Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 4I.)>+8V
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 %~0]o@LW7
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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 (.b!kfC
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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 $-\%%n0>6
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分页支持类:
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java代码: xJOp~fKG
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package com.javaeye.common.util; }T53y6J#
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import java.util.List; 8SCXA9}
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publicclass PaginationSupport { 8 v da"
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publicfinalstaticint PAGESIZE = 30; J?jxD/9Yb
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privateint pageSize = PAGESIZE; Jt)J1CAYo
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privateList items; N_(-\\mq
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privateint totalCount; %-|$7?~
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privateint[] indexes = newint[0]; `'pfBVBz
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privateint startIndex = 0; 'a~F'FN$
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public PaginationSupport(List items, int ,,?XGx
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totalCount){ P|a|4Bb+fW
setPageSize(PAGESIZE); d-I=xpB
setTotalCount(totalCount); 9rM#w"E?<
setItems(items); _#
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setStartIndex(0); q{!ft9|K\d
} ?` 2z8uD/
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public PaginationSupport(List items, int hl,x|.f}4Y
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totalCount, int startIndex){ lEw!H^O4
setPageSize(PAGESIZE); SN$3cg]z
setTotalCount(totalCount); UAC"jy1D
setItems(items); I1p{(fJ
setStartIndex(startIndex); raM{!T:
} UUvR>5@n
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public PaginationSupport(List items, int 6hHMxS^o
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totalCount, int pageSize, int startIndex){ O1oh,~W
setPageSize(pageSize); t*-_MG
setTotalCount(totalCount); pQ8f$I#v
setItems(items); =
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setStartIndex(startIndex); g c<Y?a-
} "rpP
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publicList getItems(){ ~6[3Km|2
return items; qGzF@p(p8
} QjTs$#eMW
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publicvoid setItems(List items){ :GM3n$
this.items = items; `/(9#E
} {k']nI.>
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publicint getPageSize(){ P R_|
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return pageSize; v5W-f0Jo
} ;Ji3|=4u
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publicvoid setPageSize(int pageSize){ T5_rPz
this.pageSize = pageSize; _t6.9CXl
} rt\.|Hr4s
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publicint getTotalCount(){ LE g#W
return totalCount; uao#=]?)
} =!($=9
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publicvoid setTotalCount(int totalCount){ gi8f)MNP?~
if(totalCount > 0){ C0&ZQvvy1:
this.totalCount = totalCount; Z|d+1i
int count = totalCount / #_: %Yd
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pageSize; Q6CVMYT
if(totalCount % pageSize > 0) eqyUI|e
count++; WogCt,
indexes = newint[count]; RuOse9
for(int i = 0; i < count; i++){ =r~ExW}+
indexes = pageSize * &E-q(3-
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i; T~d_?UAw$
} UvL=^*tm
}else{ 2hb>6Z;r]K
this.totalCount = 0; 2Xv$
} 6<YAoo
} sTxbh2
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publicint[] getIndexes(){ RZ?abE8
return indexes; X//=OpS`
} K>#QC
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publicvoid setIndexes(int[] indexes){ i8=+<d
this.indexes = indexes; <qBM+m$|)
} *~zB {
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publicint getStartIndex(){ w[u>*I
return startIndex; 0
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} \ns}
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publicvoid setStartIndex(int startIndex){ :\%ZTBLL
if(totalCount <= 0) (b7',:_U7
this.startIndex = 0; i`!>zl+D
elseif(startIndex >= totalCount) xQNGlVipZ@
this.startIndex = indexes p,3}A(>
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[indexes.length - 1]; Lv>O BHD
elseif(startIndex < 0) ~b6c:db3
this.startIndex = 0; ].@8/. rg
else{ </2Cn@
this.startIndex = indexes @CKMJ^#|
q( %)^C
[startIndex / pageSize]; RvyCc!d
} HgTBON(
}
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publicint getNextIndex(){ yB4eUa!1
int nextIndex = getStartIndex() + GGsAisF"N
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pageSize; s6Il3Kf
if(nextIndex >= totalCount) `X(H,Q}*;
return getStartIndex(); ~pwk[Q!
else /Nhc|x6zQ
return nextIndex; * b"aJ<+
} NOl/y@#
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publicint getPreviousIndex(){ "!:)qVL^
int previousIndex = getStartIndex() - nHQWO
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pageSize; R?#.z#
if(previousIndex < 0) UTO$L|K
return0; KBgFS%-W
else 2|${2u`$&y
return previousIndex; -+:t%A?
