Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 sQ340!
5q*s_acQ
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 I5q$QQK
Pc*lHoVL
据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 ;-8.~Sm
^utOVi
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 VsJ+-IHm
{?`7D:]`^
。 v@|<.
1&! i:F#
分页支持类: J}&U[ds p
n<bU' n
java代码: {ibu0
41Z@_J|&
FJDC^@ Ne
package com.javaeye.common.util; iMJt8sd
iphC\*F
import java.util.List; j&,Gv@
kBhjqI*
publicclass PaginationSupport { triU^uvh
#%Bt!#
publicfinalstaticint PAGESIZE = 30; }< H> 9iJ:
>STthPO
privateint pageSize = PAGESIZE; &muBSQ-
!DzeJWM|
privateList items; wv\K
9:4S[mz/hD
privateint totalCount; 3s/1\m%
ns%gb!FBJX
privateint[] indexes = newint[0]; !Z tqh Xr
{o5|(^l
privateint startIndex = 0; *0xL(
l<w7
\a6
public PaginationSupport(List items, int 'KA$^
KR#,6
totalCount){ !nSa4U,$w<
setPageSize(PAGESIZE); w[
v{)
setTotalCount(totalCount); ]B,tCBt
setItems(items); A|8"}Hm
setStartIndex(0); oh< -&3Jn
} {ogBoDS
GMJ4v S
public PaginationSupport(List items, int wHbkF#[:i
WVRIq'
totalCount, int startIndex){ llP
V{
setPageSize(PAGESIZE); ?{qUn8f2
setTotalCount(totalCount); YK6LJv}
setItems(items); (M$0'BV0
setStartIndex(startIndex); 4W"A*A
} KM wV;r
BQ0?B*yqd
public PaginationSupport(List items, int QcL@3QC
?YW~7zG
totalCount, int pageSize, int startIndex){ `.MZ,Xhqi"
setPageSize(pageSize); bFX{|&tHU
setTotalCount(totalCount); Cq!eAc
setItems(items); `-uE(qp
setStartIndex(startIndex); #"4ioTL2
} !G-+O#W`
D6Ad"|Z
publicList getItems(){ k`m7j[A]l
return items; p-}X=O$
} mcV<)UA}
Ei_~K';
publicvoid setItems(List items){ Ma|4nLC}
this.items = items; D`JBK?~
} ?gMx
}n==^2
publicint getPageSize(){ :cC$1zv@
return pageSize; ==[=Da~
} n{;Q"\*Sg
pJ]
Ix *M
publicvoid setPageSize(int pageSize){ 8:{id>Mm^
this.pageSize = pageSize; =IC.FT}
} ELCNf
o^@"eG$,
publicint getTotalCount(){ <IZt]P
return totalCount; XYo,5-
} n)kbQ]
1(o\GI3:
publicvoid setTotalCount(int totalCount){ 6j(/uF4!#
if(totalCount > 0){ Dx-P]j)4x
this.totalCount = totalCount; ">bhxXeiN
int count = totalCount / X`D2w:
XZIapT
pageSize; v1:.t
if(totalCount % pageSize > 0) ""-wM~^D
count++; FW |&
iS$
indexes = newint[count]; 3IMvtg
for(int i = 0; i < count; i++){ )aIcA
indexes = pageSize * ^o3,YH
|qw0:c=7!
i; ~*iF`T6
} Bg~]u+c*
}else{ ^#:;6^Su
this.totalCount = 0; \(Sly&gL
} 8TP$ ?8l
} )s
$]+HQs
:lB*km g
publicint[] getIndexes(){ D^6*Cwb
return indexes; ~ n]5iGz
} cZh0\DyU
9z#8K
zXg
publicvoid setIndexes(int[] indexes){ -8n1y[
this.indexes = indexes; fUjo',<s
} nONuw;K
Q VTL}AT2:
publicint getStartIndex(){ Z Ts*Y,
return startIndex; >-MnB
} ;\RVC7
<[db)r~c
publicvoid setStartIndex(int startIndex){ kOQ)QX
if(totalCount <= 0) s/"bH3Ob9v
this.startIndex = 0; U<j5s\Y,
elseif(startIndex >= totalCount) z0}j7ns]
this.startIndex = indexes P)Adb~r
{W,5]-
[indexes.length - 1]; 9\_s&p=:.
elseif(startIndex < 0) <<
6GE
this.startIndex = 0; =2p?_.|'
else{ c]9gf\WW
this.startIndex = indexes O=o}uB-*6
ahl|N`
[startIndex / pageSize]; eft=k}
} f-F=!^.
} F1yn@a "=J
2w.FC
publicint getNextIndex(){ 8T3,56>
int nextIndex = getStartIndex() + WzzA:X
~wa4kS<>
pageSize; 1ubu~6
if(nextIndex >= totalCount) d7V/#34
return getStartIndex(); QEJu.o
else jW:7PS
return nextIndex; NljpkeX'
} #z(:n5$F
]KFh 1
publicint getPreviousIndex(){ rp@:i _]
int previousIndex = getStartIndex() - #&|"t<}
Dge#e
pageSize; (@^9oN~}
if(previousIndex < 0) \g34YY^L3
return0; +
f6LG 0q
else p cLKE
ZK
return previousIndex; $>/d)o
} L~&S<5?
1clzDwW
} Mk*4J]PP
q2%cLbI
F
d*6f,z2=
,buX|
抽象业务类 b~.$1oZ
java代码: LDg9@esi
2O kID
WcM
!td!">r46e
/** V6merT79
* Created on 2005-7-12 V[.{cY?6
*/ *B&P[n
package com.javaeye.common.business; vC,FE
)'
4u5j
7`O
import java.io.Serializable; F+*E}QpM
import java.util.List; oRbWqN`F.
