Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 `Yn:fL7S
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 8&?Kg>M
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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 RGFanP
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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 QcJ?1GwA"
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分页支持类: sy`@q<h(
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java代码: 5v6 x
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package com.javaeye.common.util; g
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import java.util.List; `|?K4<5|
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publicclass PaginationSupport { 3)\jUVuj
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publicfinalstaticint PAGESIZE = 30; dbM~41C6
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privateint pageSize = PAGESIZE; Ji4xor
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privateList items;
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privateint totalCount; ?O3E.!Q|
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privateint[] indexes = newint[0]; ..BIoSrj
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privateint startIndex = 0; qv\n]M_&
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public PaginationSupport(List items, int rTTde^^_
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totalCount){ 6.%M:j00E
setPageSize(PAGESIZE); Xg+Eeg#
setTotalCount(totalCount);
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setItems(items); kT6h}d^/^
setStartIndex(0); jb;!"HC
} ]@E_Hx{S
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public PaginationSupport(List items, int +KV?W+g)`
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totalCount, int startIndex){ }e$^v*16
setPageSize(PAGESIZE); XY %er
setTotalCount(totalCount); }j<:hDQP
setItems(items); y4sKe:@2
setStartIndex(startIndex); }-YM>q
} JSz;>
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public PaginationSupport(List items, int <u "xHl8Io
4<%(Y-_sF
totalCount, int pageSize, int startIndex){ ..jc^'L
setPageSize(pageSize); cbe&SxJ
setTotalCount(totalCount); <12 ia"}
setItems(items); ?VCdT`6=
setStartIndex(startIndex); U9w0kcUw#J
} #r5IwyL
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publicList getItems(){ wW2b?b{*Z
return items; "&h{+DHS
} co!o+jP
s<3cvF<
publicvoid setItems(List items){ Hq<Sg4nz
this.items = items; 2J?ON|2M
} 0"l*8%g
Y9V%eFY5E
publicint getPageSize(){ K1y]
return pageSize; E"i<fr
T
} %L;z ~C
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publicvoid setPageSize(int pageSize){ l Tpn/
this.pageSize = pageSize; O3ij/8f
} ivTx6-]
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publicint getTotalCount(){ K]c|v
i_D
return totalCount; scr`] tD
} pO]{Y?X:
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publicvoid setTotalCount(int totalCount){ #63)I9>
if(totalCount > 0){ nV`n=x
this.totalCount = totalCount; DX3xWdnr
int count = totalCount / Xn:5pd;?B6
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pageSize; '7BJ.
if(totalCount % pageSize > 0) /hrVnki*
count++; *[XVkt`H
indexes = newint[count]; _#f+@)vR
for(int i = 0; i < count; i++){ `)i'1E[9
indexes = pageSize * YdgDMd-1
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i; S
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} Ug}dw a
}else{ Sr$&]R]^
this.totalCount = 0; -@*[
} op!ft/Yyb
} :vsBobiJ
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publicint[] getIndexes(){ 1#nR$
return indexes; o 8fB
} XFj\H(D
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publicvoid setIndexes(int[] indexes){ o`tOnwt
this.indexes = indexes; I`e$U
} |4E5x9J
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publicint getStartIndex(){ UQX.
return startIndex; *yx5G-#?
} YJ6y]r
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publicvoid setStartIndex(int startIndex){ Z~X \Z.
if(totalCount <= 0) vw.rkAGY
this.startIndex = 0; oc|%|pmRd<
elseif(startIndex >= totalCount) .$ o0$`}
this.startIndex = indexes %R?B=W7;Q
K[,d9j`^
[indexes.length - 1]; _1>Xk_
elseif(startIndex < 0) s)dL^lj;
this.startIndex = 0; kdq<)>"
else{ blVt:XS{,m
this.startIndex = indexes d17RJW%A
[quT&E
[startIndex / pageSize]; !
