Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 +cRn%ioVi
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 6dYMwMH
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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 [-x7_=E#
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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 _VXN#@y
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分页支持类: *z2s$EZ
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java代码: T8NxJmYqB
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package com.javaeye.common.util; ?@8[e9lLD
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import java.util.List; ,z?':TZ
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publicclass PaginationSupport { :Tq~8!s
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publicfinalstaticint PAGESIZE = 30; 3uMy]HUQ
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privateint pageSize = PAGESIZE; -{A<.a3P}=
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privateList items; NEF#
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privateint totalCount; WPDyu.QD
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privateint[] indexes = newint[0]; S[QrS7
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privateint startIndex = 0; YbLW/E\T
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public PaginationSupport(List items, int 4.(4x&
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totalCount){ w=@Dv
setPageSize(PAGESIZE); Vz[C=_m
setTotalCount(totalCount); mcok/,/
setItems(items); &?RQZHtg
setStartIndex(0); ~_ a-E
} `,0}ZzaV&
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public PaginationSupport(List items, int ?hM64jI|
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totalCount, int startIndex){ ,2)6s\]/b
setPageSize(PAGESIZE); +^<](z
setTotalCount(totalCount); Q7A MRrN
setItems(items); E!AE4B1bd
setStartIndex(startIndex); S@sO;-^+
} kNL\m[W8$
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public PaginationSupport(List items, int RrgGEx
{BHO/q3
totalCount, int pageSize, int startIndex){ .{KVMc
setPageSize(pageSize); 4Xv*wB1
setTotalCount(totalCount); b u"!jHPB
setItems(items); jA/w|\d!
setStartIndex(startIndex); m4yL@d,Yw
} bJ;'`sw1
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publicList getItems(){ i 3SHg\~Z
return items; .>nRzgo
} 4Z,!zFS$`
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publicvoid setItems(List items){ cs'{5!i]
this.items = items; cFWc<55aX6
} a@*\o+Su
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publicint getPageSize(){ u~-8d;+?y
return pageSize; :a)u&g@G
} tRfo$4#NY
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publicvoid setPageSize(int pageSize){ GM<-&s!Uj
this.pageSize = pageSize; ofv)SCjd
} &8 x-o,
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publicint getTotalCount(){ v}Fr@0%
return totalCount; 0K2`-mL
} r0gJpttDl
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publicvoid setTotalCount(int totalCount){ :08,JL{
if(totalCount > 0){ D5HZ2cz|a
this.totalCount = totalCount;
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int count = totalCount / .VzT:4-<Q"
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pageSize; $p?aVO
if(totalCount % pageSize > 0) 680o)hh4m>
count++; abLnI =W`
indexes = newint[count];
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for(int i = 0; i < count; i++){ }U9G
indexes = pageSize * ^]-6u:J!
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} %- 0t?/>
}else{ 7x4PaX(
this.totalCount = 0; qeZ? 7#Gf
} KMjhZap%
} *w&Y$8c(
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publicint[] getIndexes(){ `lt"[K<
return indexes; .xWC{}7[
} n#OB%@]<V
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publicvoid setIndexes(int[] indexes){ /C G"]!2 "
this.indexes = indexes; QW(Mz Hg
} 3x'|]Ns
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publicint getStartIndex(){ xx%j.zDI]
return startIndex; ` v@m-j6
} [e}]}t8m
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publicvoid setStartIndex(int startIndex){ wov\kV
if(totalCount <= 0) zuy4G9P
this.startIndex = 0; l&Q`wR5e
elseif(startIndex >= totalCount) zv,jM0-
this.startIndex = indexes =mp;.k95
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[indexes.length - 1]; (\YltC@q%
elseif(startIndex < 0) D!-g&HBTC
this.startIndex = 0;
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else{ iVq'r4S
this.startIndex = indexes ^N{h3b8
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[startIndex / pageSize]; .Od!0(0
} lBvR+9Qw
} * kDC liL
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publicint getNextIndex(){ O so#+
int nextIndex = getStartIndex() +
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pageSize; :hk5 .[
if(nextIndex >= totalCount) 9} M?P
return getStartIndex(); 9u}Hmb
else HjD8u`qQ
return nextIndex; 0e ~JMUb
} ""F5z,'
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publicint getPreviousIndex(){ RF4vtQC=
int previousIndex = getStartIndex() - ']z{{UNUN
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pageSize; =O_4|7Zl
if(previousIndex < 0) 9YQb&
return0; &zeyE;/Hj
else *>'V1b4}
return previousIndex; V0.vQ/
} rt~d6|6
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} (G4at2YLd
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抽象业务类 FvXZ<(A{
java代码: )E@.!Ut4o
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/** xU>WEm2
* Created on 2005-7-12 \lf;P?M^
*/ x_6[P2"PP
package com.javaeye.common.business; {V$|3m>:*
