Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 |On6?5((e
VEn%_9(]
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 SVpe^iQ]1\
!6}Cs3.
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 un/R7"
~cez+VQe
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 .Q#Eb %%
Q2 edS|
。 -yAIrvO1q
W"0 #
分页支持类: _Yhpj}KZ
C/w;g3
java代码: ~Ch`A@=5
{.2C>p
\\T
I4A^#
package com.javaeye.common.util; p$=3&qR 6
FStfGN
import java.util.List; +Q '|->#
L%<1C\k
publicclass PaginationSupport { i a|F
J'7Oxjlg
publicfinalstaticint PAGESIZE = 30; m$ JQ[vgh
V&>7i9lEz
privateint pageSize = PAGESIZE; y^XwJX-f
N7;2BUIXJ
privateList items; M-Js"cB[
Pf!K()<uJ
privateint totalCount; w9oiu$7),
qzLRA.#f^
privateint[] indexes = newint[0]; X}Csl~W8in
byMO&Lb*
privateint startIndex = 0; r9%W?fEBp
_Nj;Ni2rD
public PaginationSupport(List items, int f(C0&"4e
h>n;A>k@N
totalCount){ }Yt0VtLt
setPageSize(PAGESIZE); v3/cNd3
setTotalCount(totalCount); QO
k%Q$^G
setItems(items); B;@yOm=
setStartIndex(0); 5M(?_qj
} FxUH?%w
SAoqq
public PaginationSupport(List items, int B845BSmh
n-\B z.
totalCount, int startIndex){ |fA[s7)
setPageSize(PAGESIZE); MHbRG_zW
setTotalCount(totalCount); x}roPhZ
setItems(items); E*ic9Za8`h
setStartIndex(startIndex); 9-@w(kMu
} _S[H:b$?
tsk}]@W
public PaginationSupport(List items, int QL)UPf>Kp
QA%GK4F70
totalCount, int pageSize, int startIndex){ f;b(W
setPageSize(pageSize); mkWIJH
setTotalCount(totalCount); XI0O^[/n{
setItems(items); U/ZbE?it>
setStartIndex(startIndex); }C'z$i( y
} 4j | vzyc
lDH0bBmd0
publicList getItems(){ h!Ka\By8#
return items; ve.4""\a
} qmK!d<4
l5R H~F
publicvoid setItems(List items){ %'>. R
this.items = items; $a-~ozr`C
} `KL`^UqR
T#( s2
publicint getPageSize(){ S)~h|&A(
return pageSize; =DtM.oQ>
} "qF&%r'
^fx9R5E$:
publicvoid setPageSize(int pageSize){ E`X+fJx
this.pageSize = pageSize; /M#A[tZ3
} '*T7tl
z><JbSE?
publicint getTotalCount(){ E u@TCw8@
return totalCount; >GjaA1,
} hVlL"w*1
_W!g'HP-D
publicvoid setTotalCount(int totalCount){ >Z3}WMgBN
if(totalCount > 0){ fLys$*^)^
this.totalCount = totalCount; $0wl=S
int count = totalCount / KomF)KQ2r
`@`CZg
pageSize; % va/x]K
if(totalCount % pageSize > 0) +EpT)FJX
count++; :+;F" _
indexes = newint[count]; |e9}G,1
for(int i = 0; i < count; i++){ h?TE$&CL?
indexes = pageSize * YZoudX'"
Q!"Li
i; nc3 1X
} :;JJvYIs
}else{ +28FB[W
this.totalCount = 0; <y!BO
} x3vz4m[
} B!Qdf8We
Bb1dH/8
publicint[] getIndexes(){ C[pAa 8
return indexes; #v v
k7
} -_2=NA?t
gy>2=d
publicvoid setIndexes(int[] indexes){ BBp
Hp
this.indexes = indexes; dJ|]W|q<
} Z|7Y1W[
"+rX*~
publicint getStartIndex(){ H,uOshR
return startIndex; O@ "6)/
} aMHIOA%Kh
xF ,J[Aj
publicvoid setStartIndex(int startIndex){ }vm17`Gfy
if(totalCount <= 0) bFTWuM
this.startIndex = 0; N7jAPI@a\i
elseif(startIndex >= totalCount) <:ZN
this.startIndex = indexes zcA"\
B4{A(-Tc
[indexes.length - 1]; ;%%=G;b9
elseif(startIndex < 0) 8RocObY_W
this.startIndex = 0; !|`YNsR
else{ 3)T5}_
this.startIndex = indexes `yVJ `}hm
|d Soq~Vz
[startIndex / pageSize]; >#V8l@IH
} EJ86k>]
} R{*p\;
SQliF[-
publicint getNextIndex(){ (K2 p3M^
int nextIndex = getStartIndex() + #!5GGe{I
."h;H^5
pageSize; B[Tw0rQ
if(nextIndex >= totalCount) mMa7Eyaf
return getStartIndex(); CjO/q)vV
else eDy}_By^
return nextIndex; =|jOio=s:
} *M8 4Dry`y
; id
publicint getPreviousIndex(){ D}_\oE/n
int previousIndex = getStartIndex() - BgE]xm
+}:c+Z<
pageSize; S4tdWA
if(previousIndex < 0) EKDv3aFQZ#
return0; \(Hg_]>m
else tBf u{oC
return previousIndex; [y:6vC
} OCX?U50am
$y`|zK|G-
} #_H=pNWe
20K<}:5t1
H{+U; 6b
NcPzmW{#;g
抽象业务类 "cti(0F-d
java代码: LxG :?=O.