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} wP|Amn+;
} SRP.Mqg9
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publicint getNextIndex(){ 1\t# *N
int nextIndex = getStartIndex() + iY~.U`b`
NA :_yA"
pageSize; /m"#uC!\
if(nextIndex >= totalCount) pxGDzU
return getStartIndex(); yuef84~
else E%.w6-
return nextIndex; hXAgT!ZD
} "d5nVO/
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publicint getPreviousIndex(){ ;#i$5L!*B
int previousIndex = getStartIndex() - >$/<~j]
ce&Q}_
pageSize; xr*%:TwCta
if(previousIndex < 0) CjQ)Bu*4
return0; "e-RV
else "VIoVu
return previousIndex; $`a>y jma
} >b1#dEY
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} ',_E;(
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抽象业务类 `)aIFAW
java代码: 7A,lQh
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/** M+|J;caX
* Created on 2005-7-12 DN X-\
*/ 7Rq|N$y.3
package com.javaeye.common.business; n5NwiSE
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import java.io.Serializable; 78MQoG<
import java.util.List; w7d<Ky_C
o9XT_!Cwg
import org.hibernate.Criteria; !
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import org.hibernate.HibernateException; id?B<OM
import org.hibernate.Session; rYKGBo8"
import org.hibernate.criterion.DetachedCriteria; W'xJh0o
import org.hibernate.criterion.Projections; #Fwf]{J
import ob_*fP
1;E^3j$
org.springframework.orm.hibernate3.HibernateCallback; c e\|eN[
import llE_-M2gH
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org.springframework.orm.hibernate3.support.HibernateDaoS 'JpCS
E9bc pup
upport; e[($rsx
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import com.javaeye.common.util.PaginationSupport; CG0jZB#u
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public abstract class AbstractManager extends 9 *+X^q'
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HibernateDaoSupport { B)`@E4i
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privateboolean cacheQueries = false; +EOd9.X\~
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privateString queryCacheRegion; \'Z^rjB
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publicvoid setCacheQueries(boolean x-@}x@n&[
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cacheQueries){ JBK(Nk
this.cacheQueries = cacheQueries; C[JGt9{Y
} }~O`(mnD}K
S)\Yc=~h
publicvoid setQueryCacheRegion(String L#~z#
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queryCacheRegion){ 4Q?3gA1
this.queryCacheRegion = ?.~hex#M@
= lMs1}S9
queryCacheRegion; ,3,(/%=k
} 7i##g,
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publicvoid save(finalObject entity){ Oh'C[
getHibernateTemplate().save(entity); 6V&HlJH
} [rO TWN
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publicvoid persist(finalObject entity){ y{#9&ct&
getHibernateTemplate().save(entity); VSDG_:!K
} *Z}9S9YtN
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publicvoid update(finalObject entity){ Y7GHIzX
getHibernateTemplate().update(entity); 7H$wpn
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} 9k*1_
Mrly(*!U"@
publicvoid delete(finalObject entity){ ZD#{h J-
getHibernateTemplate().delete(entity); E5. @=U,c
} tg"NWp6
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publicObject load(finalClass entity, yk0#byW`
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finalSerializable id){ py%_XL=w,
return getHibernateTemplate().load slH3c:j\
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(entity, id); @#1T-*
} vD91t/_+
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publicObject get(finalClass entity, 8-geBlCE,
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0
finalSerializable id){ /s[D[:P_
return getHibernateTemplate().get 1MYA/l$
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(entity, id); 9~|hGo
} PCX X[N
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publicList findAll(finalClass entity){ E,gpi
return getHibernateTemplate().find("from Bxf]Lu,\U@
v[!ZRwk4w3
" + entity.getName()); Xo/0lT
} 'FC#O%l
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publicList findByNamedQuery(finalString Uy;e5<<
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namedQuery){ b75en{aDi*
return getHibernateTemplate D"ecwx{%;C
@mm~i~~KA
().findByNamedQuery(namedQuery); Xd@_:ds
} )o N#%%SB<
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publicList findByNamedQuery(finalString query, b3^d!#KVM
)D8V;g(7F
finalObject parameter){ "3e1 7dsY
return getHibernateTemplate 2&KM&NX~
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().findByNamedQuery(query, parameter);
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} F&)(G\
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publicList findByNamedQuery(finalString query, jImw_Q
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finalObject[] parameters){ %WO4uOi:@
return getHibernateTemplate pUm|e5
]]!&>tOlI
().findByNamedQuery(query, parameters); 1Farix1YDq
} "H3DmsB
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publicList find(finalString query){ k35E,?T
return getHibernateTemplate().find Tp&7CNl|
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(query); !v?WyGbUg
} .yN.