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import java.io.Serializable; tip+q d
import java.util.List; R_ ,U Mt
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import org.hibernate.Criteria; mPN@{.(j
import org.hibernate.HibernateException; &5spTMw8
import org.hibernate.Session; rc>4vB_ha
import org.hibernate.criterion.DetachedCriteria; wh\}d4gN
import org.hibernate.criterion.Projections; gk[aM~p
import zH4D 8@[7O
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org.springframework.orm.hibernate3.HibernateCallback; +[A QUc
import '}JhzKNj
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org.springframework.orm.hibernate3.support.HibernateDaoS E$:*NSXj
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upport; m!4ndO;0vh
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import com.javaeye.common.util.PaginationSupport; X_ cV%#
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public abstract class AbstractManager extends 1i"WDu*h3
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HibernateDaoSupport { 3n1;G8Nf
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privateboolean cacheQueries = false; -p&" y3<p
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privateString queryCacheRegion; Zq|I,l0+E
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publicvoid setCacheQueries(boolean _AYK435>N
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cacheQueries){ }bpQq6ZF
this.cacheQueries = cacheQueries; M~#g RAUJ
} Gg3,:A_ w
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publicvoid setQueryCacheRegion(String N/'b$m5=
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} FlT%>Gw
queryCacheRegion){ OU(8V^.
this.queryCacheRegion = kr5">"7
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queryCacheRegion; hh)`645=x
} nQtWvT
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publicvoid save(finalObject entity){ C8:f_mJU
getHibernateTemplate().save(entity); 2K6qY)/_
} `?qF$g9u~
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publicvoid persist(finalObject entity){ |`,2ri*5A
getHibernateTemplate().save(entity); K5VWt)Z#
} nH'e?>x~e
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publicvoid update(finalObject entity){ f:,DWw`B
getHibernateTemplate().update(entity); $}q23
} L>NL:68yN
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publicvoid delete(finalObject entity){ S9D<8j^
getHibernateTemplate().delete(entity); D~iz+{Q4
} 1 ~*7f>
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publicObject load(finalClass entity, ")5":V~fN
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finalSerializable id){ c?*=|}N
return getHibernateTemplate().load 7\[@m3s
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(entity, id); ?V.cOR`6
} SrJGTuXg
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publicObject get(finalClass entity, %y[h5*y*
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finalSerializable id){ ^_W#+>&--
return getHibernateTemplate().get J#(LlCs?@c
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(entity, id); cn3\kT*
} F4z{LhZ
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publicList findAll(finalClass entity){ EU;9*W<
return getHibernateTemplate().find("from ZzpUUH/r
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" + entity.getName()); ]Sz:|%JP1
} uym*a4J
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publicList findByNamedQuery(finalString (gU!=F?#m
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namedQuery){ %E>Aw>]v
return getHibernateTemplate 50wulGJud
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().findByNamedQuery(namedQuery); N!=v4f
} }C?'BRX
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publicList findByNamedQuery(finalString query, 2- h{N
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finalObject parameter){ v$v-2y'%
return getHibernateTemplate @n /nH?L
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().findByNamedQuery(query, parameter); ,^< R{{{-A
} ZJJY8k `
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publicList findByNamedQuery(finalString query, *OsQ}onv
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finalObject[] parameters){ 1n8/r}q'H
return getHibernateTemplate @*XV`_!h
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().findByNamedQuery(query, parameters);
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} V)k4:H
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publicList find(finalString query){ AV]2euyn
return getHibernateTemplate().find )dw'BNz5hT
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(query); 4F:\-O
} G e@{_
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publicList find(finalString query, finalObject G~a ZJ,
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parameter){ Ll't>)
return getHibernateTemplate().find &6!)jIWJ
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(query, parameter); ;igIZ$&
} vA{-{Q
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public PaginationSupport findPageByCriteria :3Ox~o
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(final DetachedCriteria detachedCriteria){ M7~2iU<#
return findPageByCriteria Wn2NMXK
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); _TZRVa_
} h[Y1?ln&h
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public PaginationSupport findPageByCriteria [9L:),&u
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(final DetachedCriteria detachedCriteria, finalint C,r;VyW6BI
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startIndex){ f$$ /H>MJ
return findPageByCriteria g!|kp?