n ,H;PB
N-5lILuJJ
/** ~JBQjb]
* Created on 2005-7-12 v[~ U*#i
*/ wlkS+$<
package com.javaeye.common.business; m2 OP=z@)
Q}1PPi,
import java.io.Serializable; ]zD/W%c
import java.util.List; <;acWT?(
2Gx&ECa,
import org.hibernate.Criteria; #$#{QEh0}
import org.hibernate.HibernateException; mDo]5 i<
import org.hibernate.Session; ?B[Z9Ef"8l
import org.hibernate.criterion.DetachedCriteria; w%L0mH2]ng
import org.hibernate.criterion.Projections; /.}&yRR
import 5#iv[c
2sf/^XC1
org.springframework.orm.hibernate3.HibernateCallback; Ib!`ChZ
import !.F`8OD`u
) .#,1
org.springframework.orm.hibernate3.support.HibernateDaoS (I\aGGW
8mMrGf[Q\
upport; H,?AaM[V
2o{Fp7l
import com.javaeye.common.util.PaginationSupport; IoA"e@~t
ofN|%g /
public abstract class AbstractManager extends AU)Qk$c
4cs`R+]o
HibernateDaoSupport { bluC P|
*X,vu2(I-=
privateboolean cacheQueries = false; fOrqY,P'
n /rQ*hr
privateString queryCacheRegion; mWO=(}Fb\
w8>p[F5`O
publicvoid setCacheQueries(boolean cDLS)
:JPI#zZun
cacheQueries){ dmf~w_(7
this.cacheQueries = cacheQueries; N=|w]t0*yc
} siOeR@>X
`oq
3G }
publicvoid setQueryCacheRegion(String /(vT49(]
x!Wl&
queryCacheRegion){ 5vY1 XZt{
this.queryCacheRegion = ToD_9i
}6
NYzBfL
x
queryCacheRegion; I<+:Ho=6
} d"Zyc(Jk
QUh`kt(E
publicvoid save(finalObject entity){ . lNf.x#u
getHibernateTemplate().save(entity); dfZ`M^NU
} 6)>otB8)J
gP |>gy#e
publicvoid persist(finalObject entity){ Hxleh><c-
getHibernateTemplate().save(entity); Py?Q::
} #q xo1uV(c
vUDMl Z
publicvoid update(finalObject entity){ o7eWL/1
getHibernateTemplate().update(entity); 8Dn~U:F/?
} wz BI<0]z
sa"}9IE*8
publicvoid delete(finalObject entity){ p%K(dA
getHibernateTemplate().delete(entity); w6pXF5ur>
} (A "yE4rYK
QZ*gR#K]Sz
publicObject load(finalClass entity, tf[)| /M
P]armg%
finalSerializable id){ 81w"*G5AM
return getHibernateTemplate().load c%1{l]
;WgUhA
;q
(entity, id); {-%8RSK=<
} z%\&n0
?/myG{E
publicObject get(finalClass entity, 8pZ Ogh
bR8`Y(=F9b
finalSerializable id){ NOKU2d4 G
return getHibernateTemplate().get yqB!0)
<
H8 xhE~'t
(entity, id); 0sTR`Xk
} qdxaP% p2
2u+!7D!w$
publicList findAll(finalClass entity){ Wrh$`JC
return getHibernateTemplate().find("from ?0?3yD-!9
P%N)]b<c*
" + entity.getName()); qB&Je$_uh
} dP`B9>r
sRqecG(n
publicList findByNamedQuery(finalString uL^`uI#I
7!\zo mx
namedQuery){ |=MhI5gsx
return getHibernateTemplate vo%"(!
IDL0!cF
().findByNamedQuery(namedQuery); FZLx.3k4
} c] t@3 m
h_SkX@"/-
publicList findByNamedQuery(finalString query, II!~"-WH
=G"ney2
finalObject parameter){ K9y~
e
return getHibernateTemplate TPak,h(1
ww #kc!'
().findByNamedQuery(query, parameter); 6CSoQ|c{
} 0%4OmLBT
%%zlqd"0
publicList findByNamedQuery(finalString query, e[0"x.gu
`csZ*$7
finalObject[] parameters){ ga(k2Q;y
return getHibernateTemplate *ZxurbX#
}r!hm?e
().findByNamedQuery(query, parameters); 3dSC`K
} _uXb>V*8
J_.cC
publicList find(finalString query){ bdG@%K',
return getHibernateTemplate().find "?<h,Hvi
b6p'%;Y/
(query); ivyaGAF}+o
} _x|.\j
3!vzkBr
publicList find(finalString query, finalObject U4<c![Pp.
L"n)fe$
parameter){ 6U.|0mG[
return getHibernateTemplate().find &/WE{W
~E!kx
(query, parameter); | L1+7
} 5t"FNL
<(M
DfP-(Lm)
public PaginationSupport findPageByCriteria Iy&,1CI"]
WqF$-rBJG^
(final DetachedCriteria detachedCriteria){ =0 !j"z=
return findPageByCriteria RZ;s_16GQ
Poa&htxe1
(detachedCriteria, PaginationSupport.PAGESIZE, 0); py+\e"s
} S(?A3 H
[[zNAq)"
public PaginationSupport findPageByCriteria _SJ:|I
u6Lx3
(final DetachedCriteria detachedCriteria, finalint HD/!J9&
%OHZOs
startIndex){ %.?V\l
return findPageByCriteria
E)ZL+(
/jGV[_Q=P
(detachedCriteria, PaginationSupport.PAGESIZE, >#k-
~|w
^YropzHZ4E
startIndex); &i.sSqSI5
} 7GWOJ^)
7CvBE;i
public PaginationSupport findPageByCriteria TEMxjowr
I.GoY[u_%
(final DetachedCriteria detachedCriteria, finalint x5mg<y2`Ng
nw0#gDI|
pageSize, / of K7/
finalint startIndex){ %yu =,J j
return(PaginationSupport) $Ery&rX.
