Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ?bA]U:
oIgj)AY<
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 )q-!5^ak
jd'R2e
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 bv];Gk*Z-
>p:fWQ6
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 }TLC b/+
bcs(#
。 |mA*[?ye@
bJ}+<##
分页支持类: 7[ji,.7
C(+BrIS*
java代码: B 1.@K }
Ww4G
cK@K\AE
package com.javaeye.common.util; #<3\}*/
l!'iLq"K(
import java.util.List; "VCr^'
Ry~LhU:
publicclass PaginationSupport { 7QFEQ}
((q(Q9(F
publicfinalstaticint PAGESIZE = 30; je%12DM
H:Le^WS
privateint pageSize = PAGESIZE; ,' B=eY,
gC 4#!P
privateList items; yh<aFYdk
=,]M$M
privateint totalCount; %V/]V,w:*R
wUndNE
privateint[] indexes = newint[0]; YT8`Vz$+
8A_(]Q
privateint startIndex = 0; {`55nwd
(7
iMIY
public PaginationSupport(List items, int s:H1v&t,<
&[pwLYf7
totalCount){ N*W.V,6yH
setPageSize(PAGESIZE); #1k,t
setTotalCount(totalCount); ocUu
setItems(items); w:v:znQrW
setStartIndex(0); .ji%%f
} Op~+yMef
(1vS)v
$L
public PaginationSupport(List items, int +(0eOO'\M
&rKhB-18)
totalCount, int startIndex){ _>I5Ud8(-
setPageSize(PAGESIZE); nX'.'3
setTotalCount(totalCount); /+YWp>6LU
setItems(items); ^u{$$.&
setStartIndex(startIndex); +=4b5*+qG
} 9b6h!(
HS9U.G>
public PaginationSupport(List items, int 1uMdgrJRR
{lJpcS
totalCount, int pageSize, int startIndex){ 39#>C~BOl
setPageSize(pageSize); _L>n!"E/
setTotalCount(totalCount); o~p^`5#
setItems(items); (ShJ!
setStartIndex(startIndex); 4LLCb7/5lP
} +>j_[O5Y
g=Jfp$*[
publicList getItems(){ , 88}5)b[
return items; s]UeDZ<a
} |1R@Jz`
>{Q2S
publicvoid setItems(List items){ 3&f{lsLAC
this.items = items; fJKOuFK
} YR2/`9s\QJ
%3wK.tR
publicint getPageSize(){ ^gImb`<6-
return pageSize; Sb.;$Be5g
} VXp
X#O
Vv]mME@
publicvoid setPageSize(int pageSize){ wW~2]*n
this.pageSize = pageSize; PoZBiw@
} fsoS!6h0k
62) F
publicint getTotalCount(){ NT 'Y h
return totalCount; PR0]:t)E
} /<~IKVz\&
t*#T~3p
publicvoid setTotalCount(int totalCount){ X@rAe37h+
if(totalCount > 0){ 9L,T @#7
this.totalCount = totalCount; qM'5cxe
int count = totalCount / %o>1$f]
b.(^CYYQ
pageSize; 7JbrIdDl|
if(totalCount % pageSize > 0) #%~wuCn<K
count++; u}$3.]-.?T
indexes = newint[count]; +FI]0r
for(int i = 0; i < count; i++){ XQ>m8K?\d
indexes = pageSize * %"D-1&%zY
%-D2I
i; gueCP+a_
} 8}2
`^<U
}else{ u- ,=C/iU
this.totalCount = 0; ^)WGc/
} }/|1"D
} rnUe/HjH
t V</x0#
publicint[] getIndexes(){ Jc*A\-qC.
return indexes; LvS`
} ;IyQqP#,<
q-'zZ#
publicvoid setIndexes(int[] indexes){ Q =Z-vTD+
this.indexes = indexes; j1)w1WY0@
} *=rl<?tX
@L0.Z1 ).
publicint getStartIndex(){ mSs%g L]g
return startIndex; Onao'sjY
} +m_quQ/ys
9496ayi
publicvoid setStartIndex(int startIndex){ Ad[-YT
if(totalCount <= 0) xpae0vw
this.startIndex = 0; YvonZ
elseif(startIndex >= totalCount) YC{od5a
this.startIndex = indexes ;-59#S&?tB
2]|+.9B
[indexes.length - 1]; &12.|
elseif(startIndex < 0) s&4Y+dk93
this.startIndex = 0; &}<IR\ci
else{ +NQw^!0qy
this.startIndex = indexes n=`UhC
EG,RlmcPp
[startIndex / pageSize]; +]G;_/[2
} @>?&Mw\c
} EyhQjsaT
-70Ut
4B
publicint getNextIndex(){ *&7Av7S
int nextIndex = getStartIndex() + @<_4Nb
b?z 8Yp6
pageSize; MOXDR
if(nextIndex >= totalCount) 2!A/]:[F
return getStartIndex(); d:3G4g
else ."${.BPn~
return nextIndex; >354O6
} =4G9ev
4
m6s32??m
publicint getPreviousIndex(){ uv, t(a.^
int previousIndex = getStartIndex() - _|3n h;-m
/p~gm\5Z
pageSize; w1[F]|
if(previousIndex < 0) a!;?!f-i
return0; ws@;2?%A
else "!2Fy-Y
return previousIndex; >#SQDVFf
} ."dmL=
p\Jz<dkN1
} RDZl@ps8
koFY7;_<?
