Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 8gP1]xD
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Mk}T
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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 +-j-)WU?,
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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 &>zH.6%$
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分页支持类: \jiE:Qt
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java代码: L+8ar9es
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package com.javaeye.common.util; 4aS}b3=n
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import java.util.List; A9.TRKb=8
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publicclass PaginationSupport { xsH1)
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publicfinalstaticint PAGESIZE = 30; |T|m5V'l
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privateint pageSize = PAGESIZE; |UB$^)Twb
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privateList items; ZM.'W}J{*
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privateint totalCount; RsZj
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privateint[] indexes = newint[0]; Y:!L
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privateint startIndex = 0; Oh! {E5!)
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public PaginationSupport(List items, int ;:6\w!fc
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totalCount){ N{v)pu.
setPageSize(PAGESIZE); 0nb%+],pX
setTotalCount(totalCount); TF8#I28AD
setItems(items); ^p3GT6
setStartIndex(0); "W7|Xp
} B->AY.&j
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public PaginationSupport(List items, int (.4lsKN<
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totalCount, int startIndex){ d6J/)nl
setPageSize(PAGESIZE); OD8
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setTotalCount(totalCount); aFTWzz
setItems(items); Zonjk%tC
setStartIndex(startIndex); &*v\t\]
} &en.
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public PaginationSupport(List items, int $r!CQ2S
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totalCount, int pageSize, int startIndex){ JIyS e:p3
setPageSize(pageSize); {srP3ll
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setTotalCount(totalCount); E#J})cPzw
setItems(items); (GC]=
setStartIndex(startIndex); UY(T>4H+h
} ;xwcK-A
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publicList getItems(){ PT~htG<Fw
return items; pkn^K+<n,
} HA,o2jZ?In
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publicvoid setItems(List items){ L I<S
this.items = items; 9+@h2"|N4*
} gQeQy
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publicint getPageSize(){ L2XhrLK.|
return pageSize; +hN>Q$E
} c~R'`Q
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publicvoid setPageSize(int pageSize){ RDdnOzx
this.pageSize = pageSize; Ev7.!
} ,\M77V
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publicint getTotalCount(){ K0gQr.J53
return totalCount; ]X6<yzu&+l
} p\&O;48=
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publicvoid setTotalCount(int totalCount){ %,T*[d&i
if(totalCount > 0){ B\Nbt!Ps
this.totalCount = totalCount; '7?Y+R@|L
int count = totalCount / x%EGxs;>^
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pageSize; 2VN].t:
if(totalCount % pageSize > 0) ?EFRf~7JP
count++;
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indexes = newint[count]; yNI0Do
2
for(int i = 0; i < count; i++){ ,6>3aD1w~q
indexes = pageSize * =z'(FP5!0
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i; uPfz'|,
} TE
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}else{ F vkyp"W3
this.totalCount = 0; S`kOtZ_N n
} =|?`5!A
} gzs\C{4D
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publicint[] getIndexes(){ 99=~vNn
return indexes; NH/A`Wm
} KfiSQ!{
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publicvoid setIndexes(int[] indexes){ le/j!
this.indexes = indexes; ve
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} l 2Sar1~1
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publicint getStartIndex(){ cACIy yQ
return startIndex; {[!<yUJ`S#
} ,`HweIq(
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publicvoid setStartIndex(int startIndex){ n#">k%bD
if(totalCount <= 0) E;a,].
this.startIndex = 0; *Ypn@YpSp
elseif(startIndex >= totalCount) "
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this.startIndex = indexes ( cs
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[indexes.length - 1]; P*&[9)d6
elseif(startIndex < 0)
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this.startIndex = 0; aGbG@c8PRi
else{ 5SY%B#;5G
this.startIndex = indexes bWo
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[startIndex / pageSize]; rDWAZ<;;
} ogFo/TKM
} &Sd5]r@+
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publicint getNextIndex(){ vqeH<$WHvy
int nextIndex = getStartIndex() + *p(_="J,
"L~Oj&AN[
pageSize; bLg!LZ|S0s
if(nextIndex >= totalCount) )V1xL_hx/
return getStartIndex(); .