J9p4\=9
getHibernateTemplate().execute(new HibernateCallback(){ H;l_;c`
publicObject doInHibernate -Ou.C7ol
r$}C<a[U
(Session session)throws HibernateException { m!ueqV"
Criteria criteria = upL3M`
I
"~.p='
detachedCriteria.getExecutableCriteria(session); G3%Ju=
int totalCount = _]pu"hZz4
P(TBFu
((Integer) criteria.setProjection(Projections.rowCount XclTyUGoK+
;}"Eqq:
()).uniqueResult()).intValue(); zdd-n[%@V
criteria.setProjection ,^97Ks
;
0FgF,
(null); ;%B9mM#p~
List items = V?1 $H
1/2cb-V
criteria.setFirstResult(startIndex).setMaxResults ,<r&]
eC
9;?u%
(pageSize).list(); ~"CGur P
PaginationSupport ps = $i5J}
W>)0=8#\
new PaginationSupport(items, totalCount, pageSize, mpMAhm:
%kjG[C
startIndex); !W9:)5^X
return ps; `+"(GaZ
} y{>f^S<
}, true); ?!6Itkg
} @2)nhW/z6
%dFJ'[jDL
public List findAllByCriteria(final Qop,~yK
ABX%oZ7[|o
DetachedCriteria detachedCriteria){ J5I@*f)l
return(List) getHibernateTemplate yy7(')wKO
.t5.(0Xk[A
().execute(new HibernateCallback(){ ;54NQB3L
publicObject doInHibernate e12QYoh
,_I
rE
(Session session)throws HibernateException { I/MY4?(T
Criteria criteria = bYnq,JRA
$2?AJ/2r$b
detachedCriteria.getExecutableCriteria(session); 0!_?\)X
return criteria.list(); #e|o"R;/`
} 2 HEU
}, true); dD=$$(
je
} a3tcLd|7J
89g
a+#7
public int getCountByCriteria(final 7upko9d/
]HuB%G|t1V
DetachedCriteria detachedCriteria){ _9
]:0bDUo
Integer count = (Integer) og5VB
jTvcKm|q
getHibernateTemplate().execute(new HibernateCallback(){ %+N]$Q
publicObject doInHibernate Pc`d]*BYi
<$0is:]
(Session session)throws HibernateException { 4a+gM._+O
Criteria criteria = b-sN#'TDg
Pwl*5/l
detachedCriteria.getExecutableCriteria(session); '|[V}K5m/f
return <m]0!ii
d-D,Gx]>$
criteria.setProjection(Projections.rowCount yx :^*/
fY[Fwjj3
()).uniqueResult(); (?7=,A7^
} ^w60AqR8
}, true); HcsVq+
return count.intValue(); j|k/&q[St
} 1
:p'
} ew~Z/ A
>v.fH6P,}
P1Hab2%+
wtY)(ka
sFTAE1|
tQ|c.`)W
用户在web层构造查询条件detachedCriteria,和可选的 olE(#}7V
u
]e-IYH
startIndex,调用业务bean的相应findByCriteria方法,返回一个 &Q883A
J
w\bwa!3Y
PaginationSupport的实例ps。 Jr2yn{s=S
^v'kEsE^*
ps.getItems()得到已分页好的结果集 -G~]e6:zD
ps.getIndexes()得到分页索引的数组 |Ns4^2
ps.getTotalCount()得到总结果数 a)QT#.
ps.getStartIndex()当前分页索引 1;ttwF>G7
ps.getNextIndex()下一页索引 ^l!SIu
ps.getPreviousIndex()上一页索引 im2mA8OH
eU1F7LS
4v\HaOk
"?NDN4l*
s6,~JF^
WigtTAh4
bC
`<A
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 z1mB Hz6
A@}5'LzL
,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 J\L'HIs
Vp/XVyL}R
一下代码重构了。 i%K6<1R;y{
3^7+fxYWo
我把原本我的做法也提供出来供大家讨论吧: oMQ4q{&|
z1J)./BO
首先,为了实现分页查询,我封装了一个Page类: xE:jcA
d$}
java代码: 1=R$ RI
9zwD%3Ufn
4X+xh|R:U
/*Created on 2005-4-14*/ TEz;:* ,CG
package org.flyware.util.page; atTR6%!6
L 4j#0I]lq
/** "cKD#
* @author Joa 3W?7hh
* 8RMM97@1Q
*/ r3'J{-kl
publicclass Page { v`A)GnNiN
|OH*c3~r
/** imply if the page has previous page */ rmX*s}B
privateboolean hasPrePage; Hd~g\
/mkT7,]
/** imply if the page has next page */ a{kJ`fK
privateboolean hasNextPage; wpK1nA+7N
,1sbY!&ekL
/** the number of every page */ yYP_TuNa
privateint everyPage; D
S U`(`
qLEYBv-3
/** the total page number */ "iSY;y o
privateint totalPage; ^Ps!
