Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 @]tGfr;le&
uPXqTkod
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 $I36>
yy1r,dw
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 <3x#(ms!!
}_22wjm~
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 z\Y^x9
F.5b|&@
。 \KXEw2S
z{0;%E
分页支持类: rM=A"
+|<b0Xd
java代码: aF"Z!HD
Hc%\9{zH
hF7mJ\
package com.javaeye.common.util; PcHFj+:
JJ0
CM:xe
import java.util.List; %Nl(Y@dD*
@e0skc
publicclass PaginationSupport { pe%)G6@G
Ur(o&,
publicfinalstaticint PAGESIZE = 30; 8#u_+;,p
U3K<@r
privateint pageSize = PAGESIZE; h}>/Z3*
Kn$1W=B1.
privateList items; ] *VF Ws
da'E"HN@G~
privateint totalCount; X/Rx]}[
5)5bt q)[
privateint[] indexes = newint[0]; M9g\/]Io;
|I5?5 J\
privateint startIndex = 0; s)8M? |[`I
%,cFX[D/)
public PaginationSupport(List items, int 5a!e%jj
PB67?d~
totalCount){ yN<fmi};c
setPageSize(PAGESIZE); V FSn!o:C
setTotalCount(totalCount); }a1Sfl@`3
setItems(items); :_a]T-GL
setStartIndex(0); [(F<|f:n
} cu?(P;mQi
]U1,NhZu
public PaginationSupport(List items, int N pND/
Sw@,<4S
totalCount, int startIndex){ vW-`=30
setPageSize(PAGESIZE); T$8~9qx
setTotalCount(totalCount); "HfU,$[
setItems(items); L{A-0Ffh
setStartIndex(startIndex); uEGPgYY (
} PbHh?iH
M .`
public PaginationSupport(List items, int WTYFtZD[yH
|kNGpwpI
totalCount, int pageSize, int startIndex){ ^r_lj$:+$
setPageSize(pageSize); LA`VqJ
setTotalCount(totalCount); x0h3jw+6
setItems(items); ![]I%'s
setStartIndex(startIndex); H"rzRd;S
} /+t[,
UZ\*]mxT
publicList getItems(){ kF,\bM
return items; <N=p:e,aN,
} `s>=Sn&UP
mhLRi\[c )
publicvoid setItems(List items){ &f<1=2dm
this.items = items; r82o[+$u0K
} o$`kpr
}t%>_
publicint getPageSize(){ _d| 62VS
return pageSize; <I%9O:R
} +aw>p_\
Ji:iKkI
publicvoid setPageSize(int pageSize){ 4<Sa,~4
this.pageSize = pageSize; 7 Y>`- \
} _=*tDa
/Ej]X`F
publicint getTotalCount(){ zL},`:(.
return totalCount; -?B9>6h"
} L0mnU)Q}C
sK%Hx`
publicvoid setTotalCount(int totalCount){ _`Q It>R
if(totalCount > 0){ =8~R$z%
this.totalCount = totalCount; YqSXi~.
int count = totalCount / r%,H*DOu
_/
}6
pageSize; ]AA%J@
if(totalCount % pageSize > 0) U\Ar*b) /T
count++; bLM"t0
indexes = newint[count]; yLz,V}
for(int i = 0; i < count; i++){ )Bn>/-
indexes = pageSize * \;*}zX
^~6] 0$yJ
i; pP0Vg'V
} !b]2q%XM
}else{ M=AvD(+ha
this.totalCount = 0; jfY{z=*]u
} OOBcJC
} \_*MJ)h)X
-[pCP_`)u
publicint[] getIndexes(){ lgonR
return indexes; RzzFhU#r
} W8,t l>(
SE^b0ZV*x
publicvoid setIndexes(int[] indexes){ },fo+vRM
this.indexes = indexes; u.kYp
} =`1m-
pH\^1xj
=
publicint getStartIndex(){ zd9]qo
return startIndex; }PFt
} &=-e`=qJ'6
t*a*v;iz
publicvoid setStartIndex(int startIndex){ t{X?PF\>o
if(totalCount <= 0) .'S^&M/$
this.startIndex = 0; Aa`MK$29F
elseif(startIndex >= totalCount) ^'7C0ps+A
this.startIndex = indexes \+{t4Im
r9]
rN
[indexes.length - 1]; N2tkCkl^x9
elseif(startIndex < 0) Y%/ YFO2vb
this.startIndex = 0; MV<!<Qmj
else{ !2Y!jz
this.startIndex = indexes {M@@)27gW
kPO6gdwq$
[startIndex / pageSize]; bR'mV-2'
} _3.G\/>[K
} p/hvQyE
w<Yv`$-`
publicint getNextIndex(){ CzSZ>E$%U
int nextIndex = getStartIndex() + W`N}
W]O@DS zR
pageSize; -MrtliepW*
if(nextIndex >= totalCount) Eq=wdI
return getStartIndex(); 7 DY WdDX
else /bmXDDYH4
return nextIndex; feI./E
} |"R_-U
`S \zqF<
publicint getPreviousIndex(){ Y$`eg|$
int previousIndex = getStartIndex() - qX5yN| A4
*#1y6^
pageSize; fVDDYo2\
if(previousIndex < 0) %AG1oWWc>.
