Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 {p9y{$
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 _Eq:Qbw#
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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 yh]#V"W3
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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 bRLmJt98P
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分页支持类: X
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java代码: +C/K@:p
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package com.javaeye.common.util; 6y%BJU.I
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import java.util.List; hs2f3;)
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publicclass PaginationSupport {
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publicfinalstaticint PAGESIZE = 30; HzQ6KYAM q
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privateint pageSize = PAGESIZE; oE"!
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privateList items; X~ P0Q
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privateint totalCount; uTbI\iq
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privateint[] indexes = newint[0]; _S,2j_R9
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privateint startIndex = 0; 6 [a CjW
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public PaginationSupport(List items, int %a8'6^k
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totalCount){ b\UQ6V
setPageSize(PAGESIZE); fR5
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setTotalCount(totalCount); s]5wzbF O
setItems(items); @K4} cP
setStartIndex(0); @s/;y VVq
} x\3 ` W
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public PaginationSupport(List items, int O*H:CW
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totalCount, int startIndex){ xPQO}wKa
setPageSize(PAGESIZE); 0Ny0#;P
setTotalCount(totalCount); #bsR L8@
setItems(items); yeE_1C .
setStartIndex(startIndex); OZ![9l
} mrqCW]#u
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public PaginationSupport(List items, int d+fmVM?p
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totalCount, int pageSize, int startIndex){ O7s0M?4
setPageSize(pageSize); #T#&qo#
setTotalCount(totalCount); '3[Ecy#
setItems(items); dI>)4( )
setStartIndex(startIndex); ]AERi]
B
} $w[@L7'(
z+PSx'#}
publicList getItems(){ _f|Au`7m
return items; D<L]'
} C(?>l.QGw
;)0vxcMB
publicvoid setItems(List items){ ]8+%57:E
this.items = items; /:ma}qGy
} ^ T(l3r
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publicint getPageSize(){ "Z&qOQg%3
return pageSize; ^yy\CtG
} ?7^('
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publicvoid setPageSize(int pageSize){ kzJNdYtdH
this.pageSize = pageSize; jtQ2vJ-
} |A'8 'z&q
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publicint getTotalCount(){ t
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return totalCount; Jc`LUJT
} Ip.5I!h[Xb
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publicvoid setTotalCount(int totalCount){ *:
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if(totalCount > 0){ %j2YCV7
this.totalCount = totalCount; eK/[jxNO
int count = totalCount / =c-j4xna>
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pageSize; AJt0l|F
if(totalCount % pageSize > 0) y"e'Gg2
count++; T-fW[][&$
indexes = newint[count]; <%>Q$b5
for(int i = 0; i < count; i++){ 9m!4 U2N,s
indexes = pageSize * Y&Pi`E9=
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i; _m3PAD4
} OjJlGEl w
}else{ o6xl,T%
this.totalCount = 0; E|6X.Ny]
} Ulj2Py}
} /
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publicint[] getIndexes(){ SQ>.P
return indexes; *Z|!%C
} <G 2;nvRr
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publicvoid setIndexes(int[] indexes){ UgSSZ05Lq
this.indexes = indexes; W
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} MCL?J,1?r
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publicint getStartIndex(){ ^q
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return startIndex; >I]t|RT])
} TL]2{rf~
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publicvoid setStartIndex(int startIndex){ f]T#q@|lE
if(totalCount <= 0) }k \a~<'X
this.startIndex = 0; U>:CX
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elseif(startIndex >= totalCount)
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this.startIndex = indexes \w^U<_zq
jTSw 0\}
[indexes.length - 1]; eoTOccb!
elseif(startIndex < 0) `o/tpuI
this.startIndex = 0; Kk9 JZ[nT'
else{ 7S2Bm]fP
this.startIndex = indexes yZmQBh$
{r[*}Bv
[startIndex / pageSize]; WZ6!VE{
} [g&Q_+,j
} p*#SSR9<
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publicint getNextIndex(){ =]-!
