Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 {14sI*b16
[Ontip
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 u\P)x~-TM
y];@ M<<?e
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 @j+X>TD
'Z`fZ5q
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 _VI3b$
p5 )+R/
。 )ioIn`g^-
fhbILg
分页支持类: ;ksxz
Xr$hQbl5D
java代码: p^i]{"sjbU
:IX_}|
cvO;xR
package com.javaeye.common.util; <G#z;]N
V|G[j\]E<
import java.util.List; 6uubkt
-K U@0G
publicclass PaginationSupport { 8b:\@]g$
VO+3@d:
publicfinalstaticint PAGESIZE = 30; ["XS|"DM
8,YxCm ie
privateint pageSize = PAGESIZE; 0/0rWqg
/
8`;3`lZ
privateList items; MRL,#+VxA
dX;G[\
privateint totalCount; 77o&$l,A|
jG~UyzWH;
privateint[] indexes = newint[0]; V'XvwO@
J&jig?t
privateint startIndex = 0; 7T@"2WYat
~AG."<}
public PaginationSupport(List items, int kU$M 8J.
)0xEI
totalCount){ aIABx!83>
setPageSize(PAGESIZE); NZ?| #53
setTotalCount(totalCount); .47tj`L
setItems(items); lp%i%*EQ*
setStartIndex(0); ]#Q'~X W
} FAP1Bm
hV>@qOl
'
public PaginationSupport(List items, int et0yS%7+?@
z]F4Z'(e.
totalCount, int startIndex){ 32ae? d
setPageSize(PAGESIZE); m=p<.%a
setTotalCount(totalCount); NP5;&}uv*!
setItems(items); >" z&KZKI
setStartIndex(startIndex); >Gyg`L\
} {uuvgFC
I6,sN9`
K
public PaginationSupport(List items, int 6mbHfL>cO
d( +E0
totalCount, int pageSize, int startIndex){ XG_Iq ,
setPageSize(pageSize); UONW3}-
setTotalCount(totalCount); 7]6HXR @
setItems(items); A1nEp0%Y
setStartIndex(startIndex); M/^kita
} 2gb MUdpp
{ei,>5K
publicList getItems(){ w=S7zzL)
return items; /]*#+;;%
} W mT(>JBO
2e @zd\
publicvoid setItems(List items){ |`yzH$,F
this.items = items; ewb/Z[4
} POCF T0R}
zO07X*Bw
publicint getPageSize(){ (6Sf#M
return pageSize; ^XQr`CqI
} V`z2F'vT
H<6/i@ly
publicvoid setPageSize(int pageSize){ ,0R2k `m!
this.pageSize = pageSize; M:OJL\0
} 9AROvq|#
I+^B] @"
publicint getTotalCount(){ 9#AsSbBpf
return totalCount; @43o4,
} >f*[U/{ K
a>{b'X^LV
publicvoid setTotalCount(int totalCount){ |. zotEh
if(totalCount > 0){ ]Ak@!&hyak
this.totalCount = totalCount; -j 6U{l
int count = totalCount / )!``P?3?
&]2z)&a
pageSize; C^x+'. ^N
if(totalCount % pageSize > 0) g)Byd\DS
count++; +T@a/(Gl
indexes = newint[count]; `kP
(2b
for(int i = 0; i < count; i++){ =7c1l77z
indexes = pageSize * :
*Nvy={c
hA81(JWG
i; r&|-6OQZZ
} VIxt;yE
}else{ Sh_ =dzM
this.totalCount = 0; ?"no~(EB
} @Pc]qu
} l&d 6G0
g(0
|p6R
publicint[] getIndexes(){ $LF
return indexes;
Bjz\L0d
} s2@}01QPo
_~`\TS8
publicvoid setIndexes(int[] indexes){ ]<;m;/H
this.indexes = indexes; Svmyg]
} b:}`O!UBw
Z Tx~+'(
publicint getStartIndex(){ Y@S?0
return startIndex; /WVnyz0
} |WB<yA1
MKdBqnM(F
publicvoid setStartIndex(int startIndex){ ZN2g(
if(totalCount <= 0) t_q`wKDE
this.startIndex = 0; nJ|8#U7
elseif(startIndex >= totalCount) !t["pr\
?