return0; 3I"NI.>*
else *K(k Kph
return previousIndex; +}^|dkc
} W|25t)cJ8h
z.3<{-n}0i
} ;8ET!&k*>E
skIiJ'db
bo@,4xw
BTTLy^
抽象业务类 4M}|/?<Br
java代码: 7G5y)Qb
0n:?sFY>
?;|@T ty%
/** F{k$Atb?g/
* Created on 2005-7-12 BXg!zW%+
*/ p$Kj<:qiP
package com.javaeye.common.business; yiVG ]s
(j' {~FB
import java.io.Serializable; 7qe7Fl3
import java.util.List; *@_u4T7|{
keLR1qf
import org.hibernate.Criteria; Y?yo\(Cdx
import org.hibernate.HibernateException; D~#Ei?aH
import org.hibernate.Session; i:o}!RZ>
import org.hibernate.criterion.DetachedCriteria; ZFS7{:
import org.hibernate.criterion.Projections; nbI=r+
import A4G,}r *n
(CdJ;-@D
org.springframework.orm.hibernate3.HibernateCallback; d^F|lc ]8
import J["H[T*
^GMJ~[]
org.springframework.orm.hibernate3.support.HibernateDaoS gmh5
%2M
XTJvV
upport; vS OT*0r
01udlW.
import com.javaeye.common.util.PaginationSupport; bfgz1
`u
VeZey)Q
public abstract class AbstractManager extends OAv>g pw
iF!mV5#
HibernateDaoSupport { Sd},_Kh
pDu{e>S|:
privateboolean cacheQueries = false; *AZ?~ i^o
M`GP^Ta
privateString queryCacheRegion; 5Go0}'*%
Dv&>*0B
publicvoid setCacheQueries(boolean xS'zZ%?
F4Zn5&.)
cacheQueries){ i+f7
this.cacheQueries = cacheQueries; UVB/vqGg
} 1Cm~X$S.
s]U4B<q
publicvoid setQueryCacheRegion(String Q1Ux!$_
E&*:
jDg
queryCacheRegion){ 'b^l'KN:S
this.queryCacheRegion = Z@3l%p6V
'>@4(=I
queryCacheRegion; V vu(`9u]
} | h}B{D
<FY&h#
publicvoid save(finalObject entity){ x(8n
9Q>
getHibernateTemplate().save(entity); !z"Nv1!~|
} ?"6Ov ]
) Qq'Wp3i
publicvoid persist(finalObject entity){ W>B^S
getHibernateTemplate().save(entity); 2i\Q@h
} 17}$=#SX
l&Z
Sm
publicvoid update(finalObject entity){ =SAV|
getHibernateTemplate().update(entity); @F>F#-2
} \m4T3fy
?i~g,P]NK
publicvoid delete(finalObject entity){ YNSyi@
getHibernateTemplate().delete(entity); < f(?T`
} z{:-!oF&CB
f~=r*&U
publicObject load(finalClass entity, V<8K@/n@
62[8xn=(%
finalSerializable id){ 3HZ~.
return getHibernateTemplate().load J~KX|QY.S
8eluO ?p
(entity, id); %j7:tf=
} O:Va&Cyj*
I"@p aLZ
publicObject get(finalClass entity, q"akrI38
ebC)H
finalSerializable id){ KOey8tB)1
return getHibernateTemplate().get ju|]Qlek
6;o3sf@Tf
(entity, id); xRum*}|4
} !KcWH9
i|]7(z#OyI
publicList findAll(finalClass entity){ R(k}y,eh.`
return getHibernateTemplate().find("from PWH^=K
=E(#YCx
" + entity.getName()); }aF
} w(U:U-MNe
ESTM$k}X
publicList findByNamedQuery(finalString }7eh F6
zI^]esX!2_
namedQuery){ kA4@`YCl
return getHibernateTemplate ,2L$G&?
X32C}4-B
().findByNamedQuery(namedQuery); gl{B=NN
} a 7#J2 r
@PI%FV z~p
publicList findByNamedQuery(finalString query, fRB5U'
^C/
finalObject parameter){ ]kD"&&HV
return getHibernateTemplate jVO{$j
$A2n{
().findByNamedQuery(query, parameter); k?*KnfVh!
} _ \D"E>oM
`!vUsM .d
publicList findByNamedQuery(finalString query, |4;UyHh
ST1'\Eo
finalObject[] parameters){ .5w azvA
return getHibernateTemplate LlHa5]E@6
edipA
P~!
().findByNamedQuery(query, parameters); 7I9aG.;
} ^{F_a
aI3CNeav
publicList find(finalString query){ 8|@9{
return getHibernateTemplate().find e(?]SU|
f>2MI4nMG
(query); wM~H(=s`D
} +1rkq\{l
7b[wu~'(
n
publicList find(finalString query, finalObject GIyF81KR 3
),(V6@Z?
parameter){ \?**2{9&)
return getHibernateTemplate().find Kcy@$uF{2
o*5U:'=5}
(query, parameter); IgIYguQ
} q_V0+qH
PLX>-7@
public PaginationSupport findPageByCriteria ,WDX(
nhT-Ido
(final DetachedCriteria detachedCriteria){ H,QTYXi "
return findPageByCriteria QA3/
o`n$b(VZ
(detachedCriteria, PaginationSupport.PAGESIZE, 0); EON:B>2a
} kV;fD$iW;
7fHc[,
public PaginationSupport findPageByCriteria .uF[C{RnO
nXy>7H[0
(final DetachedCriteria detachedCriteria, finalint Q >Qibr
"4o=,$E=
startIndex){ h6~$/`&]b
return findPageByCriteria _n;;][]S
OsqNB'X
(detachedCriteria, PaginationSupport.PAGESIZE, ]QVNn?PA8
U75Jp%bL
startIndex); pO7Zs
} iK5_u2]Q
9QQyl\
public PaginationSupport findPageByCriteria gNYqAUG5
UC
HZ2&
(final DetachedCriteria detachedCriteria, finalint 3]RyTQ
Hc^W%t~
pageSize, tM4Cx
finalint startIndex){ s{0aBeq
return(PaginationSupport) 8NBT|N~N
;&V s4
getHibernateTemplate().execute(new HibernateCallback(){ >J9oH=S6
publicObject doInHibernate }%7NF*
vS\Nd1~ ?