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publicList find(finalString query, finalObject [l:}#5\]4
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f@
parameter){ $G D@e0
return getHibernateTemplate().find du_TiI
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(query, parameter); )Bpvi4O
}
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public PaginationSupport findPageByCriteria *sYvV,
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(final DetachedCriteria detachedCriteria){ Vohd
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return findPageByCriteria xt=ELzu$
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); K>S:Z
} Rw]lW;EN<
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public PaginationSupport findPageByCriteria <NlL,
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(final DetachedCriteria detachedCriteria, finalint ~X<Ie9m1x
Cs?[
startIndex){ Lf0Wc'9{
return findPageByCriteria E`gUNAKQ
1#
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(detachedCriteria, PaginationSupport.PAGESIZE, a@s@E
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startIndex); {qbxiL-
} zA%$l&QN]
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public PaginationSupport findPageByCriteria 1b`WzoJgH
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(final DetachedCriteria detachedCriteria, finalint
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l2
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pageSize, dH_g:ocA
finalint startIndex){ 3}gf%U]L
return(PaginationSupport) vq-#%o
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getHibernateTemplate().execute(new HibernateCallback(){ MVXy)9q
publicObject doInHibernate v|@1W Uc,g
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(Session session)throws HibernateException { /^Ng7Mi!
Criteria criteria = ![3l
K
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detachedCriteria.getExecutableCriteria(session); vD3j(d
int totalCount = SU>cJ*
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((Integer) criteria.setProjection(Projections.rowCount /& wA$h
/@feY?glc
()).uniqueResult()).intValue(); L6n<h
criteria.setProjection 5rlZ'>I.
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(null); @8"cT-
List items = (c|Ry[$|
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criteria.setFirstResult(startIndex).setMaxResults *Y<1KXFU
_>4Qh#6K
(pageSize).list(); @zi_@B
PaginationSupport ps = tr-muhuK
Dh.pH1ZY3n
new PaginationSupport(items, totalCount, pageSize, Eq6.
s)10
<= Aqi9 1
startIndex); bXRSKp[$
return ps; (bD'SWE
} vR?E'K3
}, true); SnFAv7_
} Kl]LnN%A{
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public List findAllByCriteria(final 8G?OZ47k#
xn,I<dL39
DetachedCriteria detachedCriteria){ jrZH1dvE
return(List) getHibernateTemplate +hUz/G+3
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().execute(new HibernateCallback(){ A`ScAzx5{
publicObject doInHibernate uG{/yJeU
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(Session session)throws HibernateException { #xfPobQ>il
Criteria criteria = &l
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detachedCriteria.getExecutableCriteria(session); +MvO+\/
return criteria.list(); Rn5{s3?F~2
} YW'l),Z
}, true); {LoNp0i1a
} #S') i1;
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public int getCountByCriteria(final thrv_^A
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DetachedCriteria detachedCriteria){ DhzmC
Integer count = (Integer) KxUO=v<u
{D7v[P+
getHibernateTemplate().execute(new HibernateCallback(){ ,pR.HCR#Y
publicObject doInHibernate DE!P[$J
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(Session session)throws HibernateException { =q?s B]n
Criteria criteria = zsmlXyP'e!
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detachedCriteria.getExecutableCriteria(session); )A=&3Ui)ab
return M:d }
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criteria.setProjection(Projections.rowCount }x(Ewr
1}"Prx-
()).uniqueResult(); /\d@A B^5I
} RAAu3QKu
}, true); NNn sq@?6
return count.intValue(); k5o{mWI b
} }^]TUe@a
} pfF2!`7pI
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7O\ Qxc\
C jZIBMGc
6![}Jvu>
用户在web层构造查询条件detachedCriteria,和可选的 $J!WuOz4^i
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 [VY265)g
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PaginationSupport的实例ps。 EN;4EC7tE
CQ/ps,~M
ps.getItems()得到已分页好的结果集 %{ +>\0x
ps.getIndexes()得到分页索引的数组 G}#p4\/
ps.getTotalCount()得到总结果数 ak$D1#hY
ps.getStartIndex()当前分页索引 /5"RedP<
ps.getNextIndex()下一页索引 C1po]Ott*
ps.getPreviousIndex()上一页索引 [J
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:
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 CC|=$(PgT
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 *:8,w?Nt
LXf*
一下代码重构了。 0i~?^sT'
mG.H=iw
我把原本我的做法也提供出来供大家讨论吧: 2*TPW
nZ8jBCh
首先,为了实现分页查询,我封装了一个Page类: ]7J* (,sp
java代码: qTI_'q
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/*Created on 2005-4-14*/ ^|ul3_'?