this.startIndex = indexes I,r 3.2u
%&yD^q_
[indexes.length - 1]; Yp`6305f
elseif(startIndex < 0) w
1E}F
this.startIndex = 0; _=_]Yx
else{ *Bt`6u.>e,
this.startIndex = indexes /AR;O4X+
q($lL~Ls
[startIndex / pageSize]; JqO#W1h~R|
} TIV1?S
} PZF>ia}
d{f3R8~Q.
publicint getNextIndex(){ <)zh2UI
int nextIndex = getStartIndex() + B(mxW8y
EO,;^RtB
pageSize; A`7uw|uO$
if(nextIndex >= totalCount) 'r%`(Z{~
return getStartIndex(); daaEN(
else QY2!.a^q
return nextIndex; sa`7_KB
} $.}fL;BzVz
ih?_ fW
publicint getPreviousIndex(){ +0=u]
int previousIndex = getStartIndex() - EvMhNq~y5
w.cQ|_
pageSize; vL13~q*F
if(previousIndex < 0) :rb<mg[
return0; P sD+?
else )@3ce'
return previousIndex; QJo)
} Xu$xO(
#Xri%&~
} ke~O+]
_y)#N<
J[UL
f7:
0gVylQ
抽象业务类 "JSg/optc
java代码: 7g5sJj
+V&b<y;?>
;0}$zy1EZ
/** WZRrqrjq
* Created on 2005-7-12 A~-e?.
*/ K$Y!d"D
package com.javaeye.common.business; H!&]Di1Eh
TeQWrms
import java.io.Serializable; BpCzmU
import java.util.List; E`>-+~ZUsk
9p(s FQ
[
import org.hibernate.Criteria; .*D~ .!
import org.hibernate.HibernateException; E/ (:\Cm^
import org.hibernate.Session; KS'? DO
import org.hibernate.criterion.DetachedCriteria; 4D[W;4/p
import org.hibernate.criterion.Projections; -)
$$4<L
import =4yME
lMp)T**
org.springframework.orm.hibernate3.HibernateCallback; -<}_K,Ky`
import qSMSTmnQ
El0|.dW
org.springframework.orm.hibernate3.support.HibernateDaoS Og%qv
Bj 6
K|Std)6
upport; /wI$}X5o~
p0uQ>[NV0
import com.javaeye.common.util.PaginationSupport; Aa.bE,W
V_!hrKkL
public abstract class AbstractManager extends Gy
'l; 2
1c,$D5#
HibernateDaoSupport { ,g{`M]Ov
TH)gW
privateboolean cacheQueries = false; G F,/<R #
G[6V=G
privateString queryCacheRegion; ?`,UW; Br6
iO3@2J
publicvoid setCacheQueries(boolean Tm[IOuhM'?
X'ryfa1|
cacheQueries){ c^UG}:Y
this.cacheQueries = cacheQueries; BG~h9.c
} 9<P1?Q
!3 $Ph
publicvoid setQueryCacheRegion(String k5=0L_xc
,;H)CUe1"
queryCacheRegion){ qbHb24I
this.queryCacheRegion = ve=oH;zf
Gs.id^Sf
queryCacheRegion; FbJlyWND
} +D`IcR-x
"m _wYX
publicvoid save(finalObject entity){ c5<M=$
getHibernateTemplate().save(entity); g-meJhX%
} Am!$\T%2
r.[!n)*
publicvoid persist(finalObject entity){ O|#^ &d
getHibernateTemplate().save(entity); )fpZrpLXE
} D^I%tn=F
Cz
Jze
publicvoid update(finalObject entity){ me$7\B;wy
getHibernateTemplate().update(entity); :^1 Xfc"
} E*.D_F
?H0 #{!s
publicvoid delete(finalObject entity){ &I:5<zK{
getHibernateTemplate().delete(entity); mE%H5&VSI
} m/JpYv~
EP'2'51
publicObject load(finalClass entity, B:a&)Lwp0
%[-D&flKC
finalSerializable id){ Sh*LD
QL<?
