Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 M 0}r)@
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 F-ZTy"z
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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 qnyacI
nmn/4>
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 #akJhy@m$
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分页支持类: TI8\qIW
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java代码: i
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package com.javaeye.common.util; @BLB.=
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import java.util.List; G?v<-=I
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publicclass PaginationSupport { LodP,\T
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publicfinalstaticint PAGESIZE = 30; HdlOGa6C
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privateint pageSize = PAGESIZE; KsIHJr7-
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privateList items; &;?+ ^L>
tH; 6Mp;f
privateint totalCount; %`pi*/(
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privateint[] indexes = newint[0]; o% Q7 el$f
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privateint startIndex = 0; !otseI!!/
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public PaginationSupport(List items, int M*n94L=Sg&
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"
totalCount){ 6@lZVM)E
setPageSize(PAGESIZE); VTR4uT-
setTotalCount(totalCount); v(0ujfSR0
setItems(items); au19Q*r9
setStartIndex(0); G[ns^
} c/.s`hz
=#4>c8MM
public PaginationSupport(List items, int %x,HQNRDU
1O,5bi>t7
totalCount, int startIndex){ 4E=QO!pVv
setPageSize(PAGESIZE); Chl^LEN:
setTotalCount(totalCount); dY.X/f
setItems(items); eN5F@isy
setStartIndex(startIndex); VWt=9D;
} |g \_xl
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public PaginationSupport(List items, int IHCxM|/k(M
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totalCount, int pageSize, int startIndex){ 88:YU4:l`N
setPageSize(pageSize); VDv.N@)7
setTotalCount(totalCount); zk3\v
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setItems(items); 28M^F~0
setStartIndex(startIndex); 9Bpb?
} ?{ \7th37
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publicList getItems(){ :I/9j=@1
return items; HZ!<dy3
} z|],s]F>G
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publicvoid setItems(List items){ Rf)|p;
this.items = items; 5`&@3
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} f'"PQr^9
/T {R\
publicint getPageSize(){ ~C>;0a;<:
return pageSize; `K@N\VM
} lxZ9y
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publicvoid setPageSize(int pageSize){ z^*g2J,
this.pageSize = pageSize; @N[<<k7g
} -#;ZZ\fdj
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publicint getTotalCount(){ % &H^UxC
return totalCount; )mAD <y+
} JgHYuLB
3&E@#I^],
publicvoid setTotalCount(int totalCount){ EJz!#f~
if(totalCount > 0){ .
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this.totalCount = totalCount; Q~Nq5[
int count = totalCount / !s$1C=z5u
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pageSize; r91i :
if(totalCount % pageSize > 0) sqF.,A,
count++; CD#U`jf
indexes = newint[count]; F@ pf._c
for(int i = 0; i < count; i++){ K&{ _s
indexes = pageSize * Lwm /[
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i; t{s>B]i^_w
} 1x/ R
}else{ Q$:,N=%
this.totalCount = 0; .#sX|c=W
} I)jAdd
} 8?'=Aeo
;){ZM,Ox
publicint[] getIndexes(){ ]fh(b)8_,
return indexes; I5[@C<b
} Je"XIhBr
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publicvoid setIndexes(int[] indexes){ dR>$vbjh1Z
this.indexes = indexes; gyy}-^`F
} 9' H\-
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publicint getStartIndex(){ 3 %r*~#nz
return startIndex; 45Zh8 k
} o&k,aCQC
*yZta:(w-W
publicvoid setStartIndex(int startIndex){ >}0H5Q8@
if(totalCount <= 0) 1PWi~1q{Q
this.startIndex = 0; 3AP=
elseif(startIndex >= totalCount) Yc)Dx3
this.startIndex = indexes &{wRB l #
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[indexes.length - 1]; Y>E` 7n
elseif(startIndex < 0) zcOm"-E-
this.startIndex = 0; ^I6Vz?0Jl
else{ c9nv=?/}f
this.startIndex = indexes )FA:wsy~E
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[startIndex / pageSize]; R;U4a2~
} x}`)'a[
} Xa"I
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publicint getNextIndex(){ G:|]w,^i
int nextIndex = getStartIndex() + (<H@W/0$
f/.f08
pageSize; 8OS^3JS3"
if(nextIndex >= totalCount) ]H`pM9rC
return getStartIndex(); 09Q5gal
else ,OkI0[
return nextIndex; g6][N{xW0
} BG1hk!