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else @[;'b$T$
return nextIndex;
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} 3RtVFDIZA"
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publicint getPreviousIndex(){ 6$b=Tr=0
int previousIndex = getStartIndex() - ;U(]#pW!t
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pageSize; .b";7}9{
if(previousIndex < 0) MN<LZC%$
return0; eke[{%L
else Cu+p!hV
return previousIndex; {]dxFhe)
} 3=
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} d~<$J9%
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抽象业务类 )]fiyXA
java代码: zx$YNjeV
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/** 3
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* Created on 2005-7-12 Xe);LhDC
*/ Y~}MfRE3z
package com.javaeye.common.business; LLgw1 @-D
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import java.io.Serializable; 9Kd=GL_
import java.util.List; 8ae`V!5
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import org.hibernate.Criteria; 7rdmj[vu
import org.hibernate.HibernateException;
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import org.hibernate.Session; &| (K#|^@
import org.hibernate.criterion.DetachedCriteria; "pDU v^ie
import org.hibernate.criterion.Projections; ;T^s&/>E
import ={BC0,
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org.springframework.orm.hibernate3.HibernateCallback; 9?\cm}^?
import hrKeOwKHU
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org.springframework.orm.hibernate3.support.HibernateDaoS }n&nuaj
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upport; +t,b/K(?]
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import com.javaeye.common.util.PaginationSupport; VrW]|jIu*
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public abstract class AbstractManager extends bhUE!h<
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HibernateDaoSupport { [k
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privateboolean cacheQueries = false; o`CM15d*7o
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privateString queryCacheRegion; RJ?)O#}
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publicvoid setCacheQueries(boolean Q9cSrU[$
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cacheQueries){ cpk\;1&t
this.cacheQueries = cacheQueries; !mK()# 6
} Sd6O?&(
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publicvoid setQueryCacheRegion(String %i?
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queryCacheRegion){ ,It0brF
this.queryCacheRegion = j*QdD\)
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queryCacheRegion; )L&y@dy)
} w
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publicvoid save(finalObject entity){ fExFpR,`
getHibernateTemplate().save(entity); 76T7<.S
} ~;oXLCL0})
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publicvoid persist(finalObject entity){ _!2lnJ4+5
getHibernateTemplate().save(entity); o+x%q<e;c
} pS8\ B
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publicvoid update(finalObject entity){ ;C-ds
getHibernateTemplate().update(entity); uV gA <*0
} FtJaX])b
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publicvoid delete(finalObject entity){ |~A*?6:@
getHibernateTemplate().delete(entity); S(3h{Y"#
} iU+SXsXLR4
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publicObject load(finalClass entity, GpPM ?
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finalSerializable id){ T
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return getHibernateTemplate().load n_{&dVE
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(entity, id); QV."ZhL5 =
} 7y^)n<'co
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publicObject get(finalClass entity, @~gPZm
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finalSerializable id){ $/^Y(0
return getHibernateTemplate().get GQg
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(entity, id); W.4R+kF<
} "#Z e3Uy\
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publicList findAll(finalClass entity){ G!`%.tH
return getHibernateTemplate().find("from yPfx!9B
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" + entity.getName()); `/1rZ#
} Q:)4
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publicList findByNamedQuery(finalString =0&XdxX
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namedQuery){ 4r;le5@
return getHibernateTemplate e|C2/U-
hcU^!mp
().findByNamedQuery(namedQuery); "u^2!d
} 8]&Fu3M^
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publicList findByNamedQuery(finalString query, =_&,^h@'3e
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finalObject parameter){ n jd2
return getHibernateTemplate 1f3g5y'z5
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().findByNamedQuery(query, parameter); 3B[tbU(
} 4qDa:D"5
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publicList findByNamedQuery(finalString query, v$` 3}<3-
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finalObject[] parameters){ E_&;.hw
return getHibernateTemplate 0Runex[
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().findByNamedQuery(query, parameters); "o%okN
} no\G
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publicList find(finalString query){ '3^_:E5y
return getHibernateTemplate().find %dw0\:P?Q
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(query); 0<A*I{,4L
} Q~^v=ye
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publicList find(finalString query, finalObject LP7jCt
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parameter){ `?&C5*P
return getHibernateTemplate().find hJFxT8B/
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(query, parameter); 0dx%b677d
} p8]X Ne
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public PaginationSupport findPageByCriteria NWwKp?
