Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ~-dL #;
moe5H
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 N3C 8%
J3;dRW
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 w
=MZi=p
R3`Rrj Z
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 orU++,S4Pm
\Gzo^w
。 F|ib=_)3
ww0m1FzX
分页支持类: ^Ko{#qbl/
3aK/5)4|B
java代码: BAUo`el5
(l~3~n
;:0gN|+
package com.javaeye.common.util; @['4 X1pqt
q/|WkV `m
import java.util.List; .*0`}H+_
XyM?Dc5,
publicclass PaginationSupport { +ISXyGu
C/sDyv$
publicfinalstaticint PAGESIZE = 30; ^KK9T5H
8N58w)%7`
privateint pageSize = PAGESIZE; HDTdOG)
g;M\4o
privateList items; *`(/wE2v]
=z]8;<=pL
privateint totalCount; JW`Kh*,~<
4
Ii@_r>
privateint[] indexes = newint[0]; XI rNT:h4
[;]@PKW?w
privateint startIndex = 0; JN{xh0*
_tGR:E
public PaginationSupport(List items, int tFYIKiq2
$S|2'jc
totalCount){ 8/4Gr8o
setPageSize(PAGESIZE); wG&+*,}
setTotalCount(totalCount); ilyQgEjC
setItems(items); UpA{$@
setStartIndex(0); N,><,7!q$,
} 0 CJ4]mYl
E?&
x5?
public PaginationSupport(List items, int bhFAt1h
rI[Lg0S
totalCount, int startIndex){ ]:Q7Gys
setPageSize(PAGESIZE); d\cwUXf
J
setTotalCount(totalCount); ,0~/ Cn
setItems(items); /&+6nOP
setStartIndex(startIndex); qM$~5uu
} P'nbyF
GW(-'V/
public PaginationSupport(List items, int Q)l]TgvSe
^z[-pTY
totalCount, int pageSize, int startIndex){ (5"BKu1t
setPageSize(pageSize); cZ"
Ut
setTotalCount(totalCount); $j~oB:3n7
setItems(items); _n3Jf<Y
setStartIndex(startIndex); Oc]&1>M
} I:~L!%
z"eh.&T
publicList getItems(){ J6!t"eB+
return items; ;,z^!bD
} g>[|/ z P
W
biUz2)
publicvoid setItems(List items){ UeRx ^
this.items = items; =](c7HEQf
} kUJ\AK
qdn\8Pn
publicint getPageSize(){ dwc$?Bg,5
return pageSize; YLlw:jN
} vWJhSpC[
5T[9|zJs
publicvoid setPageSize(int pageSize){ ==psPyLF@
this.pageSize = pageSize; i*9[El
} `TkIyGr
mne^PSI:
publicint getTotalCount(){ ?-F SDNQ
return totalCount; u+]v.Mt
} |wf:|%
y> S.B/d
publicvoid setTotalCount(int totalCount){ F:/R'0
if(totalCount > 0){ 5JbPB!5;
this.totalCount = totalCount; OpwZTy}1}
int count = totalCount / t[6 g9 e$
;+-$=l3[a
pageSize; Sa&~\!0t
if(totalCount % pageSize > 0)
,i2%FW
count++; qj71
rj
indexes = newint[count]; cJ&e^$:Er
for(int i = 0; i < count; i++){ Ii?"`d +JA
indexes = pageSize * pGi "*oZD
ou44vKzS
i; XR^VRn6O
} A
a2*f[
}else{ s z.(_{5!
this.totalCount = 0; blZiz2F
} ~6'6v8
} P,"z
lLHHuQpuj
publicint[] getIndexes(){ %iI0JF*Ez
return indexes; Z6&s 6MF
} =+{.I,g}g@
tUq* -9
V
publicvoid setIndexes(int[] indexes){ ZkYc9!anY
this.indexes = indexes; >GiM?*cC
} {uO8VL5+Qx
9p!V?cH#8
publicint getStartIndex(){ n=RAE^[M
return startIndex; XN"V{;OP1
} Z'GOp?
Gvt.m&_
publicvoid setStartIndex(int startIndex){ *seKph+'c
if(totalCount <= 0) KQ/v](77
this.startIndex = 0; .2hQ!)+
elseif(startIndex >= totalCount) vi6EI
wZG
this.startIndex = indexes }>xgzhdT
oll~|J^sg
[indexes.length - 1]; )_T[thf]
elseif(startIndex < 0) v&(X&q
this.startIndex = 0; 2
G_*Pqc
else{ a#1LGH7E8
this.startIndex = indexes 1vu4}%nD
h*hV
[startIndex / pageSize]; gQ
h0-Dnw
} ]Bs ?
} L6j
5pI
$*%Ml+H-
publicint getNextIndex(){ uLb-
NxQ-
int nextIndex = getStartIndex() + @Qx|!%
Ms(;B*
pageSize; uw+v]y
if(nextIndex >= totalCount) 8Es]WR5
^
return getStartIndex(); @hm%0L
else TE*$NxQ 2
return nextIndex; 0+8ThZ?n
} bF'~&<c
76)(G/
publicint getPreviousIndex(){ j:|60hDz^
int previousIndex = getStartIndex() - d\, 4Wet;#
##u+[ !
