Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 T8nOb9Nrj
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 _!vxX]
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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 M1{ru~Z9
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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 Dt)O60X3>
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分页支持类: oqLM-=0<}
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java代码: wrORyj
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package com.javaeye.common.util; &bh%>[
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import java.util.List; n'WhCrW
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publicclass PaginationSupport { e}F1ZJz
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publicfinalstaticint PAGESIZE = 30; d&N[\5q
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privateint pageSize = PAGESIZE; 8eAc 5by
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privateList items; zO@7V>2
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privateint totalCount; ]]R!MnU:$
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privateint[] indexes = newint[0]; J83{&N2u
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privateint startIndex = 0; 0j'H5>m"
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public PaginationSupport(List items, int e*nT+Rp
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totalCount){ 4`KQ@m
setPageSize(PAGESIZE); ">-mZ'$#L
setTotalCount(totalCount); 5.]eF$x2
setItems(items); ,JLY
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setStartIndex(0); l.Psh7B2
} o ?9k{
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public PaginationSupport(List items, int JA")L0a_
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totalCount, int startIndex){ v/1&V+"^kd
setPageSize(PAGESIZE); H@j
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setTotalCount(totalCount); 4ONou&T
setItems(items); J&vmW}&
setStartIndex(startIndex); ]< Ugg
} <`rl[C{
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public PaginationSupport(List items, int z 8w&;Ls
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totalCount, int pageSize, int startIndex){ Msk^H7
setPageSize(pageSize); 6wmMg i_m
setTotalCount(totalCount); _&]B
setItems(items); H&yK{0H
setStartIndex(startIndex);
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} `.0WK
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publicList getItems(){ cTq}H_hC
return items; XSw!_d
} B\tP{}P8{
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publicvoid setItems(List items){ <8'-azpJ6<
this.items = items; U}=o3u
} &~6W!w
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publicint getPageSize(){ App9um3:
return pageSize; o'`:$
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} M?3Nh;
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publicvoid setPageSize(int pageSize){ 7Zf
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this.pageSize = pageSize; YpGG^;M$
} WZ3GI
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publicint getTotalCount(){ >=WlrmI
return totalCount; hm&cRehU
} 5*n3*rbU:
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publicvoid setTotalCount(int totalCount){ :M |<c9I
if(totalCount > 0){ 1U/ dc.x5
this.totalCount = totalCount; Q#Vg5H4
int count = totalCount / 5i$iUDuT>(
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pageSize; w<0F-0:8
if(totalCount % pageSize > 0) 9(CY"Tc3
count++; BbV @ziL
indexes = newint[count]; {zri6P+s
for(int i = 0; i < count; i++){ z|^+uL
indexes = pageSize *
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} OX
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}else{ TrEo5H ;
this.totalCount = 0; &.ilku/
} V*C%r:5 ,v
} KcK,%!>B
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publicint[] getIndexes(){ v95O)cC:W
return indexes; qSg=[7XOO
} G%RL8HU
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publicvoid setIndexes(int[] indexes){ (9phRo)>
this.indexes = indexes; p /x]
} ma%PVz`I;9
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publicint getStartIndex(){ y-/,,,r
return startIndex; H E'1Wa0r
} NY,ZTl_
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publicvoid setStartIndex(int startIndex){ kW!`vQm~
if(totalCount <= 0) eBs4:R_i
this.startIndex = 0; e0nr dM[i
elseif(startIndex >= totalCount) ;L{#TC(]J]
this.startIndex = indexes 43HZ)3!me
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[indexes.length - 1]; keMfK]9
elseif(startIndex < 0) ?:
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this.startIndex = 0; =rB=! ;
else{ [l7 G9T}/[
this.startIndex = indexes 0YApaL+jt
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[startIndex / pageSize]; MB:VACCr
} 4uV,$/
} WYayr1
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publicint getNextIndex(){ DJGq=*
int nextIndex = getStartIndex() + [Up0<`Q{I_
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pageSize; l[cBDNlrC;
if(nextIndex >= totalCount) 1vG]-T3VC
return getStartIndex(); O*:8gu'Y2
else @TWt M#
return nextIndex; (X(296<;
} |rhCQ"H
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publicint getPreviousIndex(){ K~MTbdg
int previousIndex = getStartIndex() - [&B}{6wry
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pageSize; [tP6FdS/M=
if(previousIndex < 0) mH/$_x)o
return0; i,h)
else }z/Y
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return previousIndex; xwm-)~L4T
} {;kH&Pp
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} I {o\d'/
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抽象业务类 Kr*s]O
java代码: VHUOI64*
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/** #3L=\j[
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* Created on 2005-7-12 u3Jsu=Nx-
*/ >~% _U+6
package com.javaeye.common.business; +EnJyli
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import java.io.Serializable; ST^@7f_
import java.util.List; G#~6a%VW
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import org.hibernate.Criteria; 1 ^k#g,
import org.hibernate.HibernateException; ];|;") #=
import org.hibernate.Session; >;ucwLi
import org.hibernate.criterion.DetachedCriteria; z
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import org.hibernate.criterion.Projections; X[XSf=
import 1Xv- e8M
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org.springframework.orm.hibernate3.HibernateCallback; KLc<c1BZ
import TAbC-T.EV
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org.springframework.orm.hibernate3.support.HibernateDaoS mB:I8g7
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upport; jx=2^A/i2-
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import com.javaeye.common.util.PaginationSupport; Tk'YpL#U
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public abstract class AbstractManager extends TV>UD
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HibernateDaoSupport { 4YVxRZ1[3
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privateboolean cacheQueries = false; JvHGu&Nr!
