Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 &!{wbm@
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .wD>0Ig
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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 ^#R-_I
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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 sM?bUg0w
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。 22|f!la8n
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分页支持类: |Mp_qg?g
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java代码: 9Osjh G
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package com.javaeye.common.util; ^b`}g
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import java.util.List; l{4=La{?j
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publicclass PaginationSupport { X9nt;A2TU+
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publicfinalstaticint PAGESIZE = 30; aI|<t^X
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privateint pageSize = PAGESIZE; 2C %{A
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privateList items; } VE[W
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privateint totalCount; sb_>D`>
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privateint[] indexes = newint[0]; ^" ywltW>
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privateint startIndex = 0; f3-=?Z
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public PaginationSupport(List items, int f&(u[W
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totalCount){ FpfOxF6A3
setPageSize(PAGESIZE); !xMyk>%2
setTotalCount(totalCount); Nm<3bd
setItems(items); _{,e-_hYM
setStartIndex(0); MyuFZ7Q4$
} mY.[AIB
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public PaginationSupport(List items, int r,i^-jv;
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totalCount, int startIndex){ W)V"QrFK
setPageSize(PAGESIZE); [Y*p
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setTotalCount(totalCount); d>NElug
setItems(items); r M'snW)
setStartIndex(startIndex); 4NwGP^n
} Y{@ez
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public PaginationSupport(List items, int ~LHG
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totalCount, int pageSize, int startIndex){ ^MUtmzh
setPageSize(pageSize); Ol"p^sqwj
setTotalCount(totalCount); vN7a)s
setItems(items); aD3'gc,l
setStartIndex(startIndex); S8<O$^L^
} R{@WlkG}
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publicList getItems(){ "VkraB.i
return items; $t-HJ<!
} .BlGV 2@^#
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publicvoid setItems(List items){ tp_*U,
this.items = items; h5x FP
} G(|ki9^@"9
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publicint getPageSize(){ .5|wy<
return pageSize; E@R7b(:*
} HlPf
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publicvoid setPageSize(int pageSize){ LwkZ (Tt
this.pageSize = pageSize; I8`@Srw8
} MH`f!%c
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publicint getTotalCount(){ >I8R[@
return totalCount; ?^2(|t9KU
} n'1pNL:
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publicvoid setTotalCount(int totalCount){ @1gX>!
if(totalCount > 0){ U9IN# ;W
this.totalCount = totalCount; Gu|}ax"
int count = totalCount / CP'?Om2
br>"96A1l
pageSize; E*.D_F
if(totalCount % pageSize > 0) _%;$y5]v
count++; OYgD9T.8^
indexes = newint[count]; 3F[z]B
for(int i = 0; i < count; i++){ 1N1MD@C?P
indexes = pageSize * 4{X5ZS?CkI
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i; zy8W8h(?
} +I5@Gys
}else{ /{d7%Et6
this.totalCount = 0; Obrv5%'
} Q~#udEajI
} gx#xB8n
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publicint[] getIndexes(){ W7S`+Pq
return indexes; 7P?z{x':T
} 0tC+?
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publicvoid setIndexes(int[] indexes){ 7*M+bZ`x
this.indexes = indexes; ckBcwIXlP&
} 8U*}D~%!
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publicint getStartIndex(){ X.}:gU-
return startIndex; +S5"4<
} \d2Ku10v[
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publicvoid setStartIndex(int startIndex){ *ELbz}Q
if(totalCount <= 0) C3u/8Mrt7
this.startIndex = 0; )Pakb!0H@t
elseif(startIndex >= totalCount) lDnF(
this.startIndex = indexes sikG}p0mx<
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[indexes.length - 1]; B5~S&HQ?B6
elseif(startIndex < 0) 0ym>Hbax)
this.startIndex = 0; B4r4PSB>!