+`F(wk["m
import org.hibernate.Criteria; [4yHXZxza
import org.hibernate.HibernateException; DGJ:#UE
import org.hibernate.Session; ?^|[Yzk
import org.hibernate.criterion.DetachedCriteria; I[%IW4jJ
import org.hibernate.criterion.Projections; 8>x5|
import G!FdTvx$
va@;V+cD
org.springframework.orm.hibernate3.HibernateCallback; 9'(_*KSH
import ho>@ $9
xI<l1@
org.springframework.orm.hibernate3.support.HibernateDaoS />xEpR3_A
Apu-9|oP
upport; 8g=O0Gb
C6gSj1
import com.javaeye.common.util.PaginationSupport; +vZYuEq_
t M5(&cQ!d
public abstract class AbstractManager extends GIlaJ!/
)nHMXZ>Td
HibernateDaoSupport { }e7/F[c.U
7Ydqg&
privateboolean cacheQueries = false; ?Z|y-4 &>
pKLcg"{[F
privateString queryCacheRegion; ^fKKsfIf
D0#U*tq;
publicvoid setCacheQueries(boolean ZvuY]=^3
ky !ZJR
cacheQueries){ xDe^>(,"
this.cacheQueries = cacheQueries; p cD}SY
} y6am(ugE
Gh_5$@ hF
publicvoid setQueryCacheRegion(String !o|
ex+z;
kYS#P(1
queryCacheRegion){ x6>WvFZ
this.queryCacheRegion = g,E)F90
K;/f?3q
queryCacheRegion; Cdl"TZ<
} 4=q4_ \_T
oi Q3E
publicvoid save(finalObject entity){ >$}Mr%49
getHibernateTemplate().save(entity); SMvlEj^
} ]UOzz1
Wr Wz+5M8
publicvoid persist(finalObject entity){ g?1bEOA!
getHibernateTemplate().save(entity); 1q'_J?Xmd
} LZ#A`&qUd
uYTyR;a
publicvoid update(finalObject entity){ Iv7BIK^0
getHibernateTemplate().update(entity); >CCy2W^W
} Q]/g=Nn
^~
b0f6?s
publicvoid delete(finalObject entity){ j; /@A
lZl
getHibernateTemplate().delete(entity); ^N}{M$
} t":^:i'M
(N}\Wft%
publicObject load(finalClass entity, 2wU,k(F_
R
"W=V
finalSerializable id){ {w>ofyqfp&
return getHibernateTemplate().load E#w2'(t
U&kdR+dB
(entity, id); g7%vI8Y)@
} )$Fw<;4
^CwS'/fdN
publicObject get(finalClass entity, `5t~
Vlp
<y-2ovw*
finalSerializable id){ %|}7YH41
return getHibernateTemplate().get MMRO@MdfV
w4y???90)
(entity, id); I~
SFY>s
} :)_P7k`>e/
c1%ki%J#
publicList findAll(finalClass entity){ VjSbx'i
return getHibernateTemplate().find("from d#,
78z/D|{"
" + entity.getName()); 2\}6b4
} p'SY 2xq-,
NLWj5K)1P
publicList findByNamedQuery(finalString kJXy)
#|xj*+)H
namedQuery){ %gEfG#S
return getHibernateTemplate nRZ T~S4
ctC!b{S"@
().findByNamedQuery(namedQuery); {-c[w&q
} j|% C?N
.9bP8u2B{
publicList findByNamedQuery(finalString query, ZONe}tv:
Xo4K!U>TzZ
finalObject parameter){ =dC5q{
return getHibernateTemplate %}~Ncn_r
`WU"*HqW
().findByNamedQuery(query, parameter); W$Z""
} n;dp%SD
@h\u}Ee
publicList findByNamedQuery(finalString query, -,xsUw4
Y'LIk Q\
finalObject[] parameters){ $VE =sS.
return getHibernateTemplate 7+p=4i^@Zs
Z"<tEOs/En
().findByNamedQuery(query, parameters); c/}bx52>u
} _q\w9gN
;fDs9=3#
publicList find(finalString query){ 0jwex
return getHibernateTemplate().find hz+x)M`Y
#`2*V
(query); [318Q%W&
} bxg9T(Bj
l7JY`x
publicList find(finalString query, finalObject &mvC<_1n
RnkrI~x
parameter){ kO\aNtK
return getHibernateTemplate().find *XlnEHv
D7x"P-ie
(query, parameter); q>ps99[=
} "(d7:!%
S-6%mYf
public PaginationSupport findPageByCriteria DbkKmv&
Hlq#X:DCn
(final DetachedCriteria detachedCriteria){ '`Z5.<n7p
return findPageByCriteria f~? MNJ2
rt\4We,7
(detachedCriteria, PaginationSupport.PAGESIZE, 0); m;nT ?kv
} {)0"?$C_H
*<_8]C0>
public PaginationSupport findPageByCriteria sk_Q\0a
+O@0gl
(final DetachedCriteria detachedCriteria, finalint x,
^j=n
(-(sBQ a+
startIndex){ 8FThu[
return findPageByCriteria poYO
]MP6VT
(detachedCriteria, PaginationSupport.PAGESIZE, x-/ `c
%9A6c(L
startIndex); #}W^d^-5t5
} W`^Zb[
Z;QbqMj
public PaginationSupport findPageByCriteria
um[nz
*.J)7~(P
(final DetachedCriteria detachedCriteria, finalint >\ :kP>U
+idj,J|
pageSize, y-93 >Y
finalint startIndex){ yb#NB)+E@
return(PaginationSupport) O&?i8XsB
qqSf17sW
getHibernateTemplate().execute(new HibernateCallback(){ 4cni_m]
publicObject doInHibernate iy{*w&p
q]Cmaf (
(Session session)throws HibernateException { 7N/v
Criteria criteria = Ii/#cdgF
~g+?]Lk}
detachedCriteria.getExecutableCriteria(session); MGd 7Ont
int totalCount = lmZSsx
#AzZ4<;7
((Integer) criteria.setProjection(Projections.rowCount R*D0A@
|*Dklo9{
()).uniqueResult()).intValue(); \4`~J@5Y
criteria.setProjection MkG3TODfHB
Yqy7__vm
(null); 3EN?{T<yf
List items = hGx)X64Mw
A7|!&fi
criteria.setFirstResult(startIndex).setMaxResults p*8LS7UT
vcnUb$%
(pageSize).list(); w^?uBeqR
PaginationSupport ps = mVN^X/L(y
xZ }1dq8
new PaginationSupport(items, totalCount, pageSize, ika/ GG
J)iy6{0"
startIndex); Rdd[b?
