Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ^"3\iA:
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 "pt+Fe|@c;
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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 16"#i
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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 cVO,~I\\
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。
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分页支持类: V,V*30K5
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java代码: }$o*
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package com.javaeye.common.util; Lp_$?MCD.
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import java.util.List; k@#5$Ejc2
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publicclass PaginationSupport { U1OFDXHG
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publicfinalstaticint PAGESIZE = 30; AgIazv1
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privateint pageSize = PAGESIZE; Rv=DI&K%n
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privateList items; i=YXKe6fD
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privateint totalCount; Ng\/)^
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privateint[] indexes = newint[0]; lWW+5
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privateint startIndex = 0; wMGk!N
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public PaginationSupport(List items, int >*I N
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totalCount){ 7W"/N#G
setPageSize(PAGESIZE); x<)G( Xe*
setTotalCount(totalCount); /D<"wF }@J
setItems(items); _5mc('
setStartIndex(0); f\fdg].!
} |'tW=
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public PaginationSupport(List items, int L'lF/qe^
"< v\M85&
totalCount, int startIndex){ ['z!{Ez
setPageSize(PAGESIZE); n|Pr/ddL
setTotalCount(totalCount); ?>af'o:
setItems(items); &-M]xo^
setStartIndex(startIndex); f|U0s
} baee?6
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public PaginationSupport(List items, int Zmf'{t T5
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totalCount, int pageSize, int startIndex){ Ur^j$B}
setPageSize(pageSize); @9Q2$
setTotalCount(totalCount); Ow3P-UzU3
setItems(items); p,F^0OU2}:
setStartIndex(startIndex); 9IA$z\<<w
} %a];
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publicList getItems(){ ZU^IH9
return items; 2edBQYWd
} M`vyTuO3SO
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publicvoid setItems(List items){ m
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this.items = items; 'Hw4j:pS
} nBN&.+3t
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publicint getPageSize(){ [ |[>}z:
return pageSize; q]\X~
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} SHD^}?-|
. w H*sb
publicvoid setPageSize(int pageSize){ =oX>Ph+ P
this.pageSize = pageSize; ;
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} =p@8z
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publicint getTotalCount(){ Z)pz,
return totalCount; I;7nb4]AmF
} B@O@1?c[
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publicvoid setTotalCount(int totalCount){ NOt@M
if(totalCount > 0){ iWE)<h
this.totalCount = totalCount; -Xz&}QA
int count = totalCount / 5l DFp9
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pageSize; FB:<zmwR
if(totalCount % pageSize > 0) #z!^<,
count++; aRJcSV
indexes = newint[count]; Jq
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for(int i = 0; i < count; i++){ 5Y\!pf7SQ|
indexes = pageSize * Kmz7c|
9 [jTs3l:
i; 5,pSg
} %zeATM[`
}else{ C`V)VJM
this.totalCount = 0; T*~H m
} %UZVb V
} ^j )BKD-
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publicint[] getIndexes(){ ]"~51HQZ
return indexes; X"q!Y#)
} &v!WVa?
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publicvoid setIndexes(int[] indexes){ wGsRS[
this.indexes = indexes; Z5(enTy-
} Ad$n4Ze
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publicint getStartIndex(){ gRJfX%*F
return startIndex; |o<8}Nja6
} tMp=-"
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publicvoid setStartIndex(int startIndex){ c+dg_*^
if(totalCount <= 0) <#+44>h
this.startIndex = 0; &<pKx!
elseif(startIndex >= totalCount) a j\nrD1
this.startIndex = indexes ~8T(>!hE1h
!yOeW0/2[
[indexes.length - 1]; SC &~s$P;
elseif(startIndex < 0) jJZgK$5+
this.startIndex = 0; C'A]i5
else{ 1"#*)MF
this.startIndex = indexes *e#<n_%R
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[startIndex / pageSize]; xI*#(!x"G
} DI|:p!Nx
} L,,*gK
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publicint getNextIndex(){ zTbVp8\pI
int nextIndex = getStartIndex() + C0*@0~8$9
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pageSize; fV:4#j
if(nextIndex >= totalCount) D4JLtB'=
return getStartIndex(); TXXy\$
else 4Kwh?8.
