Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 tsg`c;{
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 q~> +x?30
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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 'zm5wqrkAd
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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 op`9(=DJ]
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。 "B:FSWM_-
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分页支持类: #@DJf
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java代码: *xxk70Cb
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package com.javaeye.common.util; &fB=&jc*j
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import java.util.List; |j0_^:2r=
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publicclass PaginationSupport { t >"`rcg
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publicfinalstaticint PAGESIZE = 30; EY"of[p
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privateint pageSize = PAGESIZE; P+f}r^4}
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privateList items; [j/|)cj
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privateint totalCount; wuXQa
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privateint[] indexes = newint[0]; @H`jDaB9
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privateint startIndex = 0; pZS]i
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public PaginationSupport(List items, int a&JY x
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0*5
totalCount){ YT8q0BR]
setPageSize(PAGESIZE); :N<Qk
setTotalCount(totalCount); _fk}d[q0
setItems(items); gN<7(F
setStartIndex(0); ]8%E'd
} PsUO8g'\
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public PaginationSupport(List items, int >g !Z|ju
b/[X8w'VP
totalCount, int startIndex){ 'sZGLgT;m
setPageSize(PAGESIZE); -KC@M
setTotalCount(totalCount); @}6<,;|DQ
setItems(items); H,TApF89A
setStartIndex(startIndex); "=DQ { (L
} WwsNAJ
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public PaginationSupport(List items, int ,X3D<wl
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totalCount, int pageSize, int startIndex){ <|k :%
setPageSize(pageSize); .b_ppieNY
setTotalCount(totalCount); y2+f)Xp_.C
setItems(items); OD7A(28
setStartIndex(startIndex); 0B8Wf/j?M
} BTwc(oL
ngZq]8=o
publicList getItems(){ KgM|:'
return items; .t[u_tBL
} bp'%UgA)1
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b
publicvoid setItems(List items){ fUf1G{4
this.items = items; %iNgHoH
} F-ZTy"z
5)Z=FUupA~
publicint getPageSize(){ qnyacI
return pageSize; nmn/4>
}
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publicvoid setPageSize(int pageSize){ awR !=\
this.pageSize = pageSize; xkFa
} 1v:Ql\^cT
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publicint getTotalCount(){ YSxr(\~j
return totalCount; 8 !:2:
} &i3SB[|
sHPAr}14
publicvoid setTotalCount(int totalCount){ GmNCw5F
if(totalCount > 0){ e~gNGr]L/
this.totalCount = totalCount; ^`#7(S)a/
int count = totalCount / Y.I~.66s
rr,A Vw
pageSize; .s4vJKK0
if(totalCount % pageSize > 0) ;/V])4=
count++; FWeUZI+
indexes = newint[count]; #Ev}Gf+5Q
for(int i = 0; i < count; i++){ =U~53Tg
indexes = pageSize * hwUb(pZ
,k_ b-/
i; <=_!8A
} BYdGK@ouk
}else{ ~Qif-|[V
this.totalCount = 0; W2-l_{
} 00IW9B-
} pvl];w
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publicint[] getIndexes(){ i{N?Y0YQs0
return indexes; ?4 wl
} 9[\do@
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publicvoid setIndexes(int[] indexes){ TT9
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this.indexes = indexes; k;<@2C
} lE%KzX?&
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publicint getStartIndex(){ A-m IWTa
return startIndex; 3%r/w7Fc
} PUD8
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publicvoid setStartIndex(int startIndex){ sa<\nH$_X
if(totalCount <= 0) ;~r- P$kCY
this.startIndex = 0; 19[o XyFI
elseif(startIndex >= totalCount)
,
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this.startIndex = indexes +MHIZI
*ze/$vz-
[indexes.length - 1]; 8(-
29
elseif(startIndex < 0) 4 5wqX h
this.startIndex = 0; _~tF2`,Y_p
else{ dpchZ{
this.startIndex = indexes fup?Mg-
\kKd:C{
[startIndex / pageSize]; z|],s]F>G
} -]}#Z:&
} lmUCrs37
,hJx3g5#n
publicint getNextIndex(){ ~x4]p|)</
int nextIndex = getStartIndex() + 6b2h\+AP
!S7?:MJ?p\
pageSize; Z$c&Y>@)
if(nextIndex >= totalCount) /g%RIzgW
return getStartIndex(); _7u&.l<;
else E}%Pwr
return nextIndex; 5cM%PYU4:v
} ^vV AuO
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publicint getPreviousIndex(){ fUis_?!
