Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 qU2>V
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 )-jvp8%BK
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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 6f1;4Jfp
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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 ]"CAP%
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分页支持类: NqF-[G<
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java代码: F=P|vYL&&
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package com.javaeye.common.util; )Fm
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import java.util.List; ;H\,w/E9
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publicclass PaginationSupport { xc*ys-Nv
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publicfinalstaticint PAGESIZE = 30; 9Hc#[Ml
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privateint pageSize = PAGESIZE; wk5a &
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privateList items; y|lP.N/
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privateint totalCount; np>*O }r*
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privateint[] indexes = newint[0]; ~RMOEH.o
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privateint startIndex = 0; BO[A1'>
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public PaginationSupport(List items, int |Xu7cCh$me
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totalCount){ iySmNI
setPageSize(PAGESIZE); G3OQbqn
setTotalCount(totalCount); @wa/p`gj5w
setItems(items); JTs.NY
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setStartIndex(0); Dl"y|
} P)}:lTe
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public PaginationSupport(List items, int (ZI&'"H
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totalCount, int startIndex){ T[;{AXLeI
setPageSize(PAGESIZE); 8?)Da&+f
setTotalCount(totalCount); -u9{R \S
setItems(items); Fvv6<E
setStartIndex(startIndex); Tw`l4S&
} rB7(&(n>^
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public PaginationSupport(List items, int tr'95'5W.
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totalCount, int pageSize, int startIndex){ RE7[bM3a
setPageSize(pageSize); hZJ Nh,,w
setTotalCount(totalCount); v~xG*e
setItems(items); }=L
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setStartIndex(startIndex); ! TRiFD
} x)GoxH~#
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publicList getItems(){ M1g|m|H7
return items; :c.i Z
} *Js<VR
#".{i+3E
publicvoid setItems(List items){ r%a$u%)oD
this.items = items; 4t+88e
} L_A|
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publicint getPageSize(){ q6D hypB
return pageSize; oJR!0nQ
} h*KhH>\
[+%*s3`c#
publicvoid setPageSize(int pageSize){ ~/.&Z`ls
this.pageSize = pageSize; Y{S/A *X
} i4-L!<bJ
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publicint getTotalCount(){ .9E`x>C
return totalCount; Vw#07P#A
} 2Hd6
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publicvoid setTotalCount(int totalCount){ v0y7N_U5n
if(totalCount > 0){ F 4hEfO3
this.totalCount = totalCount; q'@UZ$2
int count = totalCount / 4 IHl'*D[#
:V"}"{(6
pageSize; +Rvj]vd}&
if(totalCount % pageSize > 0) Gah e-%J
count++; C8jZcs#4
indexes = newint[count]; XR&*g1
for(int i = 0; i < count; i++){ {P3,jY^
indexes = pageSize * LRI_s>7
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i; 1,mf]7k$
} FStfGN
}else{ ox*Ka]
this.totalCount = 0; mPu5%%
} urN&."c
} +`4|,K7'
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publicint[] getIndexes(){ C&SYmYj^c
return indexes; 6SmSu\lgV
} GphG/C (
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publicvoid setIndexes(int[] indexes){ YnMph0\Y^
this.indexes = indexes; sM4wh_lO
} aR\=p:%jGI
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publicint getStartIndex(){ +:t1P V;l
return startIndex; `?$R_uFh:
} v3/cNd3
7}#vANm
publicvoid setStartIndex(int startIndex){ (PNvv/A
if(totalCount <= 0) m ;KP
this.startIndex = 0; $`Ou *
elseif(startIndex >= totalCount) j`
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this.startIndex = indexes s 2$R2,
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[indexes.length - 1]; Oo0$n]*;W
elseif(startIndex < 0) IKU-
this.startIndex = 0; <O*q;&9
else{ QL)UPf>Kp
this.startIndex = indexes <ya3|ycnS
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[startIndex / pageSize]; S38D
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} %1 v)rg
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} X3"V1@-i4$
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publicint getNextIndex(){ 15zL,yo
int nextIndex = getStartIndex() + h!Ka\By8#
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pageSize; XJlun l)(K
if(nextIndex >= totalCount) ;?y?s'>t&
return getStartIndex(); @ NVq
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else 6^zv:C%
return nextIndex; !98s[)B:
} k&**f_b
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publicint getPreviousIndex(){ +<iw|vr
int previousIndex = getStartIndex() - A>PM'$"sT
z><JbSE?