k@^)>J^
ydw')Em
抽象业务类 {$b]K-B
java代码: 9k1n-po
%A04'dj`zQ
#,Rmu
/** w _n)*he)z
* Created on 2005-7-12 z"|^Y|`m
*/ ^b'[81%
package com.javaeye.common.business; A >Js`s
MbYAK-l.h
import java.io.Serializable; bPWIf*3#
import java.util.List; aB.`'d)V
7cH[}v`pn
import org.hibernate.Criteria; %c):^;6p
import org.hibernate.HibernateException; ]*?qaIdqu
import org.hibernate.Session; Ao2t=vg
import org.hibernate.criterion.DetachedCriteria; $5l 8V
import org.hibernate.criterion.Projections; VUk2pEGO.
import 88G Q F
al1Uf]xh
org.springframework.orm.hibernate3.HibernateCallback; 9 u{#S}c`
import ~!\n
U]O7RH
org.springframework.orm.hibernate3.support.HibernateDaoS r/SV.`
k
Ji gc@@B.
upport; .M!HVq47m
d
n3sh<
import com.javaeye.common.util.PaginationSupport; K[O'@v
s#>Bwn&b)
public abstract class AbstractManager extends j*xxOwf
?J|~G{yH
HibernateDaoSupport { k1W
q$KCwG
%R(1^lFI$
privateboolean cacheQueries = false; 0@vSl%I+
r!'\$(m E
privateString queryCacheRegion; Q
u{#4qToA
1t6VS 3
publicvoid setCacheQueries(boolean ki48]#p
F.zn:y X5
cacheQueries){ ;CD@RP{$n
this.cacheQueries = cacheQueries; qdWsP9}q
} v<$a .I(
hT]\*},
publicvoid setQueryCacheRegion(String X0O@,
YLk/16r
queryCacheRegion){ WbB0{s
this.queryCacheRegion = +Ccj@#M;
X2v|O3>/N
queryCacheRegion; @#xh)"}
} blEs!/A`
{dTtYL$'"
publicvoid save(finalObject entity){ *%bQ p
getHibernateTemplate().save(entity); A70x+mjy^T
} =y.? =`"
|p}qK
Fdi
publicvoid persist(finalObject entity){ /z9oPIJ=*
getHibernateTemplate().save(entity); QE1DTU
} #**vIwX-Q
2Ck'A0d
publicvoid update(finalObject entity){ A@^Y2:pY
getHibernateTemplate().update(entity); d#'aT mu!
} *DcJ).
:_X9x{
publicvoid delete(finalObject entity){ eTw sh]
getHibernateTemplate().delete(entity); gZ8n[zxf6
} hi^@969
ju~js
publicObject load(finalClass entity, Sxa+"0d6
\4zb9CxOZ
finalSerializable id){ ~ (I'm[
return getHibernateTemplate().load 2|8e7q: +*
nO.RB#I$F
(entity, id); d2Pqi* K
} Ev+m+
!N ua
publicObject get(finalClass entity, b=(?\
QpbyC_:;$4
finalSerializable id){ '7Q5"M'
return getHibernateTemplate().get z]:{ruvH
PZ06
_
(entity, id); .93B@u
} 2j*;1
WrP4*6;"
publicList findAll(finalClass entity){ KG=h!]Meq
return getHibernateTemplate().find("from ~;>
psNy
6HeZ<.d&
" + entity.getName()); m_
>+$uL
} OFH!z{*
?Zu2=<DU
publicList findByNamedQuery(finalString qD0sD2 x
HE6kt6
namedQuery){ f}qR'ognUu
return getHibernateTemplate av~dH=&=
&iYy
().findByNamedQuery(namedQuery); jg%HaA<zO
} W(.q.Sx>
>..C^8 "
publicList findByNamedQuery(finalString query, %an"cQ
]
&Cv0oi&B
finalObject parameter){ AM?62
return getHibernateTemplate `0'Bg2'
oS.fy31p
().findByNamedQuery(query, parameter); jr,j1K@_t
} ]w*w@:Zk
lM/)<I\8
publicList findByNamedQuery(finalString query, Ni bOtIZ
O{@m ,uY
finalObject[] parameters){ >AFX}N#
return getHibernateTemplate :56f
E3%:7MB
().findByNamedQuery(query, parameters); SY &)?~C
} KPW2e2{4@
j6@5"wx
publicList find(finalString query){ A 9\]y%!
return getHibernateTemplate().find &"G4yM
|1M+FBT$w
(query); vQK*:IRKK
} X=_`$
0
V)Oj6nD]
publicList find(finalString query, finalObject OZ,%T9vP
!LDuCz
-
parameter){ tw{V7r~n
return getHibernateTemplate().find WJD1U?`
$d:>(_p=A
(query, parameter); "lU%Pm]>
} GP|G[
ur*@TIvD
public PaginationSupport findPageByCriteria $;@LPE
+T\c<lJ9
(final DetachedCriteria detachedCriteria){ X%1j-;Wr@
return findPageByCriteria Y5rR
H#zsk*=QD
(detachedCriteria, PaginationSupport.PAGESIZE, 0); oz54IO
} 8}5dyn{cvE
ciQG.]
public PaginationSupport findPageByCriteria `VJJ"v<L
R>
r@[$z+
(final DetachedCriteria detachedCriteria, finalint =6o,{taZ.~
_@-D/g
startIndex){ pz L !42
return findPageByCriteria IG}`~% Z
iobL6SUZ
(detachedCriteria, PaginationSupport.PAGESIZE, 0H<&*U_V
qQzf&"
startIndex); +aa( YGL
} {Vg8pt
Yr7%C
public PaginationSupport findPageByCriteria iP nu *29
f[}N
(final DetachedCriteria detachedCriteria, finalint n4* hQi+d
1a|Z !Vzi
pageSize, ?=C?3R
finalint startIndex){ y}TiN!M
return(PaginationSupport) {i}z|'!
