Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ^h4Q2Mv o
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 +w%MwPC7`
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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 rM_8piD
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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`yS'
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分页支持类: _ N.ZpKVu
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java代码: rnEWTk7&
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package com.javaeye.common.util; L#m1!+J
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import java.util.List; CdC&y}u
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publicclass PaginationSupport { }#a d
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publicfinalstaticint PAGESIZE = 30; N=)N
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privateint pageSize = PAGESIZE; GyRU/0'BME
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privateList items; ro|dB
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privateint totalCount; svHs&v
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privateint[] indexes = newint[0]; 6psK2d0
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privateint startIndex = 0; w)5eD+n\-
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public PaginationSupport(List items, int !n@Yg2 w
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totalCount){ ikw_t?
setPageSize(PAGESIZE); #q6jE
setTotalCount(totalCount); 3K_J"B*7
setItems(items); ,4)zn6tC
setStartIndex(0); !J3g, p*
} l)4KX{Rz{A
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public PaginationSupport(List items, int j_j~BXhIS
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totalCount, int startIndex){ 6L}$R`s5H
setPageSize(PAGESIZE); Kj;Q;Ii
setTotalCount(totalCount); !c[?$#W4
setItems(items); 1I<fp $h
setStartIndex(startIndex); Cevl#c5p>
} ~Yb5FYE
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public PaginationSupport(List items, int T9}G:6
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totalCount, int pageSize, int startIndex){ |p-, B>p!
setPageSize(pageSize); a{GPAzO+
setTotalCount(totalCount); hV)D,oN3
setItems(items); C-V,3}=*2
setStartIndex(startIndex); |~Z.l
} O@ F0UM`!
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publicList getItems(){ NhU~'k
return items; *GH`u*C_
} *%=BcV+,
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publicvoid setItems(List items){ )+OI}
this.items = items; +C' u!^)
} o:W>7~$jr=
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publicint getPageSize(){ idPx!
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return pageSize; A,Wwt
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} ;6KcX \g-
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publicvoid setPageSize(int pageSize){ NTbmI$(
this.pageSize = pageSize; ]bLI!2Kr
} u!hY
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publicint getTotalCount(){ :PE{2*
return totalCount; HkVnTC
} Tty_P,
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publicvoid setTotalCount(int totalCount){ #^4p(eZ[}
if(totalCount > 0){ _kg<KD=P
this.totalCount = totalCount; %UT5KYd!=N
int count = totalCount / _2xNio&
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pageSize; z6)b XL[f
if(totalCount % pageSize > 0) *:gx1wd
count++; t~]n"zgovz
indexes = newint[count]; rofj&{w
for(int i = 0; i < count; i++){ `u$
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indexes = pageSize * H=RzY-\a%
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} Z}#'.y\ f
}else{ zisf8x7^W
this.totalCount = 0; .ZQD`SRrI
} "{(|}Cds
} Heh.CD)Q
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publicint[] getIndexes(){ >9dzl#
return indexes; 17P5Dr&
} q)te/J@
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publicvoid setIndexes(int[] indexes){ D+m#_'ocL
this.indexes = indexes; _/V<iv
} KCP$i@Pjv
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publicint getStartIndex(){ M$_E:u&D
return startIndex; 5|O~
} fE`p
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publicvoid setStartIndex(int startIndex){ f#mNx
if(totalCount <= 0) xB-\yWDZe
this.startIndex = 0; k;/K']4y
elseif(startIndex >= totalCount) TWE>"8]
this.startIndex = indexes 2iM]t&^<+
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[indexes.length - 1]; vT@*o=I
elseif(startIndex < 0) [l44,!Z&
this.startIndex = 0; E$SYXe [,
else{ 2_T2?weD5
this.startIndex = indexes Ig&H0S
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[startIndex / pageSize]; Nm$Ba.Rg
} abMB-
} @};
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publicint getNextIndex(){ >AK9F.
