Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 \9?<E[
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 1c4%g-]7
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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 >>8w(PdTn%
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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 ["IJh
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分页支持类: :y
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java代码: mpivg
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package com.javaeye.common.util; :V2Q n-N
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import java.util.List; Xda<TX@-
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publicclass PaginationSupport { _Kj.
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publicfinalstaticint PAGESIZE = 30; V<pqc&f.
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privateint pageSize = PAGESIZE; vWovR`
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privateList items; DmrfD28j~F
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privateint totalCount; %Tb|Yfyr C
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privateint[] indexes = newint[0]; |*NrS<"
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privateint startIndex = 0; u_"h/)C'H
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public PaginationSupport(List items, int 4w6K|v<X
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totalCount){ gWo~o]f
setPageSize(PAGESIZE); R"o,m
setTotalCount(totalCount); 5mNXWg7#]
setItems(items); gc~h!%'.I
setStartIndex(0); uPXqTkod
} &s;^q
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public PaginationSupport(List items, int N8q Z{CWn
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totalCount, int startIndex){ kAliCD)
setPageSize(PAGESIZE); }gi'%e
setTotalCount(totalCount); 5;
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setItems(items); r3_gPK
setStartIndex(startIndex); 4Z<l>!
} ({VBp[Mh
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public PaginationSupport(List items, int F s\P/YX
{:X];A$
totalCount, int pageSize, int startIndex){ ]e~^YZOs
setPageSize(pageSize); * _lo;
setTotalCount(totalCount); *SMPHWH[c
setItems(items); F\rSYjMyk
setStartIndex(startIndex); 7YjucPH#
} [s{:}ZuKc
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publicList getItems(){ 5(7MQuRR
return items; BQ:Kx _
} L)'rM-nkFh
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publicvoid setItems(List items){ "BfmX0&?
this.items = items;
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} %u0;.3Gw
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publicint getPageSize(){ si_HN{
return pageSize; }C"*ACjF
} gA1in
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publicvoid setPageSize(int pageSize){ PB67?d~
this.pageSize = pageSize; xBfe8lor
} pQ:PwyU
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publicint getTotalCount(){ ASa!yV=g
return totalCount; aZ>\*1
} i!oj&&
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publicvoid setTotalCount(int totalCount){ ?67I|@^
if(totalCount > 0){ u=}bq{
this.totalCount = totalCount; o[[r_v_d
int count = totalCount / ,Z7Z!.TY!
s [F' h-y
pageSize; 3t{leuO'
if(totalCount % pageSize > 0) M .`
count++; K!c@aD:#
indexes = newint[count]; ?EQ^n3U$
for(int i = 0; i < count; i++){ 3e6Y
indexes = pageSize * q;zf|'&*7C
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i; 5vF}F^
} qZsddll
}else{ ~)a;59<$
this.totalCount = 0; 0s9z @>2
} ~P#zhHw
} <N=p:e,aN,
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publicint[] getIndexes(){ .7gE^
return indexes; Qb't*2c%
} r82o[+$u0K
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publicvoid setIndexes(int[] indexes){ }t%>_
this.indexes = indexes; _d| 62VS
} <I%9O:R
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publicint getStartIndex(){ wV[V#KpX8-
return startIndex; 4<Sa,~4
} 7 Y>`- \
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publicvoid setStartIndex(int startIndex){ /Ej]X`F
if(totalCount <= 0) MhI)7jj`mt
this.startIndex = 0; -?B9>6h"
elseif(startIndex >= totalCount) JD{MdhhV
this.startIndex = indexes ?6iatI !