FK^xZ?G
/** the number of current page */ FRQ.ix2
privateint currentPage; {-4+=7Sg1
9O;Sn +
/** the begin index of the records by the current L7rgkxI7k*
ZmsYRk~@-
query */ &=[!L0{
privateint beginIndex; @z1QoZ^w
\zBi-GI7
ZNBowZI
/** The default constructor */ `UsJaoR#f
public Page(){ ?Lg<)B9
EF)BezG5y
} "\o#YC
\s)MNs
/** construct the page by everyPage }4C_r'd6
* @param everyPage 1-y8Hy_a2
* */ 6>]_H(z7
public Page(int everyPage){ V4,Gt]4
this.everyPage = everyPage; rfwJLl/
} )\1>)BJq
~B;}jI]d[
/** The whole constructor */ PuNL%D
public Page(boolean hasPrePage, boolean hasNextPage, X:W\EeH
; J W]b]
)E9!m
int everyPage, int totalPage, 2.v{W-D[
int currentPage, int beginIndex){ AU9C#;JD
this.hasPrePage = hasPrePage; JvAXLT
this.hasNextPage = hasNextPage; o +$v0vg%T
this.everyPage = everyPage; )g@+
MR
this.totalPage = totalPage; NY.Cr.}
this.currentPage = currentPage; IBa0O|*6
this.beginIndex = beginIndex; MLd;UHU
} 5M5Bm[X
|S8$NI2
/** :!aLa}`@
* @return ;%n'k
* Returns the beginIndex.
~@'wqGTp
*/ +xYu@r%R
publicint getBeginIndex(){ kY]"3a
return beginIndex; /b,>fK^
} m*y&z'e\
S`s]zdUTP
/** [Mu9"kF
* @param beginIndex :rb;*nY!
* The beginIndex to set. W8& )UtWQ
*/ 01mu6)
publicvoid setBeginIndex(int beginIndex){ 9k6s
this.beginIndex = beginIndex; cO5F=ZxR
} HyzSHI
-Lq+FTezE
/** 7i" b\{5
* @return V(`]hH0;T
* Returns the currentPage. _#{ *I(l
*/ ~R|9|k
publicint getCurrentPage(){ Tt: (l/1
return currentPage; XUP{]w`.Z
} r?DCR\Jq
chICc</l&
/** xNIrmqm5]
* @param currentPage A+l(ew5Lw$
* The currentPage to set. T,!EL+o4
*/ %"{P?V<-V
publicvoid setCurrentPage(int currentPage){ mqZK1<r
this.currentPage = currentPage; hV@ N-u^
} ZUI6VM
qx#M6\L!
/** ;^N
lq3N
* @return `4K|L6
* Returns the everyPage. F~Dof({:
*/ GQ1/pys
publicint getEveryPage(){ $#rkvG_w
return everyPage; qm=U<'b^
} h3`}{
w
,>B11Z}PH
/** Z
)c\B
* @param everyPage |^1g*fy?
* The everyPage to set. fTj@/"a
*/ gXI-{R7Me
publicvoid setEveryPage(int everyPage){ d[6 'w ?
this.everyPage = everyPage; D9+qT<ojN
} WaB0?jI
r)gK5Mv
/** y,:WLk~
* @return icb)JZ1K
* Returns the hasNextPage. 4M&$wi
*/ a#]V|1*O
publicboolean getHasNextPage(){ ~\am%r>
return hasNextPage; CU|E-XPW
} ?>;b,^4
%Yu~56c-
/** "6d0j)YO
* @param hasNextPage 5Y+YN1
* The hasNextPage to set. yy3x]%KK
*/ ;O7"!\
publicvoid setHasNextPage(boolean hasNextPage){ :E-$:\V0}k
this.hasNextPage = hasNextPage; H4ie$/[$8
} $IQPB_:
*6yY>LW
/** /0\g!29l<
* @return +6uf6&.@~
* Returns the hasPrePage. 6:(s8e
*/ o9}\vN0F
publicboolean getHasPrePage(){ {}s/p9F4
return hasPrePage; Al?%[-u
} AE:(:U\
iZG-ca
/** g-K;J4 K%
* @param hasPrePage cg {5\Vl
* The hasPrePage to set. #TNjQNg@O
*/ ?7fqWlB
publicvoid setHasPrePage(boolean hasPrePage){ \:+\H0Bz
this.hasPrePage = hasPrePage; :!_l@ =l
} 8gavcsVE[
0U7Gl9~
/** [~8U],?1
* @return Returns the totalPage. 'd2
:a2C]
* <TVJ9l
*/ KeyKLkg>
publicint getTotalPage(){ U+VJiz<!
return totalPage; wSjy31
} 7eq.UyUxs
Yy
4Was#
/** -rsS_[$2
* @param totalPage jEKa9rt
* The totalPage to set. +PYR
*/ fXevr `
publicvoid setTotalPage(int totalPage){ h`fZ8|yw
this.totalPage = totalPage; 2^s@n3t
} qb nlD\
S?t
`/"O
} vasw@Uto)
_`Kh8G
{e
~b8.]Z^
bY`Chb.
=SJ[)|
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 ,=!s;+lu{
h%:wIkZ/
个PageUtil,负责对Page对象进行构造: a:|]F|
java代码: R(Vd[EGY
_6FDuCVD-
*RkvM?o@jC
/*Created on 2005-4-14*/ ~=wBF
package org.flyware.util.page; Ypm*or
b<fN,U<k
import org.apache.commons.logging.Log; 9F,XjPK=
import org.apache.commons.logging.LogFactory; ed,+Slg
,,XHw;{
/** w;VUP@Wm
* @author Joa f`8fNt
* z=k*D^X
*/ ZbH6$2r
publicclass PageUtil { D622:Y886
0wBr_b!