pageSize; ~u8}s4
if(previousIndex < 0) (k
M\R|
return0; O6OP{sb
else 9Pd~
return previousIndex; a-Cp"pKlVY
} PZpwi?N
~>D;2 S(a
} OP2!lEs
da!N0\.1T
HtEjM|zj
8Mg4y1)RU
抽象业务类 ER5Q` H
java代码: S
M98 7Y!B
j1YE_U
dWD,iO_"@
/** |gxU;"2`5~
* Created on 2005-7-12 Xk]5*C]6<
*/ X@9_ukdpu
package com.javaeye.common.business; ]rn!+z
lIzJO$8cM
import java.io.Serializable; [p!C+|rro
import java.util.List; A
i9*w?C
K;6K!6J:[
import org.hibernate.Criteria; #Opfc8pm'
import org.hibernate.HibernateException; FPMhHHM
import org.hibernate.Session; Z6>:k,-Ot
import org.hibernate.criterion.DetachedCriteria; )\^o<x2S
import org.hibernate.criterion.Projections; :v{$]wg
import #TW$J/Jb
+@%9pbM"z
org.springframework.orm.hibernate3.HibernateCallback; V.Xz
n
import rxa"ji!)
v_c'npC
org.springframework.orm.hibernate3.support.HibernateDaoS <mY`<(bc
<?qmB}Y
upport; J-?\,N1R7
N>ct`a)BD/
import com.javaeye.common.util.PaginationSupport; z8Dn<h
!kASEjFz|f
public abstract class AbstractManager extends }~QB2&3
mSwOP
HibernateDaoSupport { 5Tu#o()
l`I]eTo)^
privateboolean cacheQueries = false; Y[s
-&,NM
privateString queryCacheRegion; x0lX6
|D
fwsq:
publicvoid setCacheQueries(boolean h%=b"x
Q^MB%L;D
cacheQueries){ c_ygwO3.Q
this.cacheQueries = cacheQueries; }lpcbm
} [p o+a@ %
kOdS^-
publicvoid setQueryCacheRegion(String @z/]!n\~
3<mv9U(
queryCacheRegion){ \|62E):i1
this.queryCacheRegion = @/$mZ]|T
F|P2\SPL
queryCacheRegion; 1v2wP2]|;
} n+Ag |.,|
<*(~x esPS
publicvoid save(finalObject entity){ R@VO3zs W
getHibernateTemplate().save(entity); 8!UZ..
} z%Z}vWn
RTY$oUqlZ
publicvoid persist(finalObject entity){ o=`9JKB~
getHibernateTemplate().save(entity); (
?/0$DB
} }(o/+H4
LG<lZ9+y
publicvoid update(finalObject entity){ _L$)~},cT
getHibernateTemplate().update(entity); =r-Wy.a@
} Cg{$$&_(Hj
qsk71L
publicvoid delete(finalObject entity){ =dA T^e##
getHibernateTemplate().delete(entity); (ZEVbAY?i
} |%RFXkHS
VsZ_So;
publicObject load(finalClass entity, !@YYi[Gk
3@"VS_;?
finalSerializable id){ iL,3g[g
return getHibernateTemplate().load rXm!3E6JL
A\#?rK
(entity, id); ~36c0 =
} *(>$4$9n
q!ZmF1sU
publicObject get(finalClass entity, ]#:xl}'LS
w
x,;
finalSerializable id){ #[[p/nAy}A
return getHibernateTemplate().get XdS<51 C
$ 1dI
(entity, id); |Q I3H]T7
} 2(c#m*Q!b
i@I %$!cB
publicList findAll(finalClass entity){ ix#
return getHibernateTemplate().find("from ,3n}*"K
ffB]4
" + entity.getName()); unX^ MPpw
} }jk^M|Z"Oz
M^[jA](a
publicList findByNamedQuery(finalString qt:->yiq+
Wey\GQ`"8
namedQuery){ 'PYl%2
return getHibernateTemplate 3)-#yOr
~%}g"|o
().findByNamedQuery(namedQuery); d:wAI|
} 2 sOc]L:9
4dok/ +Ec
publicList findByNamedQuery(finalString query, j?mJ1J5
_0f[.vN
finalObject parameter){ <n:?WP~U
return getHibernateTemplate \c\=S
Z0:BXtW
().findByNamedQuery(query, parameter); Grub1=6l
} 0iB1_)~
tQ|I$5jNJ
publicList findByNamedQuery(finalString query, mzw*6e2T
h/k`+
finalObject[] parameters){ e5/_Vga
return getHibernateTemplate .o8Gi*PEY
ri^yal<'
().findByNamedQuery(query, parameters); n$?oZ*;
} }rQ*!2Y?
Aa Ma9hvT!
publicList find(finalString query){ 0x &^{P~
return getHibernateTemplate().find K@,VR3y /
WE"'3u^k
(query); ie,{C
} #Nd+X@j
2X]\:<[4
publicList find(finalString query, finalObject Fi`:G}
z[rB/|2
parameter){ o99 a=x6
return getHibernateTemplate().find hf-S6PEsM
,]Ma, 2
(query, parameter); *,pqpD>
} `Q hh{
CMr`n8M
public PaginationSupport findPageByCriteria B::?
"osYw\unI
(final DetachedCriteria detachedCriteria){ dWUu3
return findPageByCriteria 'YeJGzsJp
OG+ $F
(detachedCriteria, PaginationSupport.PAGESIZE, 0); re!CF8
q
} QHh#O +by#
~h/U ;Da
public PaginationSupport findPageByCriteria UGMdWq
O`=Uq0Vv
(final DetachedCriteria detachedCriteria, finalint FdqUv%(Em
k?#6j1pn
startIndex){ f,#xicSB*
return findPageByCriteria E*l"uV
x'qgpG}?]
(detachedCriteria, PaginationSupport.PAGESIZE, )'g vaT
GND[f}
startIndex); g;h&Xkp
} <gy'@w?
0d2%CsMS"D
public PaginationSupport findPageByCriteria tFQFpbI
z|2liQrf+
(final DetachedCriteria detachedCriteria, finalint 4HJrR^
Qi61(lK
pageSize, S`G\Cd;5
finalint startIndex){ [ZbK)L+_
return(PaginationSupport) &)l:m.