return nextIndex; WQNE2Q
} f:B>zp;N
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publicint getPreviousIndex(){ '1^B+m
int previousIndex = getStartIndex() - X^9d/}uTa
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pageSize; in`aGFQO
if(previousIndex < 0) U$dh1;
return0; mo{MR:>)
else ._9
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return previousIndex; R9rj/Co
} jjM\. KL]
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} YXurYwV
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抽象业务类 c#IYFTz
java代码: b1XRC`Gy
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/** SUKxkc(
* Created on 2005-7-12 :'F}Dy
*/ klgy;jSEr
package com.javaeye.common.business; !+)AeDc:j
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import java.io.Serializable; G$0c'9d*(
import java.util.List; ,j:|w+l
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import org.hibernate.Criteria; mGUO6>g
import org.hibernate.HibernateException; {j5e9pg1L|
import org.hibernate.Session; ]u l$*
import org.hibernate.criterion.DetachedCriteria; x_Jwd^`t!
import org.hibernate.criterion.Projections; R" )bDy?
import uEyH2QO
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org.springframework.orm.hibernate3.HibernateCallback; km^^T_ M/
import Ofm%:}LV
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org.springframework.orm.hibernate3.support.HibernateDaoS yme^b
;a
{!|}=45Z
upport; DrnJ;Hi"
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import com.javaeye.common.util.PaginationSupport; 8d*/HF)h
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public abstract class AbstractManager extends -[U1]R
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HibernateDaoSupport { x8\A<(G_M=
PHA-9\jC{
privateboolean cacheQueries = false; ?pgG,=?
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privateString queryCacheRegion; Le<wR
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publicvoid setCacheQueries(boolean 3d<HN6&U
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cacheQueries){ .s+aZwTMT
this.cacheQueries = cacheQueries; |#1(Z-}
} pwwH<0[
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publicvoid setQueryCacheRegion(String 1+-_s
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queryCacheRegion){ c wg
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this.queryCacheRegion = 9j W2
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queryCacheRegion; !T](Udf
} J!'@ Bd
{ hln?'
publicvoid save(finalObject entity){ AU-n&uX
getHibernateTemplate().save(entity); "qc6=:y}
} d*)CT?d&
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publicvoid persist(finalObject entity){ kJWN.
getHibernateTemplate().save(entity); %dQxJMwj
} +f*OliMD
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publicvoid update(finalObject entity){ Z2im@c67{
getHibernateTemplate().update(entity); "D?z
} z]b>VpW:
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publicvoid delete(finalObject entity){ *tm0R> ?!
getHibernateTemplate().delete(entity); JXyM\}9-X
} Qne/g}PD`
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publicObject load(finalClass entity, gTA%uRBa
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finalSerializable id){ 1hcjSO
return getHibernateTemplate().load Or
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(entity, id); V& C/Z}\
} Sz H"
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publicObject get(finalClass entity, aW!@f[%~F
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finalSerializable id){ JK.ZdY%
return getHibernateTemplate().get 5/po2V9)
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(entity, id); ('-JY
} ;FZ@:%qDm
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publicList findAll(finalClass entity){ *N{emwIq
return getHibernateTemplate().find("from H\XP\4#u
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" + entity.getName()); gY@N~'f;"
} [oF|s-"9!
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publicList findByNamedQuery(finalString .BFYY13H
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namedQuery){ tK&'<tZh
return getHibernateTemplate 5Ri6Z#qm
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().findByNamedQuery(namedQuery); rXA*NeA3v
} IpP~Uz
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publicList findByNamedQuery(finalString query, Bdj%hyW
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finalObject parameter){ sg+uBCGB
return getHibernateTemplate }1>[
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().findByNamedQuery(query, parameter); 0{#8',*}m?