R['k&jyi
getHibernateTemplate().execute(new HibernateCallback(){ g8I=s7cnb
publicObject doInHibernate y:\ ^[y IQ
vO2I"Y*\
(Session session)throws HibernateException { C9?R*2L>
Criteria criteria = HW0EP J
Ai99:J2k
detachedCriteria.getExecutableCriteria(session); '%k<? *
int totalCount = c_oI?D9
[;IW'cXNq
((Integer) criteria.setProjection(Projections.rowCount jSY&P/[xb
~}B6E)
()).uniqueResult()).intValue(); ^4D7sS;~3
criteria.setProjection .'+*>y!
m@qM|%(0x
(null); Qf?5"=:#
List items = 0H|U9
ve#*qz Y
criteria.setFirstResult(startIndex).setMaxResults =e<;B_~.
y1zNF$<q
(pageSize).list(); m%mA0r
PaginationSupport ps = ?B&Z x-krd
!y1]S .;
new PaginationSupport(items, totalCount, pageSize, % FN3/iM
t6zc$0-j"
startIndex); *""JE'wG
return ps; \M@9#bd
} CTqAhL 4}
}, true); pH#*:v!)
} yS*s[vT
p^=>N9
public List findAllByCriteria(final W6kDQ&q
#Kr\"o1]
DetachedCriteria detachedCriteria){ :j sa.X
return(List) getHibernateTemplate Y6_%HYI$
< C{-ph
().execute(new HibernateCallback(){ MT`gCvoF4P
publicObject doInHibernate Cd>GY
x2 s%qZ#
(Session session)throws HibernateException { s|/m}n
Criteria criteria = sk0N=5SB-
urJ>dw?FI
detachedCriteria.getExecutableCriteria(session); O{0TS^
return criteria.list(); ~j1.;WId[
} $]&0`F
}, true); }Pu|%\
} gH{X?
&) '5_#S
public int getCountByCriteria(final yQ^k%hHa
6mFH>T*jzH
DetachedCriteria detachedCriteria){ bu;3Ib3\
Integer count = (Integer) XDtr{r6z
D][e uB
getHibernateTemplate().execute(new HibernateCallback(){ %SWtE5HZQq
publicObject doInHibernate [31vx0$_p
y;0k |C
(Session session)throws HibernateException { 'Gn-8r+
Criteria criteria = .d\<}\zZ7J
GrwoV~
detachedCriteria.getExecutableCriteria(session); ul{u^ j
return buIy+
[G(}`u8w"
criteria.setProjection(Projections.rowCount s_`PPl_D$K
mLa0BIP
()).uniqueResult(); R.(cGZS
} *b{C`[
=V
}, true); q>$[<TsE&}
return count.intValue(); - EwtO4vLJ
} Fx^e%":@ip
} MNy)= d&<P
(thDv rT@2
r_sZw@lqJ
>JNK06T
:+1S+w
wH:'5+u:6
用户在web层构造查询条件detachedCriteria,和可选的 2>s@2=Aq
YNGG> ;L
startIndex,调用业务bean的相应findByCriteria方法,返回一个 Sa V]6/|
!PCw-&
PaginationSupport的实例ps。 =~Ac=j!q
?K<m.+4b*y
ps.getItems()得到已分页好的结果集 rUunf'w`e1
ps.getIndexes()得到分页索引的数组 X%+FM]
ps.getTotalCount()得到总结果数 4:!KtpR[O
ps.getStartIndex()当前分页索引 #8N9@
ps.getNextIndex()下一页索引 3@k;"pFa<
ps.getPreviousIndex()上一页索引 {J:ZM"GS
9]Q\Pr\Ub$
QOG
S`
fh
B3
mD0
IN? A`A
97H2hYw9l
#
;,b4O7@
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 _IAvFJI
R/H?/
,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 ` r; .
"s']@Qv
一下代码重构了。 8T5s6EmIOW
&} b'cO
我把原本我的做法也提供出来供大家讨论吧: !_+LmBd
G
%ZV a{Nc
首先,为了实现分页查询,我封装了一个Page类: kcH?l
java代码: Z`fm;7NiVG
*+p9u 1B5
;SBM7fwRk
/*Created on 2005-4-14*/ @Q"%a`mKH
package org.flyware.util.page; M5C}*c9
{5+t\~q$
/** [CH%(#>i~
* @author Joa urT!?*g,
* 1=DUFl.
*/ M) 9Ss
publicclass Page { RRaGc )B
{nH.
_
/** imply if the page has previous page */ s[:e '#^
privateboolean hasPrePage; -\;x>=#B
e![|-m%
/** imply if the page has next page */ IX eb6j8
privateboolean hasNextPage; whW"cFg
f"h{se8C
/** the number of every page */ a;p3Me7
privateint everyPage; LC5NB{b\%>
f\oB/
/** the total page number */ A"S{W^iL
privateint totalPage; %YhZ#>WT
w <
p
/** the number of current page */ &6/#
O
privateint currentPage; xz dqE
iMnp `:*
/** the begin index of the records by the current mA5x ke_)
zJ4 2%0g
query */ JLT^0wBB
privateint beginIndex; rj"oz"
_20nOg`o
#vJDb |z
/** The default constructor */ &Y"u*)bm
public Page(){ "}PaMR]
D_,}lsrb
} -#v1b>ScY
=@b/Gl
/** construct the page by everyPage >^%]F[Wo
* @param everyPage %WrUu|xj>_
* */ be `\ O
public Page(int everyPage){ ,R=Mr}@u
this.everyPage = everyPage; C?Dztkz
} ~={8b
VsOn j~@
/** The whole constructor */ =iy%;>I`
public Page(boolean hasPrePage, boolean hasNextPage, TD+V.}
X:\ r )
fZ6lnZ
int everyPage, int totalPage, tk4~ 8
int currentPage, int beginIndex){ yG?,8!/]
this.hasPrePage = hasPrePage; bit&H
this.hasNextPage = hasNextPage; //VgPl
this.everyPage = everyPage; +*[lp@zU{
this.totalPage = totalPage; ;4of7d
this.currentPage = currentPage; qp>O#tj[
this.beginIndex = beginIndex; |yiM7U,i
} t&(}`W
C|c'V-f
/** d^X;XVAvP
* @return h^ ex?