(Session session)throws HibernateException { SAYLG
Criteria criteria = ZJPmR/OV_
^ D%FX!$
detachedCriteria.getExecutableCriteria(session); ziPR>iz-
int totalCount = ",6M)3{|c
km~Ll
((Integer) criteria.setProjection(Projections.rowCount br-]fE.be
2i;7{7
()).uniqueResult()).intValue(); :cB=SYcC%
criteria.setProjection oVFnlA
Xpe)PXb
(null); %D$]VSP;
List items = &>d:R_Q]
F8-?dp f'
criteria.setFirstResult(startIndex).setMaxResults Hso|e?Z
%`Z+a.~ U
(pageSize).list(); Wbr+KX8)
PaginationSupport ps = (T`E!A0I\?
yY?b.ty
new PaginationSupport(items, totalCount, pageSize, Gx`L ks
}>)[<;M>%
startIndex); n3AaZp[
return ps; (aOv#Vor]%
} {9UEq0
}, true); .<@8gNm3
} #@<9S{F
[8tL"G6s
public List findAllByCriteria(final ^[:p|U2mA
1-lu\"H`
DetachedCriteria detachedCriteria){ ;r c`OZyE
return(List) getHibernateTemplate i&{DOI%w
M5gWD==uP
().execute(new HibernateCallback(){ -f*P
nxg
publicObject doInHibernate sMu]
/'7
O
T.*pk+<)
(Session session)throws HibernateException { X}+>!%W!}
Criteria criteria = QQWadVQo
wF((
detachedCriteria.getExecutableCriteria(session); i3rH'B-I.
return criteria.list(); eek7=Z
} |{CfWSB7~@
}, true); th;{V%:LW
} *98$dQR$
^R:cd8+?%
public int getCountByCriteria(final "[y-+)WTG
g+J-Zg6
DetachedCriteria detachedCriteria){ (sh)TBb5
Integer count = (Integer) ?@E!u|]K
}Y;K~J
getHibernateTemplate().execute(new HibernateCallback(){ gNt(,_]ZR
publicObject doInHibernate z`:lcF{V
(Jz1vEEV
(Session session)throws HibernateException { |JQQU!x
Criteria criteria = 293M\5:
o!)3?
detachedCriteria.getExecutableCriteria(session); #O+),,WS
return )c `7( nY
7(pF[LCF
criteria.setProjection(Projections.rowCount yu;P +G
xg3:} LQ
()).uniqueResult(); dq]0X?[6
} r zt Ru
}, true); ZIQ
[bE7
return count.intValue(); hEp(A8g)bQ
} Z]B~{!W1
} |UX(+;n
]*AR,0N&
{WYX~Mvvj
ZpnxecJUJ
*s:(jDlv
r-Pkfy(
用户在web层构造查询条件detachedCriteria,和可选的 H '
3f,hw5R
startIndex,调用业务bean的相应findByCriteria方法,返回一个 /pT=0=
[PDNwh0g5
PaginationSupport的实例ps。 Q\ 0cvmU
#3gp6*R
ps.getItems()得到已分页好的结果集 1,% R;7J=g
ps.getIndexes()得到分页索引的数组 {GQ^fu;q
ps.getTotalCount()得到总结果数 (L/_^!ZX
ps.getStartIndex()当前分页索引 O6LS(5j2
ps.getNextIndex()下一页索引 "hsb8-
ps.getPreviousIndex()上一页索引 LU={")TdQ
]"?)Z
PK `D8)=u
/ G7vwC
B!?%O
c9&xe"v
oC0qG[yp9S
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 njputEGX
>&}%+r\
,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 . QBF`Rz
#T'{ n1AI
一下代码重构了。 ++`0rY%
=,6z4" )
我把原本我的做法也提供出来供大家讨论吧: $7^o#2
B
pe1R(|H
首先,为了实现分页查询,我封装了一个Page类: :g Wu9Y|{
java代码: $xPaYf
H"
3fT 0
ZZzMO6US0
/*Created on 2005-4-14*/ 5Ou`z5S\k
package org.flyware.util.page; xD~5UER
pSdI/Vj'=
/** k@k&}N0{
* @author Joa K3#@SYj
* 6[ j.@[t
*/ wNpTM8rfU#
publicclass Page { rWR}Stc@]
jK& h~)
/** imply if the page has previous page */ ~d|A!S`
privateboolean hasPrePage; sN9&,&W1
i#vYyVr[
/** imply if the page has next page */ U@uGNMKR
privateboolean hasNextPage; #Y
a4ps_
a%/9v"}
/** the number of every page */ T[UN@^DP(
privateint everyPage; 2fnkw/
BBwy,\o#
/** the total page number */ TJ6*t!'*X
privateint totalPage; i:Y^{\Z?V
1mOh{:1u
/** the number of current page */ Y5- F@(
privateint currentPage; O;:mCt _H
(MxQ+D\
/** the begin index of the records by the current !Prg_6
`
v$?+MNks
query */ |
*2w5iR
privateint beginIndex; "n(hfz0y%
$P/~rZ@M@
Vc\MV0lr
/** The default constructor */ rWa2pO
public Page(){ !Qu"BF
&=] ~0$
} N8F~8lTi
IP xiV]c
/** construct the page by everyPage r*2+xDoEi
* @param everyPage Ug>~Rq]
* */ I9_RlAd
public Page(int everyPage){ CkOz
this.everyPage = everyPage; 5F)C jQ
} jnO9j_CY
6F!+T=
/** The whole constructor */ zy/@
WFPE
public Page(boolean hasPrePage, boolean hasNextPage, a*lh)l<KV
pjKWtY@=X
`VA"vwz
int everyPage, int totalPage, =Y{(%sn
int currentPage, int beginIndex){ iVhJ t#_b
this.hasPrePage = hasPrePage; >E;uU[v)I
this.hasNextPage = hasNextPage; \A 2r]
this.everyPage = everyPage; K[Y I4pt7
this.totalPage = totalPage; @ym v< Mo
this.currentPage = currentPage; QwW&\h[8?