pageSize; #mj+|/0
if(previousIndex < 0) mg;qG@?
return0; _W!g'HP-D
else 2M;{|U
return previousIndex; Pc$<Cv|vz
} `$i`i 'S
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} +(<CE#bb[
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抽象业务类 B@F 1!8l
java代码: 0]WM:6 h
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/** fg,~[%1
* Created on 2005-7-12 Bb1dH/8
*/ 2x{3' ^+l
package com.javaeye.common.business; xLGAP-mx]
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import java.io.Serializable; dJ|]W|q<
import java.util.List; #fFEo)YG
f2d"b+H#
import org.hibernate.Criteria; X&McNO6"
import org.hibernate.HibernateException; 2V
import org.hibernate.Session; W0?yPP=.
import org.hibernate.criterion.DetachedCriteria; ?d_Cy\G
import org.hibernate.criterion.Projections; r3KV.##u,
import N7jAPI@a\i
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org.springframework.orm.hibernate3.HibernateCallback; $GYy[-.`
import ]=pEs6%O3
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org.springframework.orm.hibernate3.support.HibernateDaoS #-kyZ
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upport; :Z/ig%
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import com.javaeye.common.util.PaginationSupport; +)V6"XY-(
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public abstract class AbstractManager extends (K2 p3M^
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HibernateDaoSupport { iBc(
@EJ
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privateboolean cacheQueries = false; ha(hG3C
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privateString queryCacheRegion; HDC`g
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publicvoid setCacheQueries(boolean `yxk
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cacheQueries){ kp0>8rkF
this.cacheQueries = cacheQueries; @c&)K^v8
} ,>Yz1P)L
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publicvoid setQueryCacheRegion(String I=b#tUBh8
kDm=Cjxv
queryCacheRegion){ D9Q%*DLd$_
this.queryCacheRegion = !>! l=Z
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queryCacheRegion; lk+)-J-lj'
} ))+R*k%
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publicvoid save(finalObject entity){ 3"<{YEj8U
getHibernateTemplate().save(entity); m@yaF:
R
} Pl 5+Oo
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publicvoid persist(finalObject entity){ 1ra}^H}
getHibernateTemplate().save(entity); !Dun<\
} i/WYjo
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publicvoid update(finalObject entity){ Z&PwNr/
getHibernateTemplate().update(entity); T%ha2X=
} txliZ|.O
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publicvoid delete(finalObject entity){ {E@@14]g
getHibernateTemplate().delete(entity); c !5OK4+Z
} xo?f90+(
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publicObject load(finalClass entity, ^D6 JckW
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finalSerializable id){ }-Zfljj
return getHibernateTemplate().load ?SS?I
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(entity, id); |>p\*Dl}H
} kR'!;}s
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publicObject get(finalClass entity, rj,Sk~0Q
BPC$ v\a
finalSerializable id){ [5:F
return getHibernateTemplate().get `33+OW
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(entity, id); K34y3i_
} R{4O*i8#
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publicList findAll(finalClass entity){ %M ~X:A;4
return getHibernateTemplate().find("from 20hE)!A
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" + entity.getName()); 6)Oe]{-
} X8Gw8^t
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publicList findByNamedQuery(finalString M a_! 1Y
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namedQuery){ BEu9gu
return getHibernateTemplate )D(XDN
b7HS3NYk
().findByNamedQuery(namedQuery); 3WaYeol`
} lOYwYMi
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publicList findByNamedQuery(finalString query, P3(u+UI3
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finalObject parameter){ /k7`TUK
return getHibernateTemplate V18w
t t#M4n@
().findByNamedQuery(query, parameter); e8P
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} 3wa }p^
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publicList findByNamedQuery(finalString query, |9}G
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finalObject[] parameters){ X%39cXM C
return getHibernateTemplate (\M&/X~q
>WG$!o +R
().findByNamedQuery(query, parameters); QNn$`Qz.