* Returns the beginIndex. D0,U2d
*/ hVRpk0IJDK
publicint getBeginIndex(){ #KZ6S9>@
return beginIndex; Ji SJi?
} P?*$Wf,~n
X
b-q:{r1h
/** A P><l@
* @param beginIndex g"|QI=&_J
* The beginIndex to set. \{L!hAw
*/ qve2?,i8hM
publicvoid setBeginIndex(int beginIndex){ D`3m%O(?
this.beginIndex = beginIndex; {:c*-+?
}
YuD2Q{
yhQv $D,^f
/** YC4S,fY`
* @return tUl#sqN_{
* Returns the currentPage. F*rU=cu
*/ H2 7_T]\
publicint getCurrentPage(){ TI: -Y@8
return currentPage; T1?fC)
} s =Pwkte
$-Q,@Bztq
/**
q%,q"WU
* @param currentPage Iz^~=yV)
* The currentPage to set. zh)qo
*/ FQ>KbZh
publicvoid setCurrentPage(int currentPage){ oqOv"yLJ:
this.currentPage = currentPage; x2+%.$'
} jgbUZP4J>
1pogk0h.:
/** N~g@
* @return t8 g^W K
* Returns the everyPage. FR_R"p
*/ ?B@(W(I
publicint getEveryPage(){ Z8+{ -
return everyPage; ^Fgmwa'
} m5r65=E
D
Cx3_
/** B25@6
* @param everyPage vtG_A{l
* The everyPage to set. x|n2,3%
*/ IZBU<1M
publicvoid setEveryPage(int everyPage){ BO<I/J~b
this.everyPage = everyPage; #DpDmMP9R3
} Qy`{y?T2
Am&/K\O
/** Zp]{e6J
* @return ae( o:G
* Returns the hasNextPage. H2`aw3
*/ xM}lX(V!w
publicboolean getHasNextPage(){ vs;T}'O
return hasNextPage; |H 0+.f;
} Bh?K_{e
i6M_Gk}
/** f.cIh ZF
* @param hasNextPage 4Mi~eL%D
(
* The hasNextPage to set. tKgPKWP
*/ =z^v)=uhp
publicvoid setHasNextPage(boolean hasNextPage){ G\&4_MS
this.hasNextPage = hasNextPage; hX(:xc
} :$j6
SDpaW6(_
/** _]H$rf,Rc
* @return IM),cOp=
* Returns the hasPrePage. )?RR1P-ID
*/ o,(MB[|hQ
publicboolean getHasPrePage(){ ;o }pRC
return hasPrePage; @SeE,<
} j4Ppn
We%-?l:"
/** )B.NV<m
* @param hasPrePage F-g(Hk|v
* The hasPrePage to set. 833KU_ N
*/ 0G?0 Bo
publicvoid setHasPrePage(boolean hasPrePage){ /H&:
this.hasPrePage = hasPrePage; )MqF~[k<-
} U,S&"`a
:{?8rA5
/** C5m6{Oo+-
* @return Returns the totalPage. v8p-<N)
* CJ0j2e/
*/ ';4DUhp
publicint getTotalPage(){ n_vopDMm
return totalPage; rld4uy}m
} X'4e)E3*O
,":_=Tf.
/** $ KQ7S>T
* @param totalPage =FUORj\O
* The totalPage to set. i{TErJ{}e
*/ u6h"=l{
publicvoid setTotalPage(int totalPage){ +O>1Ed
this.totalPage = totalPage; \hv1"WaJ
} 1c_qNI;:p
Ub(zwR;
} a}eM ny
5#/"0:2
9Y&,dBj+
a.QF`J4"'
zbn0)JO
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 !^BXai/
L9[? qFp
个PageUtil,负责对Page对象进行构造: ] )D\ws)a9
java代码: $[txZN
IBm&a^
:c%vl$
/*Created on 2005-4-14*/ //*>p
package org.flyware.util.page; _D7MJT
}2 zJ8A9-
import org.apache.commons.logging.Log; #]bWE$sU<
import org.apache.commons.logging.LogFactory; lSU&Yqx
~t\Hb8o
/** BoJ@bOe#
* @author Joa 0Pw?@uV
* =+ `I%>wc
*/ {<%zcNKl^L
publicclass PageUtil { 4KF
1vw
wQiRj.
privatestaticfinal Log logger = LogFactory.getLog ,p6X3zY
P<yd
(PageUtil.class); \:ntqj&A|
}TD$!