this.beginIndex = beginIndex; y-'$(x
} :~"CuB/
g:g\>@Umo
/** -$,TMqM
* @return t3 8m'J :>
* Returns the beginIndex. BO~0ON0
*/ I| w"/"U
publicint getBeginIndex(){ x
nsLf?>]
return beginIndex; AifWf2$S
} 4KhV|#-;k
i1ixi\P{0
/** 6tgt>\y
* @param beginIndex -`*a'p-=
* The beginIndex to set. :%tU'w
*/ ?pW`cFLDHF
publicvoid setBeginIndex(int beginIndex){ GZN ^k+w
this.beginIndex = beginIndex; eVjBGJ=2e
} n4;.W#\
}aa'\8
/** ,>bh$|
* @return I667Gz$j5
* Returns the currentPage. :C(=&g<]D
*/ '.IW.{;$
publicint getCurrentPage(){ SD"FErJ
return currentPage; Yg]-wQrH
} M8kPj8}{
+nrbShV
/** l+xX/A)
* @param currentPage jFQQ`O V
* The currentPage to set. 2V-
16Q'%
*/ Z3"%`*Tmq-
publicvoid setCurrentPage(int currentPage){ k^3>Y%^1
this.currentPage = currentPage; [A+
>^ {
} orzZ{87
>,V9H$n
/** x|/|jzJSX
* @return >N^Jj:~l
* Returns the everyPage. I5k$H$
*/ ^cOUQ33
publicint getEveryPage(){
sJB;3"~
return everyPage; :KQ~Cb
} I:R[;TB?y
?ZV/U!y
/** w$3,A$8
* @param everyPage .0zY}`
* The everyPage to set. }^ApJS(FQ
*/ pNG:0
publicvoid setEveryPage(int everyPage){ 7Od
-I*bt
this.everyPage = everyPage; 'F+C4QAq
} j+i\bks
G,&<<2{(f;
/** 7-bd9uVK
* @return F&!6jv
* Returns the hasNextPage. zJq~!#pZ
*/ j8v8uZ;x
publicboolean getHasNextPage(){ >8~.wXyoC
return hasNextPage; !a{^=#qq&I
} z Xg3[orF
xT3BHnQ(
/** k :(SCHf
* @param hasNextPage LA!?H]
* The hasNextPage to set. k|e7a2Wwt
*/ EaO6[E
publicvoid setHasNextPage(boolean hasNextPage){ [>jbhV'
this.hasNextPage = hasNextPage; pR*VdC _mY
} K^
vIUZ>
Kf bb)?
/** |B?cVc0
* @return g#"zQv ON
* Returns the hasPrePage. C8J[Up
*/ 1T"`vtR
publicboolean getHasPrePage(){ F|'>NL-=
return hasPrePage; &p'Y^zL-
} hr#M-K
4`4kfiS$
/** Tm~" IB*
* @param hasPrePage \o z#l'z
* The hasPrePage to set. Eq% }
*/ \{Y 7FC~
publicvoid setHasPrePage(boolean hasPrePage){ ;"a=gr
this.hasPrePage = hasPrePage; AFq~QXmr)
} J?*1*h
DwM)r7<Ex
/** U\g/ 2dM
* @return Returns the totalPage.
-WY<zJ
* 7o7)0l9!
*/ ew>XrT=Zm
publicint getTotalPage(){ ()Y~Q(5ji
return totalPage; UE8kpa)cQ
} vk}n,ecl
OSRp0G20k\
/** _~'=C#XI)
* @param totalPage hCi 60%g/n
* The totalPage to set. _zR+i]9
*/ h1j!IG
publicvoid setTotalPage(int totalPage){ ty8q11[8
this.totalPage = totalPage; "Bh}}!13
} /
kF)
8V~k5#&Ow
} P@,XEQRd`
,kyJAju>
$jjfC
p\ Q5,eg
_'#n6^Us<
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 ayn) 5q/z
:">!r.Q
个PageUtil,负责对Page对象进行构造: BOX{]EOj
java代码: T(#J_Y
R}-(cc%5
4zXFuTr($
/*Created on 2005-4-14*/ aHV;N#Lx3
package org.flyware.util.page; ?qmRbDI
;0Q4<F
import org.apache.commons.logging.Log; &xU[E!2H%
import org.apache.commons.logging.LogFactory; ZJnYIK
h\$$JeSV]
/** kDEXN
* @author Joa x,'(5*
* iJ ($YvF4
*/
Y[ j6u\y
publicclass PageUtil { 6O7'!@@
w x]0p
privatestaticfinal Log logger = LogFactory.getLog h&M{]E9=
h}>"j%I
(PageUtil.class); Z&G+bdA>,
|h KDvH
/** 034iK[ib"
* Use the origin page to create a new page |T<_ 5Ik
* @param page c/:b.>W
* @param totalRecords ~Zun&b)S
* @return /74QMx?