int nextIndex = getStartIndex() + D~NH 4B
> ^n'
pageSize; f`/JY!uj{
if(nextIndex >= totalCount) ;oob
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return getStartIndex(); 9zi/z_G
else <MT_zET
return nextIndex; Zp-
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} 9e=F
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publicint getPreviousIndex(){ Gp;[WY\
int previousIndex = getStartIndex() - ;`X -.45
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pageSize; qZ`@Ro
if(previousIndex < 0) 9OF5A<%"u
return0; {YK6IgEsJe
else ;\4}Hcg
return previousIndex; qi7dcn@d
} ?#pL\1"E
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} =2J+}ac
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抽象业务类 N7+K$)3
java代码: akJ{-
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/** _f^q!tP&d
* Created on 2005-7-12 =Q3Go8b4HJ
*/ <mrLld#_:C
package com.javaeye.common.business; 9DKmXL
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import java.io.Serializable; -uy}]s5Qu
import java.util.List; N4)&K[
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import org.hibernate.Criteria; 2/B(T5PY@
import org.hibernate.HibernateException; \&ERSk2
import org.hibernate.Session; GlQ=M )E
import org.hibernate.criterion.DetachedCriteria; aH'^`]'_=
import org.hibernate.criterion.Projections; /\
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import V%Y.N4H
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org.springframework.orm.hibernate3.HibernateCallback; ax>en]rNP
import 4sNM#]%|
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org.springframework.orm.hibernate3.support.HibernateDaoS PCt&66F
-s:JD J*
upport; /~gM,*
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import com.javaeye.common.util.PaginationSupport; 6<rc]T'|
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public abstract class AbstractManager extends sE>'~+1_O
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HibernateDaoSupport { YJrK oK}
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privateboolean cacheQueries = false; HAGWA2wQ
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privateString queryCacheRegion; ^6J*yV%
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publicvoid setCacheQueries(boolean {'>X6:
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cacheQueries){ ` Bkba:
this.cacheQueries = cacheQueries; {oBVb{<
} ZPZ1
7-
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publicvoid setQueryCacheRegion(String bsqoR8
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queryCacheRegion){ ~X`vRSrH
this.queryCacheRegion = _IT,>#ba
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queryCacheRegion; 6D0uLh
} 2S!=2u+7
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publicvoid save(finalObject entity){ HV>|f'45
getHibernateTemplate().save(entity); ~@itZ,d\
} -#rFCfPy^
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publicvoid persist(finalObject entity){ @H7dQ,%
getHibernateTemplate().save(entity); {oz04KGsH
} Ij#%Qu
Pw$'TE}
publicvoid update(finalObject entity){ wx<5*8zP
getHibernateTemplate().update(entity); LjxTRtB_
} 1<bSH n9
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publicvoid delete(finalObject entity){ Z [68ji]
getHibernateTemplate().delete(entity); <;v{`@\j{
} x6:$lZ(
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publicObject load(finalClass entity, #H7(d T
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finalSerializable id){ Eq'{uV:
return getHibernateTemplate().load gK#aC[
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(entity, id); 3 5|5|ma
} *dUnP{6 g
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publicObject get(finalClass entity, Nm\I_wjX
}=XL^a|V
finalSerializable id){ g*Cs/w
return getHibernateTemplate().get 2Ybz`O!
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(entity, id); ]!0*k#i_.
} =_
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publicList findAll(finalClass entity){ nNBxT+3*i
return getHibernateTemplate().find("from KwpNS(]I
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" + entity.getName()); &yVii^
} V4VTP]'n
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publicList findByNamedQuery(finalString I&>R]DV
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namedQuery){ dzbzZ@y
return getHibernateTemplate CHBCi) '6h
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().findByNamedQuery(namedQuery); Y*J`Wf(w
} d/R:-{J)c
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publicList findByNamedQuery(finalString query, +=O8t0y
n
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finalObject parameter){ 9O}YtX2
return getHibernateTemplate ,YH^jc
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lni%=
().findByNamedQuery(query, parameter); Ev$?c9*>
} o`G'E&
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publicList findByNamedQuery(finalString query, <V>vDno\
8a-[Q
finalObject[] parameters){ S~Nx;sB
return getHibernateTemplate C7q bofoV
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().findByNamedQuery(query, parameters); 8?I(wn
} Q&n
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publicList find(finalString query){ E$8GXo00v
return getHibernateTemplate().find gDAA>U3|$
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(query); j g$%WAEb
} NSM-p.I9
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publicList find(finalString query, finalObject yt_?4Hc"
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parameter){ {I(Euk>lR
return getHibernateTemplate().find K6|*-Wo.