return getHibernateTemplate().load /{d7%Et6
fZ]Y
(entity, id); V3xC"maA@
} d5\w'@Di
c@~\ FUr
publicObject get(finalClass entity, 7z)Hq./3@
BE:HO^-.1
finalSerializable id){ ; GRSe
return getHibernateTemplate().get #)tt}GX
7*M+bZ`x
(entity, id); ckBcwIXlP&
} 8U*}D~%!
|(*ReQ?=
publicList findAll(finalClass entity){ cMsm[D{b
return getHibernateTemplate().find("from - ~T LI&[
7d]}BLpjWz
" + entity.getName()); :xm,Ok
} ga?.7F
>jME
== U0
publicList findByNamedQuery(finalString ~M3`mO+^U
#O/ihRoaO
namedQuery){ s}uOht}
o
return getHibernateTemplate /d&zE|!
HO/Ij
().findByNamedQuery(namedQuery); |gA~E>IqF
} c-z
,}`
81O`#DfZ
publicList findByNamedQuery(finalString query, 5yI_uQR
4)!aYvaER
finalObject parameter){ :,Q\!s!
return getHibernateTemplate ?gY^,Ckj
{k%*j 4
().findByNamedQuery(query, parameter); ']4b}F:}
} b\Y<1EV^[
ZO5_n
publicList findByNamedQuery(finalString query, .EM0R\q
0WaC.C+2i
finalObject[] parameters){ B?`Gs^Y{z
return getHibernateTemplate O[U^{~iM
|`1lCyV\tE
().findByNamedQuery(query, parameters); D kl4^}
} JQj?+PI
4%LG Ph
publicList find(finalString query){ mFw`LvH?*
return getHibernateTemplate().find KbQ UA$gL=
2%'{f
(query); <La$'lG4J
} -hiG8%l5
SpU+y|\[0
publicList find(finalString query, finalObject Wl/oun~o
7+0Kg'^+n
parameter){ U$&G_&*0a
return getHibernateTemplate().find [fiB!G]?
!1$QNxgi
(query, parameter); =&;orP
} xeF0^p7Z
s!X@ l
public PaginationSupport findPageByCriteria 0?8O9i
<^c?M[j
(final DetachedCriteria detachedCriteria){ y[:\kI
return findPageByCriteria 9=O`?$y
l=ehoyER
(detachedCriteria, PaginationSupport.PAGESIZE, 0); ~[l6;bn
} fb3(9
4{=zO(>
public PaginationSupport findPageByCriteria l\xcR]O
hOw
(final DetachedCriteria detachedCriteria, finalint S.pL^Ru
Q1yMI8
startIndex){ {+%|nOWV
return findPageByCriteria S
{oW
B9^@d
(detachedCriteria, PaginationSupport.PAGESIZE, I(tMw6C$:
OJ^kESrm8
startIndex); K4~z@.