/** J/Ki]T9
* Use the origin page to create a new page d54(6N%
* @param page 4h wUH
* @param totalRecords Hp;Dp!PLa
* @return JK0L&t<
*/ {#YGor|
publicstatic Page createPage(Page page, int $>zLa_cn|
VKRj
1LXz
totalRecords){ kK+<n8R2
return createPage(page.getEveryPage(), /]4[b!OTJ
aW$(lf2;
page.getCurrentPage(), totalRecords); (@Q@B%!!K
} 3#vhQ*xU
fhlhlOg
/** H@Dj$U
* the basic page utils not including exception ;,GE!9HW
,W"Q)cL
handler uTY5.8
* @param everyPage Y%OE1F$6NN
* @param currentPage TGx:#x*k
* @param totalRecords ZZqImB.Cz6
* @return page )u~LzE]{_
*/ Xao
0cb.R
publicstatic Page createPage(int everyPage, int s>Xx:h6m
{'P7D4w
currentPage, int totalRecords){ H: q(T
>/w
everyPage = getEveryPage(everyPage); $'!r/jV
currentPage = getCurrentPage(currentPage); Z'iXuI49
int beginIndex = getBeginIndex(everyPage, Bgs3sM9
}ybveZxv5A
currentPage); {X$8yy2zC5
int totalPage = getTotalPage(everyPage, v7"' ^sZ?
IKSe X
totalRecords); vB >7W
boolean hasNextPage = hasNextPage(currentPage, ;KqH]h)
{2?o:
totalPage); qv|geBW
boolean hasPrePage = hasPrePage(currentPage); 2OFrv=F
3]Rb2$p[=
returnnew Page(hasPrePage, hasNextPage, J{c-'Of2yi
everyPage, totalPage, `[x`#irD
currentPage, iDej{95
w7}m
T3p,)
beginIndex); ]&%_Fpx
} C8i6ESmU
1B+uv0lA
privatestaticint getEveryPage(int everyPage){ q]+'{Ci@
return everyPage == 0 ? 10 : everyPage; @KRr$k
} .T0w2Dv/
Stqlp<xy
privatestaticint getCurrentPage(int currentPage){ "i/ l'
return currentPage == 0 ? 1 : currentPage; Oi#F
} xu[6h?u(h8
8/cD7O
privatestaticint getBeginIndex(int everyPage, int Iqe=)
6rlafISvO
currentPage){ ?h)Z ;,}
return(currentPage - 1) * everyPage; /*=1hF
} IfF@$eO
0 =#)-n
privatestaticint getTotalPage(int everyPage, int %:rct
#hPa:I$Oc
totalRecords){ j?sq i9#
int totalPage = 0; )`5kfj
-Bymt[
if(totalRecords % everyPage == 0) a~>.
totalPage = totalRecords / everyPage; 2t'^
else 63R?=u@
totalPage = totalRecords / everyPage + 1 ; 9AQMB1D*v4
}S84^2J_
return totalPage; F!m/n!YR
} e@[9WnxYe
Z9rmlVU6!
privatestaticboolean hasPrePage(int currentPage){ (dZu&
return currentPage == 1 ? false : true; <n+?7`d,
} ?2h)w=dO
oJ}!qrrH
privatestaticboolean hasNextPage(int currentPage,
[7d>c
;OjxEXaq
int totalPage){ m,UMb#7Y
return currentPage == totalPage || totalPage == bs{i@1$
HPM
ggRs
0 ? false : true; Ubtu?wRBW
} ^id9_RU
:ryyo$
\va'>?#o1
} [k)xn3[
Jv*[@
-.k
Imi;EHW
\ZSZ(p#1
AC*>
f&
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。 $Pw@EC]
t
As@0`x9
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 K/)*P4C-
' fXBWi6
做法如下: s^:8bFn9$
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 '~-JR>
Af'L=0
的信息,和一个结果集List: p9c`rl_N
java代码: ID+o6/V8
F$[1KjS
2flgfB}2k
/*Created on 2005-6-13*/ )3h%2C1uM
package com.adt.bo; M'Fa[n*b?!
~loJYq'y
import java.util.List; {Dv^j#
5LJUD>f9Z
import org.flyware.util.page.Page; L< 3U)Gp
4x8e~/
/** 1;O%8sp&
* @author Joa {J_1.uN=
*/ D|zlC,J,
publicclass Result { X}XTEk3[
6 <&jY
private Page page; t^N
92$|
a>w@9
private List content; *=+m;%]_
C)w11$.YQ9
/** d1&RK2
* The default constructor <A% }
*/ (;1rM}B;1
public Result(){ `U-i{i
super(); 3aMfZa<=
} j+B+>r^
-Ucj|9+(a
/** "'389*-
* The constructor using fields \_H-TbU8
* ,:RHhg
* @param page n.}A
:Z
* @param content {R`,iWV
*/ Ml)0z&jQX
public Result(Page page, List content){ iR
k.t=B
this.page = page; \?n4d#=$o
this.content = content; P(H,_7 4
} _FV<[x,nE8
)`Zj:^bz9
/** Jxyeh1zqB
* @return Returns the content. w QV4[
*/ 0}(ZW~&1
publicList getContent(){ [=Qv?am
return content; v4X\LsOP
} }o>6 y>=
zGm#erE
/**
"rnZ<A}
* @return Returns the page. y,I ?3p|S
*/ {Pi+VuLE
public Page getPage(){ jlhyn0
return page; h>s|MZQ:*
} Qi&!Ub]
z^tws*u],5
/** #g)$m}tv?