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int nextIndex = getStartIndex() + )j,Y(V$P
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pageSize; f/xQy}4+~E
if(nextIndex >= totalCount) i4T=4q
return getStartIndex(); n( RQre
else `PY=B$?{4
return nextIndex; FEY_(70
} [=<vapZt
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publicint getPreviousIndex(){ S)LvYOOB@
int previousIndex = getStartIndex() - nA*Udrcn
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pageSize; Nk63F&J7e
if(previousIndex < 0) *^y,Gg/
return0; 68*a'0
else gn//]|#H+
return previousIndex; A@uU*]TqJ8
} f/7on|bv
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} qu\cU(H|
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抽象业务类 G&Fe2&5!w
java代码: rU4;yy*b
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/** #| pn,/
* Created on 2005-7-12 !;3hN$5
*/ Y`N w E
package com.javaeye.common.business; ?e{hidg
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import java.io.Serializable; }~NM\rm
import java.util.List; gmqA 5W~y
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import org.hibernate.Criteria; Qli#=0{`
import org.hibernate.HibernateException; XX7zm_>+
import org.hibernate.Session; C'~Eq3
import org.hibernate.criterion.DetachedCriteria; lVv'_9yg
import org.hibernate.criterion.Projections; YsO3( HS
import q nb#~=x^
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org.springframework.orm.hibernate3.HibernateCallback; &w!(.uDO
import 8]K+,0m6
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org.springframework.orm.hibernate3.support.HibernateDaoS Tw,|ZA4XH
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upport; A$g'/QM
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import com.javaeye.common.util.PaginationSupport; S
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public abstract class AbstractManager extends \G0YLV~>P
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HibernateDaoSupport { {uDH-b(R
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privateboolean cacheQueries = false; 8-_atL
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privateString queryCacheRegion; *Sg6VGP
){LU>MW{&
publicvoid setCacheQueries(boolean HvR5-?qQ
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cacheQueries){ ;V?3Hwl
this.cacheQueries = cacheQueries; 2FN E ;y(
} $D='NzE/
*ESi~7;#
publicvoid setQueryCacheRegion(String ]GT+UX
>*/:"!u
queryCacheRegion){ }Ug$d>\
this.queryCacheRegion = +~>cAWZq_
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queryCacheRegion; 1Ep7CV-n}
} SoWMP2/
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publicvoid save(finalObject entity){ uZTbJ3$$
getHibernateTemplate().save(entity); 2KlVj]!7
} &^`[$LtYd
shD4";8*@
publicvoid persist(finalObject entity){ :q >)c]
getHibernateTemplate().save(entity); Quwq_.DU
} J`4V\D}n
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publicvoid update(finalObject entity){ Mp QsM-iW
getHibernateTemplate().update(entity); Dz,|sHCmk
} j0^1BVcj
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publicvoid delete(finalObject entity){
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getHibernateTemplate().delete(entity); O]Ey@7 &
} JXV#V7
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publicObject load(finalClass entity,
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finalSerializable id){ 8=@f lK
return getHibernateTemplate().load NFy V02.
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(entity, id); v.ow`MO=;
} . HN4xL
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publicObject get(finalClass entity, t7yvd7
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finalSerializable id){ i= R%MH+
return getHibernateTemplate().get K8/jfm
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(entity, id); 1+"d-`'Z2O
} qpQiMiB#g'
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publicList findAll(finalClass entity){ Ng1bjq}E2
return getHibernateTemplate().find("from TS`m&N{i")
@EURp
" + entity.getName()); g[' 7 $
} La28%10
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publicList findByNamedQuery(finalString \T[OF8yhW
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namedQuery){ DJ0jtv6nQ-
return getHibernateTemplate n2dOCntN>
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().findByNamedQuery(namedQuery); $VjMd f
} 1Q=L/keP
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publicList findByNamedQuery(finalString query, &1Y7Ne
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finalObject parameter){ WZn"I&Z
return getHibernateTemplate KSJ+3_7]k
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().findByNamedQuery(query, parameter); !u:Fn)j
} He$v'87]
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publicList findByNamedQuery(finalString query, RD0*]4>]
}
@
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finalObject[] parameters){ AQtOTT$
return getHibernateTemplate 2kOaKH[(q
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().findByNamedQuery(query, parameters); OJ7Uh_;/
} L8Q/!+K
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publicList find(finalString query){ x[fp7*TiG
return getHibernateTemplate().find 7L!}F;yT
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(query); nTw:BU4jd
} Bp5%&T k
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publicList find(finalString query, finalObject m;nH
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parameter){ [VLq/lg*
return getHibernateTemplate().find I %sw(uoE
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(query, parameter); q,_EHPc
} N?8nlrDQ
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public PaginationSupport findPageByCriteria 'K}2 m
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(final DetachedCriteria detachedCriteria){ WZjR^6
return findPageByCriteria lYS "
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); vXZP>
} ?%%vQ?