privatestaticfinal Log logger = LogFactory.getLog ;Xidv9c
,[m4+6G5
(PageUtil.class); 9LQy0Gx
X pXhg*}K
/** j@JY-^~K5
* Use the origin page to create a new page ^(xVjsHp#
* @param page Zf u" 8fX
* @param totalRecords [\HAJA,
* @return r'}#usB(
*/ \@2sI
publicstatic Page createPage(Page page, int ,38bT#p:,r
<.7W:s,f=
totalRecords){ f2|On6/
return createPage(page.getEveryPage(), 4z|Yfvq
7Ph+Vs+h
page.getCurrentPage(), totalRecords); `Geq,
} d\z':d.Tt
B7ys`eiB5C
/** HSl$ U0
* the basic page utils not including exception ]*S_fme
uuhvd h=
handler F0NNS!WP7^
* @param everyPage DA4!-\bt@
* @param currentPage `~t$k7wm=
* @param totalRecords N~arxe(K
* @return page ,KibP_<%&P
*/ 7L:R&W6
publicstatic Page createPage(int everyPage, int
qf]OSd
`|JQ)!Agx
currentPage, int totalRecords){ OaxE3bDT
everyPage = getEveryPage(everyPage); gk6j5 $Y"<
currentPage = getCurrentPage(currentPage); ^?[^o\/@R
int beginIndex = getBeginIndex(everyPage, Z42v@?R.!W
y+iuA@WCv
currentPage); 0H.B>:pv
int totalPage = getTotalPage(everyPage, kqAQrg]n
c9E9Rx
totalRecords); T{K+1SPy4
boolean hasNextPage = hasNextPage(currentPage, =09j1:''<d
*DoEDw
totalPage); ~h[lu^ZSi
boolean hasPrePage = hasPrePage(currentPage); G@Zi3 5
S+OI?QS
returnnew Page(hasPrePage, hasNextPage, Zr2QeLQC(
everyPage, totalPage, FkECY
currentPage, B
9]sSx
u&I~%s
beginIndex); ~(0Y`+gC
} j'0*|f ^z
/0YNB)
privatestaticint getEveryPage(int everyPage){ vDOeBw=
return everyPage == 0 ? 10 : everyPage; v:T` D
} 8UL:C?eY
B&Ci*#e
privatestaticint getCurrentPage(int currentPage){ 8QZk0O
return currentPage == 0 ? 1 : currentPage; z06pX$Q.<
} "AVj]jR
k~?}z.g(
privatestaticint getBeginIndex(int everyPage, int v <Ze$^e&
)J88gMk+
currentPage){ RBgkC+2
return(currentPage - 1) * everyPage; B
9Mwj:)}
} $kz5)vj "
~O
6~',KD
privatestaticint getTotalPage(int everyPage, int K6oXnz}
@x J^JcE
totalRecords){ !V-SV`+X
int totalPage = 0; y<.!TULa_
qK1V!a2
if(totalRecords % everyPage == 0) >a-+7{};
totalPage = totalRecords / everyPage; /7"1\s0 U
else |95/'a*
totalPage = totalRecords / everyPage + 1 ; `oz7Q(`
6$dm-BI
return totalPage; $-AvH(@
} >`\*{]
OB^2NL~Q~
privatestaticboolean hasPrePage(int currentPage){ *wF:Q;_<z
return currentPage == 1 ? false : true; m[7:p{
} h'fD3Gr&
Sf'5/9<DW+
privatestaticboolean hasNextPage(int currentPage, w+$gY?%
q(p0#Mk,E
int totalPage){ M2EN(Y_k0
return currentPage == totalPage || totalPage == ?Ru`ma\;
^{K8uN7
0 ? false : true; qL+y8*
} (Mm{"J3uv
A7RX2
c _a$g
} +l/j6)O`(m
S'JeA>L
lqCn5|S]
g^4FzJ
=U2Te
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 .}<B*e=y
_~(Xd@c(
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 :{
T#M$T
3ElpS^2W
做法如下: l=]vC +mU
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 XZ&v3ul
hw'2q9J|
的信息,和一个结果集List:
E$>e<
T
java代码: {G0)mp,
bg*{1^
(}}8DB
/*Created on 2005-6-13*/ RZtL<2.@
package com.adt.bo; uY~A0I5Z
ck~xj0
import java.util.List; `s_TY%&_}g
QMxz@HGa|
import org.flyware.util.page.Page; a*[\edcHU
ed*AU,^@v
/** X[~CLKH(
* @author Joa ZtLn*M
*/ ?.4l1X6Ba
publicclass Result { ibc/x v2
Xh/av[Q
private Page page; ,6S8s
Wu&Di8GhP
private List content; M<srJ8|'
w1_Ux<RF
/** K)@}Ok"#\4
* The default constructor WLl9>v^1
*/ j1kc&(
public Result(){ RHbp:Mlk
super(); R*0F)M
} 6v#G'M#r
!v L:P2
/** KxwLKaImI
* The constructor using fields n_Y]iAoc`
* (Qm;]?/
* @param page UG_0Y8$
* @param content k >CtWV5B
*/ sD3|Qj;
public Result(Page page, List content){ xH[yIfHkG@
this.page = page; e"6i>w!
this.content = content; 3T/j5m}+!
} $IT9@}*{
wcf_5T
/** ACYn87tq
* @return Returns the content. ;alFK*K6
*/ 3pW
MS&
publicList getContent(){ AZy2Pu56
return content; []0~9,u
} :a@z53X@M
$SVGpEw
/** )+,jal^7
* @return Returns the page. .A/H+.H;
*/ }2,#[mM
public Page getPage(){ 6S[D"Q94
return page; PWu2;JF
} gu[dw3L
hY 2PV7"[;
/**
]:fCyIE
* @param content & }}WP:U
* The content to set. lh_zZ!)g
*/ ?\M6P?tpo&
public void setContent(List content){ zpqNmxmF
this.content = content; # :w2Hf6Q
} J6ShIPc
A_~5|
/** 9nS!