4l*&3Ar
getHibernateTemplate().execute(new HibernateCallback(){ v+G:,Tc"
publicObject doInHibernate ;D1IhDC
W#[!8d35$
(Session session)throws HibernateException { f/x "yUq
Criteria criteria = D/WS
Z7^}G=*
detachedCriteria.getExecutableCriteria(session); p"@|2a
int totalCount = X`b5h}c
[oj"Tn(
((Integer) criteria.setProjection(Projections.rowCount SXEiyy[7v
ht|r+v-
()).uniqueResult()).intValue(); >`:+d'Jv0
criteria.setProjection 66*o2D\Q*G
PwW @I~@>
(null); 'gGB-=yvbO
List items = bv/b<N@4?$
wO#+8js
criteria.setFirstResult(startIndex).setMaxResults KB= z{g
]YP?bP,:
(pageSize).list(); Tt\w^Gv\d
PaginationSupport ps = '}u31V"SS
Pa}vmn1$
new PaginationSupport(items, totalCount, pageSize, hbeC|_+
b nGA.b
startIndex); ho1F8TG=
return ps; b5Pn|5AVj
} Q6K)EwN
}, true); U\ued=H
} F
4/Uu"J:
R=PzR;8
public List findAllByCriteria(final d3GK.8y_z
S2)S/ nf
DetachedCriteria detachedCriteria){ jGn^<T\
return(List) getHibernateTemplate u$#7W>R
.a*$WGb
().execute(new HibernateCallback(){ !U_L7
publicObject doInHibernate Kcl$|T
ydQS"]\g
(Session session)throws HibernateException { TeJ
`sJ
Criteria criteria = nY)Pxahm 7
J|-HZ-Wk|J
detachedCriteria.getExecutableCriteria(session); B! V{.p
return criteria.list(); >U?Bka!
} 4Z}{hc\J
}, true); !\1 W*6U8;
} k5D'RD
#Uh 5tc
public int getCountByCriteria(final 9eiBj
or}*tSKX
DetachedCriteria detachedCriteria){ &F_rg,q&_
Integer count = (Integer) I&8m5F?$`
Cw $^w
getHibernateTemplate().execute(new HibernateCallback(){ )1Nnn
publicObject doInHibernate a}fClI-u
f)Q]{ cb6
(Session session)throws HibernateException { 'V#ew\
Criteria criteria = A@(h!Cq
acQNpT
detachedCriteria.getExecutableCriteria(session); *]R0z|MW
return D^55:\4(
JWHt|zBg
criteria.setProjection(Projections.rowCount #G` ,
#J724`
()).uniqueResult(); '-33iG
} Wxau]uix
}, true); 8G&+
return count.intValue(); ^!o}>ls['
} (M,VwwN
} Ir"Q%>K0f
m\M+pjz
s}9tK(4v
3n(gfQo-o
KTjlWxD
D"4&9"C U
用户在web层构造查询条件detachedCriteria,和可选的 \&&(ytL
) Zo_6%
startIndex,调用业务bean的相应findByCriteria方法,返回一个 9,f<Nb(\
7G(f1Y
PaginationSupport的实例ps。 V}fKV6 v9
> '
0 ][~
ps.getItems()得到已分页好的结果集 6h6?BQSE
ps.getIndexes()得到分页索引的数组 1] Q2qs
ps.getTotalCount()得到总结果数 #0hNk%X=
ps.getStartIndex()当前分页索引 "%''k~UD4
ps.getNextIndex()下一页索引 &4&33D
ps.getPreviousIndex()上一页索引 .#55u+d,
4z%#ZIy3
rn:zKTyhw
!L.
K)9I
dP7Vsa+
?4[Oh/]R
SiqX1P
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 }BdVD t
dIpW!Pj^
,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+
F}`lLA
D`:d'ow~KQ
一下代码重构了。 uO@3vY',n
RefRoCD1
我把原本我的做法也提供出来供大家讨论吧: GyAgPz
U5CPkH1
首先,为了实现分页查询,我封装了一个Page类: Ldhk^/+
java代码: 1Uemsx%'k
q7f;ZK=f
+O$:
/*Created on 2005-4-14*/ N1N{Ol'
package org.flyware.util.page; 'K`Rbhy
~,*YmB=Z
/** T<+ht8&M8
* @author Joa I+"?,Ej$K
*
$.Q>M]xH
*/ R G0S
publicclass Page { Afy .3T @)
n5+S"
/** imply if the page has previous page */ -}X?2Q
privateboolean hasPrePage; G/z\^Q
sCtw30BL
/** imply if the page has next page */ 7ec0Xh1
privateboolean hasNextPage; p/k<wCm6
poQdI?ed,
/** the number of every page */ F|?+>c1}
privateint everyPage; 9#&W!f*qO|
l^ 0_>R
/** the total page number */ hzQ+9-qA
privateint totalPage; juMxl
tpa^k
/** the number of current page */ hB7pR"P
privateint currentPage; ^0~c7`k`V
!/6\m!e|1R
/** the begin index of the records by the current TD{=L*{+
2:iYYRrg
query */ |ck
ZyDA
privateint beginIndex; & &" 'dL
Lo9G4Cu
z^rhgs?4
/** The default constructor */ h;%i/feFg
public Page(){ Ln=>@
x*h `VS(?6
} d]CviQUq
97Zk
P=Cq
/** construct the page by everyPage Wm)-zvNY;
* @param everyPage NFY|^*bll
* */ m0|Ae@g~3
public Page(int everyPage){ Zj1ZU[BEcL
this.everyPage = everyPage; J3~hzgY
} ,](v?v.[4
Jh$"f r3
/** The whole constructor */ F)/~p&H
public Page(boolean hasPrePage, boolean hasNextPage,
\f/#<|Hm
*H5PT
CZJHE>
int everyPage, int totalPage, BbrT f"`
int currentPage, int beginIndex){ Y9i9Uc.]