return ps; e.%`
tK3J
} F7wpGtt
}, true); vd>X4e^j
} JB~79Lsdz
FV>LD% uu
public List findAllByCriteria(final xJ)hGPrAl
Iq`:h&'!L
DetachedCriteria detachedCriteria){ ;#G)([
return(List) getHibernateTemplate o/bmS57
=#||&1U$
().execute(new HibernateCallback(){ JJ5s
|&}
publicObject doInHibernate 8r7~ >p~
\J r ta
(Session session)throws HibernateException { BD+V{x}P
Criteria criteria = ,rT62w*e
7KOM,FWKe
detachedCriteria.getExecutableCriteria(session); e#MEDjm/)g
return criteria.list(); YoV^Y&:9<
} c0.i
}, true); Ly1V@
} s+;J`_M
`x2Q:&.H`
public int getCountByCriteria(final %y{#fZHc
Sdl1k+u
DetachedCriteria detachedCriteria){ s*.CJ
Integer count = (Integer) [hE0 9W
7yGc@kJ?
getHibernateTemplate().execute(new HibernateCallback(){ hm"i\JZ3N
publicObject doInHibernate u/3[6MIp
1@*qz\ YY
(Session session)throws HibernateException { kXGJZ$
Criteria criteria = 'xi[- -
@~v|t{G
detachedCriteria.getExecutableCriteria(session); `,XCD-R^
return #?/&H;n_8S
EY=`/~|c
criteria.setProjection(Projections.rowCount #jAlmxN
e|)6zh<O:
()).uniqueResult(); X_yAx)Do
} $Fx:w
}, true); \~|+*^e)
return count.intValue(); :td#zM
} by z2u
} ))Ws{
xxWrSl`fB
%$K2$dq5
n#,<-Rb-
3T)GUzt`
o RT<h
用户在web层构造查询条件detachedCriteria,和可选的 =\;yxl
$89hkUuTu^
startIndex,调用业务bean的相应findByCriteria方法,返回一个 zs!}P
4 [2^#t[
PaginationSupport的实例ps。 EugQr<sM#
sHC4iMIw
ps.getItems()得到已分页好的结果集 <xOv0B
ps.getIndexes()得到分页索引的数组 "RPX_
ps.getTotalCount()得到总结果数 [C)JI; \
ps.getStartIndex()当前分页索引 ^B[%|{cO
ps.getNextIndex()下一页索引 !vNZ-}
ps.getPreviousIndex()上一页索引 rO8Q||@>A
3QlV,)}
r83chR9
bo^d!/;
-:92<G\D
+3B^e%`NPm
72oiO[>N'
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 a xT-
x|B$n} B
,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 =/xTUI4
P} =eR
一下代码重构了。 XEd|<+P1
5r1{l%?
我把原本我的做法也提供出来供大家讨论吧: " jefB6k9h
1o5DQ'~n
首先,为了实现分页查询,我封装了一个Page类: >y<yFO{
java代码: ;DWtCtD
B/#tR^R
= ~{n-rMF
/*Created on 2005-4-14*/ XI6LPA0%
package org.flyware.util.page; +QS7F`O
Efo,5
/** E8]PV,#xY
* @author Joa `? ayc/TK
* C4V#qhj
*/ NXhQdf
publicclass Page { )*&I|L<1
I{Pny/d`
/** imply if the page has previous page */ 3wRk -sl
privateboolean hasPrePage; bJ8~/d]+
[kc%+j<g
/** imply if the page has next page */ W?W vT`
T{
privateboolean hasNextPage; F^iv1b
,,+ ~./)
/** the number of every page */ }@Mx@ S
privateint everyPage; m#[tY>Q[b
^Pc>/lY$Q%
/** the total page number */ "z+Z8l1.
privateint totalPage; =6#tJgg8
Kgi| 7w
/** the number of current page */ !ra CpL9;
privateint currentPage; F +e
J9
USVM' ~p I
/** the begin index of the records by the current 7h?yAgDv~
.F'fBT`$
query */ phIEz3Fu/
privateint beginIndex; Q>gU(
\Fhk>
)]2yTG[
/** The default constructor */ 5- Q`v/w;
public Page(){ A[juzOn\
vfT<%Kl!'