else{ `-"2(Gp
this.startIndex = indexes "Up3W%]SB
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[startIndex / pageSize]; ZC@ 33Q(
} 7MZBU~,r
} [DC8X P5<
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publicint getNextIndex(){ (q59cA w~X
int nextIndex = getStartIndex() + f6j;Y<}' g
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pageSize; JZNRMxu
if(nextIndex >= totalCount) btJ:Wt}
return getStartIndex(); $5jQm,V$K
else >Olg
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return nextIndex; -Id4P _y
} y$Sn3_9 V
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publicint getPreviousIndex(){ -uIu-a]
int previousIndex = getStartIndex() - 3'}(:X(
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pageSize; o|*ao2a
if(previousIndex < 0) l<>syHCH;L
return0; [`BMi-WQ
else +)h *)
return previousIndex; 7+0Kg'^+n
} U$&G_&*0a
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} >\y|}|?
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抽象业务类 HQw98/-_W
java代码: RZ-=UIf
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/** y{
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* Created on 2005-7-12 u9ObFm$7
*/ 6c,]N@,Zw
package com.javaeye.common.business; 0+L:+S
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import java.io.Serializable; ;gLHSHEA
import java.util.List; ecDni>W
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import org.hibernate.Criteria; l2vIKc
import org.hibernate.HibernateException; mSF>~D1_
import org.hibernate.Session; C62:G+W&o
import org.hibernate.criterion.DetachedCriteria; 2fFZ70Yh
import org.hibernate.criterion.Projections; \{``r
import yB0xa%
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org.springframework.orm.hibernate3.HibernateCallback; y (@j;Q3(r
import }N[|2nR'
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org.springframework.orm.hibernate3.support.HibernateDaoS yw2Mr+9I
P'%#B&LZo
upport; H3\4&q
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import com.javaeye.common.util.PaginationSupport; ZeM~13[
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public abstract class AbstractManager extends ^/@Z4(E
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HibernateDaoSupport { Q+@/.qJ
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privateboolean cacheQueries = false; }
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privateString queryCacheRegion; v~E\u
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publicvoid setCacheQueries(boolean DBTeV-G9~R
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cacheQueries){ t&|M@Ouet
this.cacheQueries = cacheQueries; N;Hoi8W
} (h{"/sR
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publicvoid setQueryCacheRegion(String mq#8[D
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queryCacheRegion){ +vf~s^
this.queryCacheRegion = ^.3(o{g
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queryCacheRegion; [A jY~
} up _Qv#`Q
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publicvoid save(finalObject entity){ *2,tGZ
getHibernateTemplate().save(entity); Z$*m=]2
} q,;8Ka )
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publicvoid persist(finalObject entity){ ,zF^^,lO7
getHibernateTemplate().save(entity); d.e_\]o<@
} y@XE! L
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publicvoid update(finalObject entity){ *ggai?
getHibernateTemplate().update(entity); x*'2%3C~
} 4 H9mKR
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publicvoid delete(finalObject entity){
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getHibernateTemplate().delete(entity); evSr?ys
} 6Pp3*O`/V
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publicObject load(finalClass entity, ]0o_-
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finalSerializable id){ D4OJin^}
return getHibernateTemplate().load #i;y[dQ
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(entity, id); S7v# `#
} <`)vp0
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publicObject get(finalClass entity, %/n#{;c#
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finalSerializable id){ vu@@!cT6e
return getHibernateTemplate().get Xk>YiV",?