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publicint getPreviousIndex(){ )L"J?wTe
int previousIndex = getStartIndex() - )[E7\pc
!H9zd\wc
pageSize; sv!6zJs
if(previousIndex < 0) M'NOM>8
return0; +N|t:8qaf
else >5t]Zlb`
return previousIndex; \`*]}48Z
} )<5hga][~a
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} Yg;7TKy
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抽象业务类 &sJ6k/l
java代码: <II>io;
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/** aL8Z|*
* Created on 2005-7-12 ]1q`N7
*/ b,#?LdQ%
package com.javaeye.common.business; 8`|Z9umW*
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import java.io.Serializable; Z..s /K{
import java.util.List; ^W0eRT
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import org.hibernate.Criteria; h0-CTPQ7A
import org.hibernate.HibernateException; `I(5Aj"
import org.hibernate.Session; Z:VT%-
import org.hibernate.criterion.DetachedCriteria; 07vzVsQ}p
import org.hibernate.criterion.Projections; 75c\.=G9q<
import
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org.springframework.orm.hibernate3.HibernateCallback; e#ne 5
import a.XMeB
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org.springframework.orm.hibernate3.support.HibernateDaoS uAV-wc
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upport; yY80E[v
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import com.javaeye.common.util.PaginationSupport; 41i#w;ojI
Htce<H-P
public abstract class AbstractManager extends *>jJ<8!
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HibernateDaoSupport { wkD"EuW(
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privateboolean cacheQueries = false; "X-"uIc
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privateString queryCacheRegion; }`_x%]EJ
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publicvoid setCacheQueries(boolean P2
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cacheQueries){ LC0g"{M
this.cacheQueries = cacheQueries; %5<Xa
} Gp1?drF6
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publicvoid setQueryCacheRegion(String F?4&qbdD
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queryCacheRegion){ (6i.>%|_
this.queryCacheRegion = *YP;HL
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queryCacheRegion; !InC8+be
} 'I@l$H
{br6*
publicvoid save(finalObject entity){ LbnW(wr6:(
getHibernateTemplate().save(entity); 5:SS2>~g
} Ji0FHa_
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publicvoid persist(finalObject entity){ 2E@y0[C?
getHibernateTemplate().save(entity); +?GsIp@>jh
} Z (C0+A\
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publicvoid update(finalObject entity){ (A~w IKY,
getHibernateTemplate().update(entity); @gjA8mL
} ?GeMD
/]
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publicvoid delete(finalObject entity){ 6Vu)
getHibernateTemplate().delete(entity); VB}^&{t)!
} Dn+hI_"#_
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publicObject load(finalClass entity, 6~a4-5;>z
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finalSerializable id){ /2:s g1
return getHibernateTemplate().load }KR"0G[f
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(entity, id); G)&S%R!i\N
} uevhW
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publicObject get(finalClass entity, [s~6,wz
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finalSerializable id){ 8T3Nz8Q7
return getHibernateTemplate().get P$6Pe>3
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(entity, id); =!DpW VsQ
} $dF$-y<[0
o8N,mGj}
publicList findAll(finalClass entity){ PyM59v
return getHibernateTemplate().find("from ma@!"Z8S
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" + entity.getName()); ?$ M:4mX
} N@V:nCl
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publicList findByNamedQuery(finalString Xx ou1l!