} amI$0
yVPkJ
/** construct the page by everyPage 7#Qa/[? D
* @param everyPage rQNT
* */ #80*3vi~F
public Page(int everyPage){ Ty]/F+{
this.everyPage = everyPage; SU, t,i
} 5G8`zy
LX<c(i
/** The whole constructor */ kP%Hg/f/Ot
public Page(boolean hasPrePage, boolean hasNextPage, !M~p __
\K 01F
J.x>*3<l
int everyPage, int totalPage, R6 wK'
int currentPage, int beginIndex){ *VT@
this.hasPrePage = hasPrePage; :)nn/[>fC
this.hasNextPage = hasNextPage; t"1'B!4
this.everyPage = everyPage; @]f"X>
this.totalPage = totalPage; _t:cDXj
this.currentPage = currentPage; '3uj6Wq2
this.beginIndex = beginIndex; r;w_B%9
} R<mLG $
]>@;
2%YvY
/** <p(&8P
* @return Yt*M|0bL
* Returns the beginIndex. x+5Q}ux'G
*/ [d!C6FT
publicint getBeginIndex(){ o}5:vi]
return beginIndex; =y7]9SOq
} &)Z8Qu
A"Rzn1/
/** bxP>
* @param beginIndex xiU-}H'o
* The beginIndex to set. @6GM)N\{[
*/ 1$idF
publicvoid setBeginIndex(int beginIndex){ ~nb%w?vv
this.beginIndex = beginIndex; @.kv",[{[
} L}A R{
>c7/E
/** lg;Y}?P
* @return u0$7k9mE
* Returns the currentPage. .]Z M2
*/ &RXd1>|c2
publicint getCurrentPage(){ M@Q=!!tQ(
return currentPage; }Iub{30mp
} &+`l
$h
?OKm~ Ek
/** l{#m"S7J^
* @param currentPage w;QDQ
fx0
* The currentPage to set. h.
i&[RnX
*/ `ea$`2
publicvoid setCurrentPage(int currentPage){ .Z&OKWL
this.currentPage = currentPage; W _b$E
=
} D4'?
V
Iz
`#fOY$#XB
/** '*>LZo4
* @return $},:z]%D
* Returns the everyPage. j %TYyL-
*/ Z/wh?K3y
publicint getEveryPage(){ g8XGZW!
return everyPage; W~k!qy `
} ^&&dO*0{
<zZAVGb4I
/** c7s4 g-
* @param everyPage *"fg@B5
* The everyPage to set. . F#mT h
*/ (6+6]`c$
publicvoid setEveryPage(int everyPage){ $%r|V*5
this.everyPage = everyPage; zp4ru\
} *`}_e)(k
?RpT_u
/** 'dWJ#9C
* @return YGWb!|Z$
* Returns the hasNextPage. Wlg(z%
*/ k|A!5A2
publicboolean getHasNextPage(){ 18[f_0@ #
return hasNextPage; |~\K:[T&
} 8@hzw~>
mApn(&
/** {+xUAmd
* @param hasNextPage $elrX-(vL
* The hasNextPage to set. HAO/r`7*
*/ eaX`S.!jR
publicvoid setHasNextPage(boolean hasNextPage){ T@yH.4D
this.hasNextPage = hasNextPage; tB_ V%qH
} ''5%5(Y.r
do[K-r
/** Dx <IS^>i
* @return m/eGnv;!
* Returns the hasPrePage. J~_p2TZJ\3
*/ Q`vyDoF
publicboolean getHasPrePage(){ EW5S%Y
return hasPrePage; ,xTbt4J
} raqLXO!j
e-e{-pB6
/** JA(nDD/;
* @param hasPrePage zl:
u@!'
* The hasPrePage to set. V)@MM2,
*/ 5ef&Ih.3
publicvoid setHasPrePage(boolean hasPrePage){ +XpRkX&-
this.hasPrePage = hasPrePage; ^mJvB[ u|
} 8W$="s2
5z]dA~;*2
/** ("lcL2Bq
* @return Returns the totalPage. %<M<'jxSca
* '^/E2+
*/ 6U&Uyd)
publicint getTotalPage(){ gZ+I(o{
return totalPage; `S~u4+y]
} he+[
<khx%<)P
/** zHdp'J"
* @param totalPage xc/|#TC8?
* The totalPage to set. +%<Jr<~W
*/ 'I<j`)4`d
publicvoid setTotalPage(int totalPage){ 1|nB\xgu
this.totalPage = totalPage; [e}]K:
} W@ Z=1y
EmUxM_T/2
} >|'6J!Op
U3V<ITZI8t
X,fTzkGj
PR'FSTg
L|Ydd!m
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 rL
s6MY
&*yve}su
个PageUtil,负责对Page对象进行构造: .lFSFJ ??
java代码: =
]@xXVf/
<+b:
c:6w >:
/*Created on 2005-4-14*/ E^YbyJ=1
package org.flyware.util.page; ^KaMi_--
v8@dvT<
import org.apache.commons.logging.Log; :RQ[(zD]
import org.apache.commons.logging.LogFactory; R:xmcUq}
(
[T%blaSX
/** `o3d@Vc
* @author Joa y?JbJ
* :I$2[K
*/ G6,8Xwk
publicclass PageUtil { sXa8(xc
y2U:( H:l!
privatestaticfinal Log logger = LogFactory.getLog -Fdi,\e
c[y8"M5
(PageUtil.class); bVx]r[
{
&'TA
/** :mrGB3x{
* Use the origin page to create a new page kwL)&@
* @param page LF~#4)B
* @param totalRecords uUe\[-~
* @return mr1}e
VM~!