* @param page %:?QE
;
* The page to set. xN8JrZE&
*/ p\;)^O4
publicvoid setPage(Page page){ ~J{[]wi
this.page = page; WUS9zK
} X$iJ|=vW
} Wb)l8[=
;w(1Ydo
zxUj1
=>\-ma+
/+`<X%^U
2. 编写业务逻辑接口,并实现它(UserManager, {taVAcb
8G] m7Z
UserManagerImpl) GTe:k
java代码: ca*[n~np
yGGB
p3FnYz-V
/*Created on 2005-7-15*/ vcO`j<`
package com.adt.service; bXwoJ2
.r5oN +?e
import net.sf.hibernate.HibernateException; .4FcZJvy
XuoEAu8]
import org.flyware.util.page.Page; kseJm+Hc
_I-VWDCk
import com.adt.bo.Result; \nAHpF
2U`W[
/** _JTxm>
* @author Joa uo'31V0
*/ S5u#g`I]
publicinterface UserManager { poYAiq_3T
<Iyot]E
public Result listUser(Page page)throws DbU;jorwu
'F"Y?y:!
HibernateException; RrdtU7i3
L"!ZY
} ~!:S p_y
JOx,19r
t{8v(}
'Rd*X6dv
@@3,+7%1
java代码: w1@b5-
s~X*U&}5
O& %"F8B
/*Created on 2005-7-15*/ pNE\@U|4E
package com.adt.service.impl; _c
]3nzIr
66@3$P%1p
import java.util.List; s7nX\:Bw:
9me}&Fdr
import net.sf.hibernate.HibernateException; 1~5q:X
H4'DL'83
import org.flyware.util.page.Page; ''OInfd?
import org.flyware.util.page.PageUtil; wYO"znd
tK|9qs<%
import com.adt.bo.Result; t)gi.Ed1"L
import com.adt.dao.UserDAO; yC 7Vb
P
import com.adt.exception.ObjectNotFoundException; QK!:q{
import com.adt.service.UserManager; lAn+gDP
Q|=
Q]$d
/** G9n /S=R?
* @author Joa =PFR{=F
*/ !\#Wk0Ku
publicclass UserManagerImpl implements UserManager { %:w% o$
"4ozlWx
private UserDAO userDAO; s w.AfRQP
EhIV(q9x
/** seuN,jpt
* @param userDAO The userDAO to set. ]r6BLZ[ %
*/ leES YSY:
publicvoid setUserDAO(UserDAO userDAO){ ke9QT#~p!-
this.userDAO = userDAO; Fb|e]?w
} :x""E5H
x #tu
/* (non-Javadoc) V(2j*2R!
* @see com.adt.service.UserManager#listUser 8S1P&+iKs
%bXx!x8(
(org.flyware.util.page.Page) <c[U#KrvJ
*/ j'%4{n
public Result listUser(Page page)throws iItcN;;7
5}ie]/[|
HibernateException, ObjectNotFoundException { *TW=/+j
int totalRecords = userDAO.getUserCount(); KP;(Q+qTx
if(totalRecords == 0) U09.Y
throw new ObjectNotFoundException q=HHNjj8
+H/jK @
("userNotExist"); 7"X>?@
page = PageUtil.createPage(page, totalRecords); wJb#g0
List users = userDAO.getUserByPage(page); 2Tav;LKX
returnnew Result(page, users); pVp:@0h
} \h<BDk*
89}Y5#W
}
gE/Tj$
]-o"}"3Ef
eg+!*>GaX
"ceed)(:
Yx'res4e
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 _GQz!YA
jo+w>
询,接下来编写UserDAO的代码: | aQ"3d
3. UserDAO 和 UserDAOImpl: EUYCcL'G
java代码: 1xJ
TWWj-
GnXNCeE`
W|k0R4K]]
/*Created on 2005-7-15*/ ~%u|[$
package com.adt.dao; 6~:Sgt nU
`[#x_<\t
import java.util.List; ({0)@+V8
v<\A%
import org.flyware.util.page.Page; " }gVAAvc7
q}uHFp/J
import net.sf.hibernate.HibernateException; W_O)~u8
6!iJ;1PeE
/** C8N{l:1f]
* @author Joa uNbH\qd=
*/ C.:=lo B
publicinterface UserDAO extends BaseDAO { NBh%:tu7M
u.pxz8
publicList getUserByName(String name)throws SxgYjIa-
I7 QCYB|
HibernateException; h<l1]h+x
/NT[ETMk+
publicint getUserCount()throws HibernateException; @(``:)Z<b
s}&bJ"!Z
publicList getUserByPage(Page page)throws RIM`omM
"yziXT@V
HibernateException; Thy=yz;p
$DFv30 f
} QlFZO4 P3|
+YOKA*
qJ!Z~-hS
39U5jj7i
!2CL1j0(
java代码: Mkp/0|Q*
k?BJdg)xJ
xieP "6
/*Created on 2005-7-15*/ OkAK
package com.adt.dao.impl; iVtl72O
2s*#u<I
import java.util.List; ~pk(L[G
I|oT0y&
import org.flyware.util.page.Page; 31^cz*V
<q)4la
import net.sf.hibernate.HibernateException; 6Q4X6U:WB
import net.sf.hibernate.Query; L(;WxHL
,iNv'
import com.adt.dao.UserDAO; JN/UUfj
?q`0ZuAg\<
/** c;f!!3&
* @author Joa Z!d7&T}
*/ =+5,B\~q@C
public class UserDAOImpl extends BaseDAOHibernateImpl ,?UM;^
MOn,Db$
implements UserDAO { A% Q!^d
(9\;A*CZ
/* (non-Javadoc) 6q<YJ.,
* @see com.adt.dao.UserDAO#getUserByName yAT^VRbv
GJi~y
(java.lang.String) 05Fz@31~
*/ 148V2H)
publicList getUserByName(String name)throws ?[TfpAtQ`