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namedQuery){ ^CP>|JWD^
return getHibernateTemplate d^d+8R
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().findByNamedQuery(namedQuery); XUTsW,WC
} W>&!~9H
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publicList findByNamedQuery(finalString query, UvuAN:'
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finalObject parameter){ hpYW1kfQl
return getHibernateTemplate D_ XOYzN}
$0Un'"`S
().findByNamedQuery(query, parameter); b fI= =
} ;Swy5z0=ro
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publicList findByNamedQuery(finalString query, z&CBjlh
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finalObject[] parameters){ huvn_
return getHibernateTemplate '~zi~Q7M
Y)D F.ca(
().findByNamedQuery(query, parameters); L9d|7.b
} }H|'W[Q.
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publicList find(finalString query){ D/+l$aBz
return getHibernateTemplate().find WG
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(query); $Ww.^ym
} \=Od1 i
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publicList find(finalString query, finalObject Xq}}T%jcd
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parameter){ dnkHx
return getHibernateTemplate().find kt+h\^g
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(query, parameter); >96+s)T%;
} #"fn;
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public PaginationSupport findPageByCriteria $GYy[8{:V
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(final DetachedCriteria detachedCriteria){ ,\N4tG1\
return findPageByCriteria 8+H 0
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); LMuDda
} x<PJ5G L
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public PaginationSupport findPageByCriteria )&l5I4CIf
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(final DetachedCriteria detachedCriteria, finalint @r(3
4j(`koX_
startIndex){ dVZ~n4
return findPageByCriteria taMcm}*T1
g!OcWy)7
(detachedCriteria, PaginationSupport.PAGESIZE, Q{CRy-ha
%,e,KcP'
startIndex); PcI~,e%
} `U&'71B^
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public PaginationSupport findPageByCriteria &P"1 3]^@
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(final DetachedCriteria detachedCriteria, finalint A5Q4wy`
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pageSize, ,C|{_4
finalint startIndex){ (G(M"S SC
return(PaginationSupport) ~(B%E'
6cD3(//
getHibernateTemplate().execute(new HibernateCallback(){ h6n!"z8H
publicObject doInHibernate `gyke2n
bh#6yvpMR
(Session session)throws HibernateException { Q<KF<K'0hg
Criteria criteria = 1
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detachedCriteria.getExecutableCriteria(session); %e)?Mem
int totalCount = v=Q!ioE7
;Sg,$`]
((Integer) criteria.setProjection(Projections.rowCount U@D\+T0
J _q
()).uniqueResult()).intValue(); 1Zi` \N4T
criteria.setProjection JSmg6l?[u
S!b?pl
(null); 7U^{xDg.b
List items = P1Eg%Y6
J8ScKMUN2
criteria.setFirstResult(startIndex).setMaxResults ivB,s5<
3to!C"~\K-
(pageSize).list(); %9J:TH9E)
PaginationSupport ps = .}T- R?
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new PaginationSupport(items, totalCount, pageSize, Z^=(9:
GG-b)64h`
startIndex); 06Q9X!xD
return ps; Qwve-[
} 9U4[o<G]=
}, true); =#[t!-@
} Y3s8@0b3
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public List findAllByCriteria(final s@GE(Pu7
/3VO!V]u
DetachedCriteria detachedCriteria){ B9$pG
return(List) getHibernateTemplate "]Uj _d
{d]B+'
().execute(new HibernateCallback(){ QDVSFGwr
publicObject doInHibernate T 1_B0H2
:(.:bf
(Session session)throws HibernateException { _n{_\/A6f
Criteria criteria = GN=8;Kq%
)?$@cvf
detachedCriteria.getExecutableCriteria(session); bg_io* K
return criteria.list(); _[i.)8$7
} cIC/3g}]
}, true); P}( c0/
} }_}
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public int getCountByCriteria(final %_CL/H
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DetachedCriteria detachedCriteria){ !q$>6P
Integer count = (Integer) vu}U2 0@
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getHibernateTemplate().execute(new HibernateCallback(){ 0pl'*r*9
publicObject doInHibernate (l9jczi
;]=@;? 9
(Session session)throws HibernateException { vb]uO ' l
Criteria criteria = xj&~>&U){;
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detachedCriteria.getExecutableCriteria(session); vpOGyvI
return gB+CM?