*/ ;nI] !g:
publicstatic Page createPage(Page page, int F3y9@dA]
S50k>_a;
totalRecords){ (j%~u&+-
return createPage(page.getEveryPage(), /Y/UM3/
u]g%@3Pn
page.getCurrentPage(), totalRecords); )1Y{Q Y}l
} |5X^u+_
jSJqE_ 1
/** y|jl[pyg)
* the basic page utils not including exception [ZNtCnv
FVMD>=k
handler b10cuy|a/X
* @param everyPage tl[Uw[
* @param currentPage P:hBt\5B
* @param totalRecords U2ohHJ``
* @return page 6gkV*|U,e
*/ B*eC3ok3z
publicstatic Page createPage(int everyPage, int nyX2|m&
FXpJqlhNv
currentPage, int totalRecords){ TCMCK_SQL
everyPage = getEveryPage(everyPage);
+Te\H
currentPage = getCurrentPage(currentPage); I!ED?n
int beginIndex = getBeginIndex(everyPage, <!&[4-;fU
HNb/-e ,"
currentPage); S%$ }(
int totalPage = getTotalPage(everyPage, ^8]NxV@l
)~&CvJ
totalRecords); aKJwofD
boolean hasNextPage = hasNextPage(currentPage, L{#IT.
%gInje
totalPage); /RG:W0=K
boolean hasPrePage = hasPrePage(currentPage); 2\)xpOj
=R^%(Py
returnnew Page(hasPrePage, hasNextPage, O24m;oHM
everyPage, totalPage, 99]R$eT8
currentPage, Ij 79~pn
d.[8c=$
beginIndex); #?RU;1)Cw
} ~b(i&DVK
@tF\p
privatestaticint getEveryPage(int everyPage){ \|n-
O=}=2
return everyPage == 0 ? 10 : everyPage; gGR"Z]DBk
} EHSlK5bD,
OP;v bZ
privatestaticint getCurrentPage(int currentPage){ _Mi5g_
return currentPage == 0 ? 1 : currentPage; 2kqu p)82e
} q'+)t7!
7( #:GD
privatestaticint getBeginIndex(int everyPage, int T*I{WW
\Yy$MLs
currentPage){ ['b}QW@Fx
return(currentPage - 1) * everyPage; Z/G
ev"p
} w3N[9w?1
M
"ui0
ac
privatestaticint getTotalPage(int everyPage, int hz{`h
BfXgh'Z~
totalRecords){ .7O*pJ2(H
int totalPage = 0; 0q^>ZF-@
x!hh"x
if(totalRecords % everyPage == 0) _PPy44r2
totalPage = totalRecords / everyPage; 2"COP>
else uY0lR:|
totalPage = totalRecords / everyPage + 1 ; T!uM+6|Y
QER?i;-wb
return totalPage; ]z;P9B3@&
} <g-9T -Ky
.Q<>-3\K
privatestaticboolean hasPrePage(int currentPage){ LhN|1f:9:
return currentPage == 1 ? false : true; bUs0 M0y
} UJ%R
SP@ >vl+;
privatestaticboolean hasNextPage(int currentPage, pD(j'[
Fzm*Pz3
int totalPage){ 3N8t`N
return currentPage == totalPage || totalPage == zh%#Y_[R
PoNi"Pv
0 ? false : true; 9q)Kfz
} 6o^,@~:R
`34zkPB??
j
'FVz&
} ?}qttj
W,D4.w$@'
Ig$(3p
?llXd4
yZAS# ko}}
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。 y+Ra4G#/}
Yy5h"r
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 57aXQ8u{
K)6rY(x
>
做法如下: :X"?kK0 V
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 E~,F
vx\r!]