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public PaginationSupport findPageByCriteria ]k BC,m(
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(final DetachedCriteria detachedCriteria, finalint N"0>)tG
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startIndex){ <IBUl}|\
return findPageByCriteria *y(UI/c
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(detachedCriteria, PaginationSupport.PAGESIZE, Pf;RJeD
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startIndex); )iVuac]E++
} TwF.UL@G%
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public PaginationSupport findPageByCriteria "r8N-
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(final DetachedCriteria detachedCriteria, finalint Bs|#7mA[
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pageSize, @$CPTv3e
finalint startIndex){ 6(7dr?^eGT
return(PaginationSupport) ;mr*$Iu 7|
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getHibernateTemplate().execute(new HibernateCallback(){ 8M,z#DF
publicObject doInHibernate bSQj=|h1
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(Session session)throws HibernateException { il"pKQF
Criteria criteria = 4/_!F'j
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detachedCriteria.getExecutableCriteria(session);
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int totalCount = :T>OJ"p
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((Integer) criteria.setProjection(Projections.rowCount n<@C'\j@
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()).uniqueResult()).intValue(); 1(_[awBx
criteria.setProjection Su[(IMw
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(null); @7;}6,)
List items = Q'hs,t1<
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criteria.setFirstResult(startIndex).setMaxResults 5|`./+Ghk
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(pageSize).list(); 2|(lKFkQ
PaginationSupport ps = "\]]?&
eht>4)
new PaginationSupport(items, totalCount, pageSize, [ \%a7ji#
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startIndex); ;TK$?hrv*1
return ps; *(XGNp[0
} bPkz= ^-
}, true); pB]*cd B?
} 32y 9r z
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public List findAllByCriteria(final ^4p$@5zH
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DetachedCriteria detachedCriteria){ H(O|y2
return(List) getHibernateTemplate 0QW;=@)d
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().execute(new HibernateCallback(){ 4Me3{!HJ z
publicObject doInHibernate DMSC(Sz
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(Session session)throws HibernateException { .$Yp~
Criteria criteria = k9NHdi7&2
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detachedCriteria.getExecutableCriteria(session); : w>R|]
return criteria.list(); R((KAl]dL
} i=hA. y`
}, true); NO/5pz}1
} l<(jm{q?u
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public int getCountByCriteria(final S!^I<#d K
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DetachedCriteria detachedCriteria){ Fiw^twz5
Integer count = (Integer) 3Tc90p l*t
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getHibernateTemplate().execute(new HibernateCallback(){ !t{
publicObject doInHibernate JW=q'ibR
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(Session session)throws HibernateException { F}@]Lq+
Criteria criteria = fEtBodA)
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detachedCriteria.getExecutableCriteria(session); `=Bv+
return Jp_ :.4
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criteria.setProjection(Projections.rowCount 2E!Q5 l!j
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()).uniqueResult(); |@f\[v9`
} ICc:k%wE7
}, true); rZ.z!10
return count.intValue(); o,?h}@
} *D`$oK,U
} 6TXTJ]er
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用户在web层构造查询条件detachedCriteria,和可选的 }}"|(2I
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 0xaK"\Q
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PaginationSupport的实例ps。 +Z=y/wY
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ps.getItems()得到已分页好的结果集 r029E-
ps.getIndexes()得到分页索引的数组 0< }BSv
ps.getTotalCount()得到总结果数 ,,Ivey!kL
ps.getStartIndex()当前分页索引 YOA)paq+
ps.getNextIndex()下一页索引 }gE^HH'
ps.getPreviousIndex()上一页索引 <7gv<N6BQf
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 J: I@kM
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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 U8,pe;/ln`
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一下代码重构了。 5ci1ce
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我把原本我的做法也提供出来供大家讨论吧: @%fL*^yr;C
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首先,为了实现分页查询,我封装了一个Page类: >Nx4 +|
java代码: 9;L8%T
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/*Created on 2005-4-14*/ :YLurng/]
package org.flyware.util.page; lB8gD
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/** eax"AmO
* @author Joa HXkXDX9&'.