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privateString queryCacheRegion; Dl3Df u8
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publicvoid setCacheQueries(boolean 07T"alXf:A
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cacheQueries){ &}1PH%6
this.cacheQueries = cacheQueries; Um
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} x)hp3&L
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publicvoid setQueryCacheRegion(String N'fE^jqU
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queryCacheRegion){ ^n|u$gIF8
this.queryCacheRegion = tZtyx;EP
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queryCacheRegion; NU*6MT4
} -*sDa6L
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publicvoid save(finalObject entity){ 05zBB
getHibernateTemplate().save(entity); Y5~_y?BX
} BzqM$F(
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publicvoid persist(finalObject entity){ 9S0I<<m
getHibernateTemplate().save(entity); s@sr.'yU
} |0?h6
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publicvoid update(finalObject entity){ .0:twj
getHibernateTemplate().update(entity); -hf)%o$
} \v7M`! &
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publicvoid delete(finalObject entity){ NhyVX%qt:
getHibernateTemplate().delete(entity); **V^8'W<
} (
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publicObject load(finalClass entity, 0/d+26lR
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finalSerializable id){ 48CLnyYiF
return getHibernateTemplate().load `<Xq@\H
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(entity, id); 3jIi$X06
} TY[1jW~{r
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publicObject get(finalClass entity, bv`gjR
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finalSerializable id){ klduJT
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return getHibernateTemplate().get )A9K9pZj
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(entity, id); 6LRI~*F=3
} a;J{'PHu
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publicList findAll(finalClass entity){ <JE-#i
return getHibernateTemplate().find("from m5lMh14E
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" + entity.getName()); 3!M;Z7qF]
} 0S <;T+WA
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publicList findByNamedQuery(finalString GUJ[2/V~A
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namedQuery){ lwhAF, '$
return getHibernateTemplate |?6r&bT
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().findByNamedQuery(namedQuery); _IJPZ'Hr
} S~fQ8t70
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publicList findByNamedQuery(finalString query, _ETG.SYq
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finalObject parameter){ :nYl]Rm
return getHibernateTemplate `An`"$z
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().findByNamedQuery(query, parameter); ;o]'7qGb
} WmTSxneo
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publicList findByNamedQuery(finalString query, [{e[3b*M|
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finalObject[] parameters){ ''S*B|:
return getHibernateTemplate @K/}Ob4
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().findByNamedQuery(query, parameters); %E Jv!u*-
} n5dFp%k
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publicList find(finalString query){ MkZm
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return getHibernateTemplate().find 8X`iMFa.P
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(query); s@sRdoTdF
} }N^.4HOS8
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publicList find(finalString query, finalObject T8E=}!68w}
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parameter){ ^l|{*oj2
return getHibernateTemplate().find pUx~
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(query, parameter); :&ir5xHS
} 3/V&PDC*'
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public PaginationSupport findPageByCriteria <a7y]Py
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(final DetachedCriteria detachedCriteria){ [2I1W1pd
return findPageByCriteria c'n EbelE
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); x? 3U3\W
} U 2am1}
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public PaginationSupport findPageByCriteria D@ut -J(.