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$}5M`p\&C
criteria.setProjection(Projections.rowCount VS>hi~j
}H
saJ=1U
()).uniqueResult(); Xc^(e?L4
} k>8OxpaWv?
}, true); wV{j CQ
return count.intValue(); )56L`5#tS
} hkV*UH{
} ;~WoJlEK3
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9$VdYw7D
用户在web层构造查询条件detachedCriteria,和可选的 D+oV( Pw,
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 .L^;aL
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PaginationSupport的实例ps。 2t
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ps.getItems()得到已分页好的结果集 f(K1,L:&7
ps.getIndexes()得到分页索引的数组 5GPAt
ps.getTotalCount()得到总结果数 A e2Y\ sAV
ps.getStartIndex()当前分页索引 gh"_,ZhZt
ps.getNextIndex()下一页索引 ~)X;z"y%b
ps.getPreviousIndex()上一页索引
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 !}1l8Y
w>Ft5"z
,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 b+Vlq7Bc
a<+Rw{
一下代码重构了。 0&r}'f?
@e7_&EGR?
我把原本我的做法也提供出来供大家讨论吧: b
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Esg:
首先,为了实现分页查询,我封装了一个Page类: dPgA~~
java代码: JKCV>k
: B1
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ypfjF@OT
/*Created on 2005-4-14*/ y %Y P
package org.flyware.util.page; {z'Gg
:b#5cMUe
/** :X*uE^bH
* @author Joa 6skd>v UU
* ;hFB]/.v
*/ )S_%Ip
publicclass Page { 5=4-IO6W[]
^4saB+qm
/** imply if the page has previous page */ `X`|]mWj
privateboolean hasPrePage; -r0oO~KT
[Kbna>`
/** imply if the page has next page */ FOcDBCrOe
privateboolean hasNextPage; }yCgd 5+_
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/** the number of every page */ .3
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privateint everyPage; z]O>`50Q
b|`
/** the total page number */ D,uT#P
privateint totalPage; ):Ekf2
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/** the number of current page */ 27H4en; o=
privateint currentPage; WS$~o*Z8
+Pn`AV1
/** the begin index of the records by the current e}L(tXZ
[3W+h1
query */ ;Y(~'KF
privateint beginIndex; v/wR)9
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/** The default constructor */ *P[N.5{
public Page(){ j;*=
^s
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} v8A{q
]PXpzruy
/** construct the page by everyPage #DHeEE
* @param everyPage Cd7d-'EQn
* */ hzX&BI
public Page(int everyPage){ c1_?Z
this.everyPage = everyPage; qk(u5Z
}
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8m)E~6
/** The whole constructor */ k+cHx799
public Page(boolean hasPrePage, boolean hasNextPage, ]5J*UZ}
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*|:]("i
int everyPage, int totalPage, Q|cA8Fn
int currentPage, int beginIndex){ BRMR>
~k(
this.hasPrePage = hasPrePage; 90)rOD1B
this.hasNextPage = hasNextPage; NW;wy;;
this.everyPage = everyPage; %bUpVyi!(
this.totalPage = totalPage; Ehf{Kl
this.currentPage = currentPage; }L*cP;m#
this.beginIndex = beginIndex; mko<J0|4
} o3l_&?^
'DQKpk'
/** y8un&LP
* @return HLU'1As65
* Returns the beginIndex. ]W%<<S
*/ eg-,;X#
publicint getBeginIndex(){ jxr~cp?4
return beginIndex; Dw^d!%Ala
} i1?H*:]
ALiXT8q
/** ,m:YZ;J(Xd
* @param beginIndex ,P<n\(DQ
* The beginIndex to set. g Xvuv^
*/ \0m[Ch}~ey
publicvoid setBeginIndex(int beginIndex){ RI"A'/56
this.beginIndex = beginIndex; 969*mcq'
} kQ~*iY
(yCFpb
/** Z*QsDS
* @return
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* Returns the currentPage. 0Q=4{*:?