* ,rNud]NM8
*/ hf7[<I,jov
publicclass Page { +%K~HYN
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/** imply if the page has previous page */ YgjN*8w\
privateboolean hasPrePage; 9o3?
k-)Ls~#+
/** imply if the page has next page */ 2h)Qz+|7
privateboolean hasNextPage; ktp<o.f[
8PWEQ<ev7>
/** the number of every page */ J=HN~B1
privateint everyPage; 0F
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/** the total page number */ e_cK#9+
privateint totalPage; N:Ir63X*#
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/** the number of current page */ \m:('^\6o
privateint currentPage; . lNf.x#u
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/** the begin index of the records by the current Ynp#3 r
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query */ Vjd>j; H
privateint beginIndex; Tk`|{Ph0
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/** The default constructor */ ?I\,RiZkz^
public Page(){ %36@1l-N
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} nyBT4e
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/** construct the page by everyPage 9\0$YY%
* @param everyPage 5Yww,s
* */ oY7jj=z#T
public Page(int everyPage){ tk>J
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this.everyPage = everyPage; M|{NC`fa
} 0s RcA -9
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/** The whole constructor */ :H+8E5
public Page(boolean hasPrePage, boolean hasNextPage, MIh\z7gW
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)lq+Gv[%F
int everyPage, int totalPage, q1m{G1W
n
int currentPage, int beginIndex){ IaU%L6Q]
this.hasPrePage = hasPrePage; &
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this.hasNextPage = hasNextPage; RdNLf
this.everyPage = everyPage; hML-zZ
this.totalPage = totalPage; 0Q)YZ2
this.currentPage = currentPage; }]JHY P\
this.beginIndex = beginIndex; aM(x--UR=
} \xQu*M:!
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/** +oL@pp0
* @return \1QY=}
* Returns the beginIndex. *kEzGgTzoS
*/ :+ "H h%
publicint getBeginIndex(){ \NKQ:F1
return beginIndex; c5:X$k\
} Z[eWey_
2<n@%'OQp
/** aPQxpK?
* @param beginIndex qv'w 7T
* The beginIndex to set. %Y>E
*/ &So1;RR,_M
publicvoid setBeginIndex(int beginIndex){ y0~ttfv
this.beginIndex = beginIndex;
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} dlIYzO<
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/** @PctBS<s
* @return (NN;1{DB8
* Returns the currentPage. RgZ9ZrE\
*/ L0GQH;Y,h
publicint getCurrentPage(){ "fW
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return currentPage; DJAKF
} TQ5kM
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/** 3rjKwh7
* @param currentPage Y*S:/b~y
* The currentPage to set. U3Z-1G~*r
*/ kg\8 (@h]
publicvoid setCurrentPage(int currentPage){ BRM!g9
this.currentPage = currentPage; W|y;Kxy
} 5pK
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/** Hmnxmgx
* @return {^1''
* Returns the everyPage. AWKJ@&pA9m
*/ > >KCd
publicint getEveryPage(){ Ps{vN
~}
return everyPage; *[|+5LVn
} tw&v@HUP
5$+ssR_?k
/** iRbe$v&N
* @param everyPage *>1^q9M
* The everyPage to set. 't5`Ni
*/ m^=El7+
publicvoid setEveryPage(int everyPage){ N/--6)5~0
this.everyPage = everyPage; T[#q0bv
} y%spI/(
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/** " 0m4&K(3,
* @return 1j:aGj>{
* Returns the hasNextPage. t,IOq[Vtk
*/ 8ZLHN',
publicboolean getHasNextPage(){ xV
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return hasNextPage; 7D4tuXUq2
} NzTF2ve(
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/** Z#bO}!