package org.flyware.util.page; W
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@
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/** ujh`&GiB+
* @author Joa O1Nya\^g<I
* tqzr+
*/ ~vB dq Yj
publicclass Page { &{ZTtK&JF
uL
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/** imply if the page has previous page */ 8om)A0S
privateboolean hasPrePage; |DLmMsS4
Oz-@e%8L
/** imply if the page has next page */ j71RlS73
privateboolean hasNextPage; gIY]hC.
8DcIM(;Z
/** the number of every page */ _`+2e-
privateint everyPage; 67]!xy
a}V<CBi
/** the total page number */ x/uC)xm
privateint totalPage; O]80";Uv
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/** the number of current page */ y4Lh:;
privateint currentPage; 2!?=I'uMA
bj7r"_
/** the begin index of the records by the current 1R"Z+tNB
(\H^KEy
query */ wkKSL
privateint beginIndex; 51Q~/
vBYk"a6SD
#BwOWra
/** The default constructor */ g<^-[w4/
public Page(){ A@)ou0[n@
]; *?`}#
} W4$F\y
%6E:SI4
/** construct the page by everyPage gp NAM"
* @param everyPage iHlee=}od
* */ Esdw^MGL2
public Page(int everyPage){ %nhE588xf
this.everyPage = everyPage; <F?UdMT4y
} Jp-6]uW
dyVfDF
/** The whole constructor */ ?b x ak
public Page(boolean hasPrePage, boolean hasNextPage, Pa-{bhllu)
jO}<W 1qy
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int everyPage, int totalPage, !xE@r,'oN
int currentPage, int beginIndex){ `c? 8i
this.hasPrePage = hasPrePage; 5Yr$tl\k
this.hasNextPage = hasNextPage; bFsJqA.A
this.everyPage = everyPage; Lrq e:\
this.totalPage = totalPage; RKb (
this.currentPage = currentPage; |vgYi
this.beginIndex = beginIndex; Zb$P`~(%
} `!y/$7p
4q*mEV
/** 5U6b\jxX
* @return Zqj EVVB
* Returns the beginIndex. /7igPNhx
*/ :I8HRkp
publicint getBeginIndex(){ >r.W \
return beginIndex; VF:95F;@
} \-CL}Z}S
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/** SHRn$<
* @param beginIndex o "1X8v
* The beginIndex to set. WT jy"p*
*/ g[(Eh?]Sc
publicvoid setBeginIndex(int beginIndex){ *Qy,?2
this.beginIndex = beginIndex; aRcVoOq
} 0gH;y+\=*
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/** Y?\PU{O
* @return DhN<e7c`
* Returns the currentPage. *H~&hs>k
*/ 3M5wF6nY[[
publicint getCurrentPage(){ Y'76! Y
return currentPage; `_!R;f
} U &RZx&W
J
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/** =H8Y
* @param currentPage R<;;Ph
* The currentPage to set. t^"8
v3'h
*/ J*t_r-z
publicvoid setCurrentPage(int currentPage){ mZ~f?{
this.currentPage = currentPage; sE! $3|Q
} HM &"2c
3|=L1Pw#
/** @0-vf>e3-
* @return F"0=r
* Returns the everyPage. 0}N"L ml
*/ sf8F h
publicint getEveryPage(){ 6Cgc-KNbk
return everyPage; $^`@ lyr
} P.-
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(: @7IWZf@
/** 96i#
* @param everyPage :*MR$Jf
* The everyPage to set. >1 hhz
*/ </D )i
publicvoid setEveryPage(int everyPage){ 6UM1>xq9A
this.everyPage = everyPage; /i(R~7;?