* @param content l`#XB:#U
* The content to set. S1_X@[t
*/ xR9<I:^&
public void setContent(List content){ NF/@'QRT
this.content = content; -Oj}PGj$e\
} #Y)Gos
Z^Y_+)=s
/** 4';~@IBf
* @param page v
};r
* The page to set. DA>_9o/l
*/ L;wfTZa
publicvoid setPage(Page page){ Mi|PhDXMh
this.page = page; >]6inS9
} [&IJy
} bnll-G|
'|v??`o#
IU
f1N+-z
tS$^k)ZXip
B,`B!rU
2. 编写业务逻辑接口,并实现它(UserManager, "O`{QVg:
9*AH&/EXth
UserManagerImpl) RbexsBq
java代码: 3*N-@;[>b
aT v
XynDo^+ru
/*Created on 2005-7-15*/ %RlG~a
package com.adt.service; +
?z=,')
n|G x29E
import net.sf.hibernate.HibernateException; }3G`f> s
/h/f&3'h
import org.flyware.util.page.Page; zli@X Z#
u}zCcWP|L
import com.adt.bo.Result; ]Q?`|a+i
H9 d!-9I
/** DK!QGATh
* @author Joa j3<|X
*/ 3<5E254N
publicinterface UserManager { P>*B{fi^
m@|0iDS
public Result listUser(Page page)throws #>I*c_-
Zd2B4~V
HibernateException; M qy5>f)
OxGS{zs
} \S]"nHX
<=]wh|D
0nz=whS{
XkG:1H;Q%
b^SQCX+P
java代码: E?L^L3s
ZGstD2N$
6 WD(
/*Created on 2005-7-15*/ %Tc P[<
package com.adt.service.impl; Td7f
;7Hse^Oc
import java.util.List; d0@&2hO
m)5,ut/
import net.sf.hibernate.HibernateException; pN-l82]'
Bz&6kRPv
import org.flyware.util.page.Page; >8I?YT.
import org.flyware.util.page.PageUtil; ~ULD{Ov'F
d&!;uzOx
import com.adt.bo.Result; ,BUDo9h
import com.adt.dao.UserDAO; WFl, u!"A
import com.adt.exception.ObjectNotFoundException; {F Ir|R&
import com.adt.service.UserManager; 0|1)cO}Dy
~OuK ewr\
/** i ,[S1g
* @author Joa )oEHE7 y
*/ #:^aE|s
publicclass UserManagerImpl implements UserManager { 4Nz@s^9
-?m"+mUP
private UserDAO userDAO; [Pn(d[$z
-i,=sZXB
/** C}i1)
* @param userDAO The userDAO to set. tWBfIHiha
*/ 29W~<E8K-
publicvoid setUserDAO(UserDAO userDAO){ 0j=xWC
this.userDAO = userDAO; <{t*yMr
} f!|$!r*q
3Pj#k|(f[0
/* (non-Javadoc) P^wDt14>
* @see com.adt.service.UserManager#listUser y:C=Ni&,"
w=dTa5
(org.flyware.util.page.Page) x#_\b-
*/ S<
TUZ
/;
public Result listUser(Page page)throws *0EB{T1
2J>v4EWC
HibernateException, ObjectNotFoundException { 0
`Yg
int totalRecords = userDAO.getUserCount(); Cb`2" mpWS
if(totalRecords == 0) EAPLe{qw:q
throw new ObjectNotFoundException hI+mx
!Vtj:2PQL
("userNotExist"); 'Gr}<B$A3
page = PageUtil.createPage(page, totalRecords); Q+Sx5JUR~
List users = userDAO.getUserByPage(page); vz\^Aa
#fv
returnnew Result(page, users); OoG Nij
} BZ '63
6k1;62Ntk
} kYwV0xQ
Hp#IOsP~
T-;|E^
GN&-`E]-
~d9R:t1
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 lQkCA-
vr:5+wew
询,接下来编写UserDAO的代码: u\&F`esQ2
3. UserDAO 和 UserDAOImpl: ;ui=7[Us
java代码: &l&B[s6[
,Q7W))j
5a0&LNm
/*Created on 2005-7-15*/ KOYU'hw
package com.adt.dao; p3Ey[kURp
z 2/E?$(
import java.util.List; &8w
MGahp
j'2:z#
import org.flyware.util.page.Page; s-S#qGZ
bhqV2y*'
import net.sf.hibernate.HibernateException; a 8(mU%
+NM`y=@@
/** 3Z taj^v
* @author Joa )2&U
Rt.
*/ +\Zr\fOe|%
publicinterface UserDAO extends BaseDAO {
4s <|8
p7Q}xx
publicList getUserByName(String name)throws qm!&(8NfK
?y1G,0,
HibernateException; dTATJ)NH
p+ki1!Ed
publicint getUserCount()throws HibernateException; .huk>
c9uln
publicList getUserByPage(Page page)throws 9'{i |xG
(**k4c,
HibernateException; oP%'8%tk
eHIsTL@Fp
} <k c9KE
+nOa&d\
bb@3%r|_<
x%$as;
4ayZ.`aK
java代码: z:Q4E|IX
$-J=UT2m
x2 _?B[z
/*Created on 2005-7-15*/ 9pehQFfH
package com.adt.dao.impl; ~T'!.^/
S.E'fc1
import java.util.List;
l
;fO]{
r;~2NxMF/
import org.flyware.util.page.Page; JvI6+[
'Cq)/}0
import net.sf.hibernate.HibernateException; C7hJE-
import net.sf.hibernate.Query; >EJ`Z7E6
B]_NI=d
import com.adt.dao.UserDAO; Gc1!')g!
MODi:jsl
/** DO5H(a
* @author Joa Vs:x3)m5j
*/
mRYM,
public class UserDAOImpl extends BaseDAOHibernateImpl yE3l%<;q
av; ~e<
implements UserDAO { SI~MTUqt
7hq$vI%0
/* (non-Javadoc) xDtJ&6uFw
* @see com.adt.dao.UserDAO#getUserByName T`Jj$Lue{
$z":E(oy
(java.lang.String) #]MV
*/ ?Z{:[.
publicList getUserByName(String name)throws :5 zXW;s
{0?]weN*
HibernateException { ;vkk$
-
String querySentence = "FROM user in class ]?/7iM
'(.vB~m7*+
com.adt.po.User WHERE user.name=:name"; dJYW8pcKT
Query query = getSession().createQuery {] Zet}2
%
a9C]?