} #y2="$V
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publicList find(finalString query){ 2 }+V3/
return getHibernateTemplate().find llQDZ}T
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(query); ^d-`?zb
} ~9 K4]5K-
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publicList find(finalString query, finalObject @;Yb6&I;
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parameter){ 7?/ Fr(\
return getHibernateTemplate().find Ge|caiH1I
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(query, parameter); f+ J<sk
} c~z{/L
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public PaginationSupport findPageByCriteria N',]WZ}
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(final DetachedCriteria detachedCriteria){ Ij/c@#q.
return findPageByCriteria oP_'0h0X
c tTbvXP
(detachedCriteria, PaginationSupport.PAGESIZE, 0); ;k!bv|>n
} ejD;lvf
h dPKeqg7
public PaginationSupport findPageByCriteria +g\u=&<6
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(final DetachedCriteria detachedCriteria, finalint RG #
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startIndex){ o^7}H{AE
return findPageByCriteria Y#NlbKkzu
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(detachedCriteria, PaginationSupport.PAGESIZE, x)nBy)<
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startIndex); Pgs4/
} xOPSw|!w
&2#<6=}
public PaginationSupport findPageByCriteria $OmcEd
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(final DetachedCriteria detachedCriteria, finalint FpCj$y~3
;]+kC
pageSize, BX2&tQSp
finalint startIndex){ ?Tt/,Hl?D
return(PaginationSupport) LKftNSkg"
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getHibernateTemplate().execute(new HibernateCallback(){ s%;18V:pi
publicObject doInHibernate ]:Ocu--
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(Session session)throws HibernateException { C`7HC2Is
Criteria criteria = )xlNj$(x5n
enK4`+.7
detachedCriteria.getExecutableCriteria(session); axonqSf
int totalCount = auaFP-$`f
_N0x&9S$
((Integer) criteria.setProjection(Projections.rowCount Ui'~d(F
<`~]P$
()).uniqueResult()).intValue(); c;BQ$je}
criteria.setProjection :G,GHU'/78
cSoZq4
(null); el5F>)
List items = ,|?B5n&
!\RR UH*
criteria.setFirstResult(startIndex).setMaxResults `p*7MZ9-
?r2Im5N
(pageSize).list(); }0}J
PaginationSupport ps = ,TeDJ\k
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new PaginationSupport(items, totalCount, pageSize, ^7~=+0cF]
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startIndex); l?Bv9k.^?