的信息,和一个结果集List: ih)zG
java代码: $Y;U[_l#
Gw=B:kGk
C,wL0Yj[
/*Created on 2005-6-13*/ 9K.Vb1&
package com.adt.bo; 1Vsz4P"O $
7Sf
bx~48
import java.util.List; H[m:0eF'5
f0A{W/0n
import org.flyware.util.page.Page; 'SO %)B
:8I9\eet3
/** 9FoHD
* @author Joa vGvf<ra;H
*/ ^/)^7\@
publicclass Result { d^@ dzNv
I?]ohG K
private Page page; @#<D ^"
Wfu(*
private List content; '>NCMB{*
7jxslI&F
/** ?:pP8/y
* The default constructor ~Uj=^leYO
*/ ;m0~L=w
public Result(){ :Hn6b$Vy8
super(); :uP,f<=)K
} 6O|@xvg
oOnop-z7
/** .RE:;<|w
* The constructor using fields 2^Eg9y'
* fA&k`L(y
* @param page k@\ iGqo
* @param content VX].3=T8
*/ >i_2OV
public Result(Page page, List content){ j@=%_^:i
this.page = page; R}'bP
this.content = content; Hek*R?M|
} 6q*9[<8
;i8g41qjF
/** . kQkC:~9
* @return Returns the content. Bu#E9hJFvA
*/ U GD2
publicList getContent(){ >d*iD
return content; ^b/ Z)3
} ?iPC*
I*%-cA%l
/** G(Lzf(
* @return Returns the page. o#;b
*/ t,QyfN
public Page getPage(){ DD7h^-x
return page; $g@=Z"
} xRJ\E }/7
M.Y~1c4f
/**
S\LkL]qx
* @param content *Tas`WA
* The content to set. yGI;ye'U
*/ #~#R-
public void setContent(List content){ ~F7-HaQJ
this.content = content; %WSo b@f8
} hwu]Er.gn
@"hb) 8ng
/** nePfuG]Q
* @param page 5*E]ETo@R
* The page to set. uvMy^_}L
*/ O|\J}rm'
publicvoid setPage(Page page){ c$ao:nP)D
this.page = page; dUsYZdQs
} $()5VMb
} 9Kpa><
M2d$4-<
yQU_>_!n
FO=4:
mN~ci 0
2. 编写业务逻辑接口,并实现它(UserManager, 3)8QS
34z"Pm
UserManagerImpl) io _1Y]N
java代码: -!q:p&c
x8wD0D
GU4'&#
/*Created on 2005-7-15*/ 4P'*umJi
package com.adt.service; MTsM]o
?:
N@!jeJ
import net.sf.hibernate.HibernateException; Hx#;Z
jB`,u|FG
import org.flyware.util.page.Page; `rgn<I"
RzBF~2 >i
import com.adt.bo.Result; _XG/Pp)
}0eF~>Df
/** y6LWx:
* @author Joa lH-/L(h2
*/ Z9:-rcr
publicinterface UserManager { M1 :uJkO.
b8~Bazk
public Result listUser(Page page)throws C3*gn}[
I2TaT(e\
HibernateException; d_CKP"TA
5Eg1Q
YVt
} 1|RANy
=5Q]m6-SgV
2-7IJ\
\!>3SKs(e
*#E
FsUw
java代码: /~}}"zx&
u2[iM d
rQk<90Ar
/*Created on 2005-7-15*/ *vflscgt
package com.adt.service.impl; _I:~@
e^d0zl{
import java.util.List; XaCX!Lr,
PRr2F-!P
import net.sf.hibernate.HibernateException; &f"-d
{kp"nl$<
import org.flyware.util.page.Page; 9)}[7Mg:C
import org.flyware.util.page.PageUtil; pi /g H
;-9=RI0
import com.adt.bo.Result; $eD.W
import com.adt.dao.UserDAO; qm./|#m>
import com.adt.exception.ObjectNotFoundException; EKA#|^Q:NX
import com.adt.service.UserManager; cVubb}ou
,u!*2cWN
/** G;&-\0>W
* @author Joa 1KMLG=
*/ y&Mr=5:y
publicclass UserManagerImpl implements UserManager { W{%TlN
)\_:{ c
private UserDAO userDAO; @{YS}&Q/
} ~h3c|
/** M*z~gOZ
* @param userDAO The userDAO to set. U@gn;@\
*/ d\p,2
publicvoid setUserDAO(UserDAO userDAO){ ;gBRCZ
this.userDAO = userDAO; 0*rQ3Z
} N03HQp)g
2r!s*b\Ix
/* (non-Javadoc) Zw*v
* @see com.adt.service.UserManager#listUser )^m%i]L_
aa?w:3
(org.flyware.util.page.Page) T,]7ICF#
*/ R<[qGt|L
public Result listUser(Page page)throws :A1{ d?B
Y,WuBH
HibernateException, ObjectNotFoundException { X *&[u7No
int totalRecords = userDAO.getUserCount(); 7Bb9t
if(totalRecords == 0) |UK}
throw new ObjectNotFoundException "$N#p5
S/^"@?z,vE
("userNotExist"); (IC]?n}
page = PageUtil.createPage(page, totalRecords); "]z-: \ V
List users = userDAO.getUserByPage(page); 8S%52W|
returnnew Result(page, users); fJ/e(t
} .C&ktU4
9A}# 6
} 5"HVBfFk
2Tfz=7h$
+VCGlr
5!l0zLQPo
CPP`
qt%f
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 LUuZ9$t0J"
Cz72?[6
询,接下来编写UserDAO的代码: '<rZm=48
3. UserDAO 和 UserDAOImpl: Pm
lx8@D
java代码: kBYNf =
)+}]+xRWGj
ROk5]b.