int previousIndex = getStartIndex() - =Gj~:|;$
!Q_Kil.9
pageSize; -/B*\X[
if(previousIndex < 0) &)Zv>P8z`
return0; m@I}$
else ]!1HN3
return previousIndex; OU/3U(%n]e
} ]X7_ji(l,
.i?{h/9y
} wNl6a9#
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抽象业务类 h(~of(
java代码: 4/\Ynb.L
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/** ettBque
* Created on 2005-7-12 vd^Z^cpip
*/ XgUSJ*
package com.javaeye.common.business; {Z!t:'x8
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import java.io.Serializable; <WmjjD
import java.util.List; .MDSP/s
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import org.hibernate.Criteria; Zs0;92WL
import org.hibernate.HibernateException; 1PWi~1q{Q
import org.hibernate.Session; dci,[TEGu
import org.hibernate.criterion.DetachedCriteria; .2rpQa/h
import org.hibernate.criterion.Projections; ;sUvY* Bcm
import cw0@Z0
tqB6:p-%
org.springframework.orm.hibernate3.HibernateCallback; /IX555/dR1
import *>EV4Hl
m4~~ q[t
org.springframework.orm.hibernate3.support.HibernateDaoS R;U4a2~
2Z"\%ZD
upport; F!?f|z,/
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import com.javaeye.common.util.PaginationSupport; v3n
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public abstract class AbstractManager extends 8WQc8
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HibernateDaoSupport { XfIsf9
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privateboolean cacheQueries = false; cj2^wmkB
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privateString queryCacheRegion; ]H`pM9rC
w!d(NA<|0]
publicvoid setCacheQueries(boolean !w!k0z]
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cacheQueries){ _D+J3d(Pjk
this.cacheQueries = cacheQueries; DV({! [EP
} `4Z:qh+fJ
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publicvoid setQueryCacheRegion(String QR-pji
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queryCacheRegion){ 5YI6$ZdQ
this.queryCacheRegion = L"T :#>
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queryCacheRegion; #'i,'h+F
} ofYZ!-V
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publicvoid save(finalObject entity){ ]gA2.,)}D
getHibernateTemplate().save(entity); #c/K.?
} BOdlz#&s
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publicvoid persist(finalObject entity){ )#? K2E
getHibernateTemplate().save(entity); /
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} p]s)Xys
]}&HvrOld
publicvoid update(finalObject entity){ .M[t5I'\
getHibernateTemplate().update(entity); xA*6Z)Y
} AS4oz:B
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publicvoid delete(finalObject entity){ v`qXb$YW
getHibernateTemplate().delete(entity); 5VVU%STP
} >B$ IrM7J
lEQj62zIQ
publicObject load(finalClass entity, iK5[P
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finalSerializable id){ vMJ_n=Vf
return getHibernateTemplate().load XVKRT7U
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(entity, id); .F _u/"**
} 9A`^ (
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publicObject get(finalClass entity, xj]^<oi<
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finalSerializable id){ anKflt3
return getHibernateTemplate().get ?ZhBS3L
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(entity, id); nF,zWr[x
} ),%@X
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publicList findAll(finalClass entity){ %_39Wa
return getHibernateTemplate().find("from ['6Sq@c)
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" + entity.getName()); M,r8 No
} u@Z6)r'
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publicList findByNamedQuery(finalString vZqW,GDfXo
cwHbm%
namedQuery){ :pvVm>
return getHibernateTemplate cI@'Pr4:FJ
f$?`50D"1
().findByNamedQuery(namedQuery); 9zLeyw\
} pG v*{.