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[indexes.length - 1]; 0 {JK4]C
elseif(startIndex < 0) ~d%;~_n
this.startIndex = 0; 7Fi2^DlgX
else{ )ClMw!ZrU
this.startIndex = indexes 2vkB<[tSs
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[startIndex / pageSize]; 90qj6.SQ
} yLz,V}
} v^c<`i;
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publicint getNextIndex(){ 4iv]N 4
int nextIndex = getStartIndex() + #xP!!.DF(
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pageSize; "?SOBA!vy
if(nextIndex >= totalCount) jfY{z=*]u
return getStartIndex(); OOBcJC
else \_*MJ)h)X
return nextIndex; -[pCP_`)u
} HD:%Yv
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publicint getPreviousIndex(){ 9S1Ti6A
int previousIndex = getStartIndex() - SE^b0ZV*x
t+ S~u^
pageSize; Sq-3-w,R~
if(previousIndex < 0) G?ugMl}
return0; JOdwv4(3V
else j|&DP-@g/
return previousIndex; |#&V:GZp
} 27a*H1iQ
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} [t.%baF
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抽象业务类 T")i+v
java代码: pYfV~Q^3
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/** Y%/ YFO2vb
* Created on 2005-7-12 MV<!<Qmj
*/ ~y)bYG!G
package com.javaeye.common.business; {M@@)27gW
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import java.io.Serializable; ^RV
import java.util.List; _3.G\/>[K
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import org.hibernate.Criteria; w<Yv`$-`
import org.hibernate.HibernateException; 0F+zG)G"
import org.hibernate.Session; W`N}
import org.hibernate.criterion.DetachedCriteria; >:jM}*dnL
import org.hibernate.criterion.Projections; -MrtliepW*
import Eq=wdI
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org.springframework.orm.hibernate3.HibernateCallback; /bmXDDYH4
import -SvTg{Q{la
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org.springframework.orm.hibernate3.support.HibernateDaoS ^`rpf\GX(
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upport; `*NO_K
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import com.javaeye.common.util.PaginationSupport; zj>aaY
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public abstract class AbstractManager extends M@~~f
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HibernateDaoSupport { 2~!R*i
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privateboolean cacheQueries = false; ufw3H9F(O
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privateString queryCacheRegion; Zk=*7?!!
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publicvoid setCacheQueries(boolean C,A!tj7@
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cacheQueries){ :reP} Da7q
this.cacheQueries = cacheQueries; 3`A>j"
} |(V?,^b^ro
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publicvoid setQueryCacheRegion(String +Qh[sGDdY
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queryCacheRegion){ D XV@DQ
this.queryCacheRegion = 7}4'dW.
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queryCacheRegion; , 3X: )
} TN35CaSmq
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publicvoid save(finalObject entity){ jt{9e:2%
getHibernateTemplate().save(entity); oW1"%i%
} ~x|aoozL
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publicvoid persist(finalObject entity){ L[?nST18%
getHibernateTemplate().save(entity); /!GKh5|
}
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publicvoid update(finalObject entity){ FR
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getHibernateTemplate().update(entity); E *F*nd]K
} '>j<yaD'
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publicvoid delete(finalObject entity){ :qKF58W
getHibernateTemplate().delete(entity); \q~w<%9Dq
} -2F@~m|
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publicObject load(finalClass entity, .yZm^&
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finalSerializable id){ c$0_R;4/
return getHibernateTemplate().load P+<BOG|m
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(entity, id); ,;_rIO"
} egm)a
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publicObject get(finalClass entity, A1^Ga5 B>
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finalSerializable id){ |G(1[RNu
return getHibernateTemplate().get ?c!:81+\
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(entity, id); qM%O
} F4Zn5&.)
