final =Ybbh`$<
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DetachedCriteria detachedCriteria){ qQVqS7 t
Integer count = (Integer) E9
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}3N8EmS
getHibernateTemplate().execute(new HibernateCallback(){ `uGX/yQ#=
publicObject doInHibernate 7p2x}[ .\
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(Session session)throws HibernateException { )_+#yaC
Criteria criteria = c) 1m4SB@
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detachedCriteria.getExecutableCriteria(session); :Z`4ea"w
return U,g!KN3P
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criteria.setProjection(Projections.rowCount ts)0+x
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()).uniqueResult(); "I_3!Yu
} '!En,*'IS
}, true); DY,Sfh;tp
return count.intValue(); 7E|0'PPR
} (&X"~:nm2
} GK\'m@k
} #%sI"9
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用户在web层构造查询条件detachedCriteria,和可选的 y
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 (<1DPpy95O
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PaginationSupport的实例ps。 12cfqIo9
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ps.getItems()得到已分页好的结果集 5t0i/&zX
ps.getIndexes()得到分页索引的数组 c*6o{x}K
ps.getTotalCount()得到总结果数
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ps.getStartIndex()当前分页索引 yhUc]6`V.H
ps.getNextIndex()下一页索引 IK}T.*[
ps.getPreviousIndex()上一页索引 =m-_0xo
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 W*8D@a0 _
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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 B&L{/.v_z\
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一下代码重构了。 6x -PGq
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我把原本我的做法也提供出来供大家讨论吧: ~|!q>z
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首先,为了实现分页查询,我封装了一个Page类: ]kc_wFT<
java代码: BRH:5h
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/*Created on 2005-4-14*/ sW=@G'}3
package org.flyware.util.page; uomFE(
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/** w*bVBuXs
* @author Joa 0<i~XN0g
* Y&gfe8%5N
*/ =OjzBiHR
publicclass Page { /=Xen
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/** imply if the page has previous page */ 6W#+U<
privateboolean hasPrePage; Ro%S_!
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/** imply if the page has next page */ .+B!mmp
privateboolean hasNextPage; J-X5n 3I&
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/** the number of every page */ Ha 3XH_
privateint everyPage; )8 iDjNM<
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/** the total page number */ a(}jn|
privateint totalPage; 29GejLg|
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/** the number of current page */ t?c*(?Xa
privateint currentPage; iPkG=*Ip(%
] c'owj
/** the begin index of the records by the current PUlb(3p
`
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query */ ~I'Z=Wo
privateint beginIndex; *X<De
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}hBv?B2/1
/** The default constructor */ c%B=TAs5c
public Page(){ WMI/Y9N
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} ?X:RrZ:/
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/** construct the page by everyPage NS&~n^*k<
* @param everyPage DO%YOv
* */ 1,pg:=N9
public Page(int everyPage){ +_`F@^R_
this.everyPage = everyPage; Th!S?{v
} }!.7QpA$
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/** The whole constructor */ ltD:w{PO]
public Page(boolean hasPrePage, boolean hasNextPage, ,2?C^gxt
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}B]FHpi
int everyPage, int totalPage, #b8/gRfS
int currentPage, int beginIndex){ {'vvE3iZ
this.hasPrePage = hasPrePage; :A
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this.hasNextPage = hasNextPage; tPp}/a%D
this.everyPage = everyPage; TZHqn6
this.totalPage = totalPage; MD1,KH+O
this.currentPage = currentPage; Q!|71{5U
this.beginIndex = beginIndex; /
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} pkM32v-
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/** 95(VY)_6#A
* @return S)[2\Z{**T
* Returns the beginIndex. Xt~/8)&
*/ S[ 2`7'XV
publicint getBeginIndex(){ Ads^y`b
return beginIndex; W``e6RX-
} ")o.x7~N
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/** 9r)5d&,6
* @param beginIndex rAQ^:q
* The beginIndex to set. ''WX
*/ (
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publicvoid setBeginIndex(int beginIndex){ oYqC"g&4Z
this.beginIndex = beginIndex; "\V:W%23W{
} `[ne<F?e
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/** UbuxD })
* @return wicg8[T=B
* Returns the currentPage. }M9'N%PU
*/ @yek6E&9
publicint getCurrentPage(){ pYa<u,>pN
return currentPage; :Z+(H +lyZ
} hpw;w}m
Gge"`AT
/** E]7G4
* @param currentPage /_56H?w\
* The currentPage to set. +nqOP3
*/ N4D_ 43jz
publicvoid setCurrentPage(int currentPage){ Z`:V~8=l
this.currentPage = currentPage; :)MZgW
} A&t}s
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/** K+GjJ8
* @return Dljq
* Returns the everyPage. DSIa3!0
*/ {wMCo,
publicint getEveryPage(){ \ KPz
return everyPage; T
} Sa@Xh,y Z
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/** %Ajf|Go0/G
* @param everyPage lc/2!:g
* The everyPage to set. |X_yL3`Zb
*/ ksK
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publicvoid setEveryPage(int everyPage){ vR`KRI`{
this.everyPage = everyPage; 4b<:67
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} b0&dpMgh:
?}Mv5SO
/** 20Rgw
* @return ,qr)}s-
* Returns the hasNextPage. iE&`Fhf?