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(entity, id); j&-<e7O=
} pgw_F
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publicList findAll(finalClass entity){ k0bDEz.X
return getHibernateTemplate().find("from +/>XOY|Ie
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" + entity.getName()); Lk lD^AJA
} Uz_OUTFM
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publicList findByNamedQuery(finalString jn]:*i;i
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namedQuery){ &{e:6t
return getHibernateTemplate PfN[)s4F{R
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().findByNamedQuery(namedQuery); cGM?r}zJ
}
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publicList findByNamedQuery(finalString query, E#n=aY~u-
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finalObject parameter){
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return getHibernateTemplate {d '>J<Da
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().findByNamedQuery(query, parameter); je;|zfe]
} ^wlo;.8Y
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publicList findByNamedQuery(finalString query, /0YO`])"
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finalObject[] parameters){ Gp0yRT.
return getHibernateTemplate G-[.BWQ
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().findByNamedQuery(query, parameters); EkpM'j=
} KY+BXGW*
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publicList find(finalString query){ a}g<<{
return getHibernateTemplate().find kYZj^tR
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(query); "IJ 9vXI
} 9P& \2/ {
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publicList find(finalString query, finalObject +W+o~BE
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parameter){ Gt$PBlq0
return getHibernateTemplate().find L2IY$+=M
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(query, parameter); b *Ca*!
} |xFSGrC
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public PaginationSupport findPageByCriteria J'C%
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(final DetachedCriteria detachedCriteria){ =JE5/
return findPageByCriteria dO!B=/
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); LMaY}m>
} MDauHtF,
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public PaginationSupport findPageByCriteria `s8!zy+
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(final DetachedCriteria detachedCriteria, finalint "?>hQM1R
'MQJt2QU9{
startIndex){ *6wt+twH
return findPageByCriteria 5Ve
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\# _w=gs<i
(detachedCriteria, PaginationSupport.PAGESIZE, AvcN,
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startIndex); @a}\]REn
} ;<H\{w@D
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public PaginationSupport findPageByCriteria ,HwOMoP7
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(final DetachedCriteria detachedCriteria, finalint aucG|}B
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pageSize, r2=4Wx4(
finalint startIndex){ T:g=P@
return(PaginationSupport) +jyWqld.K1
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getHibernateTemplate().execute(new HibernateCallback(){ [! YSW'
publicObject doInHibernate SquuK1P=
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(Session session)throws HibernateException { <xh";seL
Criteria criteria = 78kT}kgW
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detachedCriteria.getExecutableCriteria(session); #;hYJ Y
int totalCount = V5rW_X:]8
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((Integer) criteria.setProjection(Projections.rowCount _)MbvF
vt(cC))
()).uniqueResult()).intValue(); EttQ<z_T
criteria.setProjection ;mwU>l,4
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(null); (3N;-
List items = lr9s`>9
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criteria.setFirstResult(startIndex).setMaxResults PvW~EJ
cm`x;[e6l
(pageSize).list(); =j~Xrytn
PaginationSupport ps = &6^QFqqW`-
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new PaginationSupport(items, totalCount, pageSize, %Wa. 2s
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startIndex); XX'mM v
return ps; `J-&Y2_/k
} %YwIR.o
}, true); G$E+qk
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} }5=tUfh)]'
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public List findAllByCriteria(final )BmO[AiOM
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DetachedCriteria detachedCriteria){ }o7"2hht
return(List) getHibernateTemplate d[y(u<Vl
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().execute(new HibernateCallback(){ V?N8 ,)j
publicObject doInHibernate
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(Session session)throws HibernateException { 5?-@}PL!Y
Criteria criteria = {xCqz0
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detachedCriteria.getExecutableCriteria(session); HBcL1wfS
return criteria.list(); 0l2@3}e
} fu{.Ir
}, true); ~c${?uf
} {J]x81}*;
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public int getCountByCriteria(final N.?)s.D(
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DetachedCriteria detachedCriteria){ jn+BH3e
Integer count = (Integer) Bb*P);#.K
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getHibernateTemplate().execute(new HibernateCallback(){ ~
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publicObject doInHibernate ok(dCAKP
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(Session session)throws HibernateException { |6!L\/}M%
Criteria criteria = Gk]6WLi
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detachedCriteria.getExecutableCriteria(session); eY8rm
return d< b ,].
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criteria.setProjection(Projections.rowCount l G $s(
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()).uniqueResult(); _!E)a
} /Bp5^(s
}, true); ^e(*{K;8
return count.intValue(); 5?XIp6%x
} o>Q=V0?