return ps; kSoAnJ|
} C7eaioW$
}, true); 1h"0B
} X7Cou6r
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public List findAllByCriteria(final HC+(FymV
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DetachedCriteria detachedCriteria){ nNq| v=L
return(List) getHibernateTemplate E!C~*l]wJx
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().execute(new HibernateCallback(){ =+A8s$Pb
publicObject doInHibernate d\'M ~VQ
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(Session session)throws HibernateException { f+-w~cN
Criteria criteria = S!up2OseW
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detachedCriteria.getExecutableCriteria(session); wa@X^]D8
return criteria.list(); oC>^V5
} (E\7Ui0Q
}, true); / QSK$ZDC
} Z!^iPB0~D
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public int getCountByCriteria(final aG`G$3 _wx
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DetachedCriteria detachedCriteria){ xAon:58m{
Integer count = (Integer) `+k&]z$m
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getHibernateTemplate().execute(new HibernateCallback(){ #0hX)7(j
publicObject doInHibernate .ye5;A}
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(Session session)throws HibernateException { JG0TbM1(Bt
Criteria criteria = "((6)U#
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detachedCriteria.getExecutableCriteria(session); ~^KemwogPN
return : ,LX3,
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criteria.setProjection(Projections.rowCount *"q ~z
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()).uniqueResult(); !NZFo S~
} Go+f0aig
}, true); 0Eo*C9FP~
return count.intValue(); +Y'(,J
} US@ak4Y6Z
}
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用户在web层构造查询条件detachedCriteria,和可选的 [gqV}Y"Md
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 KZsSTB6J
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PaginationSupport的实例ps。 SI4M<'fK
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ps.getItems()得到已分页好的结果集 m7~kRY514
ps.getIndexes()得到分页索引的数组 AdKv!Ta5b
ps.getTotalCount()得到总结果数 4B^f"6'
ps.getStartIndex()当前分页索引 )Uo)3FAn
ps.getNextIndex()下一页索引 ?.,..p
ps.getPreviousIndex()上一页索引 /2~qm/%Q
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 yI)~- E.
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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 @'7'3+ c
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一下代码重构了。 !J3g, p*
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我把原本我的做法也提供出来供大家讨论吧: "2o)1G
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首先,为了实现分页查询,我封装了一个Page类: /!P,o}l7
java代码: 9]xOuCb
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/*Created on 2005-4-14*/ OLXG0@
package org.flyware.util.page; 8I$>e (
BwEO2a{
/** u?&P6|J&
* @author Joa l> W?XH
* F$^RM3
*/ p>Qzz`@e
publicclass Page { T9}G:6
e)zE*9
/** imply if the page has previous page */ 9h9 jS~h
privateboolean hasPrePage; g\,pZ]0i
%}J[EV
/** imply if the page has next page */ LD0x 4zm$m
privateboolean hasNextPage; g~rZ=
p$`71w)'[
/** the number of every page */ @aAB#,
privateint everyPage; AVF(YD<U
I~-W4{
/** the total page number */ h.l^f>,/
privateint totalPage; .hzzoLI2
wa\Yc,R
/** the number of current page */ sn+g#v9e
privateint currentPage; '=Nb`n3%
;}@.E@s%'
/** the begin index of the records by the current iqreIMWz
iP]KV.e'/C
query */ ~k^rI jR
privateint beginIndex; _zvCc%
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m9 o{y6_j*
/** The default constructor */ U0 nSI
public Page(){ O3/][\
]w`)"{j5m
} WYSqnmi
;|}N\[fk%]
/** construct the page by everyPage
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* @param everyPage PV$)k>H-
* */ zkt`7Pg;J
public Page(int everyPage){ zl^ %x1G
this.everyPage = everyPage; BZ*',\o
} $P&{DOiKS
=.a}
/** The whole constructor */ 4'up bI
public Page(boolean hasPrePage, boolean hasNextPage, \@&oK2f
/Jj7+?
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int everyPage, int totalPage, &W+lwEu
int currentPage, int beginIndex){ kl%%b"h'
this.hasPrePage = hasPrePage; n_QSuh/Wn
this.hasNextPage = hasNextPage; DB%}@IW"
this.everyPage = everyPage; 5.! OC5tO
this.totalPage = totalPage; SQ'\K d=
this.currentPage = currentPage; .8e]-^Z
this.beginIndex = beginIndex; cq+G 0F+H
} u_H=Xm)9
i<@"+~n~GK
/** 0Xo>f"2<f
* @return QTr)r;Tro
* Returns the beginIndex. ,Ei!\U^)
*/ niC ;WK
publicint getBeginIndex(){ f#mNx
return beginIndex; 7>.d*?eao\
} 3 @a hN2
C 2t]
/** $ix:S$
* @param beginIndex @7UZ{+67*C
* The beginIndex to set. Znr6,[U+q
*/ ,Tp:. "
publicvoid setBeginIndex(int beginIndex){ 3bYPi^
this.beginIndex = beginIndex; Ey|{yUmU+
} `vjn,2S}
h4p<n&)F
/** mR,w~wP
* @return 1Hl-|n
* Returns the currentPage. ^AhV1rBB
*/ gGZ-B<
publicint getCurrentPage(){ M>qqe! c*
return currentPage; FEY_(70
} JuW"4R
|7%has3"
/** nA*Udrcn
* @param currentPage $8>kk
* The currentPage to set. s qXwDy+.