*/ n=n!Hn
publicint getCurrentPage(){ c?CjJ}-7
return currentPage; XU .FLNe
} 41WnKz9c
v3Y/D1jd"
/** DGTSk9iK(
* @param currentPage m#mM2Guxe
* The currentPage to set. ewSFB <
N
*/ VAF+\Cea=
publicvoid setCurrentPage(int currentPage){ 3ADTYt".
this.currentPage = currentPage;
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} GM{m(Y
C$xU!9K[+
/** =usx' #rb
* @return b,8W
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* Returns the everyPage. H~1*`m
*/ b/ h,qv
publicint getEveryPage(){ n0kBLn
return everyPage; `itaQGLD
} B i?DmrH
H3}{]&a
/** #vYdP#nWb
* @param everyPage [L8Bgw1
* The everyPage to set. xjiMM>|n
*/ 6|t4\'
publicvoid setEveryPage(int everyPage){ Sb+pB58&N
this.everyPage = everyPage; J_OIU#-B
} @!&\Z[",
]L%qfy4
/** {e
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* @return n|Vs2 7
* Returns the hasNextPage. B0NKav
*/ ~S15tZ $
publicboolean getHasNextPage(){ 1g5%Gr/0$5
return hasNextPage; &aldnJ
} G*ZHLLO4S\
2c@R!*
/** Glcl7f"<^
* @param hasNextPage G eN('0
* The hasNextPage to set. v_"p)4&'
*/ 8P0XY
S@
publicvoid setHasNextPage(boolean hasNextPage){ oJbD|m
this.hasNextPage = hasNextPage; Mb=vIk{Bf
} W~k"`g7uu
MQY^#N
/** 2Otd
* @return
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* Returns the hasPrePage. -mOSB(#bo
*/ nVko]y
publicboolean getHasPrePage(){ ao#{N=mn
return hasPrePage; X"YH49?
} DcE)6z#
t/LQ|/xo
/** RrRrB"!8nR
* @param hasPrePage FA<|V!a
* The hasPrePage to set. A&rk5y;
*/ CTQF+Oe8O
publicvoid setHasPrePage(boolean hasPrePage){ kB{
this.hasPrePage = hasPrePage; W'u6F-$2
} u~7mH
%eB 0)'
/** B*p`e1
* @return Returns the totalPage. A(2_hl-
* i,1=5@rw5
*/ a7s+l=
publicint getTotalPage(){ z^$DXl@)h
return totalPage; '=K
[3%U
} i"Hec9Ri
QE*O~Yj
/** ggtGecKm
* @param totalPage Rd@34"O
* The totalPage to set. UjxEbk5>^
*/ JpqZVu"7
publicvoid setTotalPage(int totalPage){ S7]\tw_L)
this.totalPage = totalPage; H6%QM}t
} =NLsT.aa
<qjNX-|
} `!WtKqr%B
m}&cX Y
t&}Z~Zp
2u9O+]EP
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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 s+IU%y/9$a
ATx6YP@7~
个PageUtil,负责对Page对象进行构造: z-};.!L^
java代码: h!.#r*vV
eD5:0;X2
(1pI#H"f9
/*Created on 2005-4-14*/ YuufgPE*H
package org.flyware.util.page; .>?h
uG<VQ2LM
import org.apache.commons.logging.Log; `q
= e<$
import org.apache.commons.logging.LogFactory; xS.Rpx/8
MO}J
/** N6K%Wkz
* @author Joa s}"5uDfn1F
* R-odc,P=
*/
qkQ_#
publicclass PageUtil { $p_FrN{
'lmZ{a6
privatestaticfinal Log logger = LogFactory.getLog w&&uk[Gh/a
&G63ReW7 @
(PageUtil.class); 5WhR|
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/** F:$Dz?F0v
* Use the origin page to create a new page [t)omPy<c
* @param page dzA5l:5
* @param totalRecords Hgu:*iYA
* @return 'p0|wM_
*/ }m '= _u
publicstatic Page createPage(Page page, int 8R!3}kx
f1eY2UtWQ
totalRecords){ Eu%19s;u
return createPage(page.getEveryPage(), O[nl#$w
TTNgnP
page.getCurrentPage(), totalRecords); mX@Un9k
} {sn :Lj0
*7L*:g
/** ,.#
SEv5
* the basic page utils not including exception sU7>q}!