} ezPz<iZ\N
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publicList findByNamedQuery(finalString query, /="~gq@
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finalObject[] parameters){ ^5=B`aich
return getHibernateTemplate xhRngHU\z<
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().findByNamedQuery(query, parameters); c+2FC@q{l
} b$Vz2Fzx
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publicList find(finalString query){ sP ls
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return getHibernateTemplate().find `F/Tv 5@L
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(query); {#)0EzV6
} 6 ~>FYX
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publicList find(finalString query, finalObject qu|B4?Y/CR
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parameter){ PG,_^QGCX
return getHibernateTemplate().find +"1NC\<*
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(query, parameter); T8^5=/
} 23h%
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public PaginationSupport findPageByCriteria ",!1m7[wF
4fe7U=# ;Y
(final DetachedCriteria detachedCriteria){ Fy.\7CL>
return findPageByCriteria %JLk$sP9y`
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); EOm:!D\
} h(5P(` M
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public PaginationSupport findPageByCriteria JJ%ePgWT
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(final DetachedCriteria detachedCriteria, finalint !H ~<
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startIndex){ zD<or&6
return findPageByCriteria *cEob b
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(detachedCriteria, PaginationSupport.PAGESIZE, |_yYLYH'
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startIndex); rta:f800z
} -N"&/)
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public PaginationSupport findPageByCriteria qM.bF&&Go
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(final DetachedCriteria detachedCriteria, finalint kV38`s>+
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pageSize, Yh>]-SCw
finalint startIndex){ 1CHeufQ
return(PaginationSupport) Ry|!pV
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getHibernateTemplate().execute(new HibernateCallback(){ f/V
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publicObject doInHibernate 7P9=)$(EH
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(Session session)throws HibernateException { ,dx3zBI
Criteria criteria = PK"c4>q
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detachedCriteria.getExecutableCriteria(session); G8;w{-{m
int totalCount = S*n@81Z
*f?4
((Integer) criteria.setProjection(Projections.rowCount u{*SX k
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()).uniqueResult()).intValue(); mL4] l(U
criteria.setProjection VP6ZiQ|
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(null); ~I}&V T
List items = $5*WLG&AK
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criteria.setFirstResult(startIndex).setMaxResults rSJ9v:
?|39u{
(pageSize).list(); 9[^gAR
PaginationSupport ps = d,=r9.
q5#J~n8Wr
new PaginationSupport(items, totalCount, pageSize, y>aZXa
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startIndex); O/<K!;(@?
return ps; ,L`$09\
} p8]68!=W\F
}, true); beu\cV3
} WASU0
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public List findAllByCriteria(final +9")KQT
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DetachedCriteria detachedCriteria){ 7bV{Q355P
return(List) getHibernateTemplate /;utcc
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().execute(new HibernateCallback(){ smry2*g
publicObject doInHibernate TEaJG9RU>v
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(Session session)throws HibernateException { +*hm-lv?
Criteria criteria = :Cp'm'omb
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detachedCriteria.getExecutableCriteria(session); 2^l[(N
return criteria.list(); G^`1]?
} -]t,E,(!
}, true);
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} {1b Zg
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public int getCountByCriteria(final $9ky{T?YG
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DetachedCriteria detachedCriteria){ 9s_,crq5
Integer count = (Integer) b%S62(qP
=-}[^u1
getHibernateTemplate().execute(new HibernateCallback(){ 1Q.\s_2
publicObject doInHibernate XGkkB
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(Session session)throws HibernateException { \
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Criteria criteria = sn?]n~z
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detachedCriteria.getExecutableCriteria(session); H[='~%D
return I;1lX
L
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criteria.setProjection(Projections.rowCount &[;HYgp
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()).uniqueResult(); [/BE8]M~
} Y>&Ew*Y
}, true); Z" uY}P3
return count.intValue(); (1NA
} $VxA0
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} .({smN,B
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用户在web层构造查询条件detachedCriteria,和可选的 tT79p.z B
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 wW/7F;54
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PaginationSupport的实例ps。 0s>/mh;
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ps.getItems()得到已分页好的结果集 ;Yg{zhJX~
ps.getIndexes()得到分页索引的数组 -^ C=]Medl
ps.getTotalCount()得到总结果数 [V)
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ps.getStartIndex()当前分页索引 u3o#{~E/#
ps.getNextIndex()下一页索引 _Y[jyD1>
ps.getPreviousIndex()上一页索引 56Vb+0J'
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 zrU{@z$l
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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 uZ=NSbYsA
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一下代码重构了。 v%RP0%%{s
A2nqf^b{#
我把原本我的做法也提供出来供大家讨论吧: is@b&V]
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首先,为了实现分页查询,我封装了一个Page类: ~jb"5CX
java代码: ]J#9\4Sq
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/*Created on 2005-4-14*/ |eWjYGwJa
package org.flyware.util.page; mSo_} je(
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/** pm6>_Kz
* @author Joa
(X?/"lC)
* q`G, L(
*/ ScSZGs 5&
publicclass Page { ru7RcYRq
Dxk+P!!K
/** imply if the page has previous page */ B)QHM+[=F
privateboolean hasPrePage; p3}?fej&|
-> J_ ~
/** imply if the page has next page */ &EpAg@9!