*/ '/="bSF
publicvoid setCurrentPage(int currentPage){ =[JstiT?E
this.currentPage = currentPage; mH.c`*
} 4Jn+Ot.,d
,V^2Oa
/** '\B0#z3
* @return
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* Returns the everyPage. <)$&V*\
*/ UuS6y9@v
publicint getEveryPage(){ MO^Q 8v
return everyPage; bG)EZ
} Mz7qC3Z
:6gRoMb]
/** m!5MGq~
* @param everyPage gmqA 5W~y
* The everyPage to set. aD^jlt
*/ ^'%Q>FVb
publicvoid setEveryPage(int everyPage){ XX7zm_>+
this.everyPage = everyPage; uG7?:) pxv
} C/?x`2'
q nb#~=x^
/** 2P/ Sq
* @return r2%Qk
* Returns the hasNextPage. F MX^k
*/ >,x&L[3
publicboolean getHasNextPage(){ l{I.l
return hasNextPage; jl>jy6T
} K
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1%$t;R
/** 2=
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* @param hasNextPage 8-_atL
* The hasNextPage to set. |(<A)C
*/ 1l5'N=hL
publicvoid setHasNextPage(boolean hasNextPage){ HvR5-?qQ
this.hasNextPage = hasNextPage; 9Y:Iha`$w
} Avww@$
$D='NzE/
/** p;qFMzyS9
* @return ?8qN8rk^+
* Returns the hasPrePage. tmd{Gx}c
*/ Up1n0
publicboolean getHasPrePage(){ Tn"@u&P
*
return hasPrePage; 5g%D0_e5
} C);3GPp
IyEfisOK?
/** Y[N@ )E_G
* @param hasPrePage T[evh]koB
* The hasPrePage to set. d]USk&8
*/ 4T6: C?V
publicvoid setHasPrePage(boolean hasPrePage){ Kv)Kn8df
this.hasPrePage = hasPrePage; Dz,|sHCmk
} SdF+b+P]
#<y/m*Ota
/** O]Ey@7 &
* @return Returns the totalPage. N1}r%!jk/
* o5['5?i} /
*/ 1pK(tm
publicint getTotalPage(){ P2&0bNY
return totalPage; ^6gEL~m|]
} 6i;q=N$'
G6}!PEwM
/** `z`=!1
* @param totalPage K8/jfm
* The totalPage to set. Ey.%:
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*/ Scug
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publicvoid setTotalPage(int totalPage){ 9K;g\? 3
this.totalPage = totalPage;
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} g[' 7 $
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} 1g,Ofr
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p-m\0tQ
Y3#8]Z_"}O
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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 QL @SE@"
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个PageUtil,负责对Page对象进行构造: uJ=d!Kn
java代码: 2c51kG77E
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/*Created on 2005-4-14*/ (0l>P]"n
package org.flyware.util.page; qo}yEl1
~$ Po3]{s
import org.apache.commons.logging.Log; D-D8La?0p
import org.apache.commons.logging.LogFactory; AQtOTT$
3s?ZyQy
/** P^ht$)Y
* @author Joa uP$i2Cy
* @NiLKcL#
*/ 1cx%+-
publicclass PageUtil { G O"E>FyB
elR1NhB|p
privatestaticfinal Log logger = LogFactory.getLog f'MRC
\
@=}NMoNH
(PageUtil.class); 9ei<ou_s
}O+S}Hbwy
/** eY%Ep=J
* Use the origin page to create a new page Lctp=X4
* @param page tKeozV[V
* @param totalRecords lfG',hlI;
* @return z8r?C
*/ xXnSo0`LF
publicstatic Page createPage(Page page, int {MN6JGb|'
,<C~DSAyZ
totalRecords){ Bio QV47B
return createPage(page.getEveryPage(), ~}/_QlX` K
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page.getCurrentPage(), totalRecords); N"0>)tG
} I *f@M}
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/** <;@E
.I\N
* the basic page utils not including exception zsj]WP6j
:^qUr`)
handler m&#D ~
* @param everyPage i+Mg[x$.