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handler #3uBq(-Z
* @param everyPage ,!`94{Ggv
* @param currentPage d<*4)MRN
* @param totalRecords bYzBe\^3q3
* @return page $}[Tj0+:
*/ $Cu/!GA4.>
publicstatic Page createPage(int everyPage, int ,gU%%>-_~w
>.R6\>N%
currentPage, int totalRecords){ m wuFXu/
everyPage = getEveryPage(everyPage); Kd_WN;l
currentPage = getCurrentPage(currentPage); j/zD`ydj
int beginIndex = getBeginIndex(everyPage, ^$][ah
*
*?mZtF
currentPage); Pn{yk`6E
int totalPage = getTotalPage(everyPage, gbc^Lb
//--r5Q
totalRecords); rT`D@
I
boolean hasNextPage = hasNextPage(currentPage, Df_W>QC
Z2chv,SqCJ
totalPage); ]{9oB-;,
boolean hasPrePage = hasPrePage(currentPage); vOYcS$,^X%
"X']_:F1a
returnnew Page(hasPrePage, hasNextPage, ;F&wGe
everyPage, totalPage, @4:cn
currentPage, $Z;HE/3
[5%/{W,~m
beginIndex); Q, E!Ew3
} {nQ}t
}B
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privatestaticint getEveryPage(int everyPage){ \Rn.ug
return everyPage == 0 ? 10 : everyPage; ErC~,5dj;n
} 3&*0n^g
vg5zsR0u
privatestaticint getCurrentPage(int currentPage){ *f8,R"]-g
return currentPage == 0 ? 1 : currentPage; 98C~%+
} tYfhKJzGC
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privatestaticint getBeginIndex(int everyPage, int F *;
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currentPage){ 2h&pm
return(currentPage - 1) * everyPage; dh/:H/k kR
} hk ./G'E
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privatestaticint getTotalPage(int everyPage, int F dv&kK!
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totalRecords){ KHr8\qLH
int totalPage = 0; +bm2vIh$
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if(totalRecords % everyPage == 0) !W$3p'8Tu
totalPage = totalRecords / everyPage; 9r1pdG_C@
else v )7d
totalPage = totalRecords / everyPage + 1 ; NtTLvO6
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return totalPage; U7crbj;c)d
} 54F([w
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privatestaticboolean hasPrePage(int currentPage){ k5-mK{RZ
return currentPage == 1 ? false : true; EZP2Bb5g
} 3UC8iq*
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privatestaticboolean hasNextPage(int currentPage, n^Z?u9VR
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int totalPage){ #UND'c(5
return currentPage == totalPage || totalPage == ,A6*EJ\w
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0 ? false : true; He!0&B\7h
} r)j#Skh].
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} !Rb7q{@>
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 T!a8c<'V
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 ]hf4= gm
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做法如下: -x_iqrB
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 |d`?wm-
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的信息,和一个结果集List: rLKDeB
java代码: HdnSs0/
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/*Created on 2005-6-13*/ 50R+D0^mh
package com.adt.bo; EEo+#
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import java.util.List; +_}2zc4
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import org.flyware.util.page.Page; 2mT+@G
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/** T
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* @author Joa iLI]aZ
*/ S8cFD):q
publicclass Result { 2bC%P})m
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private Page page; ]s SoIT
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private List content; zF$wz1
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/** b>(lF%M
* The default constructor "|%fAE
*/ E,$uNw ']
public Result(){ `->k7a0<b1
super(); 0cbF.Um8
} sg2C_]i,H
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/** .KSGma6]
* The constructor using fields
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* ZM.g+-9
* @param page }>:X|4]
* @param content :F\f}G3
*/ Ne EV!V8
public Result(Page page, List content){ el%Qxak`"
this.page = page; HXQrtJ
this.content = content; /{va<