this.hasPrePage = hasPrePage; Nmp>UE,7[
this.hasNextPage = hasNextPage; -@ZzG uS(
this.everyPage = everyPage; QB/7/PW{H\
this.totalPage = totalPage; ]yAEjn9cN
this.currentPage = currentPage; ~v2V`lxh
this.beginIndex = beginIndex; r(:
8!=~K
}
w%3Fg~Up
\E$1lc
/** ,u}<Ws8N
* @return OL=ET)Y
* Returns the beginIndex. h
L]8e>a?
*/ z;dcAdz9
publicint getBeginIndex(){ k,,!P""
return beginIndex; 731h
~x!u
} IXZ(]&we
Z|ZBKcmg
/** XogvtK*
* @param beginIndex wJ+U[a
* The beginIndex to set. Ap]4QqU
*/ L1hD}J'$4
publicvoid setBeginIndex(int beginIndex){ 'e.q
7Jpd
this.beginIndex = beginIndex; w"cM<Ewu
} '7xxCj/*
':l"mkd+`
/** f?%qUD_#
* @return `'p`PyMt`
* Returns the currentPage. rI0)F
*/ rIeM+h7W n
publicint getCurrentPage(){ :E>&s9Yj?
return currentPage; rH9uGm-*
} ]alh_U
[_WI8~gY
/** g4N%PV8
* @param currentPage jHAWK9fa
* The currentPage to set. /M3y)K`^
*/ ku{XW8
publicvoid setCurrentPage(int currentPage){ cz2,",+~
this.currentPage = currentPage; \Okc5;kB2
} S d IGU[fm
j%p CuC&"
/** =/6p#d*0
* @return M^z=1YrMd
* Returns the everyPage. dh&W;zs
*/ 2m_'z
publicint getEveryPage(){ 1"}B]5!
return everyPage; br0u@G
} p?Ed-
S
sFLcOPj-%
/** B?SNea,I4
* @param everyPage k}D[Hp:m
* The everyPage to set. _yj1:TtCNT
*/ 4,2(nYF
publicvoid setEveryPage(int everyPage){ BwC<rOU
this.everyPage = everyPage; Q0pzW:=s]
} (cvh3',
^J8uhV;w
/** |~SE"
* @return I> {!U$
* Returns the hasNextPage. {3hqp*xl
*/ 8N%z9b
publicboolean getHasNextPage(){ 7p^@;@V
return hasNextPage; u7HvdLql
} %y iD~&
h$70H ^r
/** 9b1?W?"
* @param hasNextPage Bi e?M
* The hasNextPage to set. SD?BM-&~
*/ BI};"y
publicvoid setHasNextPage(boolean hasNextPage){ `dDa}b
this.hasNextPage = hasNextPage; 2\VAmPG.Zs
} Yx5J$!Ld
4E2yH6l
/** ejVdxVr \7
* @return 5MxH)~VQoM
* Returns the hasPrePage. CWs: l3_yn
*/ || [89G
publicboolean getHasPrePage(){ }'%^jt[3
return hasPrePage; 6/| 0+G^
} 6O9iEc,HM
z!$gVWG
/** gmY/STN
* @param hasPrePage a:A n=NA
* The hasPrePage to set. +0J@y1
*/ |xh&p(
publicvoid setHasPrePage(boolean hasPrePage){ Z==!C=SBv
this.hasPrePage = hasPrePage; GM](=|F
} s`"O M^[-
v
dU%R\
/** a9=> r
* @return Returns the totalPage. 8lwFAiC8
* h3kaD
*/ CM9 XPr
publicint getTotalPage(){ |QVr`tE<
return totalPage; !tU'J"Zy
} !6H uFf
:[xvlW29
/** F.<L>
G7{1
* @param totalPage bpW!iY/q3
* The totalPage to set. 7:>sc]Z
*/ Q&xjF@I
publicvoid setTotalPage(int totalPage){ Pt)S;6j
this.totalPage = totalPage; Yt+h2ft!
} MTb,Kmw<(
%ISq>A)%
} } B0sC%cm
rfs (#
GP+2/D
TnNWO+kg
HY ;9?KJ'
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 o)&"Rf
GRT]aw
个PageUtil,负责对Page对象进行构造: 3pSj kS|?>
java代码: */w7?QOv
ydQ!4
wiJRCH
/*Created on 2005-4-14*/ 56DoO'
package org.flyware.util.page; URA0ey`
]tB@kBi "
import org.apache.commons.logging.Log; f#$|t>
import org.apache.commons.logging.LogFactory;
R_1qn
~U$":~H[
/** )JhT1j Qc
* @author Joa -#.< 12M
* #6=MKpR
*/ x7dEo%j
publicclass PageUtil { ?[)yGRzO2
Kb&V!#o)
privatestaticfinal Log logger = LogFactory.getLog i%;"[M
Z/<#n\>t0>
(PageUtil.class); 7+nm31,<O
>{5
p0
/** \\:|Odd
* Use the origin page to create a new page &nY;=Hv`WY
* @param page r\2vl8X~
* @param totalRecords +ZA)/
* @return Nu^p
*/ 83 I-X95
publicstatic Page createPage(Page page, int pJBg?D
+C+<BzR~A.
totalRecords){ ez\eOH6
return createPage(page.getEveryPage(), m\ S\3n
JoZ(_Jh%m
page.getCurrentPage(), totalRecords); *fnvZw?