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publicList findAll(finalClass entity){ b~7Jh:%@;
return getHibernateTemplate().find("from |6E
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" + entity.getName()); Q1Ux!$_
} h#i\iK&A
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publicList findByNamedQuery(finalString b1u}fp
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namedQuery){ 9UwLF`XM
return getHibernateTemplate 8j%'9vPi
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().findByNamedQuery(namedQuery); ncv7t|ZN
} Bv$UFTz
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publicList findByNamedQuery(finalString query, jM~Bu.7 i6
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finalObject parameter){ nnNv0?>d(
return getHibernateTemplate V!4a*,Pz
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().findByNamedQuery(query, parameter); f/}
} @F>F#-2
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publicList findByNamedQuery(finalString query, ?i~g,P]NK
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finalObject[] parameters){ < f(?T`
return getHibernateTemplate -ynBi;nH
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().findByNamedQuery(query, parameters); e+'%!w"B
} MIq"Wy|Zs
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publicList find(finalString query){ G@gh#[b
return getHibernateTemplate().find jd 1jG2=f
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(query); q-nER<
} ["y6b*;x
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publicList find(finalString query, finalObject nnwJYEi
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parameter){ [4*1}}gW%5
return getHibernateTemplate().find BOvF)4`
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(query, parameter); 5t\HJ`C1Z
} pMR,#[U<
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public PaginationSupport findPageByCriteria {uU 2)5i2-
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(final DetachedCriteria detachedCriteria){ ^~$\ g]
return findPageByCriteria prtK:eGe2
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); A%u_&a}
} 3J~0O2
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public PaginationSupport findPageByCriteria 9sSN<7
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(final DetachedCriteria detachedCriteria, finalint .oqIZ\iik
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startIndex){ wpXgPVZT
return findPageByCriteria 2N5`'
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(detachedCriteria, PaginationSupport.PAGESIZE, :^i^0dC
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startIndex); |mhKI is U
} -)v@jlg02
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public PaginationSupport findPageByCriteria \OQkZ.cU;
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(final DetachedCriteria detachedCriteria, finalint $TG=w
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pageSize, 0
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finalint startIndex){ -fy9<
return(PaginationSupport) B4h5[fPX
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getHibernateTemplate().execute(new HibernateCallback(){ B(_WZa!
publicObject doInHibernate k()$:-V
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(Session session)throws HibernateException { j+rG7z){K
Criteria criteria = r^0F"9eOL
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detachedCriteria.getExecutableCriteria(session); D:"{g|nW}
int totalCount = GIyF81KR 3
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((Integer) criteria.setProjection(Projections.rowCount V`kMCE;?l
-]srp;=i
()).uniqueResult()).intValue(); ;"kaF!
criteria.setProjection
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(null); OhVs#^
List items = Cr C=A=e
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criteria.setFirstResult(startIndex).setMaxResults H1/?+N}(
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(pageSize).list(); YJ_\Ns+Ow
PaginationSupport ps = zmI] cD@G
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new PaginationSupport(items, totalCount, pageSize, k*?I>%^6#T
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startIndex); mh.+."<)F
return ps; Ts.wh>`
}
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}, true); A1"SLFY
} x79Ha,
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public List findAllByCriteria(final cxIk<&i~(
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DetachedCriteria detachedCriteria){ -' g*^
return(List) getHibernateTemplate au7.4ln>Y
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().execute(new HibernateCallback(){ z^<L(/rg9"
publicObject doInHibernate UC
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(Session session)throws HibernateException { +Q$h ]^>~
Criteria criteria = tM4Cx
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detachedCriteria.getExecutableCriteria(session); IQZ#-)[T"
return criteria.list(); CVNj-&vj
} lf(`SYQnOY
}, true); !-<p,z
} _ :Ag?2
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public int getCountByCriteria(final qpIC{'A.
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DetachedCriteria detachedCriteria){ _>+8og/%@
Integer count = (Integer) R:X0'zeRr
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getHibernateTemplate().execute(new HibernateCallback(){ 3cdTed-MIh
publicObject doInHibernate #>lG7Ns|4
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(Session session)throws HibernateException { AN!s{7V3
Criteria criteria = Ae]sGU|?'