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(detachedCriteria, PaginationSupport.PAGESIZE, k4J+J.|
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startIndex); 6H$FhJF
} 8nV+e~-w
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public PaginationSupport findPageByCriteria ,f>k%_U}
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(final DetachedCriteria detachedCriteria, finalint }Sv:`9=
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pageSize, 7{*>agQh
finalint startIndex){ f]CXu3w(J
return(PaginationSupport) y<Ot)fa$
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getHibernateTemplate().execute(new HibernateCallback(){ UaeXY+O
publicObject doInHibernate "chDg(jMZ
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(Session session)throws HibernateException { .ioEIs g
Criteria criteria = b\2
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detachedCriteria.getExecutableCriteria(session); b>ySv
int totalCount = > ~O.@|
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((Integer) criteria.setProjection(Projections.rowCount NzvXN1_%
@q)d
()).uniqueResult()).intValue(); 7%M_'P4 V
criteria.setProjection ckCE1e>s
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(null); |A(Iti{v
List items = ;$g?T~v7
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criteria.setFirstResult(startIndex).setMaxResults Mo|2}nf
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(pageSize).list(); $XH^~i;
PaginationSupport ps = |[8Th4*n
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new PaginationSupport(items, totalCount, pageSize, Nh+ H 9
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startIndex); @H8EWTZ
return ps; @=u3ZVD
} {)<v&'*c~
}, true); FS1z`wYP
} w0unS`\4
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public List findAllByCriteria(final K3uRs{l|
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DetachedCriteria detachedCriteria){ veECfR;
return(List) getHibernateTemplate uyx 2;f
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().execute(new HibernateCallback(){ %;!.n{X
publicObject doInHibernate _)-o1`*-
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(Session session)throws HibernateException { dAj$1Ke
Criteria criteria = /Z4et'Lo
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detachedCriteria.getExecutableCriteria(session); BJ(M2|VH
return criteria.list(); ySI!d|_
} bg0Wnl
}, true); 32
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} >
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public int getCountByCriteria(final A+{VGP^
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DetachedCriteria detachedCriteria){ ;A[Q2(w+
Integer count = (Integer) jz0T_\8D`
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getHibernateTemplate().execute(new HibernateCallback(){ teVM*-
publicObject doInHibernate ml$o5&sN
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(Session session)throws HibernateException { WX0tgXl
Criteria criteria = Af{"pzY
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detachedCriteria.getExecutableCriteria(session); LreP4dRe
return sx<%2
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criteria.setProjection(Projections.rowCount :\U{_@?`%
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()).uniqueResult(); OZ!^ak
} 7VI*N)OZ8
}, true); pD]OT-8
return count.intValue(); dcT80sOC
} Xn\jO>[Ef
} t&DEb_"De
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用户在web层构造查询条件detachedCriteria,和可选的 xn|(9#1o
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 g$o&Udgs
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PaginationSupport的实例ps。 5rUdv}.
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ps.getItems()得到已分页好的结果集 tFl"n;~T
ps.getIndexes()得到分页索引的数组 W+1^4::+
ps.getTotalCount()得到总结果数 j1HW._G
ps.getStartIndex()当前分页索引 ?[>3QE
ps.getNextIndex()下一页索引 :P=(k2
ps.getPreviousIndex()上一页索引 Oz#{S:24M+
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 !FF U=f
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 |IUWF%~^$+
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一下代码重构了。 %GIr&V4|
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我把原本我的做法也提供出来供大家讨论吧: R,=fv
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首先,为了实现分页查询,我封装了一个Page类: 1 I",L&S1
java代码: i<g-+ Qs
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/*Created on 2005-4-14*/ {+Cy U!O
package org.flyware.util.page; H~z`]5CN
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/** r0 uwPf
* @author Joa DrK{}uM
* R0
*/ LvYB7<zk>
publicclass Page { _``=cc
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/** imply if the page has previous page */ t}tEvh
privateboolean hasPrePage; 07=mj%yV
uOdl*| T?