} $dQIs:
mR%FqaN_
/** }D*yr3b
* the basic page utils not including exception 6L9,'Bg
*k [J6
handler &|9.}Z8U
* @param everyPage h2~4G)J
* @param currentPage pKT2^Q}-h
* @param totalRecords Eectxyr?;N
* @return page vXv;1T
*/ [AS}RV
publicstatic Page createPage(int everyPage, int dJ
~Zr)>
~#PLAP3-
currentPage, int totalRecords){ kn"q:aD
everyPage = getEveryPage(everyPage); !'G~k+
currentPage = getCurrentPage(currentPage); "Sridh?
int beginIndex = getBeginIndex(everyPage, bT)]'(Xy
L',mKOej
currentPage); 6N~q`;p0
int totalPage = getTotalPage(everyPage, AjkW0FB:1
V'DA[{\*
totalRecords); UZ2TqR
boolean hasNextPage = hasNextPage(currentPage, MHi8E9_O
uO6{r v\
totalPage); YKZa$@fA?
boolean hasPrePage = hasPrePage(currentPage); @1-F^G%p8
z6*<V5<7
returnnew Page(hasPrePage, hasNextPage, 3jZ6kfj
everyPage, totalPage, Y32 "N[yw
currentPage, R=]d%L8
xQ4%e[/
beginIndex); Kibr ]w
} Hfym30
N&,]^>^u
privatestaticint getEveryPage(int everyPage){ fv!?Ga(
return everyPage == 0 ? 10 : everyPage; ?K_
'@
} pH@]Y+W
SaOYu &>
privatestaticint getCurrentPage(int currentPage){ \%0n}.A
return currentPage == 0 ? 1 : currentPage; r'GP$0rr9!
} U{@5*4
T/1gI9X
privatestaticint getBeginIndex(int everyPage, int fCWGAO2
Lel|,mc`k2
currentPage){ , %9df+5k
return(currentPage - 1) * everyPage; uXjP`/R|
} em{(4!W>
P{Lf5V9# <
privatestaticint getTotalPage(int everyPage, int 2c5-)Dt)T
&;&ho+qD
totalRecords){ ~;]W T
int totalPage = 0; nkfZiyx
l{j~Q^U})
if(totalRecords % everyPage == 0) V)(R]BK{
totalPage = totalRecords / everyPage; b^0}}12
else Jl3g{a
totalPage = totalRecords / everyPage + 1 ; 'cix`l|^
kF"@Ngv.
return totalPage; n+;6=1d7ZW
} T .FI'wy
U1nw-Q+
privatestaticboolean hasPrePage(int currentPage){ "VG+1r+]4
return currentPage == 1 ? false : true; 1KM`i
} ^(HUGl_
}7E^ZZ]f
privatestaticboolean hasNextPage(int currentPage, ~*A8+@\R
4)|8Eu[p7
int totalPage){ phnV7D(E
return currentPage == totalPage || totalPage == !K
f#@0E..
aFz5leD
0 ? false : true; 5,-U.B}
} Eow_WW;P
l
vMlL5t
hCjR&ZA
} L>yJ
&|3
$!S
uN([*'0Cg
ZOCDA2e(j
t3(]YgF
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。 J &pO%Q=b
FC i U
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 [I!6PGx
(8.Z..PH
做法如下: .qMOGbd?
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 3b' QLfU
gL_Y,A~Q{
的信息,和一个结果集List: 3 @ak<9&
java代码: 'u4<BQVV[
}by;F9&B
^?7`;/
/*Created on 2005-6-13*/ ;r_F[E2z
package com.adt.bo; a,2'+Tlo
8V^oP]Y
import java.util.List; =6"2UC&
QUU;g 2k
import org.flyware.util.page.Page; ])xx<5Jt4
P:30L'.=[
/** 5?hw !
* @author Joa %?e& WLS
*/ N(I&
publicclass Result { t2,A@2DU2
+s- lCz
private Page page; ):i&`}SY
CC#;c1t
private List content;
d
,4]VE
&?mD$Eo
/** oE#d,Z
* The default constructor ,lZB96r0
*/ ,Ax dCT
public Result(){ QUu}Xg:
super(); ]]Cb$$Td
} GB$;n?
GGnpjwXeH
/** \"X!2
* The constructor using fields tjupJ*Rt
* C:PMewn
* @param page O3I8k\`
* @param content :<}=e@/~|
*/ >-H{Z{VDd
public Result(Page page, List content){ ?b(=1S\E'^
this.page = page; ?VP8ycm
this.content = content; N5a*7EJv+
} ?OkWe<:4
sBr_a5QQ#
/** a)wJT`xu
* @return Returns the content. .zi_[
*/ o4|M0
publicList getContent(){ E[/\7v\
return content; |&RU/ a
} N<~t3/Nm
Ney/[3 A
/** 8C*c{(4
* @return Returns the page. SHe49!RA'{
*/ 9I6a"PGDb
public Page getPage(){ HZ'_r cv
return page; 0u;4%}pD
} |Y?HA&
19w*!FGX
/** 7Zlw^'q$:L
* @param content wK?vPS
* The content to set. u6AA4(
*/ Mu+0<>
public void setContent(List content){ ~ _/(t'9
this.content = content; Qk:Y2mL
} 7pe\M/kl
uScMn/%
/** R%?9z 8-
* @param page gt@m?w(
* The page to set. kqFP)!37
*/ Tf'hc]`vS
publicvoid setPage(Page page){ G3Z)Z)N
this.page = page; %J+E/
} be.*#[
} #1OOU
SLa>7`<Q
<g$~1fa
U|jSa,}
;U-jO &
2. 编写业务逻辑接口,并实现它(UserManager, %nf6%@s
1`=nWy='
UserManagerImpl) k$blEa4
java代码: Ff)8Q.m
i<#QW'R (
.%xn&3
/*Created on 2005-7-15*/ A1O'|7X
package com.adt.service; MN\HDKN
>T^;MS
import net.sf.hibernate.HibernateException; =l+yA>t|
[_k1jHr48N
import org.flyware.util.page.Page; 2LF/H$]o5
\NPmym_6J
import com.adt.bo.Result; .P8&5i)'P,
fp`;U_-&0
/** ;ub;lh 3
* @author Joa +S o4rA*9
*/ X
$jWo@
publicinterface UserManager { ZOh`(})hy
QIG$z?