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(query, parameter); hiP^*5h
} N],A&}30
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public PaginationSupport findPageByCriteria q[dls_
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(final DetachedCriteria detachedCriteria){ w6#hsRq[C
return findPageByCriteria i]F,Y;&|
/=Q7RJ@P
(detachedCriteria, PaginationSupport.PAGESIZE, 0); DZLSn Ax
} s "*Cb*
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public PaginationSupport findPageByCriteria ze,HNFg@>
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(final DetachedCriteria detachedCriteria, finalint ^pZ(^
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startIndex){ wl5!f|
return findPageByCriteria t^u X9yvx
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(detachedCriteria, PaginationSupport.PAGESIZE, G}f.fRY
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startIndex); ,{:5Z:<|
} 2ht<"
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public PaginationSupport findPageByCriteria {!6!z,
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(final DetachedCriteria detachedCriteria, finalint Ibpk\a?A{
my*UN_]
pageSize, Mx$VAV^\
finalint startIndex){ qw"`NubX
return(PaginationSupport) :5h&f
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getHibernateTemplate().execute(new HibernateCallback(){ |!rD2T\Ef
publicObject doInHibernate dos$d3B4
rD<@$KpP
(Session session)throws HibernateException { yrkd#m
Criteria criteria = +2C:]
y;#p=,r
detachedCriteria.getExecutableCriteria(session); Isoqs(Oi
int totalCount = <qHwY.
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((Integer) criteria.setProjection(Projections.rowCount #sNa}292"
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()).uniqueResult()).intValue(); ^qV*W1|0
criteria.setProjection w*Kw#m'U
/ ^!(rHf
(null);
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List items = m6'YFpf)V
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criteria.setFirstResult(startIndex).setMaxResults {WFYNEQ[
4*m\Zoq>
(pageSize).list(); E})PNf;
PaginationSupport ps = C{Aeud #5
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new PaginationSupport(items, totalCount, pageSize, .;*0odxv
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startIndex); > -k$:[l
return ps; \ m2[
} ab3" ?.3m
}, true); ScM2_k`D
} Z@~8iAgE
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public List findAllByCriteria(final Vs9fAAXS4
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DetachedCriteria detachedCriteria){ 8!:4m"Y
return(List) getHibernateTemplate nLo:\I(
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().execute(new HibernateCallback(){ tEf-BV;\y
publicObject doInHibernate 2R|2yAh
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(Session session)throws HibernateException { M|Z]B<_x
Criteria criteria = HHg=:>L z
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detachedCriteria.getExecutableCriteria(session); {N7,=(-2=
return criteria.list(); gsT%_2>CL
} 0=-h9W{zI
}, true); dd98vVj
} QN*'MA"M
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public int getCountByCriteria(final .@ 1\26<
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DetachedCriteria detachedCriteria){ o7hjx hmC
Integer count = (Integer) ^"*r'
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getHibernateTemplate().execute(new HibernateCallback(){ sA}=o.\j:
publicObject doInHibernate &wLI:x5
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(Session session)throws HibernateException { {^$rmwN
Criteria criteria = eQzSWn[
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detachedCriteria.getExecutableCriteria(session); @0Tm>s
return [&)9|EV
}bjTb!