/** imply if the page has next page */ T:W4$P
privateboolean hasNextPage; YQA,f#
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/** the number of every page */ |*tp16+6
privateint everyPage; :tv,]05t
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/** the total page number */ ."y1_dDql
privateint totalPage; RhLVg~x
*$ %a:q1U
/** the number of current page */ q{;:SgZ
privateint currentPage; $5Ff1{
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/** the begin index of the records by the current N^:9Fz
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query */ mvT(.R ..s
privateint beginIndex; O]1(FWYy
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/** The default constructor */ (;^syJrh
public Page(){ A
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} (,Df^4%7
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/** construct the page by everyPage Jz
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* @param everyPage 55c|O
* */ ]1pIj
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public Page(int everyPage){ I,@6J(9
this.everyPage = everyPage; P;]F(in=
} ysf~|r4s
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/** The whole constructor */ Qhcu>ra
public Page(boolean hasPrePage, boolean hasNextPage, _D(rI#q
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int everyPage, int totalPage, "y/?WQ>,3
int currentPage, int beginIndex){ HYSIN^<oy
this.hasPrePage = hasPrePage; m:o<X K[>
this.hasNextPage = hasNextPage; a8Nh=^Py
this.everyPage = everyPage; t"'7m^j
this.totalPage = totalPage; UVIKQpA]A
this.currentPage = currentPage; ;
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this.beginIndex = beginIndex; 1gN=-AC
} 0o*8#i/)!3
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/** 6h,(wo3Y
* @return ' x35=@
* Returns the beginIndex. o:P}Wg/NK
*/ 8::$AQL3
publicint getBeginIndex(){ 3Xy-r=N. l
return beginIndex; 6?~"V
} |kV*Jc k
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/** xx9 g''Q
* @param beginIndex e 5*hE
* The beginIndex to set. v"XGC i91L
*/ UH-*(MfB
publicvoid setBeginIndex(int beginIndex){ 90*5
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this.beginIndex = beginIndex; 6){]1h"
} /Uy"M:|V1
O%KsD[W;
/** WE.{p>
* @return `q*M4,
* Returns the currentPage. o{q{!7DH@
*/ B
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publicint getCurrentPage(){ ah0`KxO]
return currentPage; Ne{?:h.!
} z Q`jP$2
wL
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/** _Wq
* @param currentPage "ZsOd>[/
* The currentPage to set. S:oi<F
*/ |G,tlchprs
publicvoid setCurrentPage(int currentPage){ 5l 2 ?
this.currentPage = currentPage; lc,tVe_
} D rHVG
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/** kJzoFFWo$
* @return >dG;w6y'
* Returns the everyPage. ``Dq
*/ v)l8@.
publicint getEveryPage(){ pg.ri64H<
return everyPage; XJ` ]ga
} TKY*`?ct
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/** bg&zo;Ck8T
* @param everyPage I E&!YP(U(
* The everyPage to set. aM2l2
*/ =`:K{loxq
publicvoid setEveryPage(int everyPage){ bE#,=OI$
this.everyPage = everyPage; _w/EP
} 1H@>/QC
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/** |_*O '#jx
* @return 5JCG2jqx0
* Returns the hasNextPage. t.&Od;\[/
*/ WDc+6/<
publicboolean getHasNextPage(){ %?uc><&?e
return hasNextPage; pP?MWe
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} !?p%xj?
u7\J\r4,+
/** hMUs"
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* @param hasNextPage RHq/JD-
* The hasNextPage to set. SHbtWq}T
*/ i;jw\ed
publicvoid setHasNextPage(boolean hasNextPage){ xA1hfe.9
this.hasNextPage = hasNextPage;
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} g[Ib,la_a
wS+^K
/** oA7;.:3
* @return pr#z=vqH
* Returns the hasPrePage. Q/I!}C4
*/ U.XNv-M
publicboolean getHasPrePage(){ j!4et;
return hasPrePage; 4%}*&nsI-Z
} MHai%E
]dk8lZ;bo
/** Y"Ql!5=
* @param hasPrePage ;A'Z4=*~
* The hasPrePage to set. AvSM^
*/ {%{`l-
publicvoid setHasPrePage(boolean hasPrePage){ !{)tSipd
this.hasPrePage = hasPrePage;
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} BV(8y.H
gO,25::")
/** '|*?*6q
* @return Returns the totalPage. 9}uW}yJ
* 7.@TK&
*/ O:"*q&;J
publicint getTotalPage(){ +$(2:S*r
return totalPage; E3l> 3
} !]fQ+ *X0g
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/** Q~Hh\L t
* @param totalPage OhmQ,
* The totalPage to set. YJ/zU52JK~
*/ X*Dj[TD]
publicvoid setTotalPage(int totalPage){ )aao[_ZS
this.totalPage = totalPage; 3g~^[&|i
} T<@ cd|`
J}@z_^|"mJ
} 5qkH|*Z3
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 "zY](P
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个PageUtil,负责对Page对象进行构造: =rQP[ICs!