public Result listUser(Page page)throws EJMM9(DQ7
=;Au<|
HibernateException; `dq,>HdW
MTuV^0%jD
} p{r}?a
rC5
p-B%
i@*{27t
ssfr}fzH
KcWN,!G
java代码: l+KY)6o
*4\:8
V%rzk*LA
/*Created on 2005-7-15*/ @>,^":`#
package com.adt.service.impl; ]cHgleHQ
+r2+X:#~T
import java.util.List; q'T4w!V(V
>mwlsL~X
import net.sf.hibernate.HibernateException; e"{{ TcNk
hOjk3
k
import org.flyware.util.page.Page; j#!IuH\]
import org.flyware.util.page.PageUtil; cr7 }^s
_kef0K6
import com.adt.bo.Result; ]L5@,E4.
import com.adt.dao.UserDAO; =^M/{51j
import com.adt.exception.ObjectNotFoundException; L/$H"YOv
import com.adt.service.UserManager; glO^yZ s
C0T;![/4A
/** (KjoSN(
K
* @author Joa igCZ|Ru\
*/ W=N+VqK
publicclass UserManagerImpl implements UserManager { Cio
1E-4
luh$2 \5B
private UserDAO userDAO; }T(D7|^R
UXJeAE-
/** &*M!lxDN
* @param userDAO The userDAO to set. 8{^kQ/]'|
*/ Acez'@z
publicvoid setUserDAO(UserDAO userDAO){ b/+u4'"
this.userDAO = userDAO; G/)O@Ugp
} 6AAz
BtkOnbz8X
/* (non-Javadoc) 3#3n!(
* @see com.adt.service.UserManager#listUser `V}q-Zdy
0yk]o5a++
(org.flyware.util.page.Page) h0g8*HY+}
*/ KI"#f$2&
public Result listUser(Page page)throws l!D}3jD
~[t[y~Hup
HibernateException, ObjectNotFoundException { hNC&T`.-~B
int totalRecords = userDAO.getUserCount(); g|o,uD
if(totalRecords == 0) qU \w=
throw new ObjectNotFoundException `'DmDg
qqjwJ!@P
("userNotExist"); `+]Qz =}
page = PageUtil.createPage(page, totalRecords); (p" %O
List users = userDAO.getUserByPage(page); 4>wP7`/+y
returnnew Result(page, users); R$R *'l
} Zu*F#s!tUI
m+=] m_
} 8SMxw~9$
{5Q!Y&N.%
owVX*&b{
8 ?xE6
/:cd\A}
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 ju8>:y8
1KU!
tL
询,接下来编写UserDAO的代码: Cwv9 a^
3. UserDAO 和 UserDAOImpl: #|uCgdi
java代码: )HEa<P^kJl
Ki;*u_4{
g_;\iqxL
/*Created on 2005-7-15*/ 3(>B Ke
package com.adt.dao; )*u8/U
`}p0VmD{NE
import java.util.List; 7y.kQI?3
z<MsKD0Q
import org.flyware.util.page.Page; 9Gvd&U
lov!o:dJ
import net.sf.hibernate.HibernateException; &)QX7*H
Na<pwC
/** xB@ T|EP
* @author Joa " s,1%Ltt
*/ GV1pn) 4
publicinterface UserDAO extends BaseDAO { esJ~;~[@(r
v&6-a* <Z
publicList getUserByName(String name)throws 8'[~2/
(^ JI%>
HibernateException; b!+hH Hv:
-M\<nx
publicint getUserCount()throws HibernateException; 4j-Xi
x[cL
Bc<
publicList getUserByPage(Page page)throws n'"/KS+_
zrvF]|1UP
HibernateException; )~X2
&^orW
"fb[23g%@k
} N"Z{5A
G?yLo 'Ulo
irZ])a
%[GsD9_-
2_>N/Z4T
java代码: {4l8}w
_?nL+\'V
\P[Y`LYL
/*Created on 2005-7-15*/ kBS9tKBWg
package com.adt.dao.impl; q9B$"n
QL(n} {.%
import java.util.List; Lw1Yvtn
!n`fTK<$
import org.flyware.util.page.Page; &<z1k-&!