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(final DetachedCriteria detachedCriteria){ c(Xm~
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return findPageByCriteria vzAY+EEx
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ,*Wh{)
} S41S+#7t*
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public PaginationSupport findPageByCriteria Oxu}W%BF*
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(final DetachedCriteria detachedCriteria, finalint 1Xcj=I-4
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startIndex){ FBi&MZ`
return findPageByCriteria n%2c<@p#
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(detachedCriteria, PaginationSupport.PAGESIZE, Ye^#]%m
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startIndex); ,o2x,I
} JWM4S4yZHR
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public PaginationSupport findPageByCriteria /L`qOr2E
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(final DetachedCriteria detachedCriteria, finalint 5[6{o$I
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pageSize, Hm 0;[i
finalint startIndex){ $W;r S7b
return(PaginationSupport) NHdNCHhA>-
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getHibernateTemplate().execute(new HibernateCallback(){ laCVj6Rk
publicObject doInHibernate Zz|et206
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(Session session)throws HibernateException { .$&vSOgd(
Criteria criteria = n Fwg pT
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detachedCriteria.getExecutableCriteria(session); BMzS3;1_
int totalCount = j%S}
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((Integer) criteria.setProjection(Projections.rowCount o
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()).uniqueResult()).intValue(); pmUC4=&e
criteria.setProjection ],<pZ1V;
{- &wV
(null); %
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List items = 74Aecb{
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criteria.setFirstResult(startIndex).setMaxResults skLr6Cs|
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mH c
(pageSize).list(); R,hwn2@B
PaginationSupport ps = gfXit$s
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new PaginationSupport(items, totalCount, pageSize, /KgP<2p
'8^>Z.~V
startIndex); 2ak*aI
return ps; =VSUE
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} E_xCRfw_i]
}, true); U4NA'1yo
} + VhD]!
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public List findAllByCriteria(final e&pt[W}X%u
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DetachedCriteria detachedCriteria){ F @!9rl'
return(List) getHibernateTemplate meD?<g4n~"
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().execute(new HibernateCallback(){ avMre_@V
publicObject doInHibernate tiic>j\D
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(Session session)throws HibernateException { FPAj}as
Criteria criteria = p?<T
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detachedCriteria.getExecutableCriteria(session); L# .vbf
return criteria.list(); l\bgp3.+
} CDFX>>N
}, true); ;3O=lo:$~
} }(UU~V
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public int getCountByCriteria(final H1ox>sC
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DetachedCriteria detachedCriteria){ %c&<{D}r
Integer count = (Integer) 'oM&Ar$
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getHibernateTemplate().execute(new HibernateCallback(){ 8{%[|Ye
publicObject doInHibernate ,h9N,bIQg
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(Session session)throws HibernateException { hLSas#B>
Criteria criteria = G8CM
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detachedCriteria.getExecutableCriteria(session); &(X-b"2
return 'CjcFP
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criteria.setProjection(Projections.rowCount WaDdZIz4
=(as{,j
()).uniqueResult(); D"s
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} 68a
}, true); `yua?n
return count.intValue(); Xa=oEG
} uPL|3ACS
} 0(az 80
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用户在web层构造查询条件detachedCriteria,和可选的 uKpWb1(
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 E<4'4)FHuQ
@]:GTrs
PaginationSupport的实例ps。 ^U{SUWl
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ps.getItems()得到已分页好的结果集 j?oh~7Ki
ps.getIndexes()得到分页索引的数组 y/6%'56uF
ps.getTotalCount()得到总结果数 %@x.km3e2
ps.getStartIndex()当前分页索引 `&)uuLn|
ps.getNextIndex()下一页索引 ~*^aCuq\
ps.getPreviousIndex()上一页索引 >Byxb./*
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 kmF@u@5M
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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 H6%%n
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一下代码重构了。 \6c8Lqa
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我把原本我的做法也提供出来供大家讨论吧: Yuqt=\? #
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首先,为了实现分页查询,我封装了一个Page类: )2y#
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java代码: .l ufE
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/*Created on 2005-4-14*/ /.%AE|0+X
package org.flyware.util.page; tU>?j1
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/** 4ai|*8.