} OtZc;c
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用户在web层构造查询条件detachedCriteria,和可选的 %IK[d#HO
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 3h`_Qv%g
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PaginationSupport的实例ps。 \7] SG
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ps.getItems()得到已分页好的结果集 ")D5ulb\
ps.getIndexes()得到分页索引的数组 UQ}#=[)2e
ps.getTotalCount()得到总结果数 vY!'@W
ps.getStartIndex()当前分页索引 FS7@6I2Ts
ps.getNextIndex()下一页索引 oP_}C[
ps.getPreviousIndex()上一页索引 1)hO!%
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 oe,yCdPs
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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 ^~7ouA
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一下代码重构了。 f]48>LRE8
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我把原本我的做法也提供出来供大家讨论吧: Z\>mAtm
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首先,为了实现分页查询,我封装了一个Page类: dZ`c
java代码: _p;=]#+c&
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/*Created on 2005-4-14*/ {P'^X+B0*
package org.flyware.util.page; xP-\)d-.aN
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/** %![3?|8~
* @author Joa T,/:5L9
* bE6bx6=u
*/ 'J_`CS
publicclass Page { $d5}OI"g
*u ]aWx
/** imply if the page has previous page */ R3hyz~\x&
privateboolean hasPrePage; PauF)p
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/** imply if the page has next page */ ):7mK03J
privateboolean hasNextPage; 'q\[aKEX=
J=6(
4>
/** the number of every page */ "ifv1KZ#
privateint everyPage; C9^C4
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/** the total page number */ Wgb L9'}B
privateint totalPage; @G^m+-
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/** the number of current page */ Dbw{E:pq
privateint currentPage; JS^!XB'!
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/** the begin index of the records by the current k\Z7Dg$\D
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query */ d8.A8<wUr
privateint beginIndex; +*Zjo&pc
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/** The default constructor */ 7x#."6>Dy
public Page(){ i,!t u
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} K#LDmC
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/** construct the page by everyPage QC6:ZxP
* @param everyPage -lS(W^r4
* */ w5;d/r<q
public Page(int everyPage){ p|Qn?^C:
this.everyPage = everyPage; ?H!QV;ku
} R\-]t{t`
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/** The whole constructor */ S|r,RBeZ
public Page(boolean hasPrePage, boolean hasNextPage, =w ! 6un
yq12"Rs
z[WdJN{
int everyPage, int totalPage, /kAbGjp0
int currentPage, int beginIndex){ [r^WS;9n
this.hasPrePage = hasPrePage; ]JHInt
this.hasNextPage = hasNextPage; }p `A>
this.everyPage = everyPage; jIck!
this.totalPage = totalPage; S,f:nLT
this.currentPage = currentPage; Xa$-Sx
this.beginIndex = beginIndex; Yc^,Cj{OM
} ,c|Ai(U
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/** LAY~hF"
* @return )yUSuK(Vu
* Returns the beginIndex. 95sK ;`rE+
*/ !q 9PO
publicint getBeginIndex(){ ^#]eCXv
return beginIndex; Bdm05}c@u
} ak\[+wQ
rPK 1#
/** 7{p6&xXx
* @param beginIndex ~p
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* The beginIndex to set. lBLL45%BIN
*/ y.gjs<y
publicvoid setBeginIndex(int beginIndex){ 10CRgrZ
this.beginIndex = beginIndex; H18pVh
} t**MthnW
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/** jD?*sd
* @return dH)\zCt
* Returns the currentPage. IHv>V9yiG
*/ t:YMF$Z
publicint getCurrentPage(){ KM/c^a4V
return currentPage; ufJHC06
} byPqPSY
\?vn0;R4
/** !d&SVS^mo