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(final DetachedCriteria detachedCriteria, finalint 7YT%.ID
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startIndex){ :U_k*9z}=
return findPageByCriteria 8&?Kg>M
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(detachedCriteria, PaginationSupport.PAGESIZE, Rd~-.&
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startIndex); S]&f+g}&w
} ?145^ w
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public PaginationSupport findPageByCriteria g&eIfm
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(final DetachedCriteria detachedCriteria, finalint R:c$f(aKv%
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pageSize, J'c]':U
finalint startIndex){ iJ n<
return(PaginationSupport) +(n&>75
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getHibernateTemplate().execute(new HibernateCallback(){ AyHhq8Y
publicObject doInHibernate ~I[Z2&I
R-8>,
(Session session)throws HibernateException { kN (*.Q|VZ
Criteria criteria = YaiogA
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detachedCriteria.getExecutableCriteria(session); ~q]@Jp
int totalCount = mQEE?/xX;
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((Integer) criteria.setProjection(Projections.rowCount .j"iJ/
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()).uniqueResult()).intValue(); '}#=I 9=ss
criteria.setProjection *IBT!@*Q&
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(null); x\(@v
List items = m? 3!
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criteria.setFirstResult(startIndex).setMaxResults ='r86vq
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(pageSize).list(); Zo$,{rl
PaginationSupport ps = SURbH;[
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new PaginationSupport(items, totalCount, pageSize, `)5,!QPQ7u
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startIndex); F)fCj^zL
return ps; R1'tW=
} pXn(#n<
}, true); NsbC0xLd
} N
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public List findAllByCriteria(final [=3f:>ssm
*[XVkt`H
DetachedCriteria detachedCriteria){ j&6O1
return(List) getHibernateTemplate 9gWR djK:
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().execute(new HibernateCallback(){
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publicObject doInHibernate op!ft/Yyb
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(Session session)throws HibernateException { Z"ce1cB
Criteria criteria = s,z$Vt"h*K
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detachedCriteria.getExecutableCriteria(session); +-%&,>R
return criteria.list(); ~Qg:_ @@\
}
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}, true); fRcs@yZnS
} >JSk/]"
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public int getCountByCriteria(final adCTo
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DetachedCriteria detachedCriteria){ j<*
Integer count = (Integer) yW=I*f
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getHibernateTemplate().execute(new HibernateCallback(){ N<d0C
publicObject doInHibernate Xl/SDm_p
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(Session session)throws HibernateException { ~]w|ULNa3|
Criteria criteria = XJ$mRh0`K
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detachedCriteria.getExecutableCriteria(session); l_q=@y
return G5l?c@o
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criteria.setProjection(Projections.rowCount o[A y2"e?
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()).uniqueResult(); `F(ghC
} Z&Qz"V>$
}, true); n%R l$
return count.intValue(); )'1rZb5
}
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用户在web层构造查询条件detachedCriteria,和可选的 K*/X{3 J;
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 1;E^3j$
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PaginationSupport的实例ps。 yQ03&{#
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ps.getItems()得到已分页好的结果集 |19zjhl
ps.getIndexes()得到分页索引的数组 }o:sU^Pwa
ps.getTotalCount()得到总结果数 j*fs [4
ps.getStartIndex()当前分页索引 -Pt']07E
ps.getNextIndex()下一页索引 q(XO_1W0V
ps.getPreviousIndex()上一页索引 %>z)Q
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 (X?et
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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 *p.70,5,
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一下代码重构了。 HxnWM\ p
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我把原本我的做法也提供出来供大家讨论吧: iebnQf
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首先,为了实现分页查询,我封装了一个Page类: 5)=YTUCk
java代码: -oMp@2\e
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/*Created on 2005-4-14*/ ;a9`z+ K
package org.flyware.util.page; ,xOOR
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/** @E
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* @author Joa 48g`i
* 1<E:`,Mn?
*/ +AkMU|6
publicclass Page { =67tQx58
$/|2d4O:{
/** imply if the page has previous page */ 9*CJWS;
privateboolean hasPrePage; jA,|.P>
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/** imply if the page has next page */ XM:Y(#?l
privateboolean hasNextPage; z$b'y;k
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/** the number of every page */ (>M@Ukam:
privateint everyPage; )2g-{cYv
cIB[D.
