Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 4BpZJ~(p
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 K[zVa
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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 Pa:|_IXA
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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 Wmv#:U
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分页支持类: U| R_OLWAg
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java代码: 8Z=R)asGS
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package com.javaeye.common.util; 8zW2zkv2|#
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import java.util.List; =Nr-iae#
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publicclass PaginationSupport { [v!f<zSQK
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publicfinalstaticint PAGESIZE = 30; 19%imf
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privateint pageSize = PAGESIZE; 0?|<I{z2
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privateList items; }W^A*]X
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privateint totalCount; F#5~M<`.o
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privateint[] indexes = newint[0]; >Y@H4LF;1x
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privateint startIndex = 0; z},# ~L6$q
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public PaginationSupport(List items, int ^E>3|du]O
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totalCount){ 7D_=
setPageSize(PAGESIZE); +G>\-tjSD
setTotalCount(totalCount); uHRsFlw
setItems(items); !&@615Vtw
setStartIndex(0); WcbiqxK7-
} +D*Z_Yh6
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public PaginationSupport(List items, int o}p n0KO,
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totalCount, int startIndex){ .O<obq~;C
setPageSize(PAGESIZE); -jmY)(\
setTotalCount(totalCount); ZXPX,~ 5o
setItems(items); p!AAFmc
setStartIndex(startIndex); !C.4<?*|
} sU^1wB
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public PaginationSupport(List items, int [0("Q;Ec[j
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totalCount, int pageSize, int startIndex){ 9H1rO8k
setPageSize(pageSize); @_{=V0
setTotalCount(totalCount); ?:eV%`7
setItems(items); ;5( UzQU
setStartIndex(startIndex); DzRFMYBR
} pT6$DB#
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publicList getItems(){ ,|/f`Pl
return items; X2'0PXv>!
} &mM0AA'\?H
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publicvoid setItems(List items){ +&H4m=D-#a
this.items = items; E' uZA
} ` 5>b:3
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publicint getPageSize(){ hOK8(U0
return pageSize; n~Lt\K:
} *lJxH8 \
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publicvoid setPageSize(int pageSize){ m.0*NW
this.pageSize = pageSize; u:
} ;722\y(Y
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publicint getTotalCount(){ +1!ia]
return totalCount; >+T)#.wo&
} f*
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publicvoid setTotalCount(int totalCount){ b|(:[nB
if(totalCount > 0){ |JsZJ9W+J
this.totalCount = totalCount; Y}KNKO;
int count = totalCount / `kSZX:=};
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pageSize; RT8 ?7xFc
if(totalCount % pageSize > 0) G^@5H/)
count++; M )(DZ}
indexes = newint[count]; Z4bNV?OH
for(int i = 0; i < count; i++){ LFV%&y|L
indexes = pageSize * b\,+f n
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i; wb ;xRP"w
} qmP].sA
}else{ ]eV8b*d6
this.totalCount = 0; K:WDl;8(d
} 'Z]w^<
} g0E'g
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publicint[] getIndexes(){ :rP=t ,
return indexes; asqV~n
} e+=K d+:k
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publicvoid setIndexes(int[] indexes){ $<OD31T
this.indexes = indexes; tQ601H>o
} !H\F2Vxs
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publicint getStartIndex(){ ^=*;X;7
return startIndex; ]I6 J7A[
} &xExyz~`
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publicvoid setStartIndex(int startIndex){ lk =<A"^S
if(totalCount <= 0) 8xMX
this.startIndex = 0; vw@S>GlGg
elseif(startIndex >= totalCount) NCD04U5y
this.startIndex = indexes dgP3@`YS
#p{4^
[indexes.length - 1]; uEx-]F
elseif(startIndex < 0) YchH~m|
this.startIndex = 0; _','9|
else{ {\\Tgs
this.startIndex = indexes U%/+B]6jP
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[startIndex / pageSize]; f,Ghb~y
} !TcJ)0
} bN=P*hdf
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publicint getNextIndex(){ &6k3*dq
int nextIndex = getStartIndex() + 7PF%76TO
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pageSize; 8l">cVo]T
if(nextIndex >= totalCount) [.}oyz;}N
return getStartIndex(); ;O#>Y
else T6kdS]4-
return nextIndex; ]K%!@O!