* @param currentPage y>0Gmr
* The currentPage to set. Jk57| )/
*/ T@d4NF#
publicvoid setCurrentPage(int currentPage){ O@a7MzJ
this.currentPage = currentPage; O+t'E9Fa
} {Rq5=/b
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/** |xrnLdng0R
* @return \lF-]vz*
* Returns the everyPage. Bw>)gSB5$k
*/ A'n{K#
publicint getEveryPage(){ ;N!opg))d<
return everyPage; MH=Ld=i
} dst!VO:
M
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/** '^(qlCI
* @param everyPage 5ljEh -
* The everyPage to set. JhvT+"~
*/ (#nB90E{*
publicvoid setEveryPage(int everyPage){ %II o
this.everyPage = everyPage; ucFfxar"
} |}Z2YDwO/
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/** *RFBLCt
* @return m}'!W`<
* Returns the hasNextPage. 8zQN[[#n
*/ [0lO0ik>G
publicboolean getHasNextPage(){ 9JO1O:W
return hasNextPage; _gQ_ixu
} c|X}[
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/** [= Xb*~
* @param hasNextPage 3\K;y>NK
* The hasNextPage to set. );{76
*/ &}d5'IRT
publicvoid setHasNextPage(boolean hasNextPage){ `Dp4Z>|
K
this.hasNextPage = hasNextPage; NMESGNa)z
} UQjYWXvi
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/** _po5j;"_O
* @return 2yVQqwQm
* Returns the hasPrePage. K;]Dh?
*/ r`e6B!p
publicboolean getHasPrePage(){ *S'?u_Y7
return hasPrePage; -`5L;cxwk4
} %-
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x^McUfdr|
/** l=C|4@
* @param hasPrePage Z9i~>k
* The hasPrePage to set. 2\CZ"a#[
*/ H=9{|%iS
publicvoid setHasPrePage(boolean hasPrePage){ YTg8Zg-Z
this.hasPrePage = hasPrePage; '
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} =)J)xH!N
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/** 7A{Z1[7
* @return Returns the totalPage. HBA|NV3.
* o1H6E1$=
*/ s\(@f4p
publicint getTotalPage(){ u $qazj
return totalPage; 4@0Z<8Mo
} B[5<&
3dgPP@7d$
/** SPnW8
* @param totalPage y2nT)nL
* The totalPage to set. :wfN+g=
*/ 4wx{i6
publicvoid setTotalPage(int totalPage){ NKRm#
this.totalPage = totalPage; >AWWwq -
} @*WrHoa2N
<2wC)l3j*
} DIgur}q)@
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m
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tUGF8?&
G
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 J\Tu=f)
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个PageUtil,负责对Page对象进行构造: 3bHB$n
java代码: (W#^-*$R
rpEN\S%7P
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/*Created on 2005-4-14*/ ;8b!T
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package org.flyware.util.page; 3!8 u
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import org.apache.commons.logging.Log; fFXnD
import org.apache.commons.logging.LogFactory;
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/** 28j/K=0(
* @author Joa )GOio+{H
* =+H,}
*/ Dy{lgT 0k
publicclass PageUtil { ^ZFK:|Ju
f,Am;:\ |
privatestaticfinal Log logger = LogFactory.getLog b`;Cm)@X!)
<Vh}d/
(PageUtil.class); [{zfI`6
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/** Yi <1z:\
* Use the origin page to create a new page (^58$IW71
* @param page zX6Q7Bc
* @param totalRecords 4r#4h4`y|
* @return "i&9RA!1
*/ f[?JLp
publicstatic Page createPage(Page page, int @0%[4
*DQa6,b
totalRecords){ /)sP<WPQ6
return createPage(page.getEveryPage(), F6_en z
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page.getCurrentPage(), totalRecords); H`jnChD:M'
} B/Ltb^a
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/** 'f8'|o)
* the basic page utils not including exception ;_0frX
$y%IM`/w
handler LtV,djk
* @param everyPage "d2JNFIHb
* @param currentPage u,]qrlx{
* @param totalRecords :Xu9`5
* @return page JD9=gBN\?