8C40%q..
import net.sf.hibernate.HibernateException; d z|or9&
import net.sf.hibernate.Query; -uS!\
&bS,hbD t
import com.adt.dao.UserDAO; <NMEGit
b1cy$I
/** #`^}PuQ
* @author Joa )+#` CIv
*/ [+^1.N
public class UserDAOImpl extends BaseDAOHibernateImpl p:&8sO!m
"MeVE#O
implements UserDAO { ,CJWO bn3
*tA1az-jO
/* (non-Javadoc) a
.#)G[*
* @see com.adt.dao.UserDAO#getUserByName :@Pl pFK
Q3'llOx
(java.lang.String) +w`2kv
*/ w?L6!) oiz
publicList getUserByName(String name)throws b1I]>\
#<fRE"v:Q
HibernateException { p%ki>p )E|
String querySentence = "FROM user in class ,~U>'&M;
x>K Or,f
com.adt.po.User WHERE user.name=:name"; 4Z3su^XR
Query query = getSession().createQuery 6jaEv#
/|}EL%a
(querySentence); iqsCB%;5
query.setParameter("name", name); cVv=*81\
return query.list(); `bq<$e
} }RF(CwZr(
phXGnm
/* (non-Javadoc) 70?\ugxA
* @see com.adt.dao.UserDAO#getUserCount() Z-%\
<zT
*/ ic:zsuEm
publicint getUserCount()throws HibernateException { b`Zx!^
int count = 0; M/f<A$xx_
String querySentence = "SELECT count(*) FROM #~]zhHI
'ms-*c&
user in class com.adt.po.User"; }rUN_.n4z
Query query = getSession().createQuery |"}FXaO
"S[450%
(querySentence); T=DbBy0-
count = ((Integer)query.iterate().next yZY \MB/
jVe1b1rt~3
()).intValue(); bL`TySX
return count; LENq_@$
} bIDj[-CDG
_;S-x
/* (non-Javadoc) >NV@R&
* @see com.adt.dao.UserDAO#getUserByPage J3V=
46Yc
fUWG*o9
(org.flyware.util.page.Page) /xBb[44z8
*/ !/b>sN}
publicList getUserByPage(Page page)throws n`_{9R
,&A7iO
HibernateException { dl)Y'DI
String querySentence = "FROM user in class [\eeDa
Z?q]bSIT
com.adt.po.User"; C}j"Qi`
Query query = getSession().createQuery N{!i=A
5{WE~8$
(querySentence); UW={[h{.|@
query.setFirstResult(page.getBeginIndex()) @D[_}JE
.setMaxResults(page.getEveryPage()); Y1\ }5k{>
return query.list(); `,(4]tlL
} !qQl@j O
|*xA8&/
} L<cx:Vz
k9R4Y\8P
NN{?z!
tKuwpT1Qc
"S]0
至此,一个完整的分页程序完成。前台的只需要调用 X,%
0/6*]
4"(Bu/24
userManager.listUser(page)即可得到一个Page对象和结果集对象 EWhK0Vej=
9rX&uP)j^#
的综合体,而传入的参数page对象则可以由前台传入,如果用 $99n&t$Y
oCv.Ln1;Z
webwork,甚至可以直接在配置文件中指定。 {w O|)|
m])y.T
下面给出一个webwork调用示例: iq8<ov
java代码: ;4\2.*s
ub0.J#j@
?zMHP#i
/*Created on 2005-6-17*/ <NY^M!
package com.adt.action.user; `$IK`O
fplo w
import java.util.List; ys^oG$lq
Lg+Ac5y}`
import org.apache.commons.logging.Log; +) om^e@.
import org.apache.commons.logging.LogFactory; qA7>vi%
import org.flyware.util.page.Page; k"%~"9
K7B/s9/xs
import com.adt.bo.Result; |Zpfq63W
import com.adt.service.UserService; *;slV3
import com.opensymphony.xwork.Action; +o{R _
M/'sl;
/** U}[d_f
* @author Joa bH9kj/q\b
*/ |s(FLF -
publicclass ListUser implementsAction{ W\,s:6iqz
nHAS(
privatestaticfinal Log logger = LogFactory.getLog {]!mrAjD
f}ji?p
(ListUser.class); \)904W5R
ah&D%8E
private UserService userService; 6'5 7
%(#y5yJ ]
private Page page; [!uG1 GJ>
U$.@]F4&
privateList users; dL 1tl
u%KTNa0
/* 'F3f+YD
* (non-Javadoc) aiUY>M#|
* TER=*"!
* @see com.opensymphony.xwork.Action#execute() /9*B)m"
*/ $9#H04.x
publicString execute()throwsException{ n
ATuD
Result result = userService.listUser(page); ^7cGq+t
page = result.getPage(); ,kGc]{'W
users = result.getContent(); /4V#C-
return SUCCESS; t#})Awy^R
} J?1 uKR
::lKL
/** wu!59pL
* @return Returns the page. r'r%w#=`t
*/ :{v#'U/^
public Page getPage(){ 4jMFr,
return page; F#Ryu~,"
} 3{64 @s
#4%]o%.
/** CS5?Ti6
* @return Returns the users. ".V$~n(
*/ k68T`Ub\W6
publicList getUsers(){ 'Cfl*iNb
return users; Wx}8T[A}
} LVfF[
~9]hV7y5C
/** jl$ece5v
* @param page py!|\00}
* The page to set. ~d4 )/y
*/ QB uMJm
publicvoid setPage(Page page){ Xm}/0g&7
this.page = page; ~O0 $Suv
} }Yzco52
=E4LRKn
/** 9'giU r
* @param users SiRaFj4s"
* The users to set. y/cvQY0pU
*/ VcO0sa f`
publicvoid setUsers(List users){ ,t?B+$E
this.users = users; Tod&&T'UW
} \BTODZ:h
@/.;Xw]
/** 3>AMII
* @param userService nu[ML
* The userService to set. OJuG~euy
*/ q4:o#K#
publicvoid setUserService(UserService userService){ nbD*x|
this.userService = userService; >}8j+t&T
} >V?eog%~
} 'Ym9;~(@R
*20jz<
RQ'9m^
uK"=i8rs4
5oW!YJg
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, xQ-<WF1i
.+3g*Dv{&
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 (ylTp]~mR-
:Uzm
么只需要: )9{0]u;9
java代码: 2ozax)GY
mI-]/:
pk$l+sNZ=
<?xml version="1.0"?> JxdDC^> 0
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork X1x#6
oi
1QcNp(MO
1.0//EN" "http://www.opensymphony.com/xwork/xwork- 8oy^Xc+
jUYWrYJ
1.0.dtd"> NqazpB*
*e TqVG.