G6*
} d7waBsf
&*}`uJt
public PaginationSupport findPageByCriteria ?~X*\
vik A
(final DetachedCriteria detachedCriteria, finalint ;rXkU9
R?MRRq
pageSize, E
w#UlA:"v
finalint startIndex){ 44C"Pl
E
u
return(PaginationSupport) h+=xG|1R[5
v EppkS U1
getHibernateTemplate().execute(new HibernateCallback(){ -< D7
publicObject doInHibernate yw2Mr+9I
$c"byQ[3S
(Session session)throws HibernateException { 9'nM$a
Criteria criteria = N3dS%F,_
TgMa!Vz
detachedCriteria.getExecutableCriteria(session); g@0<`g
int totalCount = HY-7{irR~
$cjwY$6
((Integer) criteria.setProjection(Projections.rowCount HYU-F_|N=
uq?((
()).uniqueResult()).intValue(); }p,#rOX:A
criteria.setProjection (K9pr>le
\ OPJ*/U
(null); x-27rGN
List items = &O8vI,M
riw0w
criteria.setFirstResult(startIndex).setMaxResults 7q\&
RP[^1
(pageSize).list(); 2E5n07,
PaginationSupport ps = +g %h,@
! |4fww
new PaginationSupport(items, totalCount, pageSize, cxX/ b,
LX f r
startIndex); "#}Uh
return ps; Q1f)uwh
} (bhMo^3/*
}, true); %G6Q+LMwm
} *rKj%Me
<"/b 5kc
public List findAllByCriteria(final N;Hoi8W
-c%#Hd
DetachedCriteria detachedCriteria){ ,~8&0p
return(List) getHibernateTemplate 03N|@Tu
C_>
WU
().execute(new HibernateCallback(){ mnzB90<
publicObject doInHibernate E~}@56ER}
+"J2k9E
(Session session)throws HibernateException { @M( hyS&on
Criteria criteria = s Zn@y e^
N"/J1
detachedCriteria.getExecutableCriteria(session); Pgug!![
return criteria.list(); `U4e]Qh/+
} {7d(B1[1
}, true); <S[]VXy
} BjX*Gm6l
,4W~CkLD
public int getCountByCriteria(final %u=b_4K"j
kPRG^Ox8e
DetachedCriteria detachedCriteria){ 6&oaxAp<s
Integer count = (Integer) <Wrn/%tL
I{nrOb1G(
getHibernateTemplate().execute(new HibernateCallback(){ q,;8Ka )
publicObject doInHibernate S?Y%}
oS>VN<
(Session session)throws HibernateException { !LI
8Xk
Criteria criteria = DP@F-Q4
jJ.isr|`
detachedCriteria.getExecutableCriteria(session); ATRB9
return wWYo\WH'
itYTV?bd
criteria.setProjection(Projections.rowCount
]v2%h X
cG)U01/"
()).uniqueResult(); C>NLZMT
} F)8M9%g5m
}, true); shkyN
return count.intValue(); g9~QNA
} >DM^/EAG{
} iQd,xr
^7Z#g0{^w
oaac.7.fV
Jb;@'o6
7&`Yl[G
c`Q#4e]%_
用户在web层构造查询条件detachedCriteria,和可选的 /Fj*sS8
8*x/NaH
/\
startIndex,调用业务bean的相应findByCriteria方法,返回一个 \Gl>$5np
aM5Hp>'nI
PaginationSupport的实例ps。 Ll$,"}0T
N({0" 7
ps.getItems()得到已分页好的结果集 BbIg]E/G
ps.getIndexes()得到分页索引的数组 `;
+UWdAR
ps.getTotalCount()得到总结果数 "?AJ(>wP
ps.getStartIndex()当前分页索引 sq rY<@%
ps.getNextIndex()下一页索引 S7v# `#
ps.getPreviousIndex()上一页索引 }'`iJb\
Mg~62u
V}aZ}m{J
%\f<N1~*
`RlMfd
@f!r"P]
]mR!-Fqj
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 mI>=S
t) uS7y
,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 )BeBxo7lv
-|DBO0q
一下代码重构了。 %n{ue9
W0+m A
我把原本我的做法也提供出来供大家讨论吧: ooA%/
B<{Yj}..
首先,为了实现分页查询,我封装了一个Page类: 0/5{v6_rG
java代码: d_1uv_P
GIM'H;XG
#O1%k;BL
/*Created on 2005-4-14*/ mS?W+jy%
package org.flyware.util.page; 9,jFQb(),
^aI$97Li
/** 45 B
|U
* @author Joa itmFZZh
* Oil~QAd,
*/ oiRrpS\T.