} R=S)O.*R
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} ~NIqO4 D
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抽象业务类 5m?9O7Pg
java代码: !14l[k+\
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/** 88l{M[B2
* Created on 2005-7-12 p\tA&>3-
*/ "J2v8c
package com.javaeye.common.business; &
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import java.io.Serializable; pbGv\SF
import java.util.List; +a^0Q
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import org.hibernate.Criteria; [=>[ 2Ty
import org.hibernate.HibernateException; &Zo+F]3d
import org.hibernate.Session; P8 R^46
import org.hibernate.criterion.DetachedCriteria; J>fq5
import org.hibernate.criterion.Projections; .+~9
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import '^tC |)
H5be 5
org.springframework.orm.hibernate3.HibernateCallback; C-/+n5J
import 5.lg*vh
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org.springframework.orm.hibernate3.support.HibernateDaoS 1|$J>
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upport; w=thaF.
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import com.javaeye.common.util.PaginationSupport; $I9U.~*
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public abstract class AbstractManager extends &H2j3De
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HibernateDaoSupport { 3w+ +F@(
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privateboolean cacheQueries = false; ?_.
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privateString queryCacheRegion; 8Y;2.Z`Rz
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publicvoid setCacheQueries(boolean j+2-Xy'
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cacheQueries){ q'%!qa+
this.cacheQueries = cacheQueries; .GvZv>
} o)H|
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w}
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publicvoid setQueryCacheRegion(String x#t?`
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queryCacheRegion){ }{.V^;
this.queryCacheRegion = \# 1p
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queryCacheRegion; R[H#av
} J$&2GAi
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publicvoid save(finalObject entity){ 9/O\769"'
getHibernateTemplate().save(entity); +xNq8yS
} I<S*"[nV
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publicvoid persist(finalObject entity){ QG09=GQ
getHibernateTemplate().save(entity); T )bMHk
} >skl-f
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publicvoid update(finalObject entity){ /L` +
getHibernateTemplate().update(entity); )~#3A@
} 6`5DR~
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publicvoid delete(finalObject entity){ MgHO WoF
getHibernateTemplate().delete(entity); ;p:CrFv
}
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publicObject load(finalClass entity, i$H9~tPs
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finalSerializable id){ TZarI-A
return getHibernateTemplate().load +
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(entity, id); {-yw@Kq
} YyC$\HH6
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publicObject get(finalClass entity, ty8E;['
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finalSerializable id){ AdRK )L
return getHibernateTemplate().get ephvvj~zW4
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(entity, id); !ZayN
} "f-HOd\=
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publicList findAll(finalClass entity){ {ApjOIxk
return getHibernateTemplate().find("from H2CpZK'
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" + entity.getName()); Q=^TKsu
} O66b^*=N}x
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publicList findByNamedQuery(finalString %5j*e
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namedQuery){ :%IB34e
return getHibernateTemplate ^-(DokdBn
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().findByNamedQuery(namedQuery); `|4k>5k
} H1$n6J
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publicList findByNamedQuery(finalString query, iO}KERfU
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finalObject parameter){ *4c5b'u
return getHibernateTemplate =lx~tSiS
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().findByNamedQuery(query, parameter); 6Z{(.'Be
} >&Y\g?Z6G
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publicList findByNamedQuery(finalString query, 0_-P~^A
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finalObject[] parameters){ B\+uRiD8w
return getHibernateTemplate 18>v\Hi<
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().findByNamedQuery(query, parameters); ]qiX"<s>~C
} F:LrQu
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publicList find(finalString query){ 0m4'm<2m
return getHibernateTemplate().find <A&Zl&^1