privateboolean hasNextPage; CQpCS_M
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K
/** the number of every page */ # (- Qx
privateint everyPage; %~QO8q_7
LbII?N8`N
/** the total page number */ T t>8?
privateint totalPage; +z$pg
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/** the number of current page */ W\L`5CW
privateint currentPage; "ax..Mh\y
"{D|@Bc
/** the begin index of the records by the current h48SItY
E!O\87[
query */ bUY>st'
privateint beginIndex; `w.AQ?p@
2mq$H_
A Z{^o4<q
/** The default constructor */ #"49fMi/
public Page(){ raQ7.7
l]]l
} mP(kcMT"
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/** construct the page by everyPage UG<79"\i
* @param everyPage ]@M5&
* */ /o2P+Xr8"
public Page(int everyPage){ .uE Pnzi
this.everyPage = everyPage; 8j4z{+'TQ
} 1c@}C+F+
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/** The whole constructor */ Ia'ZV7'
public Page(boolean hasPrePage, boolean hasNextPage, Gxax2o
sk|=% }y
| 0,vQv
int everyPage, int totalPage, %riK+
int currentPage, int beginIndex){ k'PQ}
,Vb
this.hasPrePage = hasPrePage; 3.)b4T
this.hasNextPage = hasNextPage; o#[ KS:Y
this.everyPage = everyPage; Q_vW3xz
this.totalPage = totalPage; U #~;)fZ
this.currentPage = currentPage; :>81BuMvg
this.beginIndex = beginIndex; nL?oTze*p
} H- p;6C<
K)_WL]RJ.4
/** 9V.u-^o&
* @return \` w4|T
* Returns the beginIndex. u(!&:A9JFd
*/ oW;6h.
publicint getBeginIndex(){ ]LZ`LL'#Y_
return beginIndex; emW:C-/h/@
} v~/~@jv
d
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/** =@)d5^<5F
* @param beginIndex (7DXRcr<
* The beginIndex to set. 5ZY)nelc
*/ -<#!DjV6(
publicvoid setBeginIndex(int beginIndex){ hwqbi "o
this.beginIndex = beginIndex; =KT7nl
} -ti{6:H8
=\{\g7
/** Y\=FLO9
* @return 6yy;JQAke
* Returns the currentPage. }17.~
*/ &Z^l=YH,
publicint getCurrentPage(){ tV/Z)fpyH
return currentPage; IooNb:(
} n& $^04+i
!JBae2Z
/** {5|("0[F
* @param currentPage )J(q49
* The currentPage to set. .4l/_4,s_
*/ #Z~C`n
u
publicvoid setCurrentPage(int currentPage){ %5\3Aw
this.currentPage = currentPage; [= "r<W0
} %/.a]j!
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/** T$=4O9G
* @return Q7bq
* Returns the everyPage. pA4*bO+
*/ ]h9!ei
[
publicint getEveryPage(){ O3o: qly!
return everyPage; >ulY7~wUv
} \b*X:3g*
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/** G9g6.8*&
* @param everyPage },[;O^Do^{
* The everyPage to set. Pj?Dmk~
*/
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publicvoid setEveryPage(int everyPage){ gf)t)- E
this.everyPage = everyPage; j6ut}Uq
} B%\g kl
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/** &2I*0
* @return /hv#CB>1x
* Returns the hasNextPage. ug`NmIQP
*/ ;PyZ?Z;
publicboolean getHasNextPage(){ >\A8#@1
return hasNextPage; s:y
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} #&,H"?"