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detachedCriteria.getExecutableCriteria(session); ;oZ)Wt
return R;,g1m|]
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criteria.setProjection(Projections.rowCount eET&pP3Rp
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()).uniqueResult(); a=cvCf
} Ar*^;/
}, true); |L2SFB?d=
return count.intValue(); b 5yW_Ozdh
} ;OqB5qd
} CI353-`
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用户在web层构造查询条件detachedCriteria,和可选的 IxLhU45
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 .7K7h^*F
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PaginationSupport的实例ps。 V"c
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ps.getItems()得到已分页好的结果集 RuII!}*
ps.getIndexes()得到分页索引的数组 /1Ue?)g
ps.getTotalCount()得到总结果数 X 1
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ps.getStartIndex()当前分页索引 okbQ<{9
ps.getNextIndex()下一页索引 DC{>TC[p1k
ps.getPreviousIndex()上一页索引 ,) J~ ,^f6
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ;4Y%PVz~D
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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 ^#-nE7
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一下代码重构了。 x)( |[
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我把原本我的做法也提供出来供大家讨论吧: bv&;R
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首先,为了实现分页查询,我封装了一个Page类: ty8v
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java代码: ")d`dj\o
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/*Created on 2005-4-14*/ Na:w]r:y
package org.flyware.util.page; ,7<f9 EVY
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/** +HBd
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* @author Joa 8F'x=lIO
* s&RVJX>Rt
*/ 6Vz9?puD
publicclass Page { \[y`'OD~
PYGRsrcFd#
/** imply if the page has previous page */ )jt #=9ZQ
privateboolean hasPrePage; /5u<78GW1
4O35"1
/** imply if the page has next page */ ZMel{w`n
privateboolean hasNextPage; [eC2"&}
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/** the number of every page */ ouuuc9x]
privateint everyPage; J:Qa5MTWp
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/** the total page number */ k |eBJ%
privateint totalPage; 2AMo:Jqv
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/** the number of current page */ q^Y-}=w
privateint currentPage; VIv&ofyAR
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/** the begin index of the records by the current RS8Hf~0G
\SBc;
query */ b:TLV`>/&
privateint beginIndex; N<XNTf
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/** The default constructor */ ,%M$0poKM
public Page(){ mWsI}2
[k/@E+;
} )r
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/** construct the page by everyPage nCdR EXw
* @param everyPage V=o
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* */ h-`}L=
public Page(int everyPage){ T( U_
this.everyPage = everyPage; `~By)?cT_>
} E&[{4Ml
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/** The whole constructor */ Zg{KFM%
public Page(boolean hasPrePage, boolean hasNextPage, gcl5jB5)>
@X#F3;
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int everyPage, int totalPage, oY H^_V
int currentPage, int beginIndex){ R8a3
1&
this.hasPrePage = hasPrePage; .nx2";oi
this.hasNextPage = hasNextPage; ` 2V19s]
this.everyPage = everyPage; oYm[V<nIl
this.totalPage = totalPage; nH[yJGZYSA
this.currentPage = currentPage; pSdI/Vj'=
this.beginIndex = beginIndex; H _zo1AW
} ddJe=PUb
/7Cc#P6
/** K3#@SYj
* @return 8|l\EVV6
* Returns the beginIndex. ]H+8rY%+
*/ n<z[J=I
publicint getBeginIndex(){ %D\[*
return beginIndex; 3
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} l*d(;AR
:LW4E9O=H
/** GLeK'0Q@
* @param beginIndex f Sa"%8%
* The beginIndex to set. 1SCR.@k<
*/ {tYZt4!{^
publicvoid setBeginIndex(int beginIndex){ U@uGNMKR
this.beginIndex = beginIndex; w"Gm; B4
} of%Ktm5Qi
RAgg:3^
/** C26>BU<
* @return 3u*4o=4e
* Returns the currentPage. \o*5
*/ }HFN3cq;C
publicint getCurrentPage(){ 'h|DO/X~L
return currentPage; P2#XKG
} K8GP@yD]M
nxnv,AZG
/** <7/R,\Wg~
* @param currentPage 7QiIiWqIWC
* The currentPage to set. \/zq7j
*/ YIQ
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publicvoid setCurrentPage(int currentPage){ N"Zt47(
this.currentPage = currentPage; @#T|Y&
} $_"'&zQ'
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/** 3Q.#c,`jV
* @return PNgY>=Y
* Returns the everyPage. SB H(y)
*/ Czs8!S
publicint getEveryPage(){ 1\
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return everyPage; Yg%I?