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(query); )<.y{_QUN
} '-P+|bZW4
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publicList find(finalString query, finalObject WLCr ~r^
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parameter){ W4)bEWO+q
return getHibernateTemplate().find yn.[-
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(query, parameter); X5+$:jq&
} CM)V^k*
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public PaginationSupport findPageByCriteria Ka$lNL3<j
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(final DetachedCriteria detachedCriteria){ U"a7myB+jX
return findPageByCriteria i_av_I-
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); Y.%Vvg4z3
} ]^<\a=U
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public PaginationSupport findPageByCriteria 8qoA5fW>
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(final DetachedCriteria detachedCriteria, finalint Ei89Ngp\}
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startIndex){ D0h6j0r5
return findPageByCriteria C{,Vk/D-0
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(detachedCriteria, PaginationSupport.PAGESIZE, 4K,S5^`Gx
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startIndex); o 80x@ &A:
} {HjJ9ZGQ
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public PaginationSupport findPageByCriteria WnA
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(final DetachedCriteria detachedCriteria, finalint {8,_[?H
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pageSize, SZvC4lOn#
finalint startIndex){ GZm=>!T
return(PaginationSupport) DH:9iX '
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getHibernateTemplate().execute(new HibernateCallback(){ +R"n_6N
publicObject doInHibernate IH.EvierJ
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(Session session)throws HibernateException { nI8zT0o
Criteria criteria = *E-MJCv
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detachedCriteria.getExecutableCriteria(session); W3n[qVZIC
int totalCount = <]*Jhnx/
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((Integer) criteria.setProjection(Projections.rowCount Is9.A_0h
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()).uniqueResult()).intValue(); CiTWjE?|7
criteria.setProjection 9fsc>9
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(null); upFe{M@
List items = 3;R`_#t+
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criteria.setFirstResult(startIndex).setMaxResults ,q$2D,dz
{*nE8+..A
(pageSize).list(); /f hS#+V*
PaginationSupport ps = 5[~C!t;
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new PaginationSupport(items, totalCount, pageSize, }6*JX\'q
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startIndex); qJR8fQ
return ps; ] ~}~d(
} >]2 ^5C;
}, true); [~?6jnp
} bG+Gg*0p
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public List findAllByCriteria(final ,2P/[ :
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DetachedCriteria detachedCriteria){ zR?1iV.]
return(List) getHibernateTemplate qipS`:TER
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().execute(new HibernateCallback(){ rym*W\AWx
publicObject doInHibernate #r]GnC,
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(Session session)throws HibernateException { .:tR*Kst`7
Criteria criteria = "WH
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detachedCriteria.getExecutableCriteria(session); [5Zi\'~UH)
return criteria.list(); nWUau:%
} epcvwM/A
}, true); P#"_H}qC*
} T7N\b]?j@Y
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public int getCountByCriteria(final tR_DN
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DetachedCriteria detachedCriteria){ ^$<:~qq!
Integer count = (Integer) }{v0}-~@
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getHibernateTemplate().execute(new HibernateCallback(){ J$-1odL0Z
publicObject doInHibernate jI$7vmO
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(Session session)throws HibernateException { ,.&D{$1W
Criteria criteria = 3w! NTvp
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detachedCriteria.getExecutableCriteria(session); mOFp!(
return 2t7=GA+j
[ *
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criteria.setProjection(Projections.rowCount <<H'Z
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()).uniqueResult(); Htep3Ol3
} |^#Z!Hp_Y
}, true); d!"gb,ec
return count.intValue(); Hq,znRz~`
} ;9qwB
} !0cb f&^:
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用户在web层构造查询条件detachedCriteria,和可选的 N]G`]
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 o^u}(wZ{
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PaginationSupport的实例ps。 E%$[*jZ
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ps.getItems()得到已分页好的结果集 _;-b ZH
ps.getIndexes()得到分页索引的数组 (dym*_J
ps.getTotalCount()得到总结果数 ^L'<%_#.