/** the total page number */ %O02xr=
privateint totalPage; MgrJ ;?L
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/** the number of current page */ dA[S@ysvG
privateint currentPage; T@gm0igW/;
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/** the begin index of the records by the current 4fgYO]
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query */ P{[@t_
privateint beginIndex; $I4:g.gKpG
yl UkVr
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/** The default constructor */ ^M7pCetjdW
public Page(){ ' "I-! +
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} xt=ELzu$
[;, Xp/
/** construct the page by everyPage /4%ycr6
* @param everyPage bY!1t}ALh
* */ &+Yoob]P
public Page(int everyPage){ atYe$Db
this.everyPage = everyPage; y*7<tj.`b0
} Tt+E?C%Y
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/** The whole constructor */ U^Ulj/%6
public Page(boolean hasPrePage, boolean hasNextPage, o8!uvl}:9
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l
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int everyPage, int totalPage, "c*&~GSE4
int currentPage, int beginIndex){ ; wKsi_``@
this.hasPrePage = hasPrePage; wgFAPZr
this.hasNextPage = hasNextPage; /^Ng7Mi!
this.everyPage = everyPage; K3-Cuku
this.totalPage = totalPage; iZn<j'u
this.currentPage = currentPage; u7}C):@H
this.beginIndex = beginIndex; XI7:y4M
} EB2 5N~7
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/** O#3PUuE%d
* @return *Y<1KXFU
* Returns the beginIndex. o7 1f<&1
*/ zot_ jSV
publicint getBeginIndex(){ U8GvUysB!
return beginIndex; M.0N`NmS
} k.Q4oyei
kJK:1;CM?.
/** *7G5\[gI$
* @param beginIndex 3 Q~zli:
* The beginIndex to set. ?
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*/ ^zVW 3Y q
publicvoid setBeginIndex(int beginIndex){ &l
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this.beginIndex = beginIndex; !B:wzb_
} 7xoq:oP-}N
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/** X}G3>HcP
* @return $Eh:m&hq
* Returns the currentPage. |[/'W7TV%?
*/ {D7v[P+
publicint getCurrentPage(){ -Ta|
qQa
return currentPage; S7f"\[Aw
} )F65sV{
TDZ p1zpXb
/** <jIuVX
* @param currentPage /\d@A B^5I
* The currentPage to set. ;$/]6@bqB
*/ erdA?
publicvoid setCurrentPage(int currentPage){ Y:4/06I
this.currentPage = currentPage; 7O\ Qxc\
} prO ~g
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/** 8;5@5Au
* @return +~za6
* Returns the everyPage. R-OQ(]<*
*/ %{ +>\0x
publicint getEveryPage(){ G}#p4\/
return everyPage; 0^mCj<g
} `tH:oP0=
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/** BT*{&'\/
* @param everyPage @: K={AIa
* The everyPage to set. gX;)A|9e
*/ UKzXz0
publicvoid setEveryPage(int everyPage){ ~w"e 2a
this.everyPage = everyPage; y!/:1BHlm
} m t}3/d
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/** *Z2#U?_
* @return ewVks>lbz
* Returns the hasNextPage. - sL4tMP
*/ O1Nya\^g<I
publicboolean getHasNextPage(){ Q(/F7"m
return hasNextPage; WuMr";2*E
} UX@8
7O<K?;I
/** }$@ EpM
* @param hasNextPage 8RjFp2)W
* The hasNextPage to set. a3C\?5
*/ Nbd[xs-lw
publicvoid setHasNextPage(boolean hasNextPage){ tG*HUN?*
this.hasNextPage = hasNextPage; =PYS5\k
} 9F2MCqvcm
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/** g<^-[w4/
* @return FZx.Yuv
* Returns the hasPrePage. Y3bZ&G)
*/ Mu/hTTiNx
publicboolean getHasPrePage(){ .05x=28n%
return hasPrePage; <F?UdMT4y
} o?S!o}
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/** S3gd'Bahq
* @param hasPrePage a\tv,Lx
* The hasPrePage to set. <uvA([r=Vq
*/ S=qx,<J
39
publicvoid setHasPrePage(boolean hasPrePage){ [WO>}rGw4
this.hasPrePage = hasPrePage; qL~|bfN
} FQM9>l@6)>
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/** ASUleOI79(
* @return Returns the totalPage. l(d3N4iz
* @P/6NMjZ^
*/ "=!sZO?3
publicint getTotalPage(){ m.ejGm?
return totalPage; o "1X8v
} (lt{$0
'Xu3]'m*
/** e@{Rlz
* @param totalPage -YY@[5x?u
* The totalPage to set. 0X}0,
*/ ?Lbn R~/J
publicvoid setTotalPage(int totalPage){ U &RZx&W
this.totalPage = totalPage; <v3pI!)x
} v0KJKrliGO
l`."rei%)
} LL+PAvMg
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lsKQZ@LN`
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 ]|_+lik#
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个PageUtil,负责对Page对象进行构造: ,PeE'$q
java代码: '3fN2[(
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:ka^ztXG
/*Created on 2005-4-14*/
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package org.flyware.util.page; ^/~C\
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x
import org.apache.commons.logging.Log; vr }-u
import org.apache.commons.logging.LogFactory; H7}f[4S%
!