} v&DI`xn~
;-~B)M_S`
/** tE<H|_{L
* @param everyPage K*K,}W&}
* The everyPage to set. D#cyOrzy
*/ u8&Z!p\
publicvoid setEveryPage(int everyPage){ lb4Pcdj
this.everyPage = everyPage; ~=M7 3U#
} +hg3I8q:
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/** .,<1%-R34q
* @return qkDI](4
* Returns the hasNextPage. ^c"jH'#.L
*/ '3/4?wi
publicboolean getHasNextPage(){ vdivq^%=a
return hasNextPage; {6|38$Rl
} H1|?t+oP
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/** `2("gUCm
* @param hasNextPage PUT=C1,OFR
* The hasNextPage to set. #+ 0M2Sa
*/ <J<{l
publicvoid setHasNextPage(boolean hasNextPage){ |W,&
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this.hasNextPage = hasNextPage; *+Ek0M
} ,w<S|#W~+
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/** bh,[ 3X%
* @return 4tRYw0f47
* Returns the hasPrePage. k]F[>26k
*/ h\fjBDU^
publicboolean getHasPrePage(){ ^ Edfv5
return hasPrePage; X5zDpi|Dq
} +rd|A|hRq
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/** LiN$
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* @param hasPrePage )B"jF>9)[
* The hasPrePage to set. JU1~e@/'%
*/ Z]>O+
publicvoid setHasPrePage(boolean hasPrePage){ |mxDjgq
this.hasPrePage = hasPrePage; !JHL\M>A5
} XKj|f`
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/** ?PuBa`zDE
* @return Returns the totalPage. '}ptj@,
* \=VtHu92=
*/ ;w{tv($$
publicint getTotalPage(){ T"{>t
return totalPage; S'Q@ScJ
} SD"FErJ
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/** QO<jI#
* @param totalPage `06;
* The totalPage to set. jl4rbzse
*/ K
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publicvoid setTotalPage(int totalPage){ ~ (|5/
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this.totalPage = totalPage; d[@X%
} {j.bC@hWw
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} |7'df &CA
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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 Sq>dt[7
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个PageUtil,负责对Page对象进行构造: |HiE@
java代码: dU&a{$ku[
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/*Created on 2005-4-14*/ g!g#]9j
package org.flyware.util.page; MK%9:wZ
}^ApJS(FQ
import org.apache.commons.logging.Log; Sj%u)#Ub
import org.apache.commons.logging.LogFactory; >{q]&}^U
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/** [<lHCQXJ/
* @author Joa 5V?&8GTe
* {%rA1g
*/ 0IsPIi"7
publicclass PageUtil { B~1_ 28\
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privatestaticfinal Log logger = LogFactory.getLog Q:2>}QgX}
/ C:Y94B-z
(PageUtil.class); u
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/** zU5v /'h>d
* Use the origin page to create a new page qzYwt]GNS
* @param page
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* @param totalRecords CuaVb1r
* @return = 6j&4p
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*/ R{C(K(5/
publicstatic Page createPage(Page page, int `l\7+0W
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totalRecords){ ak7bJ~)X=
return createPage(page.getEveryPage(), hi_NOx
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page.getCurrentPage(), totalRecords); l.q&D< _
} vLv@&lMW
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/** u0JB\)(-/h
* the basic page utils not including exception UFXaEl}R
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handler T;Lkaxsn
* @param everyPage w#ZoZZ wh
* @param currentPage H9'$C/w
* @param totalRecords &W|[r(
* @return page I,E?h?6Y
*/ &fDIQISC
publicstatic Page createPage(int everyPage, int Tr_w]'
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currentPage, int totalRecords){ R[zpD%CI
everyPage = getEveryPage(everyPage); $.Qkb@}
currentPage = getCurrentPage(currentPage); ]&o$b ]
int beginIndex = getBeginIndex(everyPage, ;;!yC
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currentPage); ..IfP@
int totalPage = getTotalPage(everyPage, d2*fLEsF
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~
totalRecords); L^r#o-H<
boolean hasNextPage = hasNextPage(currentPage, GB23\Yv
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totalPage); ] ]u
s %
boolean hasPrePage = hasPrePage(currentPage); 1auIR/=-
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returnnew Page(hasPrePage, hasNextPage, ,kyJAju>
everyPage, totalPage, [8Y:65
currentPage, _'#n6^Us<
ayn) 5q/z
beginIndex); :">!r.Q
} 'f#{{KA
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privatestaticint getEveryPage(int everyPage){ ~Q Oe##
return everyPage == 0 ? 10 : everyPage; F|IAiE
} @D]5c ivm_
^ sOQi6pL
privatestaticint getCurrentPage(int currentPage){ =J18eH!]