* @author Joa _|vY)4B4U
* md`"zV
*/ `_5{:
9N$
publicclass Page { wYLJEuS|
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/** imply if the page has previous page */ T9O3$1eqfo
privateboolean hasPrePage; L<MH:
A&/YnJ"
/** imply if the page has next page */ u:s[6T0
privateboolean hasNextPage; ya0D50m
jxNnrIA
/** the number of every page */ Avn)%9
privateint everyPage; <vUhJgN2/
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/** the total page number */ z ,q1TU9
privateint totalPage; AvEd?
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/** the number of current page */ uQ'Izdm
privateint currentPage; )xj!7:n)
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/** the begin index of the records by the current )r.4`5Rc
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query */ 5Cjh%rj(jl
privateint beginIndex; >7I"_#x1:
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y ZR\(\?<
/** The default constructor */ ;f+bIYQz
public Page(){ Y5?OJO{h"
LyWgaf#/d
} $%BNoSK
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/** construct the page by everyPage ;@l5kdZx`
* @param everyPage ^4 ?LQ[t'
* */ '\I!RAZ
public Page(int everyPage){ ?kKr/f4N
this.everyPage = everyPage; 1a>TJdoa
} Q%
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/** The whole constructor */ ud,=O Xq
public Page(boolean hasPrePage, boolean hasNextPage, ~Ddlr9Ej
yV/A%y-P
# 8fq6z|JZ
int everyPage, int totalPage, @Rp#*{
int currentPage, int beginIndex){ Nr#" 5<W
this.hasPrePage = hasPrePage; 2E*h,Mo
this.hasNextPage = hasNextPage; }SZU'lYHoM
this.everyPage = everyPage; c6_i~0W56
this.totalPage = totalPage; IFfB3{J
this.currentPage = currentPage; U+wfq%Fz
this.beginIndex = beginIndex; $F/Uk;*d!
} }10ZPaHjl+
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/** %RX}sS
* @return ?'I pR
* Returns the beginIndex. mcqLN5
*/ r}Ec_0_lt
publicint getBeginIndex(){ @_4E^KgF
return beginIndex; 6
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} \4 5%K|
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/** C])b 3tM,7
* @param beginIndex \1R<GBC4
* The beginIndex to set. QkU6eE<M*
*/ (D1$ &
publicvoid setBeginIndex(int beginIndex){ $:D-dUr1
this.beginIndex = beginIndex; rI.CCPY~s
} HyKv5S$
[)S&PK
/** MWZH-aA(.
* @return yhJA{nL=
* Returns the currentPage. QssU\@/Q
*/ q6a7o=BP]
publicint getCurrentPage(){ g\q*,1
return currentPage; PG*:3![2
} I' TprT
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/** "ukiuCfVuW
* @param currentPage M:QM*?+)
* The currentPage to set. 3yp?|>e
*/ L
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publicvoid setCurrentPage(int currentPage){ O|I)HpG;
this.currentPage = currentPage; E/IoYuB
} +xG
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/** lPO+dm
* @return uEX+j
* Returns the everyPage. ?&rt)/DV,
*/ WO]9\"|y
publicint getEveryPage(){ AaX][2y8
return everyPage; )o%sN'U,1
} Lk>o`<*
~"8D]
/** 3L1MMUACL
* @param everyPage !5zDnv
* The everyPage to set. 2=V~n)'a
*/ $$f89, h
publicvoid setEveryPage(int everyPage){ 5eJMu=UpR
this.everyPage = everyPage; 09L"~:rg
} Q$XNs%7w5,
{sb2r%U!+
/** 5vo5t0^o
* @return 7x5wT ?2W
* Returns the hasNextPage. JNk6:j&Pf
*/ yHNx,ra
publicboolean getHasNextPage(){ )g
; !IL
return hasNextPage; o`+$h:zm@
} @r=v*hu
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/** Is1(]^EE*
* @param hasNextPage :Cdqj0O3u
* The hasNextPage to set. Cyu= c1D ;
*/ fv+t%,++:
publicvoid setHasNextPage(boolean hasNextPage){ {#C)S&o)6
this.hasNextPage = hasNextPage; (YC{BM}
} j Wjp0ii
WkUV)/j
/** B57MzIZi]
* @return #WqpU.