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publicList findByNamedQuery(finalString query, *^Z -4
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finalObject parameter){ Pvm pWa
return getHibernateTemplate dD
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P|;v >
().findByNamedQuery(query, parameter); R3#| *)q
} ZxCXru1
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publicList findByNamedQuery(finalString query, |uM=pm;H
:prx:7
finalObject[] parameters){ IFt aoK
return getHibernateTemplate 9T2y2d!X
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().findByNamedQuery(query, parameters); (r1"!~d@
} SEM-t
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publicList find(finalString query){ }JUc!cH8z
return getHibernateTemplate().find ,OkI0[
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(query); n(Um/
} sr<\fW
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publicList find(finalString query, finalObject ++|e
z{
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parameter){ Izfq`zS+\s
return getHibernateTemplate().find O? 7hT!{
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(query, parameter); mF>{cVTF
} {JfL7%
zUWWXC%R
public PaginationSupport findPageByCriteria YTfi g{a
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(final DetachedCriteria detachedCriteria){ #1'p?%K.
return findPageByCriteria ^*,?x
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); &~=d;llkT
} LO%OH
u}]
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public PaginationSupport findPageByCriteria BMn`t@ !x
, LqfwA|
(final DetachedCriteria detachedCriteria, finalint pA\"Xe&
@~i :8
startIndex){ +a+DiD>./
return findPageByCriteria v#5hK<9
8'Q&FW3"
(detachedCriteria, PaginationSupport.PAGESIZE, ji5Nq+S2
$A98h-*x
startIndex); k+eeVy
}
1<0Z@D~F
B2)5Z]
public PaginationSupport findPageByCriteria 6ziBGU#.-
fV!~SX6S
(final DetachedCriteria detachedCriteria, finalint ?]_A~_J!
- G=doP0
pageSize, 7Ewq'Vu`y
finalint startIndex){ *M6j)jqV
return(PaginationSupport) ;"NW=P&
* YLpC^&
getHibernateTemplate().execute(new HibernateCallback(){ d(, M
publicObject doInHibernate Z3 dI
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(Session session)throws HibernateException { YizwKcuZ
Criteria criteria = Se!B,'C%
0.^67'
detachedCriteria.getExecutableCriteria(session); aOmQ<N]a
int totalCount = ^W0eRT
`pd+as
((Integer) criteria.setProjection(Projections.rowCount X9YbTN
;jmT5XzL
()).uniqueResult()).intValue(); #*"I?B/fd8
criteria.setProjection 8HWEObRY
K/!>[d
(null); 2:1
kSR^Ky
List items = *3y_FTh8ra
H<l0]-S{
criteria.setFirstResult(startIndex).setMaxResults <07~EP
fTi5Ej*/?)
(pageSize).list(); }x"8v&3CM_
PaginationSupport ps = ZP<OyX?
#\6k_toZ
new PaginationSupport(items, totalCount, pageSize, yONX?cS
GP=bp_L
startIndex); l0%7u
return ps; yDi'@Z9R?
} k.%FGn'fR
}, true); ~01t_Xp qc
} [4mIww%
Ro#O{
public List findAllByCriteria(final LUA<N:
yY80E[v
DetachedCriteria detachedCriteria){ $A)[s$
return(List) getHibernateTemplate t<SCrLbz
,d8*7my
().execute(new HibernateCallback(){ Y>CZ
publicObject doInHibernate /)V8X#,
2))pB/
(Session session)throws HibernateException { 1HeE$
Criteria criteria = YF)c.Q0
oox;8d4}y
detachedCriteria.getExecutableCriteria(session); ezhK[/E=
return criteria.list(); }t1J`+x%
} Qt=OiKZ
}, true); W'5c%SI
} KWn.