criteria.setProjection(Projections.rowCount .5_w^4`b
*-` /A
()).uniqueResult(); m#'u;GP]k
} %Ix^Xb0
}, true); 2/(gf[elX
return count.intValue(); tPFV6n
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} ;QW)tv.y
} 3%k@,Vvt
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用户在web层构造查询条件detachedCriteria,和可选的 >/evL
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 %Z.>)R4
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PaginationSupport的实例ps。 [.|tD
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ps.getItems()得到已分页好的结果集 ]Alu~ Dw
ps.getIndexes()得到分页索引的数组 U4^dDj
ps.getTotalCount()得到总结果数 rK)%n!Z
ps.getStartIndex()当前分页索引 &bA;>Lu#|o
ps.getNextIndex()下一页索引 5E}0<&
ps.getPreviousIndex()上一页索引 q$U;\Mg)
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ]3 Mm"7`
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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 Q/0;r{@Tq}
ezHj?@
一下代码重构了。 xR;Xx;
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我把原本我的做法也提供出来供大家讨论吧: G}] ZZ
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首先,为了实现分页查询,我封装了一个Page类: kA\;h|Y3
java代码: qH"0?<$9
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/*Created on 2005-4-14*/ */?L_\7
package org.flyware.util.page; x{RTI#a.
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/** d p_J*8
* @author Joa i~k?k.t8
* r\_aux^z
*/ 'VR5>r
publicclass Page { l.b
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/** imply if the page has previous page */ .hZ =8y9
privateboolean hasPrePage; =a7m^e7
tHhY1[A8m
/** imply if the page has next page */ Z&J417buk
privateboolean hasNextPage; yTbBYx9Bi
RwT.B+Onuy
/** the number of every page */ d|DIqT~{W
privateint everyPage; ZYu^Q6b3
M,y='*\M
/** the total page number */ V}@c5)(j
privateint totalPage; bCA3w%,kM
]:]2f9y
/** the number of current page */ )mwY]
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privateint currentPage; nef-xxXC^I
uCmdNY
/** the begin index of the records by the current KasOh"W.P
+Y 3_)
query */ 0-FwHDxw
privateint beginIndex;
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h
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/** The default constructor */ x7{,4js
public Page(){ zCPjuS/~
Q
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} ~x>IN1Vci
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/** construct the page by everyPage KGK8;Q,O
* @param everyPage _H:SoJ'
* */ "B)DX*-\?
public Page(int everyPage){ XwlUkw"q
this.everyPage = everyPage; ^JYR^X>_
} I~4`NV0
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/** The whole constructor */ tk_y~-xz
public Page(boolean hasPrePage, boolean hasNextPage, VO++(G)
VVCCPK^<
f\/};a
int everyPage, int totalPage, gU+BRTZ&x
int currentPage, int beginIndex){ (Grj_p6O
this.hasPrePage = hasPrePage; V@cRJ3ZF
this.hasNextPage = hasNextPage; mb\vHu*53
this.everyPage = everyPage; ;zz"95X7
this.totalPage = totalPage; y "7TO#
this.currentPage = currentPage; x40R)Led
this.beginIndex = beginIndex; MZ0uc2L=
} iAup',AZg
[iL2c=_
/** y0A2{'w
* @return Z AZQFr'*
* Returns the beginIndex. B[b'OtH
*/ i?*&1i@
publicint getBeginIndex(){ $OjsaE%
return beginIndex; _k6N(c2Nd
} 4Ag+
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/** Gg,,qJO
* @param beginIndex t}*teo[
* The beginIndex to set. 3PBg3Y$