*/ B &3sV+
publicstatic Page createPage(int everyPage, int \5j#ad
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currentPage, int totalRecords){ -1w^z`;2h
everyPage = getEveryPage(everyPage); ?U
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currentPage = getCurrentPage(currentPage); >?.jN|
int beginIndex = getBeginIndex(everyPage, AuY*x;~
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currentPage); EXR6Vb,
int totalPage = getTotalPage(everyPage, u(8dsgR
6#ktw)e
totalRecords); Uy?X-"UR
boolean hasNextPage = hasNextPage(currentPage, 3E}j*lo
U|8?$/*\
totalPage); |o@U
L
boolean hasPrePage = hasPrePage(currentPage); #k,.xMJ~
0n\AUgVPF
returnnew Page(hasPrePage, hasNextPage, WP'.o
everyPage, totalPage, "`h.8=-
currentPage, COj^pdE3
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beginIndex); ,[3}t%Da
} fP 3t0cp
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privatestaticint getEveryPage(int everyPage){ (-VH=,Md
return everyPage == 0 ? 10 : everyPage; dJ>tM'G
} 8!MVDp[|"
B7sBO6Z$J
privatestaticint getCurrentPage(int currentPage){ -fN5-AC
return currentPage == 0 ? 1 : currentPage; 40[@d
} 0a1Mu>P,
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privatestaticint getBeginIndex(int everyPage, int P G
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currentPage){ W*/2x8$d
return(currentPage - 1) * everyPage; gLlA'`!
} n6 wx/:
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privatestaticint getTotalPage(int everyPage, int E:[!)UG|y
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totalRecords){ M~)iiKw~MY
int totalPage = 0; %vUUx+
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if(totalRecords % everyPage == 0) -![{Zb@
totalPage = totalRecords / everyPage; V0n8fez
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else
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totalPage = totalRecords / everyPage + 1 ; O2xqNQ`d
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return totalPage; Oq(FV[N7t
} cQ3p|a `
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privatestaticboolean hasPrePage(int currentPage){ 0^6}s1d_
return currentPage == 1 ? false : true; <SdOb#2
} #c9MVQ_
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privatestaticboolean hasNextPage(int currentPage, 65tsJ"a<
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int totalPage){ Ex6Kxd}8
return currentPage == totalPage || totalPage == <3Rq!w/
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0 ? false : true; ?"kU+tCxg
} =@nW;PUZ
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} ]qx!51S
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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。 !e~d,NIy
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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 ob/HO(h3
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做法如下: dvglh?7d
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 !:~C/B{
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的信息,和一个结果集List: zLPCWP.u
java代码: c~d*SDca
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/*Created on 2005-6-13*/ P<9T.l
package com.adt.bo; )=5*iWe
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import java.util.List; -$kbj*b##
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import org.flyware.util.page.Page; iztgk/(+G
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/** >n1UK5QD
* @author Joa |=W>4>
*/ [P]M)vJ**
publicclass Result { Q[lkhx|.B
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private Page page; I,V'J|=j
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private List content; "AIS6%,
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/** lxBcO/
* The default constructor |r4&@)
*/ ,pW^>J
public Result(){ VotI5O $
super(); $$R->
} 8:]5H}Hi
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/** 5^Lbc.h
* The constructor using fields Q?'Ax"$D
* bf[l4$3k
* @param page MN>U jFA
* @param content |+=ctpx9&
*/ o
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public Result(Page page, List content){ clr]gib
this.page = page; Z
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this.content = content; Ge24Lp;Y6
} o/!a7>xO4
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/** Nt[&rO3s
* @return Returns the content. 0IsnG?"
*/ 54f?YR
publicList getContent(){ /|<0,oz oJ
return content; @2\UjEo~
} jQ(%LYX$
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/** /!y3ZzL
* @return Returns the page. Fd._D"
*/ {[+Q\<