rp7W
}P+uU
/** #hw/^AaD-
* @param hasNextPage b.2J]6G
* The hasNextPage to set. 3_5XHOdE
*/ 2yo
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publicvoid setHasNextPage(boolean hasNextPage){ :1)DqoAJ
this.hasNextPage = hasNextPage; kJ)gP 2E
} 9TxyZL
as"N=\N
/** /\Q*MLwD
* @return =wq;@' U
* Returns the hasPrePage. ~2_lp^Y
*/ $A<ESfrs
publicboolean getHasPrePage(){ AKu_~bTk
return hasPrePage; )fU(AXSP
} kD.pzxEM
Z"I/ NGiU
/** MQcr^Y_
* @param hasPrePage |Wj;QO$C
* The hasPrePage to set. y~<@x.
*/ `&$B3)Eb
publicvoid setHasPrePage(boolean hasPrePage){ 'q%%m/,VPQ
this.hasPrePage = hasPrePage; Ps R>V)L
} Cef:tdk7
#<CIFVH
/** BC\S/5~k
* @return Returns the totalPage. l!IKUzt)7
* ")lw9t`
*/ .+K
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publicint getTotalPage(){ B>TSdn={>
return totalPage; D!TZI
} l*7?Y7FK
+'03>!V
/** K6pR8z*?
* @param totalPage D>wZ0p b-
* The totalPage to set. R21~Q:b!
*/ u@.>WHQN
publicvoid setTotalPage(int totalPage){ VS/;aG$&y
this.totalPage = totalPage; '5H4z7)
} K3p@$3hQ
+3^NaY`Y
} gX} g
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2'{}<9
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 ^abD!8
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个PageUtil,负责对Page对象进行构造: 'dt\db5p
java代码: .]76!(fWZ
=ak7ldA=2
9XV^z*E(J
/*Created on 2005-4-14*/ IjZ@U%g@;
package org.flyware.util.page; !Ua&0s%
0\a8}b||
import org.apache.commons.logging.Log; [N|xzMe
import org.apache.commons.logging.LogFactory; QD<eQsvV
jQtSwVDr
/** :%tuNJjj
* @author Joa F,v7ifo#f
* OV5e#AOy)
*/ [!?wyv3
publicclass PageUtil { T{S4|G1R6
QB 77:E
privatestaticfinal Log logger = LogFactory.getLog t =dO
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(PageUtil.class); 4#Eul
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/** mtw9AoO
* Use the origin page to create a new page J_ V,XO
* @param page zLek&s&-
* @param totalRecords FDLd&4Ex
* @return V-vlTgemwc
*/ <TjBd1
publicstatic Page createPage(Page page, int zk>h u<_
AQ@v>wr}
totalRecords){ NJ$e6$g)
return createPage(page.getEveryPage(), _bI+QC#
S;}qLjT
page.getCurrentPage(), totalRecords); If.n(t[M9
} |%ZpatZA5
fS./y=j(X
/** F 1}
* the basic page utils not including exception 7c::Qf[|
oBw}hH,hp
handler n>llSK
* @param everyPage _pSIJ3O
* @param currentPage FDq{M?6i
* @param totalRecords (2%>jg0M
* @return page 5\G)Q<A]*L
*/ ahp1!=Z-=
publicstatic Page createPage(int everyPage, int T}2:.Hk:N
NW De-<fQ
currentPage, int totalRecords){ v&2+'7]w
r
everyPage = getEveryPage(everyPage); jYdV?B
currentPage = getCurrentPage(currentPage); ;](h2Z`3s
int beginIndex = getBeginIndex(everyPage, #>q[oie1e
W uf/LKj
currentPage); sV'v*
1|
int totalPage = getTotalPage(everyPage, |#cAsf_{
9cOx@c+/
totalRecords); E$T(Qu<-
boolean hasNextPage = hasNextPage(currentPage, A\C'dZ <N
#HDesen
totalPage); !Mil?^
boolean hasPrePage = hasPrePage(currentPage); _m7co :
{]M>Y%j48
returnnew Page(hasPrePage, hasNextPage, .93S>U< _
everyPage, totalPage, )l{A{f6O
currentPage, YOKR//|3
N
^f}ui i
beginIndex); >
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} .Qk{5=l6P
`]hCUaV
privatestaticint getEveryPage(int everyPage){ ZvyjMLf
return everyPage == 0 ? 10 : everyPage; ;o%:7&
} -eq=4N=s
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privatestaticint getCurrentPage(int currentPage){ }s6G!v^2""
return currentPage == 0 ? 1 : currentPage; ;/aB)JZ5=
} CK Mv7
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privatestaticint getBeginIndex(int everyPage, int D1!