*/ (lnQ!4LK
publicstatic Page createPage(Page page, int aOHCr>po,
J50 ~B3bj`
totalRecords){ asi1c
y\
return createPage(page.getEveryPage(), [5VUcXGt*\
cP1jw%3P
page.getCurrentPage(), totalRecords); $"8k|^Z3
} `Z/ IW
}j?S?= ;m=
/** -!0LIr:"
* the basic page utils not including exception z~H Gc"~
[86'/:L\2
handler .vv*bx
* @param everyPage v'!Ntk
* @param currentPage F^YIZ,=p!
* @param totalRecords sb
@hGS
* @return page JB+pFBeY
*/ 4I-p/&Q
publicstatic Page createPage(int everyPage, int hwzUCh 5!
pPZ/ O6
currentPage, int totalRecords){ [hL1PWKs
everyPage = getEveryPage(everyPage); )sf~l6
currentPage = getCurrentPage(currentPage); \V>%yl{8
int beginIndex = getBeginIndex(everyPage, AD\<}/3U
5E!m! nBZ
currentPage); tA-B3 ]
int totalPage = getTotalPage(everyPage, sZ"U=6R
sAoM=n}!
totalRecords); EaD@clJS
boolean hasNextPage = hasNextPage(currentPage, RfBb{?PP)
YfwJBzD
totalPage); ~
ZL`E
boolean hasPrePage = hasPrePage(currentPage); 2 ?T:RB}
_vdxxhJ=P3
returnnew Page(hasPrePage, hasNextPage, )$B+3f
everyPage, totalPage, &=Zg0Q
currentPage, DOVX$N$3
Pp_3 nyQ
beginIndex); Wi?%)hur
} 8 %j{4$
yCIgxPv|7
privatestaticint getEveryPage(int everyPage){ Jyci}CU3\Q
return everyPage == 0 ? 10 : everyPage; Qe$>Jv5
} \83A|+k
<aaDW
privatestaticint getCurrentPage(int currentPage){ B bw1k
return currentPage == 0 ? 1 : currentPage; em[F|
} Kk>qgi$
I#X2UQzP
privatestaticint getBeginIndex(int everyPage, int %hbLT{w
b8Rh|"J)d
currentPage){ qW~R-g]
return(currentPage - 1) * everyPage; h+3Z.WKhwP
} +M##mRD
Om2X>/V%C
privatestaticint getTotalPage(int everyPage, int SP*JleQN
O^Vy"8Ji}y
totalRecords){ rz}l<t~H
int totalPage = 0; |3:=qpT-
$xtE+EV.p
if(totalRecords % everyPage == 0) P5}[*k%DQw
totalPage = totalRecords / everyPage; o,Zng4NY
else 1Bk*G>CX9(
totalPage = totalRecords / everyPage + 1 ; @k+G
Cf
y3nm!tjyM
return totalPage; 7ml0
} :aq>
GoSWH2N
privatestaticboolean hasPrePage(int currentPage){ ; G59}d
p~
return currentPage == 1 ? false : true; "YzTMKu
}
.x!7
bEQtVe@`
privatestaticboolean hasNextPage(int currentPage, r\n
h.}s
<,pLW~2-"
int totalPage){ mu6xL QdA
return currentPage == totalPage || totalPage == v^],loi<V
Ac!&j=ZE
0 ? false : true; RpXs3=9
} @yn^6cE
^?X ^+
mrhp)yF
} `H2F0{\og
2b4pOM7W
\ ~LU 'j
"T a9
{ 1@4}R4
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。 *%N7QyO`I
*2Vp4
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 pl#o!j( i
2rj/wakd
做法如下: 1&% d
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 $uUb$8Bu
YoF\MT]W
的信息,和一个结果集List: Jl>at
java代码: QBfhyo_
.hQ3A"
LN.Bd,
/*Created on 2005-6-13*/ Vgqvvq<S
package com.adt.bo; XY!{ g(
A )RI:?+
import java.util.List; 5"}y\
Ql q#Zdru
import org.flyware.util.page.Page; r%TLv
urT/+deR
/** [/AdeR
* @author Joa V/(`Ek-
*/ ~"JE![XR
publicclass Result { Lz9$,Y[
Ho )t=qn
private Page page; 5DkK'tCI9Z
qD(fYOX{C
private List content; lTV@b&
[ GR|$/(z=
/** +Mk*{A t
* The default constructor _Sly7_
*/ o\@ A2r3
public Result(){ ]^*_F
super(); NIGB[2V(
} 3@PUg(M
vLv|SqD
/** ;}n9yci#
* The constructor using fields 79{.O`v
* BaWQ<T8p8
* @param page ]k'#g Z$
* @param content &TP:yA[
*/ $PatHY@h
public Result(Page page, List content){ io9y;S"+
this.page = page; a1
46kq
this.content = content; +,&m7L
} g[#k.CuP
<CZI7]PM7
/** nd $H
3sf
* @return Returns the content. 6CcB-@n4
*/ -Q<z1vz
publicList getContent(){ mP9cBLz
return content; jzl?e[qPA
} &Pu+(~'Q
<X:Ud&\
/** Ne &Xf
* @return Returns the page. F^.om2V|9
*/ L!bfh`
public Page getPage(){ qpb/g6g
return page; M|/oFV
} 42b. 7E
snXB`UC
/** [NHg&R H
* @param content q%OcLZ<,
* The content to set. 8g<Q5(
*/ Z{Vxr*9oO
public void setContent(List content){ FX%t
this.content = content; a$ C2}
} hMNJ'i}
Wc~3^;U
/** NFB*1_m
* @param page CTl(_g
* The page to set. W*YxBn4
*/ _REqT
publicvoid setPage(Page page){ r0)JUc}Fyq
this.page = page; <_"B}c/2$
} 7)B&(2D&
} xU@1!%l@
rpUy$qrRc
6D/uo$1Y
WHp97S'd
F(d:t!