* @param currentPage *=]UWM~]
* @param totalRecords 1vAJ(O{-
* @return page QxuU3#l
*/ ~OLyG$JJ
publicstatic Page createPage(int everyPage, int uKTYb#E7
6ZwQ/~7H
currentPage, int totalRecords){ T!pA$eE
everyPage = getEveryPage(everyPage); @*uZ+$
currentPage = getCurrentPage(currentPage); il"pKQF
int beginIndex = getBeginIndex(everyPage, 4/_!F'j
[g}0.J`_
currentPage); $VP\Ac,!
int totalPage = getTotalPage(everyPage, iA`.y9'2
Ji1# >;&
totalRecords); '
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boolean hasNextPage = hasNextPage(currentPage, pcQkJF
}jP/XO1f
totalPage); D(Q]ddUi'
boolean hasPrePage = hasPrePage(currentPage); DGw*BN%`
'*Tt$0#o
returnnew Page(hasPrePage, hasNextPage, c>! ^\
everyPage, totalPage, <]_[o:nOP
currentPage, D{qr N6g#
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beginIndex); jK%Lewq
} XeslOsHh
K|Xe)
privatestaticint getEveryPage(int everyPage){ x8C
*
return everyPage == 0 ? 10 : everyPage; *.VNyay
} 91nB?8ZE6,
]r%fAmj
privatestaticint getCurrentPage(int currentPage){ dB QCr{7
return currentPage == 0 ? 1 : currentPage; U'~]^F%eyu
} ;?TM_%>
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privatestaticint getBeginIndex(int everyPage, int b2j~"9
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currentPage){ h2= wC.
return(currentPage - 1) * everyPage; R((KAl]dL
} 7osHKO<?2
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privatestaticint getTotalPage(int everyPage, int T-x9IoE
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totalRecords){ &Z9rQH81f>
int totalPage = 0; DK'S4%;Sp
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if(totalRecords % everyPage == 0)
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totalPage = totalRecords / everyPage; P?jI:'u!R.
else "`4M4`'
totalPage = totalRecords / everyPage + 1 ; W@%g_V}C*
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return totalPage; t1$pl6&,
} IJ:JH=8
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privatestaticboolean hasPrePage(int currentPage){ Adfnd
return currentPage == 1 ? false : true; *Uf>Xr&
} |@f\[v9`
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privatestaticboolean hasNextPage(int currentPage, M6V^ur 1
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int totalPage){ q$`>[&I~)
return currentPage == totalPage || totalPage == )t:8;;W@Ir
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0 ? false : true; [9F
} s"2+H}u
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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。 #>sIXY
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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 _kBx2>qQ
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做法如下: )@=fGN Dt
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 .&8a ;Q?c
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的信息,和一个结果集List: k%aJ%(
java代码: {K:]dO
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/*Created on 2005-6-13*/ j6L (U~%
package com.adt.bo; f9)0OHa
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import java.util.List; 9;L8%T
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import org.flyware.util.page.Page; ][YC.J
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