return currentPage == 0 ? 1 : currentPage; &xU[E!2H%
} ZJnYIK
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privatestaticint getBeginIndex(int everyPage, int Q$a{\*[:+
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currentPage){ 6]&OrS[
return(currentPage - 1) * everyPage; TEP,Dq
} TtJH7
9)h"-H;5:
privatestaticint getTotalPage(int everyPage, int Fe# 1
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totalRecords){ g&^quZ"H
int totalPage = 0; GF"hx`zyJ
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if(totalRecords % everyPage == 0) _:ReN_0
totalPage = totalRecords / everyPage; -Fi`Z$
else KWq+PeB5TS
totalPage = totalRecords / everyPage + 1 ; B?OFe'*
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return totalPage; sZ3KT&
} Mc?Qx
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privatestaticboolean hasPrePage(int currentPage){ mu\6z_e
return currentPage == 1 ? false : true; ]V[q(-Jk
} o$wEEz*4
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privatestaticboolean hasNextPage(int currentPage, =%BSKSG.
a]$1D!Anc
int totalPage){ jrCfWa}z
return currentPage == totalPage || totalPage == ML}J\7R
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0 ? false : true; 5^}\4.eXo
} 9)D6Nm
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} |-b#9JQ[A
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59 h]UX=
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 Ka'=o?'B5
T tfo^ksw
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 eJrQ\>z]V&
oro$wFxJO
做法如下: ~Sdb_EZ
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 loEPr5bL
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的信息,和一个结果集List: bYcV$KJk
java代码: aR[JD2G
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/*Created on 2005-6-13*/ mWv3!i;G<s
package com.adt.bo; hM_lsc
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import java.util.List; 'HO$C,1]
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import org.flyware.util.page.Page; kc2PoJ
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/** 2\R'@L*
* @author Joa _1!7V3|^
*/ xn?a. 3b'
publicclass Result { bc*X/).
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private Page page; R$EW4]j
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private List content; 9,c(ysv"
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/** 0!D4pvlt
* The default constructor u6J8"<
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*/ c\/=iVw,
public Result(){ <c*FCblv
super(); 50"pbzW
} |a8iZ9/D6
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/** +[Dx?XM
* The constructor using fields u :}%xD6
* Y`KqEjsC*
* @param page LmRy1T,act
* @param content Dxtp2wu%t
*/ @MoKWfc
public Result(Page page, List content){ B[qzUD*P_n
this.page = page; Ih@61>X.o*
this.content = content; !d'GE`w T
} D,FHZDt
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/** 87=&^.~`
* @return Returns the content. 1}"++Z73P
*/ <:_wbVn-
publicList getContent(){ 1kz\IQ{
return content; ] ;KJ6
} i)\L:qF5
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/** V#v`(j%
* @return Returns the page. b}\N;D.{
*/ evenq$
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public Page getPage(){ %]\kgRr
return page;
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} {GvJZ!,RCg
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/** \S_Ou
* @param content G3txj
* The content to set. CJtcn_.F
*/ .b_)%jd x
public void setContent(List content){ y@1+I~@
this.content = content; >d@&2F TO
} uMUBh 80,L
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/** .GbX]?dN
* @param page GXcJ< v
* The page to set. eJ,/:=QQ{
*/ r=Gks=NX"
publicvoid setPage(Page page){ oL-]3TY~
this.page = page; Y=%tn8<
} q$p%ZefZ
} ) g0%{dfJ
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2. 编写业务逻辑接口,并实现它(UserManager, eP.wOl
w2Us!<x
UserManagerImpl) >f^r^P
java代码: Y1L[;)H n
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uyO/55;HO
/*Created on 2005-7-15*/ m&xW6!x
package com.adt.service; ``V"
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import net.sf.hibernate.HibernateException; i1UiNJh86
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import org.flyware.util.page.Page; P|^f0Rw3.
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import com.adt.bo.Result; imo$-}A
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/** B3: ez
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* @author Joa B#exHf8
*/ w2;eh]k
publicinterface UserManager { ]5mn ew
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public Result listUser(Page page)throws 6wPaJbRtaM
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