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public int getCountByCriteria(final }`_x%]EJ
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DetachedCriteria detachedCriteria){ 'c$)}R
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Integer count = (Integer) Az6tu <
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getHibernateTemplate().execute(new HibernateCallback(){ bO
}9/Ay
publicObject doInHibernate rG'W#!^*
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(Session session)throws HibernateException { ]mx1djNA
Criteria criteria = Gyy?cn6_
bqQR";
detachedCriteria.getExecutableCriteria(session); 7Dz-xM_?
return 3Sn#
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#!w7E,UBi
criteria.setProjection(Projections.rowCount _[y<u})
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()).uniqueResult(); 1*OZu.NdK
} dz)(~@tgz
}, true); [f`7+RHrd
return count.intValue(); ;_A?Zl}
} et@<MU@`
} :Mq{ES%
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)/BbASO$)Z
用户在web层构造查询条件detachedCriteria,和可选的 p u[S
ZY8:7Q@P>
startIndex,调用业务bean的相应findByCriteria方法,返回一个 o=C'u
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PaginationSupport的实例ps。 h:<?)g~U
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ps.getItems()得到已分页好的结果集 {A{sRT=%
ps.getIndexes()得到分页索引的数组 N"zm
ps.getTotalCount()得到总结果数 \mNN ) K@
ps.getStartIndex()当前分页索引 &>vfm9
ps.getNextIndex()下一页索引 Z
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ps.getPreviousIndex()上一页索引 1raq;^e9
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 A0H6}53, $
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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 Dn+hI_"#_
9+I/bl4
一下代码重构了。 <!derr-K
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我把原本我的做法也提供出来供大家讨论吧: Pr#uV3\
}EN-WDJD\
首先,为了实现分页查询,我封装了一个Page类: W]M Fq5.
java代码: Eb9n6Fg
hWRr#030
Tvd: P^C
/*Created on 2005-4-14*/ oGz5ZDa#
package org.flyware.util.page; Pk&sY'
sQMfU{S /
/** ,(z"s8N
* @author Joa h|OWtf4
* `"y:/F"{
*/ @$5=4HA
publicclass Page { 1i;#cIG
X1^Q1?0
/** imply if the page has previous page */ !PJp()
privateboolean hasPrePage; PgYIQpV
&|fWtl;43
/** imply if the page has next page */ 'oF ('uR
privateboolean hasNextPage; *)s^+F 0
b$>1_wTL
/** the number of every page */ Lm'+z97
privateint everyPage; oh,29Gg
FA}y"I'W
/** the total page number */ ;.3
{}.Y
privateint totalPage; o8N,mGj}
x,TnYqT^
/** the number of current page */ B9S@G{`
privateint currentPage; 'm.+ S8
Dao=2JB{
/** the begin index of the records by the current
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}z-6 ,i)'k
query */ aA'of>'ib|
privateint beginIndex; D|IS@gWa
'8;'V%[+
mi@ni+2Tn
/** The default constructor */ !JA//{?
public Page(){ `pfRY!
kQO-V4z!
} ^CP>|JWD^
$Ao'mT
/** construct the page by everyPage *Nur>11D
* @param everyPage TVAa/_y2`
* */ Fmzkbt~oe
public Page(int everyPage){ XUTsW,WC
this.everyPage = everyPage; o&>aYlXd
} [I}xR(a@n
L#\5)mO.v
/** The whole constructor */ !HKW_m^3J
public Page(boolean hasPrePage, boolean hasNextPage, UvuAN:'
X u2+TK
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int everyPage, int totalPage, 'ji|'x T
int currentPage, int beginIndex){ oObQN;A@6
this.hasPrePage = hasPrePage; xMFEeSzl>S
this.hasNextPage = hasNextPage; sCE%./h]
this.everyPage = everyPage; g1) ZjABV
this.totalPage = totalPage; ~%@1-
this.currentPage = currentPage; FA{(gib@9
this.beginIndex = beginIndex; $.zd,}l@L
} +HlZ?1g
9hjzOJPuga
/** |g1Pr9{wy
* @return I/go$@E"
* Returns the beginIndex.