* @param hasNextPage D W^Zuu/)
* The hasNextPage to set. ,wXmJ)/WZ
*/ )*S:C
publicvoid setHasNextPage(boolean hasNextPage){ Kf*Dy:e
this.hasNextPage = hasNextPage; ^$sqU
} 6bLn8UT
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/** :9Jy/7/
* @return /zoy,t-i
* Returns the hasPrePage. ??U/Qi180
*/ \"Y,1in#
publicboolean getHasPrePage(){ RjVmHhX
return hasPrePage; |_>^vW1f
} q=V'pML
x!\q69nd v
/** PMV,*`"9"A
* @param hasPrePage RtzSe$O
* The hasPrePage to set. |ns?c0rM
*/ )>S,#_e*b
publicvoid setHasPrePage(boolean hasPrePage){ M
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this.hasPrePage = hasPrePage; R&J?XQ
} }v4dOGc?
e,MsF4'
/** ;R[3nb9%
* @return Returns the totalPage. kS:#|yY8%
* ?Rx(@
*/ \7"|'fz
publicint getTotalPage(){ qc5[e
return totalPage; #j=yQrJ
} G{E`5KIvm
v{fcQb
/** i i-AE L
* @param totalPage >3Q|k{97
* The totalPage to set. y!.jpF'uI
*/ \r[u>7I
publicvoid setTotalPage(int totalPage){ IT&,?u%
this.totalPage = totalPage; %S}uCqcAK
} 6/Xs}[iJ
1/2cb-V
} ~IS8DW$;
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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 OmO#} k<
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个PageUtil,负责对Page对象进行构造: "cPg_-n
java代码: z+yIP ?s}(
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/*Created on 2005-4-14*/ W%-XN
package org.flyware.util.page; U/QgO
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import org.apache.commons.logging.Log; rUj\F9*5#
import org.apache.commons.logging.LogFactory; ]b!n ;{5
-` U|5
/** EZ]4cd/i
* @author Joa EN2SI+
* vjlN@
"
*/ Q>Zc
eJ;
publicclass PageUtil { /uj^w&l#
*}d N.IL,
privatestaticfinal Log logger = LogFactory.getLog ,T<JNd'
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(PageUtil.class); 0)332}Oh
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/**
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* Use the origin page to create a new page +*:mKx@Nw
* @param page /[.V( K
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* @param totalRecords !S#3mT-
* @return 4JAz{aw'b
*/ . : Wf>:
publicstatic Page createPage(Page page, int
j)?M
)hXTgUZa
totalRecords){ Gl1XRNyC
return createPage(page.getEveryPage(), *;Mi/^pzK
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page.getCurrentPage(), totalRecords); VAz4@r7hkq
} gHrs|6q9
^H3N1eC,`F
/** &uK(. @
* the basic page utils not including exception 6*q1%rs:w
^{4BcM7eH
handler =cS&>MT
* @param everyPage jtP*C_Scv/
* @param currentPage :ZV|8xI
* @param totalRecords d+D~NA[M
* @return page oLT#'42+H
*/ L7-BuW}&
publicstatic Page createPage(int everyPage, int 1
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currentPage, int totalRecords){ ~oa}gJl:}-
everyPage = getEveryPage(everyPage); -WlYHW
currentPage = getCurrentPage(currentPage); c$Kc,`2m7
int beginIndex = getBeginIndex(everyPage, o utJ/~9;
?,>3uD#
currentPage); lFjz*g2'
int totalPage = getTotalPage(everyPage, d Fy$ w=
s5nw<V9$]
totalRecords); -3{Q`@F
boolean hasNextPage = hasNextPage(currentPage, Hd|[>4 Z
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totalPage); k&ci5MpN
boolean hasPrePage = hasPrePage(currentPage); &zdS9e-fF
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returnnew Page(hasPrePage, hasNextPage, | ys5.|
everyPage, totalPage, H5}61 JC/z
currentPage, 'f\9'v
g"m'
C6;
beginIndex); Zv;nY7B
} mqZH<.mn
hCcI]#S&
privatestaticint getEveryPage(int everyPage){ /iU<\+ H
return everyPage == 0 ? 10 : everyPage; TTz=*t+D
} ]y_:+SHc
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privatestaticint getCurrentPage(int currentPage){ A@}5'LzL
return currentPage == 0 ? 1 : currentPage; J\L'HIs
} Vp/XVyL}R
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privatestaticint getBeginIndex(int everyPage, int :y-;V