*/ !gJAK<]iW
publicvoid setBeginIndex(int beginIndex){ R<JI
this.beginIndex = beginIndex; Hi.JL
} = ng\
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/** P=u )Q _
* @return nc$?tC9V
* Returns the currentPage. |L]dJ<
*/ lzuPE,h
publicint getCurrentPage(){ x-%nnC6e
return currentPage; h"ZF,g;a
} d@#=cvW
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/** #9
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* @param currentPage %tQIKjsVaY
* The currentPage to set. Mc@p~5!M
*/ -4GSGR'L&y
publicvoid setCurrentPage(int currentPage){ |,}QhR
this.currentPage = currentPage; }14.u&4
} ]G|@F
:
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/** I<[(hPQUf
* @return V|b?H6Q
* Returns the everyPage. \a|gzC1G
*/ 2.; OHQTE
publicint getEveryPage(){ ZO0_:T#Z
return everyPage; _KD(V2W
} ijoR(R^r
R`s /^0
/** )NyGV!Zuu
* @param everyPage t'[vN~I'
* The everyPage to set. JziMjR
*/ 6 t A?<S
publicvoid setEveryPage(int everyPage){ QW~o+N~~
this.everyPage = everyPage; N#ex2c
} EH4WR/x
:_^9.`
/** _Zb_9&
* @return '| Ag,x[
* Returns the hasNextPage. sy>P n
*/ FK
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publicboolean getHasNextPage(){ %\5y6
return hasNextPage; k^ZUOWmU|
} b[BSUdCB
G%'h'AV"
/** ]=]'*Z%
* @param hasNextPage $dwv1@M2
* The hasNextPage to set. %iJ6;V4
*/ r-[z!S
publicvoid setHasNextPage(boolean hasNextPage){ pCpj#+|_)
this.hasNextPage = hasNextPage; aIqNNR
} dIM:U:c
7&HP2r
/** @?e;Jp9
* @return lzxn} TO}
* Returns the hasPrePage. 6E_YQbdy
*/ SkPv.H0Id
publicboolean getHasPrePage(){ ODEy2).
return hasPrePage; *wh'4i}u
} y& Dd
8mCr6$|%
/** %*jpQOw
* @param hasPrePage XWB>'
UDQ#
* The hasPrePage to set. tQ|b?3
*/ br'~SXl
publicvoid setHasPrePage(boolean hasPrePage){ RA\H?1;8C
this.hasPrePage = hasPrePage; e3(0L I
} n,AN&BZ
^//N-?Fx
/** :mg#&MZj<
* @return Returns the totalPage. Dvx"4EA{7{
* _@"Y3Lqi
*/ =U,;/f
publicint getTotalPage(){ - MBK/
return totalPage; nS4~1a
} TFM}P
"KFCA9u-
/** RmzK?muk
* @param totalPage MN1|k
* The totalPage to set. 9V"^F.>
*/ *b.>pY?2|
publicvoid setTotalPage(int totalPage){ ,eZ'pxt
this.totalPage = totalPage; 6qHo$#iT
} 9k83wACry
wx57dm+
} MhJ`>.z1
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8PQ$X2)
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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 7Y!^88,f.
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个PageUtil,负责对Page对象进行构造: [n< U>up
java代码: TmQ2;3%
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uIWCVR8`Y
/*Created on 2005-4-14*/ 1)
@Wcc.
package org.flyware.util.page; :X;8$.z
Zj}DlNkVu
import org.apache.commons.logging.Log; |d,1mmv@K
import org.apache.commons.logging.LogFactory; g[eI-J+F
S++}kR);
/** ZZeqOu7^
* @author Joa u\Xi]pZ@X]
* "M? (Ax
*/ wS:323
!l$
publicclass PageUtil { <'gCI Ia2
sL!6-[N
privatestaticfinal Log logger = LogFactory.getLog rc;| ,\
@l@lE0
(PageUtil.class); G=b`w;oL:
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/** hl# 9a?
* Use the origin page to create a new page nbOMtK
* @param page \kg2pF[V
* @param totalRecords J 0s8vAs
* @return p*dez!
*/ 3Um\?fj>}(
publicstatic Page createPage(Page page, int
o>W}1_
V;)'FJ)]
totalRecords){ =-vk}O0C
return createPage(page.getEveryPage(), "3\)@
'x!q*|zF2
page.getCurrentPage(), totalRecords); 9VP|a-
} |Yk23\!