dCYCHHHF
HibernateException { Zt
-1h{7
String querySentence = "FROM user in class $lIWd
idc`p?XP
com.adt.po.User WHERE user.name=:name"; _Jz8{` "
Query query = getSession().createQuery aeyNdMk-
D'<VYl"/
(querySentence); l@j.hTO<
query.setParameter("name", name); EqiFy"H
return query.list(); O-vGyNxP|
} sML=5=otx
,ea^,H6
/* (non-Javadoc) u*S=[dq
* @see com.adt.dao.UserDAO#getUserCount() qIUfPA=/_
*/ %A1@&xrbl
publicint getUserCount()throws HibernateException { R;whW:Tx
int count = 0; ))D:8l@
String querySentence = "SELECT count(*) FROM !"Yj|Nu6
|!|^ v
user in class com.adt.po.User"; ! hd</_#
Query query = getSession().createQuery s1Ok|31|
DF]9@{
(querySentence); E"iUq
count = ((Integer)query.iterate().next SEwku}
2Q7R6*<N:
()).intValue(); ^{$FI`P
return count; F+ <Z<q
} ] H~4
b2(RpY2Y
/* (non-Javadoc) a?}
.Fs
* @see com.adt.dao.UserDAO#getUserByPage zIC;7 5#
E9\vA*a
(org.flyware.util.page.Page) '# NcZy
*/ _CBWb
publicList getUserByPage(Page page)throws ;a=w5,h:
?PA$Ur21lw
HibernateException { _!;Me
)C
String querySentence = "FROM user in class 1 Q;}zHd
U/ V
com.adt.po.User"; {%)s.5Pfw
Query query = getSession().createQuery 'crlA~/
c5q9LQ/
(querySentence); "]'?a$\ky:
query.setFirstResult(page.getBeginIndex()) yw[ #
.setMaxResults(page.getEveryPage()); !?f5>Bl
return query.list(); _EnwME{@
} C$Lu]pIL*
r0t^g9K0
} #
?1Sm/5k`
[P zv4+
}<@j'Ok}.
uJx"W
yNW\?Z$@q
至此,一个完整的分页程序完成。前台的只需要调用 uY_SU-v
m p<1yY]
userManager.listUser(page)即可得到一个Page对象和结果集对象 &wd;EGGT!q
"q}FPJ^l_N
的综合体,而传入的参数page对象则可以由前台传入,如果用 bawJ$_O_
"xcX'F^
webwork,甚至可以直接在配置文件中指定。
N#V.1<Y
m^' uipa\
下面给出一个webwork调用示例: h'J|K^na
java代码: !f>d_RG
Y^Nuz/
]3ONFa
/*Created on 2005-6-17*/ r`&-9"+
package com.adt.action.user; ?1L.:CS
[=O/1T
import java.util.List; )}Q(Tl\$
HCK|~k
import org.apache.commons.logging.Log; n%h^o
import org.apache.commons.logging.LogFactory; V$0dtvGvH
import org.flyware.util.page.Page; I`[i;U{CK
i|
\6JpNA:
import com.adt.bo.Result; IJTtqo
import com.adt.service.UserService; Qjx?ri//
import com.opensymphony.xwork.Action; s?8<50s
9[!,c`pw
/** u&G.4QQF
* @author Joa Vc^HVyAx@n
*/ _0+0#! J!
publicclass ListUser implementsAction{ 6s,uXn
^@P1
JNe
privatestaticfinal Log logger = LogFactory.getLog I8oo~2Qw
a`Gx=8
(ListUser.class); 8eA+d5k\.
umz;F
private UserService userService; xw{-9k-~
A5,t+8`aci
private Page page; *5tO0_L
\txbhWN
privateList users; jq'!UN{
HW&%T7
a
/* &DqE{bBd!
* (non-Javadoc) pEECHk
* (R`B'OtGg
* @see com.opensymphony.xwork.Action#execute() r&-m=Kk$
*/ 9a'-Y
publicString execute()throwsException{ Uax+dl
Result result = userService.listUser(page); TJE\A)|>g
page = result.getPage(); 6y%0`!
users = result.getContent(); !+u"3;%h
return SUCCESS; Gm*X'[\DD
} 1[_mEtM:]B
w\)|
/** oJ#,XMKga
* @return Returns the page. at2FmBdu C
*/ :Xc@3gF
public Page getPage(){ O1')nYF7
return page; tx?dIy;
} CctJFcEZ
kw2T>
/** G0E121`h
* @return Returns the users. c1X1+b,
*/ $mF_,|
publicList getUsers(){ t6v/sZ{F
return users; `3p~m,
} c8Z wr]DF
1+?^0%AC
/** z;@*r}H
* @param page 9Fn\FYUq
* The page to set. ;#w3{
NB
*/ V I%
6.6D
publicvoid setPage(Page page){ U]a*uF~h
this.page = page; vn/.}GkpU
} H@]MXP[_
mf'V)
/** /VG2.:
* @param users A'P(a`
* The users to set. Fl(T\-Eu
*/ -G6U$
publicvoid setUsers(List users){ Ty88}V
this.users = users; Z`YJBcXR
} }i!J/tJ)b
Z|}G6]h
/** UA|u U5Q
* @param userService 1}~(Yj@f%
* The userService to set. 4Qn$9D+?
*/ K98i[,rP
publicvoid setUserService(UserService userService){ YKQr,
Now
this.userService = userService; A$6$,h
} \d::l{VB
} @JdZ5Q
Haqm^Ky$
>:lnt /N3
hB{jUP)";
^pHq66d%Z
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, },|M9I0
H#ClIh?'b
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 #m={yck *
T0]MuIJ).