/*Created on 2005-7-15*/ ?\$#L^;b}
package com.adt.dao; rypTKT|U;
{jYOsl
import java.util.List; .Jt[(;
Q.]}]QE
import org.flyware.util.page.Page; sYjpU
O>^C4c!
import net.sf.hibernate.HibernateException; P5
K' p5}#
*tgnYa[l
/** |
\'rP_I>
* @author Joa W6"v)Jc>_
*/ 3
|hHR
publicinterface UserDAO extends BaseDAO { qxFB%KqU
eU<]o<
\Qo
publicList getUserByName(String name)throws O+?<h{"
Au4yBm
u
HibernateException; r41\r,`Dj
pcT:]d[1)
publicint getUserCount()throws HibernateException; `t_W2y
,!dh2xNH^
publicList getUserByPage(Page page)throws 4W3\P9p=
YN`H
BFH
HibernateException; A-4h
J.ck~;3
} %!du,2
^@qvl%j
Y}uCP1v
\|E^v6E%0
AgFVv5
java代码: -PS#Z0>
ve%
xxn:
\8<BLmf4U
/*Created on 2005-7-15*/ Hm$=h>rY9[
package com.adt.dao.impl; =,Dqqf
WAn~+=Ax
import java.util.List; B>GE9y5
=0G!f$7^i
import org.flyware.util.page.Page; _~*,m#uxJ
N5i+3&
import net.sf.hibernate.HibernateException; Dh5X/y
import net.sf.hibernate.Query; H63,bNS s
_T2=J+"-Kp
import com.adt.dao.UserDAO; )('%R|$ /
Gm(b/qDDe
/** Kj<^zo%w
* @author Joa 1RK=,Wx
*/ ?r?jl;A&
public class UserDAOImpl extends BaseDAOHibernateImpl UN zlN
-5T=:2M
implements UserDAO { U2`'qsR1
Y=?yhAw
/* (non-Javadoc) gFHTG
* @see com.adt.dao.UserDAO#getUserByName ,4ei2`wV
sO.`x*
(java.lang.String) L2, 1Kt7
*/ <
V\I~;
publicList getUserByName(String name)throws {W]=~*w
W2z*91$
HibernateException { Sp}tD<V
String querySentence = "FROM user in class
u$-U*r
zOGU8Wg
com.adt.po.User WHERE user.name=:name"; ^_ kJKM,
Query query = getSession().createQuery 4H|(c[K;
xj[(P$,P
(querySentence); R1& [S/
query.setParameter("name", name); 55;g1o}}f
return query.list(); aBNZdX]vzO
} PJ2qfYsH=>
Pv<24:ao
/* (non-Javadoc) t
0-(U\
* @see com.adt.dao.UserDAO#getUserCount() F$^Su<w5l
*/ 6e_dJ=_
publicint getUserCount()throws HibernateException { L5qwWvbT
int count = 0; -.T&(&>^
String querySentence = "SELECT count(*) FROM %/YcL6o(
j%y$_9a7
user in class com.adt.po.User"; 6$ Gep
Query query = getSession().createQuery 40|,*wi
1}tbH[
(querySentence); om]4BRe
count = ((Integer)query.iterate().next <0S,Q+&
SF5@Vg
()).intValue(); i:Zm*+Gi
return count; $2u 'N:o
} WdnIp!
:"l-KQ0
/* (non-Javadoc) \#rIQOPl?
* @see com.adt.dao.UserDAO#getUserByPage Vo7dAHHL
%s&ChM?8F
(org.flyware.util.page.Page) >-O/U5<!
*/ ]ix!tb.Q
publicList getUserByPage(Page page)throws @"o@}9=d
kWNV%RlSx
HibernateException { aM{xdTYaU
String querySentence = "FROM user in class &m[Qn!>i6
WyZL9K{?
com.adt.po.User"; M4d47<'*~
Query query = getSession().createQuery {U84 _Pi
U-:ieao@
(querySentence); )x]3Zq
query.setFirstResult(page.getBeginIndex()) F* .g;So
.setMaxResults(page.getEveryPage()); gl]E_%tH
return query.list(); cetvQAGXY
} #^4,GLIM
Vur bW=~g
} P)uDLFp]
8o/}}=m$
5r?m&28X
NuYkz"O]
1]}#)-
至此,一个完整的分页程序完成。前台的只需要调用 Y2O"]phi@
;/0 Q1-
userManager.listUser(page)即可得到一个Page对象和结果集对象 !o>H1#2l
/[9t`
的综合体,而传入的参数page对象则可以由前台传入,如果用 e5OsIVtjr
sg8/#_S1i
webwork,甚至可以直接在配置文件中指定。 M{$j
)LdyC`S\c
下面给出一个webwork调用示例: .-JCwnP
java代码: Q//,4>JKf
&<+ A((/i
3mSXWl^?
/*Created on 2005-6-17*/ &EM\CjKv"
package com.adt.action.user; (D
9Su^:1
@rHK(25+d
import java.util.List; YhRWz=l
/5#rADOS
import org.apache.commons.logging.Log; <HRBMSR+
import org.apache.commons.logging.LogFactory; FVKW9"AyW
import org.flyware.util.page.Page; 8&Myva
&bhq`>
import com.adt.bo.Result; (708H_
import com.adt.service.UserService; >5wx+n)/)
import com.opensymphony.xwork.Action; gZEi]/8_
5"/J^"!h
/** .7
asW(
* @author Joa *c)uGz'cD
*/ /1 RAAa
publicclass ListUser implementsAction{ \V>?Do7
+`sv91c
privatestaticfinal Log logger = LogFactory.getLog gt\MS;jMa
:d8W+|1u
(ListUser.class); cv(PP-'\
Q.Aw2
private UserService userService; <jS~ WI@
5~.ZlGd
private Page page; unJ R=~E
U#n#7G6fRp
privateList users; fGv#s
X
zFQ&5@43
/* &wU'p-V
* (non-Javadoc) 8_&CT
:u>
* _Cw:J|l.