ps.getStartIndex()当前分页索引 axv-UdE;
ps.getNextIndex()下一页索引 "rw'mogRL
ps.getPreviousIndex()上一页索引 7QaZ|\c
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 +^a@U^V
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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 ShOB"J-
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一下代码重构了。 P}-S[[b73s
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我把原本我的做法也提供出来供大家讨论吧: 3;Tsjv}
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首先,为了实现分页查询,我封装了一个Page类: }$:ha>
java代码: EtDzmpJR>
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/*Created on 2005-4-14*/ Qa1G0qMEIF
package org.flyware.util.page; Vje LPbk)
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/** 7Y^2JlZu=
* @author Joa 'zuA3$SR
* dV"Kx
*/ &I/C^/F&
publicclass Page { i.+#a2
>
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/** imply if the page has previous page */ weIlWxy
privateboolean hasPrePage; )lVplAhZD
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/** imply if the page has next page */ 7] 17?s]t,
privateboolean hasNextPage; WQHlf0]
wE_#b\$=b
/** the number of every page */ 9bD ER
privateint everyPage; |LE*R@|3$
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/** the total page number */ hle@= e/n
privateint totalPage; %UCuI9
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/** the number of current page */ pbqJtBBDDS
privateint currentPage; 3L;&MG=
E D_J8+
/** the begin index of the records by the current )eBCO~HS
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query */ "R-Pe\W
privateint beginIndex; 2}.EFQp+
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/** The default constructor */ M\=/i\-
public Page(){ /^Zgv-n
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} yzz(<s:o/
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/** construct the page by everyPage wU5= '
* @param everyPage QBTjiaYGa'
* */ Fpntd IU
public Page(int everyPage){ X6o
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this.everyPage = everyPage; ['@R]Si"!
} efm#:>H
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/** The whole constructor */ [\)irCDv
public Page(boolean hasPrePage, boolean hasNextPage, gOn^}%4.I
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int everyPage, int totalPage, ]q@W(\I
int currentPage, int beginIndex){ MJ`BlE,Fmb
this.hasPrePage = hasPrePage; zY\MzhkX,
this.hasNextPage = hasNextPage; | PzXN+DW
this.everyPage = everyPage; =p$:vW
this.totalPage = totalPage; |dk9/xdX
this.currentPage = currentPage; l1}HJmom
this.beginIndex = beginIndex; o%?~9rf]]
} M\be a
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/** RQd5Q.
* @return __,}/|K2
* Returns the beginIndex. @m ?&7{y#?
*/ O:te;lQK
publicint getBeginIndex(){ #Pq.^ ^
return beginIndex; Z$ Mc{
} Tg#%5~IX
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/** ^+Stvj:N
* @param beginIndex t+O7dZt%r
* The beginIndex to set. sqk$q pV6
*/ ,2^zX]dgM
publicvoid setBeginIndex(int beginIndex){ (ysDs[?\
this.beginIndex = beginIndex; 7D wf0Re`
} jxA*Gg3cT5
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/** X5Ff2@."y|
* @return ^[-3qi
* Returns the currentPage. N+0`Jm
*/ <!.Qn
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publicint getCurrentPage(){ 5SmgE2 }
return currentPage; UNd+MHE74I
} &io*pmUm6
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/** D*o[a#2_
* @param currentPage (= ,w$
* The currentPage to set. rQD7ZN_ R
*/ ,#QLc
publicvoid setCurrentPage(int currentPage){ gIaPS0Q
this.currentPage = currentPage; =[V
} Z\P&i#
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/** A;#GU`
* @return $sR-J'EE!