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/** XKR?vr7A2
* the basic page utils not including exception jh=:Q P/
}K&K{ 9}
handler ;Y)?6^"
* @param everyPage Z4t9q`}h
* @param currentPage ^ S%4R'
* @param totalRecords p?dMa_g
* @return page v#nFPB=z
*/ Fd ]! 7
publicstatic Page createPage(int everyPage, int g0ug:- R
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currentPage, int totalRecords){ ;vd%=vR
everyPage = getEveryPage(everyPage); Tl25t^Y
currentPage = getCurrentPage(currentPage); 0<o#;ZQ]
int beginIndex = getBeginIndex(everyPage, 1`h`-dqr#
OCRx|
currentPage); S"}FsS;k<?
int totalPage = getTotalPage(everyPage, vK$T$SL
;f6G&>p
totalRecords); 38 B\ \
boolean hasNextPage = hasNextPage(currentPage, F1/f:<}
Oz n7C?\*
totalPage); :v&GAs6H
boolean hasPrePage = hasPrePage(currentPage); _b#9^2o
FiIN\
returnnew Page(hasPrePage, hasNextPage, !H.&"~w@
everyPage, totalPage, u}u2{pO!
currentPage, 3K54:
9{>m04888
beginIndex); Nf$Y-v?i
} Q<78<#I
gp$+Qd
privatestaticint getEveryPage(int everyPage){ .$?s :t
return everyPage == 0 ? 10 : everyPage; *D|6g|Hb
} h`5au<h<
Q_@
Z.{
privatestaticint getCurrentPage(int currentPage){ f\|33)k
return currentPage == 0 ? 1 : currentPage; GR|Vwxs<@P
} p6jR,m8S
4; j#7
privatestaticint getBeginIndex(int everyPage, int Q&n|tQ*4
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currentPage){ KiCZEA
return(currentPage - 1) * everyPage; 2-{8+*_'
} JU"!qXQr
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privatestaticint getTotalPage(int everyPage, int C#vh2'
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totalRecords){ E!ZDqq
int totalPage = 0; v&uIxFCR
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if(totalRecords % everyPage == 0) ayC*n'
totalPage = totalRecords / everyPage; ;/e!!P]jP
else A03PEaZO
totalPage = totalRecords / everyPage + 1 ; *rW] HNz
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return totalPage; } |sP;Rpu
} *D`,z3/*
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privatestaticboolean hasPrePage(int currentPage){ auS$B%
return currentPage == 1 ? false : true; AbfLV942
} Url8Z\;aM
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privatestaticboolean hasNextPage(int currentPage, `uGX/yQ#=
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int totalPage){ 9]hc{\
return currentPage == totalPage || totalPage == )_+#yaC
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0 ? false : true; ! 4i
} :Z`4ea"w
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} cZ o]*Gv.
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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。 n>! E ]
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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 lt(,/
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做法如下: } #%sI"9
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 rLP4l~V
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的信息,和一个结果集List: a}e7Q<cGj
java代码: 0Z9jlwcQ
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/*Created on 2005-6-13*/ !%5{jO1
package com.adt.bo; 1w\Y._jK
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import java.util.List; W%Um:C\I
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import org.flyware.util.page.Page; d6(qc< /!r
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/** 36lIV,YnU
* @author Joa m,=$a\UC
*/ )Cx8?\/c=x
publicclass Result { o@;w!'
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private Page page; zSkM8LM2
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private List content; l;?.YtMg
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/** 9>zN 27
* The default constructor t7-sCC0
*/ l:faI&o.@
public Result(){ LzgD#Kz
super(); HqN|CwGgJ:
} ydlH6 >
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/** yv'mV=BMJ!
* The constructor using fields k&^Megcb
* u5idH),<
* @param page 8t6h^uQ
* @param content {d )Et;_
*/ .# M5L
public Result(Page page, List content){ v~@Y_`l
this.page = page; ;z%& 3u/
this.content = content; !3T x\a`?/
} %/UQ0d~b
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/** 9:BGA/?
* @return Returns the content. 7<N X;Fx
*/ A"9aEOX-?i
publicList getContent(){ 8V4Qyi|@F
return content; c&R .
} _X@:-_
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/** 9|#h )*
* @return Returns the page. _&B