2. 编写业务逻辑接口,并实现它(UserManager, D,c!#(v cK
sB?2*S"X)<
UserManagerImpl) MMMqG`Px
java代码: {bT9VZ>
X6Un;UL
~ct2`M$TL(
/*Created on 2005-7-15*/ RG&I\DTyt
package com.adt.service; W0Ktw6
/r276Q
import net.sf.hibernate.HibernateException; ITVQLQ
q<n[.u1@
import org.flyware.util.page.Page; Ks#A<! ;=
G;/Q>V
import com.adt.bo.Result; w'A tf
yB.G=90
/** kB8
M i
* @author Joa tE[H8
*/ x5oOF7#5
publicinterface UserManager { C`)_i3
^
RL6Vkd?
public Result listUser(Page page)throws xPt*CB
GMz8B-vk
HibernateException; bMsECA&
0mTEim
} rOW;yJ[
)u0O_R
lK*jhW?3:
.l\r9I(
[9OSpq
java代码: dXl]Pe|v
8"x9#kyU<3
RAV^D.
/*Created on 2005-7-15*/ 3E,DipHg
package com.adt.service.impl; _wz2
f3G1r5x
import java.util.List; fp{G|.SA
{SJsA)9:#
import net.sf.hibernate.HibernateException; sm
gXt O*Rfqk
import org.flyware.util.page.Page; /YFa
;2 W
import org.flyware.util.page.PageUtil; Ad/($v5+
T6uMFD4 |
import com.adt.bo.Result; 'd/*BjNp)
import com.adt.dao.UserDAO; oSY7IIf%L
import com.adt.exception.ObjectNotFoundException; Wwhgo.Wx
import com.adt.service.UserManager; v5T`K=qC
Me,<\rQ
/** 0 _A23.Y
* @author Joa +Rqbf
*/ Iyyo3awc
publicclass UserManagerImpl implements UserManager { P$ucL~r
Ns<?b;aK
private UserDAO userDAO; Ux}W&K/?'
W pN.]x
/** RBE7485
* @param userDAO The userDAO to set. Lc]1$
*/ PNpu*#Z`
publicvoid setUserDAO(UserDAO userDAO){ 2n)gpLIJ
this.userDAO = userDAO; .x-J44i@/
} vd (?$
@7W?8
/* (non-Javadoc) \}#@9=
* @see com.adt.service.UserManager#listUser Pu;yEh
jO8X:j09A
(org.flyware.util.page.Page) mb1Vu
*/ j (ygQ4T
public Result listUser(Page page)throws (.?ZKL
_Yq@ FOu
HibernateException, ObjectNotFoundException { O~PChUU*Y
int totalRecords = userDAO.getUserCount(); fx)KNm8Lx
if(totalRecords == 0) f*m[|0qI<X
throw new ObjectNotFoundException fu R2S70d
){P^P!s$
("userNotExist"); RlRs}yF
page = PageUtil.createPage(page, totalRecords); |4mVT&63(
List users = userDAO.getUserByPage(page); ,lm=M5b
returnnew Result(page, users); -V5w]F'
} OJ1tV% E
P!e= b-T
} x[X`a
89HsPB1"t
>c~RI7uu
}y6q\#G
rN5tI.iC
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 |cd-!iJX-
@i LIU}+
询,接下来编写UserDAO的代码: e2w&&B-
3. UserDAO 和 UserDAOImpl: Lm6**v
java代码: mgQIhXH5L
gU;&$
|=K_F3aJ
/*Created on 2005-7-15*/ 6BAW
package com.adt.dao; )`+YCCa6F
jfp z`zE
import java.util.List; Ig \#f
)D/ 6%]O
import org.flyware.util.page.Page; :]WqfR)#
4kl Ao$
import net.sf.hibernate.HibernateException; R_N:#K.M
2k5/SV
X
/** F9flSeN
* @author Joa j0mM>X HB
*/ ,6,]#R
:J
publicinterface UserDAO extends BaseDAO { 7%;_kFRV
%,UPJn
publicList getUserByName(String name)throws X.FGBR7=q
|E3X
HibernateException; f_=~H<j!
T!|=El>
publicint getUserCount()throws HibernateException; s'\$t
eu#'SXSC
F
publicList getUserByPage(Page page)throws szmmu*F,U:
s?C&s|'.
HibernateException; yj_4gxJ\
IV `%V+
f
} SA"8!soY3
q3P+9/6
_NZ@4+aW
wvby?MhPY
#&
?g %'
java代码: 1iBP,:>*
vbG]mMJ
Hi}RZMr1
/*Created on 2005-7-15*/ 1;F`c`0<
package com.adt.dao.impl; 9KuD(EJS
n/4i|-^
import java.util.List; +&=?BC}L9^
aSutM
import org.flyware.util.page.Page; Ea $aUORm
]9 w76Z
import net.sf.hibernate.HibernateException; j+IrqPKC^
import net.sf.hibernate.Query; 7^6uG6
`'S0*kMT
import com.adt.dao.UserDAO; sW@krBxMv
rNDrp@A>
/** jeUUa-zR3
* @author Joa p9eRZVy/
*/ q(M:QWA q
public class UserDAOImpl extends BaseDAOHibernateImpl jM)C4ii.-$
RP4Ku9hk
implements UserDAO { LW)H"6v
1fU,5+PH
/* (non-Javadoc) {R6HG{"IS6
* @see com.adt.dao.UserDAO#getUserByName &HZmQ>!R D
Di.3113t
(java.lang.String) ]; $] G-
*/ %kshQ%P)?