(querySentence); Mu>WS)1lS
query.setParameter("name", name); 2 yY.rs
return query.list(); 0;6^fiSY;
} uY"Bgz:=d
aEJds}eE6)
/* (non-Javadoc) >ow5aOlQ&
* @see com.adt.dao.UserDAO#getUserCount() K3xs=q]:@
*/ e ab_"W
publicint getUserCount()throws HibernateException { 2(%C
int count = 0; ~V:@4P
String querySentence = "SELECT count(*) FROM 6+Bccqn|
\5ZDP3I
user in class com.adt.po.User"; Ic,V,#my
Query query = getSession().createQuery O>~ozW&
V+y yy-/
(querySentence); \y\@=j
count = ((Integer)query.iterate().next u,f$cR
9-6E(D-ux
()).intValue(); rf[w&~R
return count; NMCMY<o
} _go1gf7
dK^WZQ
/* (non-Javadoc) z}sBx9;
* @see com.adt.dao.UserDAO#getUserByPage /CT g3Q"KQ
hOTqbd}
(org.flyware.util.page.Page) Y7L1`<SC
*/ ex}6(;7)O
publicList getUserByPage(Page page)throws ]|#%`p56
FfET45"l
HibernateException { )K"7=TvY
String querySentence = "FROM user in class EWX!:BKf
p0b2n a
!
com.adt.po.User"; no`> r}C
Query query = getSession().createQuery >kN%R8*Sx
6Pzz= ai<
(querySentence); q,->E<8
query.setFirstResult(page.getBeginIndex()) 9bVPMq7}i
.setMaxResults(page.getEveryPage()); k5X& |L/
return query.list(); rERHfr`OU
} ySXQn#}-,
`dpm{sn
} U`HSq=J
]!=,8dY
D$W09ng-
tc2e)WZP
r:QLO~l/
至此,一个完整的分页程序完成。前台的只需要调用 N7WQ{/PSG
nYF;.k
userManager.listUser(page)即可得到一个Page对象和结果集对象 )vcyoq
tI-u@
g
的综合体,而传入的参数page对象则可以由前台传入,如果用 l^,"^vz
^vQ,t*Uj=
webwork,甚至可以直接在配置文件中指定。 }1)tALA
*>%tx k:)
下面给出一个webwork调用示例: O,+ZD^
java代码: m0(]%Kdw
}wkZ\q[
@$bEY#*C
/*Created on 2005-6-17*/ [ {|868
package com.adt.action.user; pMy];9SvW
t R(Nko
import java.util.List; @9X+ BdQU
'U8% !
import org.apache.commons.logging.Log; o7A+O%dX
import org.apache.commons.logging.LogFactory; 2&+Nr+P
import org.flyware.util.page.Page; ^o@N.+`&<
u#&ZD|
import com.adt.bo.Result; =,4iMENm!
import com.adt.service.UserService; X":T>)J-
import com.opensymphony.xwork.Action; FO/[7ZH
q(C <w
/** {*jo,<4ee
* @author Joa o8A1cb4<T
*/ D+u#!t[q
publicclass ListUser implementsAction{ X\yy\`o
j4fv-{=$
privatestaticfinal Log logger = LogFactory.getLog Dno'-{-
`uN}mC!r]
(ListUser.class); #@cOyxUt
)^^Eh=Kbj
private UserService userService; $afE=
qC*
E/6@>.T?'
private Page page; q]qKU`m!Q`
4U1!SR]s
privateList users; `YinhO:Z
OlwORtWzZ
/* -? |-ux
* (non-Javadoc) x%WL!Lo
* \j$q';9p
* @see com.opensymphony.xwork.Action#execute() p!wx10b
*/ C72!::o
publicString execute()throwsException{ >2%*(nL
Result result = userService.listUser(page); `BA,_N|6
page = result.getPage(); N;A#K7A[@
users = result.getContent(); 5,,b>Z<
return SUCCESS; F^mMyK
} k ='c*`IE
2Kg+SLU[~
/** [!k#au+#c
* @return Returns the page. 4-wCk=I
*/ l^$8;$Rq
public Page getPage(){ PI5a'k0F
return page; Y4 <
} XC
D &Im
-hpJL\ng
/** REe<k<>p~
* @return Returns the users. =%\y E0#
*/ !4blX'<w
publicList getUsers(){ i3s,C;7[2
return users; uoIvFcb^
} D_W,Jmet
o_K.
+^$
/** LG/6_t}
* @param page e_6-+l!f
* The page to set. e9 `n@
*/ Uo7V)I;o
publicvoid setPage(Page page){ M2.Pf s
this.page = page; 3,QsB<9Is
} 9\aR{e,1
QS*!3?%
/** O6[, K1,
* @param users yHka7D
* The users to set. FuKp`T-H
*/ 9~En;e
publicvoid setUsers(List users){ !}TZmwf'
this.users = users; Y~j)B\^{
} '^!1A GF
aIA9rn
/** Eed5sm$H
* @param userService xXJl Qbs
* The userService to set. PZDj)x_%B&
*/ S5W*,?
publicvoid setUserService(UserService userService){ '|9fDzW"]
this.userService = userService; rerl-T<3
} (q@DBb4
} )G
a%Eg9
_Kw<4$0<p
B}(+\Q$I
[YsN c
me7?