<xwork> {0Yf]FQb-a
9iIhte.
<package name="user" extends="webwork- ,GbR!j@6
Q0`wt.}V2
interceptors"> n`B:;2X,
r"gJX
<!-- The default interceptor stack name wtQ++l%{G
Olt?~}
--> `_Zg3_K.dS
<default-interceptor-ref .nf#c.DI
wY{-BuXv
name="myDefaultWebStack"/> .=7vI$ujd
Mlg0WrJ|2
<action name="listUser" L2[($l
hc(#{]].
class="com.adt.action.user.ListUser"> KEo,m
<param ios&n)W&
WtsFz*`)y
name="page.everyPage">10</param> r4b 6 c
<result 7?!d^$B
ed{ -/l~j
name="success">/user/user_list.jsp</result> (&Kk7<#`
</action> 5FPM`hLT
B?gOHG*vd>
</package> Drgv`z
+<Nn~1
</xwork> >^?u
.gM3
`t>l:<@%
iJ)_RSFK
9IdA%RM~mH
CAig]=2'
:S{BbQ){]
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 \j}ZB<.>
K^)Eb(4
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 '5#^i:
hohfE3rd
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 7FP*oN?
$D~0~gn~
jE.N ev/
Ws3)gvpPA
S:#lH?<_
我写的一个用于分页的类,用了泛型了,hoho 13$%,q)
u
OmtyX
java代码: hlvK5Z
&.)^
%Tp\z
x$A+lj]x
package com.intokr.util; xA2YG|RU=b
EqkN3%IG
import java.util.List; c)6m$5]
]NQfX[
/** r..iko]T
* 用于分页的类<br> L:$ ,v^2
* 可以用于传递查询的结果也可以用于传送查询的参数<br> U*rcd-@
* DD+7V@
* @version 0.01 :DK {Vg6
* @author cheng 8?B!2
*/ !]A
public class Paginator<E> { 0I-9nuw,^;
privateint count = 0; // 总记录数 ('4_
xOb
privateint p = 1; // 页编号 [NjXO`5#]
privateint num = 20; // 每页的记录数 k{R>
privateList<E> results = null; // 结果 ,1.p%UE]>
{K~ 'K+TPu
/** 6IN
e@
* 结果总数 hIYNhZv
*/ +[6G5cH
publicint getCount(){ /wGM#sFH
return count; '|6]_
} @(EAq<5{
1SQ3-WUs
publicvoid setCount(int count){ F/,NDZN
this.count = count; t4."/.=+
} 9R!atPz9
1fp?
/** F$y$'Rzu_B
* 本结果所在的页码,从1开始 )J o:pkM
* F>SRs =_
* @return Returns the pageNo. Co9^OF-k
*/ P1.[
publicint getP(){ f=l rg KE
return p; nmee 'oEw
} |"q5sym8Y_
W<h)HhyG
/** rm'SOJVA
* if(p<=0) p=1 ]6k\)#%2
* f=+mIZ
* @param p JMCKcZ%N
*/ g.k"]lP
publicvoid setP(int p){ .r=4pQ@#
if(p <= 0) ?>9/#Nv
p = 1; rET\n(AJ
this.p = p; x;O[c3I
} q^@Q"J =v
7(1|xYCx$
/** :I] Mps<
* 每页记录数量 dohA0
*/ #H&|*lr
publicint getNum(){ ;DQ ZT
return num; A7{\</Z
} P_^ +A
L?b~k=
/** w?PkO p
* if(num<1) num=1 Qab>|eSm
*/ Ve$o}h-
publicvoid setNum(int num){ J'6PmPzY|
if(num < 1) Xz6<lLb
num = 1; df8k7D;~e
this.num = num; l ~"^7H?4e
} @-07F,'W,
@(w@e\Bq
/** {f_={k
* 获得总页数 7DogM".}~Q
*/ 5+4IN5o]=
publicint getPageNum(){ Df-DRi
return(count - 1) / num + 1; /obfw^
} a@K%06A;'
JJ-( Sl
/** Uk wP
* 获得本页的开始编号,为 (p-1)*num+1 *gb*LhgO
*/ b<[Or^X
]
publicint getStart(){ *uRBzO}
return(p - 1) * num + 1; k!j5tsiR
} ^]Y>[[
0@0w+&*"@
/** 4&lv6`G `
* @return Returns the results. D(op)]8
*/ GRIti9GD
publicList<E> getResults(){ H064BM
return results; /|m2WxK)
} S&5&];Ag
H\" sgoJ
public void setResults(List<E> results){ s*KhF'fN
this.results = results; XAKs0*J>
} h]&GLb&<?
wD}l$& +
public String toString(){ 3PWL@>zi
StringBuilder buff = new StringBuilder W&W5lArr
#<"~~2?
(); JPI3[.o
buff.append("{"); |)DGkOtd
buff.append("count:").append(count); mkk6`,ov
buff.append(",p:").append(p); sRR(`0Zp
buff.append(",nump:").append(num); G^|:N[>B
buff.append(",results:").append .[KrlfI
F@jZ ho
(results); VR 8-&N
buff.append("}"); J$DE"|-
return buff.toString(); hp50J
} MTh<|$
w$iX.2|9%u
} |Pax =oJ\M
%)8}X>xq
./Zk`-OBT