*/ M1oCa,8M+
publicboolean getHasNextPage(){ 9wAP%xh
return hasNextPage; */qv}
} 9^}GUJy?
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/** +^"|FtKhE
* @param hasNextPage VWNmqeP
* The hasNextPage to set. z24-hC
*/ LAvAjvRc
publicvoid setHasNextPage(boolean hasNextPage){ yC _X@o-n
this.hasNextPage = hasNextPage; Fs=nAn#
} HAU8H'h
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/** 4e5Ka{# <
* @return .jRXHrK;
* Returns the hasPrePage. k r/[|.bq
*/ CE+\|5u
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publicboolean getHasPrePage(){ vu*08<M~i|
return hasPrePage; WM"I
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} czT$mKj3
w.V8-9{
/** H-S28%.
* @param hasPrePage E]e6a^J#
* The hasPrePage to set. bZKK'd$I
*/ \dCdyl6V
publicvoid setHasPrePage(boolean hasPrePage){ 3|~(9b{+
this.hasPrePage = hasPrePage; !u=[/>
} ?vk&k(FT
OgzPX^q/=
/** KQ 2]VN"?_
* @return Returns the totalPage. $60+}B`m
* :oZ30}
*/ Lu<'A4Q1
publicint getTotalPage(){ kdF#Nm
return totalPage; `5gcc7b
} x JepDCUJ>
h?idRaN_
/** A\?O5#m:$
* @param totalPage ;,F}!R
* The totalPage to set. AMkjoy3+]
*/ #kxg|G[Ol
publicvoid setTotalPage(int totalPage){ rK`*v*
this.totalPage = totalPage;
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} ~Ipl'cE
=*I>MgCJ
} jd$lu^>I
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z43 H]
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 g Ts5xDvJ
4sG^bZ,
个PageUtil,负责对Page对象进行构造: Dzp9BRS
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java代码: Hm*n,8_
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/*Created on 2005-4-14*/ B!9<c9/ P]
package org.flyware.util.page; dhV=;'
_I75[W!
import org.apache.commons.logging.Log; o^lKM?t
import org.apache.commons.logging.LogFactory; [P"#?7 N
*P9)M%
/** F9Mv$g79
* @author Joa &%FpNU9
* sl`\g1<{`
*/ )<!y_;$A
publicclass PageUtil { qQ^]z8g6P
<b{ApsRJf
privatestaticfinal Log logger = LogFactory.getLog }yXa1#3
b}axw+
(PageUtil.class); (?$}Vp
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/** 8+lM6O ~!
* Use the origin page to create a new page ]G&d`DNV
* @param page nIdvff
* @param totalRecords Azu$F5G!n
* @return :Oy9`vv
*/ v vOG]2z
publicstatic Page createPage(Page page, int Ey 4GyAl
D4[t@*m>7
totalRecords){ 8 \%*4L'
return createPage(page.getEveryPage(), bluhiiATd
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page.getCurrentPage(), totalRecords); !,|yrB&`S
} 8NA2C.gOZ
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/** Gi?"
* the basic page utils not including exception h=?#D0
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handler {&G0jsA
* @param everyPage l2._Z
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* @param currentPage mD=x3d
* @param totalRecords w
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* @return page vz/.*u
*/ pWK7B`t
publicstatic Page createPage(int everyPage, int ^jq QG+`?
e")s1`
currentPage, int totalRecords){ %Q]m6ciAM
everyPage = getEveryPage(everyPage); 3)p#}_u{
currentPage = getCurrentPage(currentPage); RCgZ GP
int beginIndex = getBeginIndex(everyPage, {rf.sN~M
vm
1vX;
currentPage); "0pu_
int totalPage = getTotalPage(everyPage, IL*C/y
"Lw[ $
totalRecords); ~X)Aw3}F
boolean hasNextPage = hasNextPage(currentPage, Z;-=x p
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totalPage); IP9mv`[
boolean hasPrePage = hasPrePage(currentPage); hvwKhQ}wX
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returnnew Page(hasPrePage, hasNextPage, tg.[.vKs
everyPage, totalPage, Fzt{^%\`
currentPage, hCuUX)>Bt
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beginIndex); ,_F@9Up
} qwoF4_VN
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privatestaticint getEveryPage(int everyPage){ [x{'NwP?