} ]JR +ayk7
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publicint getPreviousIndex(){ OB}Ib]
int previousIndex = getStartIndex() - yF/j Fn
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pageSize; .o}v#W+st
if(previousIndex < 0) wS3'?PRX
return0; .tr!(O],h
else H%lVl8oQ
return previousIndex; W(/h Vt
} HLi%%"'
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} CTA3*Gn
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抽象业务类 #)VF3T@#'
java代码: a-J.B.A$Z/
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/** -|9=P\U8S
* Created on 2005-7-12 \lNN Msd&
*/ M"To&?OI
package com.javaeye.common.business; |e0`nn=
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import java.io.Serializable; PTV:IzoW
import java.util.List; Ef{Vp;]
9(<@O%YU
import org.hibernate.Criteria; 2I{"XB
import org.hibernate.HibernateException; pI<f) r
import org.hibernate.Session; l}M!8:UzU
import org.hibernate.criterion.DetachedCriteria; 1m0c|ckb
import org.hibernate.criterion.Projections; Z<{QaY$"
import dUdT7ixo
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org.springframework.orm.hibernate3.HibernateCallback; )Xyn
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import 11;zNjD|
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org.springframework.orm.hibernate3.support.HibernateDaoS oe~b}:
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upport; P0jtp7)7
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import com.javaeye.common.util.PaginationSupport; 6;5Ss?ep
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public abstract class AbstractManager extends Rbv;?'O$L
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HibernateDaoSupport { Z;)%%V%o
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privateboolean cacheQueries = false; BING{ew
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privateString queryCacheRegion; LBP`hK:>W~
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publicvoid setCacheQueries(boolean Yc*;/T}
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cacheQueries){ BTrn0
this.cacheQueries = cacheQueries; ]5:8Z@
} )dd@\n$6
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publicvoid setQueryCacheRegion(String koi^l`B$
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queryCacheRegion){ 63 B?.
this.queryCacheRegion = &b& ,
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queryCacheRegion; y4fdq7i~}9
} 9=2$8JN=(l
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publicvoid save(finalObject entity){ b>JDH1)
getHibernateTemplate().save(entity); qJUK_6|3
} NQ2E
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publicvoid persist(finalObject entity){ $ L]lHji
getHibernateTemplate().save(entity); ~61v5@
} KKf
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publicvoid update(finalObject entity){ uM6+?A9@l
getHibernateTemplate().update(entity); E-g_".agO
} `*KHSA
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publicvoid delete(finalObject entity){ v|2T%y_
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getHibernateTemplate().delete(entity); iAU@Yg`pt
} =w0R$&b&
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publicObject load(finalClass entity, bA->{OPkT
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finalSerializable id){ {Y9q[D'g .
return getHibernateTemplate().load 7D5]G-}x.
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(entity, id); i
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} Pgea NK5Y
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publicObject get(finalClass entity, 6!FQzFCZq
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finalSerializable id){ I~XSn>-H
return getHibernateTemplate().get S{m%H{A!
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(entity, id); PwLZkr@4^
} -3Vx76Y
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publicList findAll(finalClass entity){ '!$Rw"K.
return getHibernateTemplate().find("from c!9nnTap
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" + entity.getName()); @;RXLq/8
} V~5jfcd
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publicList findByNamedQuery(finalString vRO
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namedQuery){ d>C$+v>
return getHibernateTemplate 'b{]:Y
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().findByNamedQuery(namedQuery); _5N]B|cO
} N?"]
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publicList findByNamedQuery(finalString query, kPLxEwl
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finalObject parameter){ +; AZ+w]ZF
return getHibernateTemplate @I!0-OjL
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().findByNamedQuery(query, parameter); ,01"SWE
} ?.;c$'
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publicList findByNamedQuery(finalString query, [HZv8HU|
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finalObject[] parameters){ &KRX[2
return getHibernateTemplate Npy:!
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().findByNamedQuery(query, parameters); JcxThZP~
} 9zy!Fq
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publicList find(finalString query){ TbW38\>.R
return getHibernateTemplate().find jtc]>]6i
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(query); g7W"
} |8tilOqI
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publicList find(finalString query, finalObject j#q-^h3H
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parameter){ A2jUmK.&
return getHibernateTemplate().find q5)O%l !