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currentPage){ >G6kF!V
return(currentPage - 1) * everyPage; SGWb*grt
} ]<;7ZNG"Y5
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privatestaticint getTotalPage(int everyPage, int NfV|c~?d
v -}f
P
totalRecords){ d @R7b^#g
int totalPage = 0; P0l
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if(totalRecords % everyPage == 0) \f9WpAY
totalPage = totalRecords / everyPage; |]?f6^|4
else F1#{(uW
totalPage = totalRecords / everyPage + 1 ; {r_HcI(h
0;bdwIP3
return totalPage; ,a #>e
} }dkXRce*
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privatestaticboolean hasPrePage(int currentPage){ wpK1nA+7N
return currentPage == 1 ? false : true; ,1sbY!&ekL
} yYP_TuNa
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privatestaticboolean hasNextPage(int currentPage, qLEYBv-3
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int totalPage){ ^Ps!
return currentPage == totalPage || totalPage == >+M[!;m}
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0 ? false : true; jY=y<R_oK
} J&A1]T4d
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} &
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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。 >(RkoExO/
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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 w+)${|N?
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做法如下: .LDZqWr-
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 KuJ)alD;1
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的信息,和一个结果集List: 1-y8Hy_a2
java代码: 6>]_H(z7
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cGV%=N^BE<
/*Created on 2005-6-13*/ 2IB{FO/
package com.adt.bo; p1UloG\
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import java.util.List; 0s;~9>
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import org.flyware.util.page.Page; _.s,gX
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/** UR'[?
* @author Joa u@_|4Bp,"
*/ M/o?D <'
publicclass Result { BN 9e S
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private Page page; x=DxD&I!J
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private List content; lh;fqn`
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/**
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* The default constructor +xYu@r%R
*/ YS|Dw'%g /
public Result(){ $Tbsre\MJ
super(); 5;)^o3X>
} UT3Fi@
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/** EE"8s7ZF
* The constructor using fields l[E^nh>
* h.Qk{v
* @param page 7!J-/#!
* @param content Jqxd92 bI
*/ "1a;);S=*)
public Result(Page page, List content){ |ke0G
this.page = page; -64lf-<
this.content = content; (_pw\zk>
} g (w/
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/** n-9xfn0U~#
* @return Returns the content. XM\\Imw
*/ >w.;A%|N
publicList getContent(){ do8[wej<:
return content; /r7xA}se^
} ?}Zo~]7E
# xO PF9
/** R'gd/.[e
* @return Returns the page. j@4MV^F2c
*/ _[[0rn$
public Page getPage(){ %IO*(5f
return page; 4Fp[94b
} DdR0u0JH0
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/** Zn9u&!T&
* @param content gKb,Vrt
* The content to set. 63E6nW M
*/ $#rkvG_w
public void setContent(List content){ qm=U<'b^
this.content = content; h3`}{
w
} ,>B11Z}PH
Z
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/** UNDl&C2vz
* @param page p$,G`'l
* The page to set. }# s{."
*/ Rw'}>?k]
publicvoid setPage(Page page){ 8&EJ.CQ
this.page = page; 3k'Bje?9~
} N}#Rw2Vl
} Q"I(3 tp9[
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kN/YnY*J<
,=+t2Bn
uB)q1QQsqp
2. 编写业务逻辑接口,并实现它(UserManager, T7nI/y
LzL)qdL
UserManagerImpl) Pg}QRCB@
java代码: 1o&z