么只需要: _V`DWR
*
java代码: JU&+c6>
vm>b m
# W"=ry3{
<?xml version="1.0"?> ?6'rBH/w
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork rj!0GI
#c2ymQm
1.0//EN" "http://www.opensymphony.com/xwork/xwork- R:B^
qe5feky
1.0.dtd"> J=/5}u_gw
*2jK#9"MP
<xwork> r&FDEBh
Yw0[[N<SW
<package name="user" extends="webwork- Ewg:HX7<(
R##~*>#
interceptors"> 4[N^>qt =
y!xE<S&Y
<!-- The default interceptor stack name W^"AU;^V56
JchSMc.9
--> 0wS+++n$5
<default-interceptor-ref Y".RPiTL
* RtgC/
name="myDefaultWebStack"/> Q|@4bz i)
av~5l4YL
<action name="listUser" .ji_nZ4.+
Ha)ANAD
class="com.adt.action.user.ListUser"> :,)lm.}]t
<param <F04GO\
"jw<V,,
name="page.everyPage">10</param> T1H"\+
<result OrK&RC
)m. 4i =X
name="success">/user/user_list.jsp</result> 7B?c{
</action> Pi|o` d
=9T$Gr
</package> 64
5z#_}C$
8U_{|]M
</xwork> W6Y@U$P#G
M9f35
:
Dwzg/F(
yq$,,#XDD=
tor!Dl@Mo
aM;W$1h
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 ]LM-@G+Jz
#Skv(IL
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。 M'/aZ#
b
{26ONa#i
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 bcupo:N
n93=8;&
8,uB8C9
TjG4`:*y#m
aFLO{t r`
我写的一个用于分页的类,用了泛型了,hoho HJY2#lSha6
CJhL)0Cs
java代码: `He,p -
$cZUM}@
(P`3 @H
package com.intokr.util; \J6j38D5
@$z<i `4
import java.util.List; e>AE8T
{`w;39$+
/** t2"FXTAq
* 用于分页的类<br> y a_<^O
9
* 可以用于传递查询的结果也可以用于传送查询的参数<br> nqf,4MR
* Ox@P6|m
* @version 0.01 >
%KuNy{
* @author cheng +}a ]GTBgA
*/ {*ob_oc
public class Paginator<E> { znHnVYll(
privateint count = 0; // 总记录数 y.q(vzg\_
privateint p = 1; // 页编号 x+]\1p
privateint num = 20; // 每页的记录数 s8h-,@p
privateList<E> results = null; // 结果 )K2HK&t:
&
j+oJasI
/** M8TSt\
* 结果总数 -neKuj
*/ 95V@X
^Ee
publicint getCount(){ Zcc9e03
return count; `Ry]y"K
} LupkrxV
:Q@&5!]>d
publicvoid setCount(int count){ +k>.Q0n%m
this.count = count; 5v6Eii:
} &ZQJ>#~j^
&:7ZQ1
/** k%G1i-]4
* 本结果所在的页码,从1开始 o-Ga3i 8
* ZR'H\Z
* @return Returns the pageNo. i _%Q`i
*/ s@7H1)U
publicint getP(){ RG4 sQ0
return p; /7YF mI/0
} YSe.t_K2C
9tqF8pb7v
/** _x5 3g
A
* if(p<=0) p=1 tq|hPd<C
* @i*|s~15
* @param p 7!N2-6GV
*/ mtjh`
publicvoid setP(int p){ FeTL&$O
if(p <= 0) f1(+
bE%
p = 1; D~\$~&_]=
this.p = p; c[ ]4n
} QMpoa5ZQG
3F<VH
/** @W9x$
* 每页记录数量 s4uhsJL V$
*/ k{Aj^O3gD
publicint getNum(){ icgSe:Ci
return num; mOlI#5H
} ze]h..,]K
*VZ5B<Ic
/** r#B+(X7LM
* if(num<1) num=1 "^]cQ"A
*/ r#Oo
nZ
publicvoid setNum(int num){ _Wa.JUbv
if(num < 1) (/j); oSK
num = 1; W!&vul5
this.num = num; qC?:*CXH
} b 'pOJS
GF^071]G
/** 6}oXP_0U
* 获得总页数 ,9o"43D:a|
*/ dB5b@9*
publicint getPageNum(){ >#y^;/bb
return(count - 1) / num + 1; bAm(8nT7w
} EB8\_]6XJ
;y2/-tL?
/** d:U9pC$
* 获得本页的开始编号,为 (p-1)*num+1 [`):s= FC
*/ #gcF"L||
publicint getStart(){ .8G@%p{,
return(p - 1) * num + 1; _Iv6pNd/
} %$Aqle[
heK7pH7;d
/** n;T7= 1_"
* @return Returns the results. UZpIcj cL
*/ <N9[?g)
publicList<E> getResults(){ 5x>}O3Q_
return results; UTH_^HAN#G
} Sh8"F@P8
"
_ka<R..
public void setResults(List<E> results){ ;hjwD
this.results = results; CtS l
} \0f{S40
W0]gLw9*
public String toString(){ 5qP:/*+
StringBuilder buff = new StringBuilder %GS(:]{n
#: [<iSk
(); Ch3jxgQY
buff.append("{"); 9
o&`5
buff.append("count:").append(count); 6gs01c,BA
buff.append(",p:").append(p); #Q`dku%V:
buff.append(",nump:").append(num); >b{q.
buff.append(",results:").append %eO0wa$a
]3l 9:|
(results); iB& 4>+N+
buff.append("}"); j_.5r&w
return buff.toString(); t8+X%-r
} u!W0P6
t?'!$6
} ~S7D>D3S
aiu5}%U
ftF@Wq1f