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(query, parameter); [K0(RDV)%
} K(,F~.<
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public PaginationSupport findPageByCriteria N5b!.B x-w
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(final DetachedCriteria detachedCriteria){ @r/nF5
return findPageByCriteria b}TS0+TF
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); wEvVL
} ?+}_1x`
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public PaginationSupport findPageByCriteria + @s"zp;F
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(final DetachedCriteria detachedCriteria, finalint bAtSV u
7! INkH]
startIndex){ 5taT5?n2
return findPageByCriteria
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(detachedCriteria, PaginationSupport.PAGESIZE, ExL0?FemWV
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startIndex); -4{<=y?"a
} LuvY<~u
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public PaginationSupport findPageByCriteria .jjG(L
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(final DetachedCriteria detachedCriteria, finalint P:MT*ra*,
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pageSize, mSl.mi(JiZ
finalint startIndex){ Trz@~d/[,n
return(PaginationSupport) |imM#wF
hy"\RW
getHibernateTemplate().execute(new HibernateCallback(){ 0[?Xxk}s0
publicObject doInHibernate <k'h:KB?`
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(Session session)throws HibernateException { :(*V?WI
Criteria criteria = K:#I
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detachedCriteria.getExecutableCriteria(session); =R$u[~Xl2X
int totalCount = @>Km_Ax
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((Integer) criteria.setProjection(Projections.rowCount ^ Q ?
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()).uniqueResult()).intValue(); _H7x9
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criteria.setProjection #( 146
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(null); ra
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List items = O`t&ldU
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criteria.setFirstResult(startIndex).setMaxResults p}pjfG
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(pageSize).list(); qHlQ+:n
PaginationSupport ps = . ~~T\rmI
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new PaginationSupport(items, totalCount, pageSize, 7CURhDdk
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startIndex); ^EQ<SCh
return ps; F8,RXlGfA[
} ,G?WAOy,
}, true); lE(HFal0-(
} tpQ(g%
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public List findAllByCriteria(final bI9~jWgGp
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DetachedCriteria detachedCriteria){ Zaf:fsj>
return(List) getHibernateTemplate jZkcBIK2
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().execute(new HibernateCallback(){ LxSpctiNx
publicObject doInHibernate !")tU+:
6Vnsi%{
(Session session)throws HibernateException { Nkth>7*
Criteria criteria = W/bQd)Jvk
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detachedCriteria.getExecutableCriteria(session); Q6!zZ))~
return criteria.list(); sfugY(m
} z3m85F%dR
}, true); WUXx;9 >
} o&)8o5
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public int getCountByCriteria(final 6@F9G4<Z
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DetachedCriteria detachedCriteria){ 17"uf.G
Integer count = (Integer) N gGp
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getHibernateTemplate().execute(new HibernateCallback(){ Ma']?Rb`
publicObject doInHibernate S3*`jF>q
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(Session session)throws HibernateException { a;qryUyG
Criteria criteria = =M[bnq*\
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detachedCriteria.getExecutableCriteria(session); jTtu0Q|
return .*S#aq4S
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criteria.setProjection(Projections.rowCount &4x}ppX
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()).uniqueResult(); 'ud{m[|
} x$.^"l-vX
}, true); L;NvcUFn
return count.intValue(); yT"Eq"7/Y#
} '/n1IM$7
} ;yLu R
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用户在web层构造查询条件detachedCriteria,和可选的 y@: h4u"3
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 .* ?wF