* Returns the everyPage. 1r;.r|
*/ b0"R |d[i
publicint getEveryPage(){ @mrGG F
return everyPage; LzJNQd'
} !)TO2?,^
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/** Zp*0%x!e
* @param everyPage F
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* The everyPage to set. 7Yd]#K{$
*/ {pW(@4U
publicvoid setEveryPage(int everyPage){ / qo`vk A
this.everyPage = everyPage; \hT=U*dMR
} # ~T
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/** 4mJ[Wr\y
* @return ImVHX~qHJ
* Returns the hasNextPage. )rFcfS+/
*/ ;NeN2 |I]
publicboolean getHasNextPage(){ 74q|FQ
return hasNextPage; $mp'/]
} Ik74%x7G`
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/** QnNddCiu=
* @param hasNextPage o{wXq)b
* The hasNextPage to set. X:Z*7P/
*/ 6t(I.>-
publicvoid setHasNextPage(boolean hasNextPage){ $S _VR
this.hasNextPage = hasNextPage; a4iq_F#NF
} 4P\?vz"
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/** xnm!$ $W
* @return G.#sX
* Returns the hasPrePage. \@i4im@%xU
*/ kan4P@XVS
publicboolean getHasPrePage(){ m6=Jp<
return hasPrePage; =ADdfuKN
} L
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'
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/** 3m9ab"
* @param hasPrePage )dgooq
* The hasPrePage to set. -^%YrWgd?
*/ $"G=r(MW
publicvoid setHasPrePage(boolean hasPrePage){ t&99ZdE
this.hasPrePage = hasPrePage; &;O)Dw
} IrZ!.5%tV
p&~= rp`E
/** Y"&1jud4xl
* @return Returns the totalPage. t*'U|K4L/
* }yW*vy6`
*/ =`MU*Arcs[
publicint getTotalPage(){ v{dvB:KP5X
return totalPage; pl.K*9+
} rWo&I_{
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/** ^7
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* @param totalPage
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* The totalPage to set. -h/KrB
*/ >^fkHbgNQ
publicvoid setTotalPage(int totalPage){ H*]B7?S
this.totalPage = totalPage; ^Gs=U[**
} %[9d1F3
~HH6=qjU)
} ;5fq[v^P:
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 *?GV(/Q
M>BcYbXf
个PageUtil,负责对Page对象进行构造: }JKK"d}U
java代码: BCK0fk~
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/*Created on 2005-4-14*/ 09psqXU@I
package org.flyware.util.page; }L1-2
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import org.apache.commons.logging.Log; If*t$f>y4N
import org.apache.commons.logging.LogFactory; LgX"Qk&Ca
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/** i!jR>+
* @author Joa lrXi*u]
* UFoxv)
*/ tL!R^Tf
publicclass PageUtil { C;&44cU/]
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privatestaticfinal Log logger = LogFactory.getLog ~J Xqyw}
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(PageUtil.class); s}pn5zMp:8
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/** '&.QW$B\B_
* Use the origin page to create a new page ATb[/=hP<R
* @param page lB0: 4cIj
* @param totalRecords UvtSNP&/2d
* @return 9Xv>FVG!
*/ 0DFxVH_xN
publicstatic Page createPage(Page page, int mar
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eaI!}#>R+
totalRecords){ P{-f./(JD
return createPage(page.getEveryPage(),
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page.getCurrentPage(), totalRecords); ,%FBELqOW
} P,ox))+6
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/** &!lGx7zf
* the basic page utils not including exception p+;[i%`
~HH#aXh*
handler -R[ *S "
* @param everyPage (\QkXrK
* @param currentPage 0m|$ vb
* @param totalRecords )aOPR|+
* @return page HktvUJ(Ii
*/ -|l^- Qf!
publicstatic Page createPage(int everyPage, int Q[+o\{ O
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currentPage, int totalRecords){ `zjEs8`'
everyPage = getEveryPage(everyPage); Q9`}dYf.
currentPage = getCurrentPage(currentPage); ]y:ez8RFPU
int beginIndex = getBeginIndex(everyPage, q~^qf
nbpGxUF`]
currentPage); ].j;d2xT\
int totalPage = getTotalPage(everyPage, m&H@f:
#sOkD
totalRecords); ItZqLUJm
boolean hasNextPage = hasNextPage(currentPage, Fnnk}I}
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totalPage); pD+_ K
boolean hasPrePage = hasPrePage(currentPage); a/Cd;T2
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returnnew Page(hasPrePage, hasNextPage, k|^e=I
everyPage, totalPage, m{/?6h 1
currentPage, b|cUKsL5
ng-g\&-
beginIndex); n6PXPc
} |g3a1El
eRK
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privatestaticint getEveryPage(int everyPage){ [,Io!O
return everyPage == 0 ? 10 : everyPage; MVGznf?