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*/ b;5
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publicint getBeginIndex(){ !1Nh`FN
return beginIndex; r(JP&
@
} '~zi~Q7M
q2*1Gn9!j
/** $J#Z`%B^y
* @param beginIndex ,@\z{}~v
* The beginIndex to set. e <+b?@}=B
*/ @ ?bY,
publicvoid setBeginIndex(int beginIndex){ =ba1::18
this.beginIndex = beginIndex; 5-UrHbpCZ#
} kc<5wY_t
lLLPvW[Q
/** gnw">H
* @return gi$ 'x^]#
* Returns the currentPage. #x \YA#~
*/ 2x~Pq_?y
publicint getCurrentPage(){ M,<UnAVP-
return currentPage; aI1tG
} FmgMd)#
fpJ%{z2
/** Xq}}T%jcd
* @param currentPage sK8sxy
* The currentPage to set. :KS"&h{ SY
*/ z=Xh
publicvoid setCurrentPage(int currentPage){ }yw>d\] f
this.currentPage = currentPage; mSGpxZ,IE
} k}!'@
yJMo/!DZ
/** nX8ulGG s
* @return eo^C[#
.
* Returns the everyPage. wV\G$|Y
*/ #"fn;
publicint getEveryPage(){ Ok<,_yh
return everyPage; j{6O:d6([$
} 4K*st8+bl-
~RV"_8`V9
/** &a)d,4e<M
* @param everyPage +'_ peT.8
* The everyPage to set. ,\N4tG1\
*/ MHJRBn{}
publicvoid setEveryPage(int everyPage){ O+]'*~a
this.everyPage = everyPage; 1C0'
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} XW~a4If
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/** #Y'ewu;qJ
* @return p-H}NQ\
* Returns the hasNextPage. T[MDjhv'
*/ tToP7q^
publicboolean getHasNextPage(){
\UZ7_\
return hasNextPage; @76I8r5l
} zx@L sp
c/V0AKkS
8
/** Rln\
* @param hasNextPage syCT)}T6z
* The hasNextPage to set. RwhKW?r+
*/ )a9C3-8Y'
publicvoid setHasNextPage(boolean hasNextPage){ POf xN.
this.hasNextPage = hasNextPage; t#w,G
} g!OcWy)7
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/** )Br#R:#
* @return Ctx>#uN6
* Returns the hasPrePage. z m]R76
*/ {a15s6'd
publicboolean getHasPrePage(){ g |H
return hasPrePage; $k`j";8uR
} 5
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(LJ7xoJ^
/** `ZT/lB`
* @param hasPrePage JP^\
* The hasPrePage to set. *Ea)b-
*/ AQ,"):ofvT
publicvoid setHasPrePage(boolean hasPrePage){ }<&?t;
this.hasPrePage = hasPrePage; We vd6)\
} &h_Y?5k K
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/** }pGjc_:']
* @return Returns the totalPage. sE
^YOT<
* 6cD3(//
*/ ^f9@=I
publicint getTotalPage(){ /:"^,i\t
return totalPage; ]c
bXI
} R7O<>kt
^ E.mG>
/** e X6o7a
* @param totalPage Q<KF<K'0hg
* The totalPage to set. YMVi7D~;Q$
*/ ewWw
publicvoid setTotalPage(int totalPage){ gtT&97tT<
this.totalPage = totalPage; `g4N]<@z
} W|"bV 6d3
uGHM ]"!)