publicList getUserByName(String name)throws q8P.,%
[{u(C!7L`
HibernateException { c]k*}W3T
String querySentence = "FROM user in class ,M5}4E7L%s
"/{RhY<
com.adt.po.User WHERE user.name=:name"; b\7iY&.C|
Query query = getSession().createQuery i]{1^pKq
t<iEj"5
(querySentence); s@4nWe
query.setParameter("name", name); e.d
#wyeX
return query.list(); &DG->$&|
} $tqJ/:I
26?W
nu60
/* (non-Javadoc) 5Qwh(C^H
* @see com.adt.dao.UserDAO#getUserCount() }n:?7
*/ PUJ2`iP1^3
publicint getUserCount()throws HibernateException { +0wT!DZW\=
int count = 0; .wA+S8}S
String querySentence = "SELECT count(*) FROM +EXJ\wy
VSX@e|Nj
user in class com.adt.po.User"; T=f|,sK +7
Query query = getSession().createQuery >r@.F%
Uh
eC
(querySentence); iRo.RU8>
count = ((Integer)query.iterate().next rf:XRJ<4
m0w;8uF2UV
()).intValue(); ]va>ex$d
return count; e> rRTN
} YV% 5y1i
{~GYj%-^
/* (non-Javadoc) _9H*agRe
* @see com.adt.dao.UserDAO#getUserByPage 4LcX<BU9
2zSG&",2D
(org.flyware.util.page.Page) ]
Wy)
*/ ocbB&
publicList getUserByPage(Page page)throws *.-.iY.a]
N{SQ(%V
HibernateException { WO5O?jo'
String querySentence = "FROM user in class wFh8?Z3u_
Gl %3XdU
com.adt.po.User"; Z7rJ}VP
Query query = getSession().createQuery mbRqJT>@
F7L &=K$2y
(querySentence); [S]S^ej*8
query.setFirstResult(page.getBeginIndex()) YpAg
.setMaxResults(page.getEveryPage()); s&kQlQ=
return query.list(); r[(xjn
} mP38T{
rB~W Iu
} YYEJph@06q
b !@Sn/
s`j~-P
1 2++RkL#
LTV{{Z+
至此,一个完整的分页程序完成。前台的只需要调用 z{"2S="
g[
0<m#"
userManager.listUser(page)即可得到一个Page对象和结果集对象 B&+`)E{KB
_\PNr.D8
的综合体,而传入的参数page对象则可以由前台传入,如果用 9j]sD/L5q
jr7C}B-Fb^
webwork,甚至可以直接在配置文件中指定。 87)zCq
jc[_I&Oc_
下面给出一个webwork调用示例: M2x["
java代码: aV o;~h~
l.\re"Q
P7ph}mB
/*Created on 2005-6-17*/ f'I z
G.R
package com.adt.action.user; > oA?6x
w;}@'GgL
import java.util.List; E5el?=,i
u~
~R9.
import org.apache.commons.logging.Log; ^_t%kmL`
import org.apache.commons.logging.LogFactory; oRKEJNps
import org.flyware.util.page.Page; O1 .w,U
lkyzNy9R
import com.adt.bo.Result; Cz4)Yz
import com.adt.service.UserService; \T]EZ'+O
import com.opensymphony.xwork.Action; i&njqK!wS
-LDCBc"
/** .6O"|
Mqb
* @author Joa ri`R<l8
*/ +_v$!@L8
publicclass ListUser implementsAction{ g-`~eG28D5
72sD0)?A
privatestaticfinal Log logger = LogFactory.getLog k4qp u=@U
Wk:hFHs3
(ListUser.class); *19ax&|*S
,\ 2a=Fp
private UserService userService; tx"sH]n
-U<Upn)2
private Page page; 6{[pou&
"G-1>:
privateList users; I -Xlx<
A*./,KT
/* O\K_q7iO6
* (non-Javadoc) ml@2wGyf
* "fg](Cp[z
* @see com.opensymphony.xwork.Action#execute() ]0;864X0
*/ |/gW_;(
publicString execute()throwsException{ $F.([?)k?
Result result = userService.listUser(page); 2^t#6XBk/
page = result.getPage(); 22kp l)vbU
users = result.getContent(); Om M=o*d
return SUCCESS; w;Q;[:y
} 9Rm/V5
=fm]D l9h*
/** h8\
T
* @return Returns the page. TF2>4 p
*/ as=m`DqOh
public Page getPage(){ ^:9$@+a
return page;
tvXW
} Z5c~^jL$-
ZKg{0DY
/** f84:hXo6
* @return Returns the users. oG$)UTzGc
*/ izKfU?2]X@
publicList getUsers(){ 7W6cM%_B
return users; ,!V]jP)
} iK?b~Q
{;2vmx9
/** +A~\tK{
* @param page r>jC_7
* The page to set. <foCb%$(?
*/
^ kST
publicvoid setPage(Page page){ /-6S{hl9Ne
this.page = page; ZVeaTK4_
t
} CG'.:`t
0&ByEN99
/** GE>[*zN
* @param users .^$YfTabq
* The users to set. !v]b(z`Y
*/ "O8gJ0e
publicvoid setUsers(List users){ .I}:m%zv
this.users = users; rF\"w0J_
} fYE(n8W3
y~IuP c
/** XC7%vDIt
* @param userService .To;"D;j,
* The userService to set. 2oJb)CB
*/ v^ d]rSm
publicvoid setUserService(UserService userService){ X-Wz:NA
this.userService = userService; DF6c|
} m]*Bx%-1c
} k%y9aO
T32BnmB{
.qk]$LJF7
[![%9'+P
,ZblIOWb
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, CE15pNss
10#oG{9
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 : S$l"wrh\
Pmi#TW3X
么只需要: P;PQeXKw
java代码: {brMqE>P#
>:=|L%]s;\
~)?