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PaginationSupport的实例ps。 ):6 8%,
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ps.getItems()得到已分页好的结果集 tGh~!|P
ps.getIndexes()得到分页索引的数组 aFb==73aLw
ps.getTotalCount()得到总结果数 .B]MpmpK
ps.getStartIndex()当前分页索引 bz2ztH9 n
ps.getNextIndex()下一页索引 pnowy;
ps.getPreviousIndex()上一页索引 #@9/g
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 t?x<g <PJ4
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 r6MMCJ|G
;4^Rx
一下代码重构了。 fF$<7O)+]
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我把原本我的做法也提供出来供大家讨论吧: 7Oa#c<2]
g1/[eoZzk
首先,为了实现分页查询,我封装了一个Page类: vv3*
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java代码: 0d"[l@UU0
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/*Created on 2005-4-14*/ mPtZO*Fc
package org.flyware.util.page; EyD=q! ZVZ
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/** jk; clwyz/
* @author Joa +,TRfP
Fb
* 85 |OGtt
*/ 8>2.UrC
publicclass Page { j9x<Y]
h5{'Q$Erl
/** imply if the page has previous page */ 1MP~dRZ$
privateboolean hasPrePage; xd q?/^E
L%*!`TN
/** imply if the page has next page */ hYT0l$Ng
privateboolean hasNextPage; W#4 7h7M
@; zl
/** the number of every page */ w;[NH/A^a
privateint everyPage; [fya)}
@Q
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/** the total page number */ 7 S#J>*
privateint totalPage; UqFO|r"M
LEbB(x;@
/** the number of current page */ KQaxvU)L
privateint currentPage; @w#-aGJO
q1$N>;&
/** the begin index of the records by the current p*R;hU
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query */ $<dH?%!7
privateint beginIndex; UN;H+gNnN
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/** The default constructor */ fnjPSts0
public Page(){ :j9l"5"
<Dl*l{zba
} VuhGx:Xl
*KZYv=s,u
/** construct the page by everyPage M)J5;^["
* @param everyPage 9-VNp;V
* */ -j#2}[J7
public Page(int everyPage){ iW]j9} t
this.everyPage = everyPage; v}}F,c(f
} :}L[sl\R
ajbA\/\G;
/** The whole constructor */ 3Gp$a;g
public Page(boolean hasPrePage, boolean hasNextPage, '1P2$#
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int everyPage, int totalPage, ~RW+GTe
int currentPage, int beginIndex){ |B?m,U$A!
this.hasPrePage = hasPrePage; AP n| \
this.hasNextPage = hasNextPage; h0*!;Z7
this.everyPage = everyPage; u:6Ic)7'
this.totalPage = totalPage; 59LZv-l
this.currentPage = currentPage; )al]*[lY
this.beginIndex = beginIndex; VZp5)-!\
} !_]Y~[
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/** 2@n{yYwy
* @return [`#CXq'
* Returns the beginIndex. @wGPqg
*/ SB;&GHq"n
publicint getBeginIndex(){ e/KDw
return beginIndex; !fV+z%:
} Avge eJi
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/** IA fcT!{
* @param beginIndex 1*P~!2h
* The beginIndex to set. .wEd"A&j
*/ *<$*"p
publicvoid setBeginIndex(int beginIndex){ SXSgld2uS
this.beginIndex = beginIndex; I13y6= d
} & TCkpS
zq3\}9
/** }kw#7m54
* @return @+&LYy72
* Returns the currentPage. DTX0
*/ DzAg"6=CS
publicint getCurrentPage(){ yJ[0WY8<kC
return currentPage; QGMV}y
} <O(4TO
|%BOZT
/** 70yFaW
* @param currentPage fF!Yp iI"
* The currentPage to set. h/QXPdV
*/ qJf?o.Pv
publicvoid setCurrentPage(int currentPage){ poc`q5i+
this.currentPage = currentPage; -mbt4w
} w1FcB$
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/** u4*BX&
* @return U45e2~1!O
* Returns the everyPage. $!-yr7
*/ k90YV(
publicint getEveryPage(){ W-$Z(Z
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return everyPage; ")1:F>
} *l(7D(#
WJ]T\DI
/** *[Imn\hu
* @param everyPage H9Gh>u]}
* The everyPage to set. R)?*N@.s
*/ 0gu_yg! R
publicvoid setEveryPage(int everyPage){ vRYQ{:
this.everyPage = everyPage; >1X|^
} F0m-23[H
[@_Jj3`4
/** cRC6 s8
* @return +X\FBvP&
* Returns the hasNextPage. c^5~QGuQ
*/ vJLK,[
publicboolean getHasNextPage(){ s2a{>II6
return hasNextPage; {Ea
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} xf'V{9*
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/** ,Y@Gyx!4
* @param hasNextPage a)!o @
* The hasNextPage to set. p
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*/ #]-SJWf3
publicvoid setHasNextPage(boolean hasNextPage){ lPe&h]@ >
this.hasNextPage = hasNextPage; JB\UKZXw
} p0]=QH
mwO6g~@`
/** ^23~ZHu
* @return m%0p\Y-/
* Returns the hasPrePage. 9v#CE!