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, CXZO
|?tUUT!`t
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 2GHmA_7P
ks=l
Nz9
么只需要: vuOixAkw
java代码: rTgCmr'&
?/SI A9VK
{5$.:Y
<?xml version="1.0"?> U1Z.#ETnM
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 4}4K6y<q
h]DS$WZ
1.0//EN" "http://www.opensymphony.com/xwork/xwork- 3%g\)Cs
R43yr+p
1.0.dtd"> 5$(qnOi
ncGg@$E
<xwork> L*rND15
*gJ:irah
<package name="user" extends="webwork- ";&5@H|
\KGi54&Y
interceptors"> sI@y)z
3Pj 6(cf
<!-- The default interceptor stack name zJ*|tw4
u Z(vf
--> r fl-(_3
<default-interceptor-ref @-7h}2P Q
f:=y)+@1My
name="myDefaultWebStack"/> 6eUM[C.
{GTOHJ2
<action name="listUser" E>bK-jG
bpQ5B'9
class="com.adt.action.user.ListUser"> r&u&$"c
<param sbxOnwP\
tML[~AZh
name="page.everyPage">10</param> l;N?*2zm[
<result aCq ) hR
|6M:JI8
name="success">/user/user_list.jsp</result> u@;6r"8q
</action> Y[hTO.LF
yBd#*3K1
</package> U]aH4N
K>"]*#aBv
</xwork> ?"d25LyN
WSt&?+Y
x*Lm{c5+
u~WE}VC
^1#"FU2cP
Qh4<HQ<9
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 O%1X[
?k5m1,fHW
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。 D8`dEB2|S
r+4<Lon~
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 3kTOWIX
HF2w?:
vZDM}u
0/1Ay{ns
YA";&|V
我写的一个用于分页的类,用了泛型了,hoho |>/T*zk<
*Zj2*e{Z9U
java代码: :sf(=Y.qA
p~n62(
J=%(f1X<W
package com.intokr.util; 20Umjw.D
[VD)DO5
import java.util.List; {Qe7/ln!
V Z#@7t
/** [&tN(K9*
* 用于分页的类<br> !\)9fOLs
* 可以用于传递查询的结果也可以用于传送查询的参数<br> 9Y6Ear .W
* XLog+F$`
* @version 0.01 %^5|3l3y
* @author cheng ;;A8TcE
'
*/ 4iXB`@k
public class Paginator<E> { :`pgdn
privateint count = 0; // 总记录数 0[f8Gb3
privateint p = 1; // 页编号 _a~uIGN
privateint num = 20; // 每页的记录数 &<oZl.T
privateList<E> results = null; // 结果 ([mC!d@a
\:'|4D]'I
/** a2'si}'3
* 结果总数 MmZs|pXk
*/ 9kpCn.rJ
publicint getCount(){ yF~iVt
return count; 6N6}3J5
} qu}&4_`%:V
4
Qo(Wl
publicvoid setCount(int count){ 3 NLC~CJ
this.count = count; ^Yz.}a##w2
} Vy-kogVt
>ZE8EL
/** <~rf;2LZ
* 本结果所在的页码,从1开始 /2<1/[#
* y; .U-}e1
* @return Returns the pageNo. ,KfBG<3
*/ dbmty|d
publicint getP(){ Y&G]M
return p; \Q
CH.~]
} <b5J"i&m
4v=NmO}
/** \Y>!vh X
* if(p<=0) p=1 3I" <\M4x
* 'Q^P#<<
* @param p l2AAEB_C.
*/ e=8z,.Xk
publicvoid setP(int p){ &fyT}MA
if(p <= 0) xE[CNJ%t^,
p = 1; |i}5vT78
this.p = p; _ ?\4k{ET
} O%>FKU>(?
R*DQm
/** 3U_,4qf
* 每页记录数量 c`F~vrr)X
*/ *c0\<BI
publicint getNum(){ i uNBw]
return num; tn"n~;Bh?:
} Hq>"rrVhx
T|/B}srm
/** O%$XgEJ8p
* if(num<1) num=1 {<p-/|Z52
*/ ~ sC< V
publicvoid setNum(int num){ |%i|P)]
if(num < 1) NV[_XXTv7
num = 1; l6AG!8H
this.num = num; U&(TqRi,
} uTX0lu;
Nydhal00
/** GC<zL}
* 获得总页数 |x
Nd^
*/ 7jf%-X
publicint getPageNum(){ DKvNQ:fI>9
return(count - 1) / num + 1; 6G6B!x
} f19~B[a
b{Qg$ZJeR
/** x}c%8dO#J
* 获得本页的开始编号,为 (p-1)*num+1 F1q a`j^'
*/ *<5zMSZO
publicint getStart(){ W=$cQ(x4Z
return(p - 1) * num + 1; P+hp'YK1
} #nzVgV]
.Lvg
$d
/** bsn.HT"5
* @return Returns the results. qMA K"%x
*/ ,rO>5$ w.
publicList<E> getResults(){ jgkJF[t`
return results; #Q6.r.3@x
} ]Zj6W9]m
r=`]L-}V
public void setResults(List<E> results){ #Fl5]> |
this.results = results; *1>zE>nlP
} Bl
>)G X\l
s--\<v
public String toString(){ =s\RK
StringBuilder buff = new StringBuilder :J'ibb1
,)CRozC\}K
(); 4;_<CB
buff.append("{"); o|FY-+
buff.append("count:").append(count); IhRYV`:
buff.append(",p:").append(p); -%h0`hOG{
buff.append(",nump:").append(num); 60A
E~
buff.append(",results:").append UP*\p79oO
nj@l5[
(results); +dt b~M
buff.append("}"); On^jHqLaE
return buff.toString(); )]^xy&:|
} _BA2^C':c{
pFUW7jE
} mHnHB.OL
)Q!3p={S*
*/kX|Sur