<?xml version="1.0"?> H A}f,),G
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork \:>
Wpqw
e T'nl,e|
1.0//EN" "http://www.opensymphony.com/xwork/xwork- 5>J=YLq
k`".
1.0.dtd"> "uLjIIl
Ax oD8|
<xwork> &h*S
y
q_
=b<.;
<package name="user" extends="webwork- xUF_1hY
`RMI(zI3g.
interceptors"> ]4+s$rG
CukC6ub
<!-- The default interceptor stack name 6io , uh!
b]E|*
--> D71;&G]0
<default-interceptor-ref p2PY@d}}.
OdMO=Hy6d
name="myDefaultWebStack"/> wOB azWa
.I3?7
<action name="listUser" z9W`FBg
a:~@CUD
>I
class="com.adt.action.user.ListUser"> R];Oxe
<param 1e xl0]-
!?
^h;)a
name="page.everyPage">10</param> i?Ss: v^
<result )o!XWh
H7i$xWs
name="success">/user/user_list.jsp</result> #6Xs.*b5C
</action> ThW,Y"
l
2A4FaBq"
</package> 3M5#4n\v$
L]a`"CH:a$
</xwork> KCe13!
bg|!'1bD`5
eMK+X \
AvR2_
l0*Gb
-ZW0k@5g
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 H.K.C(
4LI0SwD#^/
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。 ()PKw,pD
wo5ZxM
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 vUC!fIG
w^K^I_2ge
v"+k~:t*
]L2Oz
QD{:vG
g
我写的一个用于分页的类,用了泛型了,hoho 4VN aq<8
Ct$82J
java代码: dsK&U\ej}
Ju@Q6J5
0f ER*.F
package com.intokr.util; ')+0nPV
'%v#v 3'
import java.util.List; ,]R8(bD)
HOt>}x
/** g.%
* 用于分页的类<br> ba@ax3
* 可以用于传递查询的结果也可以用于传送查询的参数<br> tXF]t
* jW*1E*"
* @version 0.01 eX&Gw{U-f
* @author cheng g1DmV,W-Q
*/ ?_6YtR,{
public class Paginator<E> { 2k7bK6=nm
privateint count = 0; // 总记录数 :lcea6iO
privateint p = 1; // 页编号 D)='8jV7
privateint num = 20; // 每页的记录数 ]^"k8v/
privateList<E> results = null; // 结果 jm>3bd
'p)Q68;&
/** "YFls#4H-
* 结果总数 )"@t6.
*/ "u}9@}*
publicint getCount(){ f<[jwhCWV
return count; +2cs#i
} ~QG?k
kD~uGA
publicvoid setCount(int count){ exR^/|BR
this.count = count; "5DJu~
} ]XUl@Y.
c $;\i
/** vfvlB[
* 本结果所在的页码,从1开始 1uG=`k8'k
* -Q$nA>trKA
* @return Returns the pageNo. 7r{qJ7$%
*/ 6=|&tE
publicint getP(){ vg%QXaM
return p; GA^mgm"O
} 34C``i
-$Y8!5 4
/** jThbeY[
* if(p<=0) p=1 ,^T]UHRO
* o sdOw8
* @param p f|0lj
*/ 8q_0,>w%
publicvoid setP(int p){ yM$J52#d#
if(p <= 0) ~2%3FV^
p = 1; :Am-8
this.p = p; +Takde%~
} ?_4^le[;
3_ 2hC!u!K
/** )y50Mb0+
* 每页记录数量 W04av_u 5
*/ tbj=~xYf
publicint getNum(){ 2/Nq'
return num; n`5WXpz4;
} 2RNrIU I2
to3?$-L
/** _'iDF
* if(num<1) num=1 ;x[pM_
*/ fp !:u
publicvoid setNum(int num){ ]S/G\z
if(num < 1) ~Yk"Hos
num = 1; O8 RzUg&
this.num = num; r%MyR8'k]
} XI}I.M
MQ w9X
/** g{ (@uzqG
* 获得总页数 g^lFML|
%
*/ Y}1P~
publicint getPageNum(){ Z.jCera.
return(count - 1) / num + 1; wa?+qiWnrl
} Z] { @H
t[O+B6
/** c cr" ep
* 获得本页的开始编号,为 (p-1)*num+1 zeOb Aw1O
*/ 26nBBS,;
publicint getStart(){ ya>N.h
return(p - 1) * num + 1; !LSs9_w
} ,VG9)K1K
x`2pr
/** ]Y5dl;xrM)
* @return Returns the results. {CP o<lz
*/ #eEvF
publicList<E> getResults(){ 9".Uc8^p/F
return results; HTNA])G
} 02M7gBS
=YoTyq\
public void setResults(List<E> results){ m.146
this.results = results; i+U51t<
} (4ZLpsbJ
sL~,
public String toString(){ `i4I!E
StringBuilder buff = new StringBuilder ,)uPGe"y
Gc}0]!nrW9
(); r%[1$mTOR
buff.append("{"); {d}26 $<$]
buff.append("count:").append(count); Em9my2oE
buff.append(",p:").append(p); :|($,3*
buff.append(",nump:").append(num); 0~i q G
buff.append(",results:").append cUM_ncYOP
w%~qB5wF6
(results); ?1DUNZ6
buff.append("}"); Ns~g+C9
return buff.toString(); ;_bq9x
} Bfn]-]>sD
Zih5/I
} VVN#
$
hLn&5jYHvt
hs,5LV)|y