*/ 7:e{;iG
publicboolean getHasPrePage(){ b8H{8{wi|
return hasPrePage; 0RzEY!9g+
} 6u?>M9
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/** gZVc 5u<
* @param hasPrePage &L3M]
* The hasPrePage to set. "6A
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*/ {aZ0;
publicvoid setHasPrePage(boolean hasPrePage){ RCJ|P~*
this.hasPrePage = hasPrePage; IM*y|UHt
} g/4[N{Xf
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/** \-E^lIVF
* @return Returns the totalPage. ??5Q)Erm1
* pG_;$8Hc
*/ k``_EiV4t
publicint getTotalPage(){ yER(6V'\iQ
return totalPage; >k|5Okq g
} ]43/`FX
L]7=?vN=8
/** />C^WQI^
* @param totalPage 53_Hl]#qZ
* The totalPage to set. "%)qRe
*/ \Zk;ikEY
publicvoid setTotalPage(int totalPage){ cUk7i`M;6
this.totalPage = totalPage; `Uq#W+r,
} aNsBcov3O
7lTC{7C57
} ~ZaY!(R<
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 *YI98
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个PageUtil,负责对Page对象进行构造: #Bze,?@
java代码: UhF-K#Z9
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/*Created on 2005-4-14*/ RIR\']WN
package org.flyware.util.page; _1X!EH"
q$L%36u~/
import org.apache.commons.logging.Log; '$Dn
import org.apache.commons.logging.LogFactory; 2B1q*`6R
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/** 85= )lu
* @author Joa rCEyQ)R_}
* !"AvY y9
*/ m~BAyk^jo3
publicclass PageUtil { F-Qzrqu S
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privatestaticfinal Log logger = LogFactory.getLog 8bGd} (
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(PageUtil.class); E*&vy
Ha#=(9.
/** d2FswF$C
* Use the origin page to create a new page pp?D7S
* @param page m[osg< CR_
* @param totalRecords TvoyZW\?w
* @return >-?f0K
*/ E,Z$pKL?
publicstatic Page createPage(Page page, int XTs8s12
_~m5^Q&
totalRecords){ L<c4kw
return createPage(page.getEveryPage(), t|?ez4/{z
j a[Et/r
page.getCurrentPage(), totalRecords); k?yoQL*
} y8y5*e~A-)
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/** Cl.x'v
* the basic page utils not including exception !<|4C6X:4
sfH_5
#w
handler 5&g@3j]
* @param everyPage Oamg]ST
* @param currentPage W-f=]eWg
* @param totalRecords f^ZRT@`O
* @return page &;6`)M{*}
*/ 1UgEI"#a6g
publicstatic Page createPage(int everyPage, int `cn#B
BV
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currentPage, int totalRecords){ k8yEdi`
everyPage = getEveryPage(everyPage); Eh`7X=Z7E
currentPage = getCurrentPage(currentPage); Ufj`euY
int beginIndex = getBeginIndex(everyPage, 9)yJ:
N#F
.~db4d]
currentPage); KM0ru
int totalPage = getTotalPage(everyPage, L<S9
wo}H'Q}Hj
totalRecords); }v;V=%N+v
boolean hasNextPage = hasNextPage(currentPage, '6`3(TK.a
yf)%%&
totalPage); 3Aip}<1
boolean hasPrePage = hasPrePage(currentPage); Mexk~zA^
;a!S!%.h
returnnew Page(hasPrePage, hasNextPage, S>+|OCl";
everyPage, totalPage, hNiE\x
currentPage, ^#-l
q)
@s>Czm5
beginIndex); D8Ic?:iX[
} dbLZc$vPj
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privatestaticint getEveryPage(int everyPage){ YDsb3X<0'
return everyPage == 0 ? 10 : everyPage; iU918!!N
} LP^$AAy
z
kP_6T09
privatestaticint getCurrentPage(int currentPage){ f5"k55 }
return currentPage == 0 ? 1 : currentPage; )}R0Y=e
} ~NgA
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privatestaticint getBeginIndex(int everyPage, int BZ#(
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currentPage){ pad*oPH,
return(currentPage - 1) * everyPage; s+Pq&<nV-
} "^[ 'y7i
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privatestaticint getTotalPage(int everyPage, int NYUL:Tp
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totalRecords){ 7"D",1h
int totalPage = 0; ]%SH>
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if(totalRecords % everyPage == 0) _ye |Y