* @see com.opensymphony.xwork.Action#execute() zd_HxYrN
*/ X]loJoM9
publicString execute()throwsException{ | ea~'N1
Result result = userService.listUser(page); }dxDtqb
page = result.getPage(); Bk}><H
users = result.getContent(); dtPoo\@
return SUCCESS; "Pl9 nE
} >3gi yeJ
GdVhK:<>
/** j,d*?'X
* @return Returns the page. )>7%pz
*/ o&hIHfZri
public Page getPage(){ Jd,)a#<j
return page; u4"SH(
} Uu 7dSU
n}mR~YqD
/** L'i-fM[#
* @return Returns the users. jEz+1Nl)
*/ @=5qT]%U3J
publicList getUsers(){ :y2p@#l#
return users; +uWYK9
} UwY-7Mmo
8SmnMt
/** hSGb-$~F
* @param page O g%U
* The page to set. *[eL~oN.c
*/ <e%F^#y_
publicvoid setPage(Page page){ J!ntXF
this.page = page; |KY EK|
}
LzDI0a.
L5IbExjV
/** <As9>5|%
* @param users g`k?AM\
* The users to set. a4gi,pz$]
*/ pbHsR^
publicvoid setUsers(List users){ to"'By{9
this.users = users; P%Ay3cR+E
} i77GE
YYg)
/** ~Cc.cce5
* @param userService % p?brc
* The userService to set. r$wZt
*/ +]:2\TTGI
publicvoid setUserService(UserService userService){ *FR$vLGn
this.userService = userService; qP*}.Sqk7
} utlpY1#q/
} r'BAT3
'j%F]CK
Xl |1YX1&m
ExHAY|UA
XH7xT@
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, BsZ{|,oQnZ
;oH,~|K
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 9H]_4?aX
D~K;~nI
么只需要: Ap\AP{S4
java代码: rAQF9O[
,%#
,}D}oo*
<?xml version="1.0"?> Uf*EJ1Ei
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork n,M)oo1G
^4v*W;Q
1.0//EN" "http://www.opensymphony.com/xwork/xwork- T_<BVM
c:M$m3Cs?
1.0.dtd"> tGcya0RL
Zs zs1{t
<xwork> (y4#.vZh:
2_QN&o ~h
<package name="user" extends="webwork- d6 _C"r
h7_)%U<J2
interceptors"> K_-d(
*HM?YhR
<!-- The default interceptor stack name ,je`YEC
P}3}ek1Ax
--> GgFi9Ffj
<default-interceptor-ref T&"i _no*
;eB ~H[S/
name="myDefaultWebStack"/> 9vGs;
f%qt)Ick
<action name="listUser" ?Ce#BwQ>
Vs0 SXj
class="com.adt.action.user.ListUser"> ":?T%v>
<param \ SCy$,m
`kN#4p
name="page.everyPage">10</param> ~KIDv;HSb[
<result jkrx]`A{~
{GqXP0'
name="success">/user/user_list.jsp</result> U Lmg$T&
</action> U!q[e`B
eQX`,9:5
</package> ,35&G"JK5
@y~P&HUN
</xwork> Yig0/"
MXAEX2xmme
&w~Xa( uu
73NZ:h%=
FY;+PY@I{
>X Qv?5
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 mU{4g`Iw
~0tdfK0c
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。 yDd[e]zS`
8LM#WIm?
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 !)OB@F%U
/nB'kg[h\
uOk%AL>
Mn^zYW|(
f$xhb3Qn
我写的一个用于分页的类,用了泛型了,hoho +/'<z
)q?$p9
java代码: z)L}ECZh9
-]"T^wib
2g`[u|
package com.intokr.util; ~5#)N{GbY
?s{C//
import java.util.List; X}JWf<=q
9k2,3It
/** KXBL
eR&^
* 用于分页的类<br> R ZcH+?7
* 可以用于传递查询的结果也可以用于传送查询的参数<br> bcJ@-i0V
* 8cr NOZS6
* @version 0.01 saK;[&I*
* @author cheng (ppoW
*/ ;( KMGir
public class Paginator<E> { WVL#s?=g
privateint count = 0; // 总记录数 J 3?Dj
privateint p = 1; // 页编号 hH4o;0rqJ
privateint num = 20; // 每页的记录数 Sni=gZ K
privateList<E> results = null; // 结果 #3.)H9
*%- ?54B
/** -Ds|qzrN%
* 结果总数 LF=c^9t
*/ wL
eHQ]
publicint getCount(){ LcUlc)YH5
return count; r\mPIr|
} j 2}v}
[yd6gH
publicvoid setCount(int count){ W8/(;K`/
this.count = count; i-13~Dk
} !UNNjBBP7
^8742.
/** ?V+wjw
* 本结果所在的页码,从1开始 P>htQ
* V/H@vKN2
* @return Returns the pageNo. wc[c N+p
*/ T Oy7?;|=
publicint getP(){ 8W{~wg`
return p; G' Hh{_:
} u6_jnZGB
fPE ?hG<x
/**
^CQ1I0
* if(p<=0) p=1 O)5#Fcp(
* ]gP8?s|
* @param p UH40~LxIma
*/ &:8T$UV
publicvoid setP(int p){ ?M"HXu
if(p <= 0) 9t}xXk
p = 1; 8eww7k^R
this.p = p; G2@KI-
} )5i*/I\
p":@>v?
/** )k%M.{&bji
* 每页记录数量 u9}!Gq
*/ \dNhzd#
publicint getNum(){ "t+r+ipf])
return num; N9*UMVU
} cdp{W
w b+<a
/** 8nu> gA
* if(num<1) num=1 @W)/\AZ3
*/ *f*f&l