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/** wY"BPl]b
* @author Joa %Ot*k%F
* #]r'?GN
*/ PQP|V>g
publicclass PageUtil { 1v 4M*
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privatestaticfinal Log logger = LogFactory.getLog !V-(K_\t
i&j]FX6q
(PageUtil.class); +*wr=9>
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/** }8'b}7!
* Use the origin page to create a new page ~.CmiG.7
* @param page CW
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* @param totalRecords b8!
* @return slaH 2}$xR
*/ v1p^="IHI
publicstatic Page createPage(Page page, int (*9-Fa
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totalRecords){ U:bnX51D4
return createPage(page.getEveryPage(), 85lcd4&~
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page.getCurrentPage(), totalRecords); KxDp+]N]
} 8vQR'<,
odn3*{c{x
/** ?in)kL
* the basic page utils not including exception 6FY.kN\
$g),|[x+(
handler ] !n3j=*
* @param everyPage f{2I2kJr
* @param currentPage Dt(xj}[tC
* @param totalRecords ^I)+u>fJ
* @return page N_/+B]r }T
*/ a'A<'(yv
publicstatic Page createPage(int everyPage, int fk!9` p'
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currentPage, int totalRecords){ ~K"nm {.
everyPage = getEveryPage(everyPage); MjWxfW/
currentPage = getCurrentPage(currentPage); VOIni<9y
int beginIndex = getBeginIndex(everyPage, P3nBxw"
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currentPage); 3R-5&!i
int totalPage = getTotalPage(everyPage, ]B$J8.{q0
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totalRecords); zRbY]dW
boolean hasNextPage = hasNextPage(currentPage, 9ENI%Jz
<@Vf:`a!P>
totalPage); k SgE_W)
boolean hasPrePage = hasPrePage(currentPage); p$uPj*
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returnnew Page(hasPrePage, hasNextPage, .(3ec/i4CF
everyPage, totalPage, N9*:]a
currentPage, SPXvi0Jg
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beginIndex); qDU4W7|T`
} jw`05rw:
`WnsM;1Y"
privatestaticint getEveryPage(int everyPage){ crN*eFeW
return everyPage == 0 ? 10 : everyPage; `- (<Q;iO
} Gp+\}<^Z
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privatestaticint getCurrentPage(int currentPage){ 3+(lKd
return currentPage == 0 ? 1 : currentPage; HUAYtUBH
} )W InPW
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privatestaticint getBeginIndex(int everyPage, int dfKGO$}V
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currentPage){ ;Rpib[m
return(currentPage - 1) * everyPage; U| VL+9#hd
} 6q>}M
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privatestaticint getTotalPage(int everyPage, int e([>sAx!1
x)GheM^
totalRecords){ GM?s8yZ<
int totalPage = 0; N-_APWA
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if(totalRecords % everyPage == 0) =J)<Nx.gA
totalPage = totalRecords / everyPage; k54\H.
else dR;N3KwY
totalPage = totalRecords / everyPage + 1 ; GBT|1c'i
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return totalPage; s\pukpf@
} #QIY+muN
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privatestaticboolean hasPrePage(int currentPage){ T!ZjgCY}
return currentPage == 1 ? false : true; y_}vVHT,
} NjpWK;L
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privatestaticboolean hasNextPage(int currentPage, )E*f30
}7(+#ISK6
int totalPage){ P.C?/7$7Z+
return currentPage == totalPage || totalPage == ]& ckq
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0 ? false : true; ?]$<Ufr
} `Wg"m~l$N
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} |-b\N6
}
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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。 _ia&|#n
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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 R/Bjc}J'
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做法如下: ''@Tke3IG6
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 (ct1i>g
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的信息,和一个结果集List: hmo4H3g!N
java代码: cB){b'WJ
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/*Created on 2005-6-13*/ N=C t3
package com.adt.bo; [mu8V+8@d4
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import java.util.List; ElUFne=
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import org.flyware.util.page.Page; )/@KdEA:
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/** iv_3R}IbX
* @author Joa ,--#3+]XU
*/ 9e
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publicclass Result { Hq 5#.rZ#
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private Page page; #X'-/q`.
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private List content; /)J]ItJlz
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