return everyPage == 0 ? 10 : everyPage; }f?$QSF
} W&T-E,
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privatestaticint getCurrentPage(int currentPage){ j.=VZ
return currentPage == 0 ? 1 : currentPage; \u9l4
} ViKN|W>T
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privatestaticint getBeginIndex(int everyPage, int *QH@c3vUe\
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currentPage){
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return(currentPage - 1) * everyPage; ~M _@_
} a9}7K/Y=d
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privatestaticint getTotalPage(int everyPage, int 4,4S5u[|
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totalRecords){ I!Z=3 $,
int totalPage = 0; R6v~Sy&n!
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if(totalRecords % everyPage == 0) N`,ppj
totalPage = totalRecords / everyPage; DP_ ]\V<sT
else $F2A
totalPage = totalRecords / everyPage + 1 ; ?d&l_Pa0e
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return totalPage; bys5IOP{]o
} KW`^uoY$
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privatestaticboolean hasPrePage(int currentPage){ "tdF#>x
return currentPage == 1 ? false : true; {wA(%e3_
} EX@wenR
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privatestaticboolean hasNextPage(int currentPage, h9-^aB$8^
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int totalPage){ 40h
return currentPage == totalPage || totalPage == FabgJu
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0 ? false : true; @$mh0K>
} r9sq3z|%
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} eO%w
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 ,!
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 y Ny,$1
H.o=4[
做法如下: BLaF++Fop
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 8=TM _
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的信息,和一个结果集List: ZQ1,6<^9i[
java代码: )?y${T
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/*Created on 2005-6-13*/ ~ p~
package com.adt.bo; 6K Cv
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import java.util.List; fbg:rH\_
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import org.flyware.util.page.Page; p ;]Qxh
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/** pf% yEz
* @author Joa ^ruz-N^Y!
*/ 2y`X)
publicclass Result { KwAc Ga}J
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private Page page; K&4FFZ
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private List content; V
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/** \JLea$TM:
* The default constructor )gVz?-u+D
*/ GAP,$xAaW
public Result(){ mE"(d*fe'
super(); :@@aIFRv
} ^vw[z2"
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/** &v)/mc7D
* The constructor using fields
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* :lU#Dm]
* @param page 0}mVP
* @param content w<LV5w+
*/ X<sM4dwxE
public Result(Page page, List content){ :8t;_f
this.page = page; )ko[_OJj
this.content = content; Bv xLbl}
} =Jax T90x
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/** 'ws@I?!r
* @return Returns the content. H#H[8#
*/ 2WUl8?f2Y
publicList getContent(){ 1<G, 0Lt
return content; )vD:
} i~"lcgoO
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/** a)S{9q}%
* @return Returns the page. s5\<D7
*/ sK@]|9ciQ
public Page getPage(){ dvcLZK
return page; 50e
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} uCHM
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/** LGh#
* @param content SuA
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* The content to set. cO8yu`4!e
*/ B7.<A#y2
public void setContent(List content){ 7Hg;SK6t0
this.content = content; :#OaE,
} 9K>~9Za
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/** Qk2*=BVh
* @param page =F% <W7
* The page to set. 1*?XI
*/ ~^/BAc
publicvoid setPage(Page page){ KBDNK_7A
this.page = page; ]+5Y\~I
} yu}T><Wst
}
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2. 编写业务逻辑接口,并实现它(UserManager, siOyp]
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UserManagerImpl) 8/@*6J
java代码: P N(<=v&E
JMfv|>=
oXQI"?^+
/*Created on 2005-7-15*/ l!<(}?u9
package com.adt.service; 79uAsI2-Y
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import net.sf.hibernate.HibernateException; &8dj*!4H
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import org.flyware.util.page.Page; [5PQrf~Mo
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import com.adt.bo.Result; [+!~RV_
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/** zG7y$\A
* @author Joa swg*fhJFB
*/ G[+{[W
publicinterface UserManager { WeIi{<u8R
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public Result listUser(Page page)throws UW Px|]RC
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HibernateException; / &em%/
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} _=K\E0I.m
uyoV)
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java代码: m' eM&1Ba
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/*Created on 2005-7-15*/ ^V"08
package com.adt.service.impl; 2E.D0E Cu
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import java.util.List; ^qtJcMK+hq
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