java代码: EVUq--)~
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/*Created on 2005-4-14*/ aJe^Tp(
package org.flyware.util.page; 6ubL1K
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import org.apache.commons.logging.Log;
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import org.apache.commons.logging.LogFactory; JwRF(1_sM
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/** -;XKcS7Ue
* @author Joa P;8>5;U4-
* G"59cv8z4R
*/
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publicclass PageUtil { deeU@x`f<
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privatestaticfinal Log logger = LogFactory.getLog `L5~mb;7*
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(PageUtil.class); %F9{EXJy
&G >(9
/** EIbXmkHl<
* Use the origin page to create a new page %=<IGce
* @param page xf>z @)e
* @param totalRecords y3;q_4.
* @return tPyyZ#,
*/ ExXM:1 e26
publicstatic Page createPage(Page page, int /_-;zL
x/MZ(A%D
totalRecords){ >71&]/Rv
return createPage(page.getEveryPage(), uH^PQ
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page.getCurrentPage(), totalRecords); geefnb
} PaCzr5!~f
YIp-Y}6
/** OAZ#|U
* the basic page utils not including exception 0ZPV'`KGp
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handler ?vGffMm
* @param everyPage A?"h@-~2
* @param currentPage HT_TP q
* @param totalRecords xq-$\#O
* @return page td -3h,\\
*/ VnJMmMM
publicstatic Page createPage(int everyPage, int \H5Jk$*
l t]B#, '
currentPage, int totalRecords){ <<|H=![
everyPage = getEveryPage(everyPage); =OV2 uq
currentPage = getCurrentPage(currentPage); :Px\qh}K
int beginIndex = getBeginIndex(everyPage, 6j8<Q 2
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currentPage); K,}w]b
int totalPage = getTotalPage(everyPage, zy N (4
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totalRecords); =ziy`#fm,
boolean hasNextPage = hasNextPage(currentPage, vU/ D7
vh>{_
#
totalPage); Gwd{#7FM`
boolean hasPrePage = hasPrePage(currentPage); -Ubj6 t_K
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returnnew Page(hasPrePage, hasNextPage, JF qf;3R
everyPage, totalPage,
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currentPage, ^4`&EF
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beginIndex); h[ 6hM^n
} abY0)t
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privatestaticint getEveryPage(int everyPage){ T }uE0Z,
return everyPage == 0 ? 10 : everyPage; :?r*p>0$
} n2;9geq+
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privatestaticint getCurrentPage(int currentPage){ C?QfF{!7
return currentPage == 0 ? 1 : currentPage; o G_~3Kt
} ixOw=!@
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privatestaticint getBeginIndex(int everyPage, int +6%7CC 6
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currentPage){ ~440#kj<
return(currentPage - 1) * everyPage; )Ul&1UYA
} oa9)Dv
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privatestaticint getTotalPage(int everyPage, int o#d$[oa
wd`R4CKhP]
totalRecords){ KHJ=$5r)
int totalPage = 0; \3 KfD'L
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if(totalRecords % everyPage == 0) *Pb.f
totalPage = totalRecords / everyPage; (/q}mB
else *!u?
totalPage = totalRecords / everyPage + 1 ; s4IKSX
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return totalPage; #6FaIq92V
} O&P>x#w
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privatestaticboolean hasPrePage(int currentPage){ vadM1c*z
return currentPage == 1 ? false : true; u-/3(dKt
} xDe47&qKM
}@4|7
privatestaticboolean hasNextPage(int currentPage, v =bv@c
i0&)
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int totalPage){ ,yi2O]5e>!
return currentPage == totalPage || totalPage == }moz9a
<\xQ7|e
0 ? false : true; >huq t|S*9
} :dbV2'vIQ
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A@{ !:_55
} j<|6s,&
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Ty iU1, oO
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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^6.!;W
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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 ^8U6"O6|X
@%keTTZ
做法如下: =z']s4
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 qIUC2,&g
Dl@{}9
的信息,和一个结果集List: A<