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currentPage){
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return(currentPage - 1) * everyPage; q]+)c2M
} i;avwP<0
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privatestaticint getTotalPage(int everyPage, int TnxU/)
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totalRecords){ 9;pzzZ
int totalPage = 0; X}?ESjZJ
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if(totalRecords % everyPage == 0) <>&89E%j'
totalPage = totalRecords / everyPage; c&A]pLn+x
else 7 BK46x
totalPage = totalRecords / everyPage + 1 ; 776 nWw)
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return totalPage; PAr|1i)mB
} .f+9 A>
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privatestaticboolean hasPrePage(int currentPage){ jDJ.
return currentPage == 1 ? false : true; *XOS. $zGz
} B%y! aQep
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privatestaticboolean hasNextPage(int currentPage, 8k%H[Smn:
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int totalPage){ XX:q|?6_ 4
return currentPage == totalPage || totalPage == V-:`+&S{^
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0 ? false : true; Gzj3Ka
} &R0OeRToUb
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} &E`9>&~J
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 =s6E/K
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 i@Vs4E[b
U* 4{"
做法如下: &1oaZY w
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 o;*]1
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的信息,和一个结果集List: n~9 i^
java代码: GPMrs)J*!
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/*Created on 2005-6-13*/ N: A3kp
package com.adt.bo; 5nY9Ls(e
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import java.util.List; 6/VNuQ_#
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import org.flyware.util.page.Page; { _-wG3f|
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/** ;Sy/N||
* @author Joa S ]vW&r3`
*/ 6xyY+
publicclass Result { FBYll[8
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private Page page; {WIY8B'c
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private List content; 3.B4(9:>,
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/** (/('nY
* The default constructor S_ZLTcq<1
*/ Al=(sHc'
public Result(){ T4Xtuu1
super(); 4,gol?a
} =rtS#u
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/** x GwTk
* The constructor using fields poTl|y @
* bkxk
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* @param page P=&'wblm?
* @param content 2%`^(\y
*/ D!c1;IHZ
public Result(Page page, List content){ wwo(n$!\
this.page = page; m*\B2\2gJ
this.content = content; B:B8"ODV
} UwZu:[T6H
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/** ]z+*?cc
* @return Returns the content. ROP C |
*/ =fL6uFmxI@
publicList getContent(){ E]e,cd
return content; @TdQZZ}G\x
} v<{wA`'R+
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/** -08&&H
* @return Returns the page. pp*bqY
*/ aJEbAs}
public Page getPage(){ tniPEmeS
return page; 8f /T!5
} av'd%LZP
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/** mrK,Ql
* @param content i_[^s:*T
* The content to set. ?SB[lbU
*/ $&ex\_W
public void setContent(List content){ sI^@A=.@
this.content = content; T@%;0Ro~
} R;0W+!fE
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/** UOn! Y@
* @param page 7( yXsVq
* The page to set. `Ev A\f
*/ Uuwq7oFub
publicvoid setPage(Page page){ +vSCR(n
this.page = page; 6 {b%Jfo
} JZs|~@
} ,k4z;
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2. 编写业务逻辑接口,并实现它(UserManager, Y&oP>n! ei
):/<H
UserManagerImpl) y_}K?
java代码: } l :mN
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/*Created on 2005-7-15*/ 9\AEyaJFZ
package com.adt.service; 7$g*N6)Q
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import net.sf.hibernate.HibernateException; C1ZFA![
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import org.flyware.util.page.Page; 4]Un=?)I
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import com.adt.bo.Result; U@o2gjGN
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/** :6 Hxxh
* @author Joa o 8~f
*/ I
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publicinterface UserManager { &