} v=Q!ioE7
2p4iir
Z?V vFEt%
<PM.4B@
z, FPhbFn
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 1/&^~'
J#jFX
F\
个PageUtil,负责对Page对象进行构造: 2cSc
8
java代码: B I=57
!;P[Y"h@r
0d1!Q!PH3
/*Created on 2005-4-14*/ S!b?pl
package org.flyware.util.page; o{QV'dgu
>[:qJ|i%
import org.apache.commons.logging.Log; sB$" mJ
import org.apache.commons.logging.LogFactory; _!Pi+l4p/}
D7muf
/** H328I}7
* @author Joa ivB,s5<
* t=|}?lN<
*/ J^S!GG'gb
publicclass PageUtil { ?GqH/
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$yq76
privatestaticfinal Log logger = LogFactory.getLog '-Oh$hqCx|
yE(<F2
(PageUtil.class); f2&6NC;
5.DmMG[T^=
/** 2%J] })
* Use the origin page to create a new page R&g&BF
* @param page s^4wn:*$zd
* @param totalRecords `^
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* @return teC/Uf5
*/ TBky+]p@
publicstatic Page createPage(Page page, int =#[t!-@
OW@"j;6
3`
totalRecords){ :$gs7<z{rm
return createPage(page.getEveryPage(), Zsmv{p
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page.getCurrentPage(), totalRecords); qk>SM|{
} yeBfzKI{b
XsDZ<j%x89
/** >< P<k&
* the basic page utils not including exception 7=Pj}x)
j>l
handler hJ8%r_
* @param everyPage 2I& dTxIa
* @param currentPage DY{v@
<3
* @param totalRecords 2v;&`04V<
* @return page m,J
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*/ :(.:bf
publicstatic Page createPage(int everyPage, int <#199`R
/q,=!&f2
currentPage, int totalRecords){ H8B2{]HAt
everyPage = getEveryPage(everyPage); ;uv$>Fauk
currentPage = getCurrentPage(currentPage); !VsdKG)
int beginIndex = getBeginIndex(everyPage, +nim47
Xwjm T
currentPage); V~Z)^.6
int totalPage = getTotalPage(everyPage, XD|Xd|/ {
uEG4^
totalRecords); ;!lwB
boolean hasNextPage = hasNextPage(currentPage, bv7xh*/
'.8eLN
totalPage); 1?3+>
boolean hasPrePage = hasPrePage(currentPage); #W
l^!)#j?
13)6p|6x
returnnew Page(hasPrePage, hasNextPage, [dUAb
everyPage, totalPage, .IVKgQ
B
currentPage, *uP;rUY
vu}U2 0@
beginIndex); Uovna:"
} 3Zs0W{OxU
X+<9-]=
privatestaticint getEveryPage(int everyPage){ @g]+$Yj
return everyPage == 0 ? 10 : everyPage; \2#K {
} Pn4jI(
Z_<NUPE
privatestaticint getCurrentPage(int currentPage){ RlU ?F
return currentPage == 0 ? 1 : currentPage; -*hPEgcV9
} |9Yx`_DF
l-!"
privatestaticint getBeginIndex(int everyPage, int 9C{Xpu
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currentPage){ 6W3."};
return(currentPage - 1) * everyPage; +lZ-xU1
} yx6^ mis4
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privatestaticint getTotalPage(int everyPage, int 0;,Y_61
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totalRecords){ HZS.%+2
int totalPage = 0; qu]a+cYY
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if(totalRecords % everyPage == 0) =CS$c?
totalPage = totalRecords / everyPage; &gJ@"`r4
else |u$*'EsP
totalPage = totalRecords / everyPage + 1 ; w)1SZ}
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return totalPage; sSD&'K=lq
} yd'cLZd<}
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privatestaticboolean hasPrePage(int currentPage){ .x/H2r'1
return currentPage == 1 ? false : true; !vc5NKv#n
} ~k?t
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privatestaticboolean hasNextPage(int currentPage, gbh/`
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int totalPage){ xB?!nd
return currentPage == totalPage || totalPage == 3[l\l5'm8
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0 ? false : true; D&@ js!|5
} b
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} uH7rt
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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。 RU=g|TL
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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 3/&
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做法如下: B>z^W+Unyn
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 C:bA:O
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的信息,和一个结果集List: Q&%gpa).W
java代码: zJ ;]z0O
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/*Created on 2005-6-13*/ wLt0Fq6QG
package com.adt.bo; 99]s/KD2yb
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import java.util.List; VeQ [A?pER
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import org.flyware.util.page.Page; /w2IL7}
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/** W&Xi&[Ux
* @author Joa -~lrv#5Q
*/ !VrBoU4<d
publicclass Result { !}1l8Y
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private Page page; |L-- j
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private List content; *]k E3
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/** [`KQ\4u
* The default constructor tEibxE
*/ \S~<C[P
public Result(){ n
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