} l<:\w.Gl
m(IyW734I
/** f0
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* @return QBb%$_Z
* Returns the hasNextPage. CTJwZY7
*/ #Ve@D@d[
publicboolean getHasNextPage(){ 7yUX]95y8
return hasNextPage; .+&M,%
x
} >DR$}{IV
WJy\{YAG
/** j[Gg[7q{y
* @param hasNextPage +aN"*//i
* The hasNextPage to set. vQy+^deW
*/ z/wwe\ a5
publicvoid setHasNextPage(boolean hasNextPage){ 3L9@ELY4
this.hasNextPage = hasNextPage; /6:qmh2
} :D~J(Y2
e'r-o~1eN
/** !vq|*8
* @return '<xV]k|v
* Returns the hasPrePage. %H4>k#b@$
*/ Rp0^Gwa
publicboolean getHasPrePage(){ C(kL=WD
return hasPrePage; EkoT U#w5
} GOD{?#c$
[F
24xC+
/** g0#w
4rGF)
* @param hasPrePage i?f;C_w
* The hasPrePage to set. MH|R @g
*/ *
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publicvoid setHasPrePage(boolean hasPrePage){ i&j]FX6q
this.hasPrePage = hasPrePage; q^h/64F
} lYS*{i1^ '
sQn@:Gk
/** =3dd1n;8>
* @return Returns the totalPage. wH+|
&C
* 1vdG\$
*/ LIn2&r:U
publicint getTotalPage(){ fJ&\Z9zY
return totalPage; /rHlFl|Wy
} 0<+eN8od.
G\K!7k`)!
/** Nka 3H7`
* @param totalPage d<[L^s9
* The totalPage to set. f$qkb$?]}
*/ (wf3HEb_
publicvoid setTotalPage(int totalPage){ j<)`|?@e(
this.totalPage = totalPage; L;v.X'f
} 51xf.iB
|)S*RQb\
} .R)uk
51;[R8'w
~SS3gL v
q@1xYz:J
SGu`vN]
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 Z>pZ|
Q 3/J@MC
个PageUtil,负责对Page对象进行构造: Y|buQQ|
java代码: A=wG};%_
)r?-_qj=
sgRWjrc/
/*Created on 2005-4-14*/ a%5/Oc[[
package org.flyware.util.page; +
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}ld^zyL
import org.apache.commons.logging.Log; ^U##9KkP
import org.apache.commons.logging.LogFactory; jZ''0Lclpc
/0Mt-8[
/** yW&ka3j\
* @author Joa [Y.=bfV!
* e'->S g
*/ D 9UM8Hxi
publicclass PageUtil { k 7:Z\RGy
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privatestaticfinal Log logger = LogFactory.getLog V[n,fEPBr
ja6V*CWb
(PageUtil.class); D@kf^1G
;=WwJ Np~
/** '4CD
}
* Use the origin page to create a new page KDb`g}1Q
* @param page 0{
* @param totalRecords 3-'3w ,
* @return Jhfw$ DF
*/ E6z&pM8<8
publicstatic Page createPage(Page page, int @9R78Zra
)S;3WnQ)
totalRecords){ txE+A/>i9
return createPage(page.getEveryPage(), :(@P
*"j
)_Z^oH ]<
page.getCurrentPage(), totalRecords); ,T$ GOjt
} 3R-5&!i
3O;"{E=
<
/** }Rw6+;
* the basic page utils not including exception X4{<{D`0t8
S&QXf<v
handler h1l%\ 3ZH
* @param everyPage &x;n^W;#
* @param currentPage >P]gjYN
* @param totalRecords )j\_*SoH
* @return page J4@-?xj=\q
*/ zQ#*O'-n
publicstatic Page createPage(int everyPage, int I?^(j;QpS
.h\Py[h<^
currentPage, int totalRecords){ 7D1$cmtH
everyPage = getEveryPage(everyPage); IR#BSfBZ
currentPage = getCurrentPage(currentPage); c=zSq%e
int beginIndex = getBeginIndex(everyPage, !qU1RdZ
N9*:]a
currentPage); uP(t+}dQ+3
int totalPage = getTotalPage(everyPage, IUNr<w<
CD%Cb53
totalRecords); XMdCQ=
boolean hasNextPage = hasNextPage(currentPage, H \'1.8g/
ZCViZWo
totalPage); 64]8ykRD-
boolean hasPrePage = hasPrePage(currentPage); DEbMb6)U
PQa0m)H@
returnnew Page(hasPrePage, hasNextPage, tY:
Nq*@
everyPage, totalPage, zWH)\>X59
currentPage, x,zYNNx5g
@b,6W
wc
beginIndex); pb)kN%
} gS8+S\2
*,IK4F6>:
privatestaticint getEveryPage(int everyPage){ - Ry+WS=
return everyPage == 0 ? 10 : everyPage; ;<_a ,5\Q
} P$Oj3HD LM
}2iR=$2
privatestaticint getCurrentPage(int currentPage){ A=IpP}7J
return currentPage == 0 ? 1 : currentPage; esj6=Gh
} 2pU'&8
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privatestaticint getBeginIndex(int everyPage, int '#h ORQB
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currentPage){ W)J MV
return(currentPage - 1) * everyPage; #9Ect@?N0
} &GkD5b