* Returns the hasPrePage. 5R}K8"d
*/ m]D3ec\K'
publicboolean getHasPrePage(){ 8K@>BFk1.
return hasPrePage; w8iXuRv
} /*kc|V
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/** ,6AnuA
* @param hasPrePage %`)lCK)2
* The hasPrePage to set. r~q3nIe/,
*/ (T 8In
publicvoid setHasPrePage(boolean hasPrePage){ _-c1" Kl
this.hasPrePage = hasPrePage; 6haw\ *
} Ygs:Ox"[-G
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/** up==g
* @return Returns the totalPage. Xt9vTCox
* d$qi.%<kh
*/ 7,7-E&d
publicint getTotalPage(){ Or3GrZ!H
return totalPage; tQWjNP~
} -|g9__|@
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/** #w6ty<b;
* @param totalPage qac8zt#2
C
* The totalPage to set. cf+EQY
*/ P1qQ)-J
publicvoid setTotalPage(int totalPage){ aGbHDo
this.totalPage = totalPage; !))!!{
} HnsPXF'8g
K=N8O8R$y
} t/B4?A@C
U~I
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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 x^~@`]TV^
8.ej65r*
个PageUtil,负责对Page对象进行构造: GFTOP%Tgl
java代码: 8Ao-m38
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/*Created on 2005-4-14*/ Dt:NBN
package org.flyware.util.page; Iq@&?,W
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import org.apache.commons.logging.Log; 51gSbkVX
import org.apache.commons.logging.LogFactory; 8T5W6Zs1
76(/(v.x
/** !x[].Urj
* @author Joa f<y-{.VnN$
* '_B;e=v`
*/ ?*L{xNC#
publicclass PageUtil { Z>PS>6
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privatestaticfinal Log logger = LogFactory.getLog 1YScZ
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(PageUtil.class); C Ef*:kr
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/** 9Yhlq$;g
* Use the origin page to create a new page J b?x-%Za
* @param page &t,"k'p
* @param totalRecords ~xt]g zp{
* @return "h7Np/ m3
*/ i6P'_
publicstatic Page createPage(Page page, int p735i`8
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totalRecords){ WP5Vev9*+
return createPage(page.getEveryPage(),
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page.getCurrentPage(), totalRecords); 7G=Q9^J.H
} ijACfl{!:t
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/** =wznkqyhi
* the basic page utils not including exception yA~1$sA1
d]vom@iI
handler y<kg;-& 8
* @param everyPage s1bb2R
* @param currentPage uaqV)H
* @param totalRecords i
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* @return page nm,(Wdr
*/ &mkL4jXG
publicstatic Page createPage(int everyPage, int wGgeK,*_
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currentPage, int totalRecords){ *nB-]
w/
everyPage = getEveryPage(everyPage); "#P#;]\ `
currentPage = getCurrentPage(currentPage); #'4Psz
int beginIndex = getBeginIndex(everyPage, !.{"Ttn;s
7QdboEa
currentPage); _'Rg7zHTp-
int totalPage = getTotalPage(everyPage, Ys]cJ]
-_BX\iP{
totalRecords); cq~~a(IS
boolean hasNextPage = hasNextPage(currentPage, 2oo\ SmO]
J\hqK*/8
totalPage); MIY`"h0*
boolean hasPrePage = hasPrePage(currentPage); -oi@1g@
=g |5VXW5
returnnew Page(hasPrePage, hasNextPage, !NMiWG4R
everyPage, totalPage, S2
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currentPage, z\-/R9E/5-
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beginIndex); '.]<lh!