totalPage = totalRecords / everyPage; /N+dQe
else q$UJ$7=f8
totalPage = totalRecords / everyPage + 1 ; 6v!`1}
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return totalPage; "cGk)s
} 0o4XUW
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privatestaticboolean hasPrePage(int currentPage){ F<1fX 7c
return currentPage == 1 ? false : true; -IudgO]
} qo~O|~
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privatestaticboolean hasNextPage(int currentPage, //MUeTxR
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int totalPage){ h4}84}5d
return currentPage == totalPage || totalPage == X`/k)N>l
3*bU6$|5FP
0 ? false : true; qZh/IW
} =*.~BG
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} ,Vax&n+J
}#+^{P3 ;
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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。 rXq.DvQ
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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 ?R
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xH,a=8&9
做法如下: 7z,C}-q
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Q\vpqE!9
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的信息,和一个结果集List: kH1~k,|\&K
java代码: Kw^ 7>\
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I][*j
/*Created on 2005-6-13*/ Lb-OsKU
package com.adt.bo; Ee#q9Cx^J
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import java.util.List; }v{LRRi
3 \,4 ]l|
import org.flyware.util.page.Page; 7EEl+;wK
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/** G!##X: 6'
* @author Joa gJ+'W1$/
*/ Y|qTyE%
publicclass Result { ?j.,Nw4FC
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private Page page; 3,w_".m`#
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private List content; 1GRCV8"Z^
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/** M3y NAN
* The default constructor 1&OW4_
*/ q
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public Result(){ RB\uK
1+
super(); :OZrH<SW
} _f,C[C[e&
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/** T>Z<]s
* The constructor using fields 0mVNQxHI
* \@zHON(
* @param page ;(%QD
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* @param content Ax@$+/Z!
*/ ~~P5k:
public Result(Page page, List content){ kTB0b*V
this.page = page; Om@;J%u/
this.content = content; 5DZ#9m/
} gD?l-RT>
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/** dT8S~-d%
* @return Returns the content. X?',n
1
*/ }.(B}/$u
publicList getContent(){ bJ%h53
return content; +sA2WK]
} |df Pki{
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/** 3hH<T.@)
* @return Returns the page. _H%c;z+
*/ B 3I`40#
public Page getPage(){ `h\j99
return page; ioCsV
} / SB;Von
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/** 'H!Uh]!
* @param content !pW0qX\1n
* The content to set. _{KG
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*/ ND;#7/$>
public void setContent(List content){ m(!FHPvN
this.content = content; Fxz"DZY6
} fr3d
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/** eym4=k ~
* @param page "8MF_Gu):
* The page to set. 7$=InK
*/ M }D}K\)
publicvoid setPage(Page page){ 2ilQXy
this.page = page; vE?G7%,
} aFYIM`?(
} oc`H}Wvn
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3 0H?KAV
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2. 编写业务逻辑接口,并实现它(UserManager, o*H<KaX
EQM{
UserManagerImpl) T8g$uFo
java代码: /x$ nje,.
=H8;iS2R
6&x@.1('z
/*Created on 2005-7-15*/ 7:1Lol-V
package com.adt.service; ZE}}W_
:I#V.
import net.sf.hibernate.HibernateException; &QgR*,5eo
SJ,v?=S!
import org.flyware.util.page.Page; C'x&Py/#
:o3N;*o>)0
import com.adt.bo.Result; l_p2Riv
,J@
/** GTd,n=
* @author Joa .k !{*
*/ {wKB;?fUvk
publicinterface UserManager { { <