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privatestaticint getTotalPage(int everyPage, int R PoBF~>
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totalRecords){ 0{vH .b
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int totalPage = 0; AI Kz]J0;
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if(totalRecords % everyPage == 0) vhAgX0k
totalPage = totalRecords / everyPage; a2tEp+7?
else &0tW{-Hv"
totalPage = totalRecords / everyPage + 1 ; 9x|`XAB
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return totalPage; jT}={[9b
} MtaGv#mJ
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privatestaticboolean hasPrePage(int currentPage){ ZWo~!Z [Y
return currentPage == 1 ? false : true; k54\H.
} _> x}MW+
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privatestaticboolean hasNextPage(int currentPage, @!u{>!~0
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int totalPage){ X^K^az&L
return currentPage == totalPage || totalPage == /t`\b
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0 ? false : true; {\CWoFht>
} 0c`nk\vUy
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} V7r_Ubg@K
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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。 IZ7o6Etti
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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 2#sFY/@
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做法如下: $
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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 Pd\4hy
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的信息,和一个结果集List: "a(4])
java代码: Z,e|L4&
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/*Created on 2005-6-13*/ \X _}\_c,d
package com.adt.bo; _uLpU4# ?
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import java.util.List; ,]7ouH$H}
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import org.flyware.util.page.Page; /51$o\4S
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/** #}+H
* @author Joa ] xHiy+
*/ H-+U^@w
publicclass Result { fmj}NV&ma
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private Page page; a1y<Y`SC9
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private List content; {?0'(D7.
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/** I`X!M!dB)
* The default constructor [`b,SX
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*/ {$hWz (
public Result(){ nPdkvs
super(); i .uyfV&F
} q
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/** 41<h|WA
* The constructor using fields z$R&u=J
* ;mQ|+|F6X
* @param page 5\C(2naf
* @param content
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*/ [0y,K{8t
public Result(Page page, List content){ |ymW0gh7o$
this.page = page; Ye&/O<G'V
this.content = content; \-pwA j?
} L?+N:G
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/** //BJaWq
* @return Returns the content. [|oG}'Xz
*/ 1C{0 R.
publicList getContent(){ C/Tk`C&
return content; N=C t3
} `e<IO_cg
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/** SNOc1c<~
* @return Returns the page. Y4 z
*/ ,HTwEq>-G
public Page getPage(){ kD )31P
return page; 2|lR@L sr
} zPp22
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/** #%k_V+o3
* @param content 8c-ys-"#
* The content to set. s 0Uid&qE
*/ e}yF2|0FD
public void setContent(List content){ (0q`eO2
this.content = content; DSqA}r
} NMK$$0U
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/** \ YF@r7
* @param page 4;J.$
* The page to set. >~Zj
*/ X}(X\rp
publicvoid setPage(Page page){ [-VH%OM
this.page = page; j!i*&
} 8xAI n>,_
} >y#MEN>?
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