} LKgo(&mY
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privatestaticint getEveryPage(int everyPage){ q;.LK8M
return everyPage == 0 ? 10 : everyPage; 45H9pY w
} Y/T-2)D
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privatestaticint getCurrentPage(int currentPage){ \|C*b<
return currentPage == 0 ? 1 : currentPage; T0N6k acl
} q<[o 4qY
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privatestaticint getBeginIndex(int everyPage, int jB,VlL
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currentPage){ (5e4>p&+
return(currentPage - 1) * everyPage; gF:|j(
} qq"0X! w
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privatestaticint getTotalPage(int everyPage, int 0|ekwTx.
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totalRecords){ '4}8WYKQ
int totalPage = 0; +1^L35\@
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if(totalRecords % everyPage == 0) {a]u
totalPage = totalRecords / everyPage; 4'"WD0
else =R)w=ce
totalPage = totalRecords / everyPage + 1 ; 8?ip,Q\
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return totalPage; [#%@,C
} Sa@T#%oU
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privatestaticboolean hasPrePage(int currentPage){ ?kS#g
return currentPage == 1 ? false : true; `A<2wd;
} X6=o vm
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privatestaticboolean hasNextPage(int currentPage, %CQv&d2
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int totalPage){ !6hV|2aJy
return currentPage == totalPage || totalPage == sl:1P^b
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0 ? false : true; :i|Bz6Ht4
} v8zO Y#?
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} q2/kegAT
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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。 Z29LtKr
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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 7g:Lj,Z4L
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做法如下: 53>(2 _/[r
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 O~;
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的信息,和一个结果集List: y;_F[m
java代码: 5s@xpWVot
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/*Created on 2005-6-13*/ *S?'[PS]1
package com.adt.bo; u8gqWsvruM
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import java.util.List; =Y*@8=V
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import org.flyware.util.page.Page; pu_?)U
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/** Dl,sl>{
* @author Joa NKTy!zWh
*/ w`v`aw]
publicclass Result { lbPn<
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private Page page; |T]&8Q)S
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private List content; ,L4zhhl!_
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/** f:6F5G
* The default constructor ^]Q.V
*/ %<8r`BMo
public Result(){ WJ^]mpH9
super(); EMpq+LrN
} 9W,%[
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/** h!Y##_&&4
* The constructor using fields 9|Ylv:sR
* nM *}VI
* @param page ?zfm"o
* @param content KK{_s=t%<
*/ lM#,i\8Q
public Result(Page page, List content){ o ZQ@ Yu3
this.page = page; ym_as8A*Q
this.content = content; 7 U-}Y
} @pH6FXVGzt
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/** =)Fb&h]G^
* @return Returns the content. 5z\,]
*/ 5>UQ 3hWo
publicList getContent(){ %Y"pVBc
return content; ?uU_N$x
} $zF%F.rln
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/** ]{|lGtK %
* @return Returns the page. Q [C26U
*/ $$EEhy
public Page getPage(){ 1OqVV?oz
return page; KW3<5+w]c
} <L<^uFB
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/** q*tGlM@R?
* @param content bZ:xH48MY
* The content to set. Bs|Xq'1M!;
*/ %yd(=%)fMB
public void setContent(List content){ y4$$*oai&
this.content = content; Xfbr;Jt"<
} B/o8r4[80
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/** PgA1:i&'
* @param page 8aKS=(Z!j
* The page to set. o7WAH@g
*/ ijvDFyN>
publicvoid setPage(Page page){ bC98<if
this.page = page; =qpGAv_#
} k+*pg4'
} |QMmF" 0
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2. 编写业务逻辑接口,并实现它(UserManager, H=w):kL|
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UserManagerImpl) g'{?j~g
java代码: Ryh 0r
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