} 5/:BtlFx
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privatestaticint getCurrentPage(int currentPage){ bN6FhKg|
return currentPage == 0 ? 1 : currentPage; cI9} YSk
} ~v2E<S3
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privatestaticint getBeginIndex(int everyPage, int A{5^A)$
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currentPage){ 1CkBfK
return(currentPage - 1) * everyPage; 0i[,`>-Av
} /e^q>>z
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privatestaticint getTotalPage(int everyPage, int .kl _F7
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totalRecords){ *Txt`z[|
int totalPage = 0; 9Ytf7NpR
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if(totalRecords % everyPage == 0) H5f>Q0jq
totalPage = totalRecords / everyPage; +Mb;;hb
else uY,(3x
totalPage = totalRecords / everyPage + 1 ; TNA?fm
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return totalPage; m"{D}(TA
} CH6^;.
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privatestaticboolean hasPrePage(int currentPage){ Pd99vq/
return currentPage == 1 ? false : true; *CHLs^)
} 8y-Sd\0g
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privatestaticboolean hasNextPage(int currentPage, 'WEypz
;+%(@C51GE
int totalPage){ zCvt"!}RRa
return currentPage == totalPage || totalPage == Tl.dr
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0 ? false : true; zj ;'0Zu
} Y <'T;@
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} `u%`Nj
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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。 Voi`OCut
fdIO'L_
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 > .L\ >
1 m)WM,L
做法如下: JG%y_
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1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 '%@fW:r~
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的信息,和一个结果集List: jG"n);WF
java代码: I`?6>Z+%)
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;VY0DAp{
/*Created on 2005-6-13*/ n%o"n?e
package com.adt.bo; eIEr\X4\~~
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import java.util.List; tta\.ic
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import org.flyware.util.page.Page; c#?JW:^|Df
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/** l$ABOtM@
* @author Joa ,J|8P{ZO
*/ VTOZ#*f
publicclass Result { fVlTsc|e
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private Page page; s2-`}LL
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private List content; wb@TYvDt
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/** $9pFRQC'q
* The default constructor KTV~g@Jf
*/ Yx4TUA$c'
public Result(){ oMH-mG7:K
super(); :J|t! `
} F]e]
*.X!AJ;M=O
/** P4xQ:$2!
* The constructor using fields ? Xb8B5
* j]uL9\>
* @param page r+T@WvS%W
* @param content |5o0N8!b[
*/ ZT>?[`Vgc
public Result(Page page, List content){ &F4khga`^:
this.page = page; 2!Ip!IQ:
this.content = content; g4(vgWOW`
} pIKQx5;
p<5ED\;N;
/** XG]ltSOy
* @return Returns the content. M=Y}w?
*/ DH(Qmd
publicList getContent(){ V=)0{7-9
return content; )24c(
} t2)S61Vr
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/** o"5Bg%H
* @return Returns the page. \`:X37n)0q
*/ 2&st/y(hs
public Page getPage(){ DA)mkp
return page; <ob+Ano$
} t{\,vI
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/** 9C?;'
* @param content ZeVb< g
* The content to set. aJ[K' 5|
*/ 3z^l
public void setContent(List content){ X2avo|6e
this.content = content; k 7 !{p
} H-&Z+4 +Xs
f9A^0A?c
/** qd@x#"qT
* @param page %1E:rw@
* The page to set. 0/".2(\}T
*/ bVEt?E*+
publicvoid setPage(Page page){ Ood8Qty(
this.page = page; K)m\xzT/
} FBn`sS8hH
} Ep/kb-~-
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2. 编写业务逻辑接口,并实现它(UserManager, i
#5rk(^t
h{ s- e.
UserManagerImpl) j7&57'
java代码: $ b Q4[
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