publicclass Page { ^Lc, w
fB=j51Lw
/** imply if the page has previous page */ {
Ba_.]x
privateboolean hasPrePage; ZH)thd9^b
Ba}<X;B }
/** imply if the page has next page */ .+A2\F.^
privateboolean hasNextPage; o?|
]ciY
GL-Pir
/** the number of every page */ nN%Zed2O@6
privateint everyPage; nV/;yl4e{
m;cgX#k5
/** the total page number */ *@eZt*_
privateint totalPage; bH}?DMq]O
w6
/** the number of current page */ \R[f< K%
privateint currentPage; ,1
^IFBJ
K3^2;j1F Q
/** the begin index of the records by the current LEd@""h
_ SJFuv/
query */ G-[.BWQ
privateint beginIndex; Ex+E66bE
7-Mm+4O9
}B`T%(11=
/** The default constructor */ !B/5@P
public Page(){ MLvd6tIv,
kYZj^tR
} HhB&vi
"IJ 9vXI
/** construct the page by everyPage tjJi|
* @param everyPage a v"dJm
* */ 4 3G2{
public Page(int everyPage){ =X3Rk)2r
this.everyPage = everyPage; |"+UCAU
} CwaW>(`v
u=
Vt3%q
/** The whole constructor */ o(stXa
public Page(boolean hasPrePage, boolean hasNextPage, J+u z{
gaU(ebsE
FO:k
>F
int everyPage, int totalPage, | Zj=E$
int currentPage, int beginIndex){ s x2\
this.hasPrePage = hasPrePage; ZC97Z sE
this.hasNextPage = hasNextPage; cD'|zH]
this.everyPage = everyPage; 8,L)=3m-
this.totalPage = totalPage; 4W<8u(
this.currentPage = currentPage; JIXZI\Fk
this.beginIndex = beginIndex; &?*H`5#?G
} i#I7ncX
hQ}y(2A.XI
/** TG6E^3a P
* @return Qe;R3D=T;
* Returns the beginIndex. .R_-$/ZP
*/ cH`ziZ<&m1
publicint getBeginIndex(){ UIo jXR<
return beginIndex; ebiOR1)sN
} MI,kKi
c JOT{
/** ,HwOMoP7
* @param beginIndex Q\pI\]p:
* The beginIndex to set. Z$y~:bz
*/ $O9,Gvnxx
publicvoid setBeginIndex(int beginIndex){ 'wjL7PI
this.beginIndex = beginIndex; r:5u(2
} q|QkJr<
J3y4D}
/** <_#a%+5d
* @return jg3T1ROL
* Returns the currentPage. IzlmcP3
*/ g|<$\}
publicint getCurrentPage(){ -"5r-q q*
return currentPage; <xh";seL
} 78kT}kgW
>dfk2.6e
/** #;hYJ Y
* @param currentPage ;v m$F251
* The currentPage to set. F/:Jp3@
*/ i\C~]K~O!
publicvoid setCurrentPage(int currentPage){ =2/[n8pSsM
this.currentPage = currentPage; "$ U!1
} "bA8NQIP
9uW\~DwsZ%
/** mI,!8#
* @return :xZ^Jq91
* Returns the everyPage. Ja{[T
*/ fBnlB_}e
publicint getEveryPage(){ u5A$VRMN
return everyPage; S3sxK:
} vJsx_i\i
aH*5(E]
/** 1? Im"
* @param everyPage :,Mg1Zf
* The everyPage to set. dPmNX-'7
*/ %<h+_(\h
publicvoid setEveryPage(int everyPage){ wqAj=1M\
this.everyPage = everyPage; Q6hWHfS
} dReJ;x4
]::g-&%Um
/** N _|tw
* @return hw0u?++
* Returns the hasNextPage. kB=\a(
*/ t{Z:N']H
publicboolean getHasNextPage(){ GI)eq:K_U8
return hasNextPage; qHE( p+]E
} "U*6?]f
lH"4"r
/** #_'|
TT>p#
* @param hasNextPage '<Jqp7$dL
* The hasNextPage to set. qx`)M3Mu|<
*/ f~{4hVA
publicvoid setHasNextPage(boolean hasNextPage){ E\vW>g*W
this.hasNextPage = hasNextPage; />dYk Iv
} UJk/Lxv
-P-&]F5
/** -P We
* @return ,m1F<Pdts
* Returns the hasPrePage. M6H#Y2!ZbC
*/ []hC*
publicboolean getHasPrePage(){ &'oZ]}^0
return hasPrePage;
f~w!Z
} 8'o6:
b9 TsuY
/** O^sOv!!RH/
* @param hasPrePage xMHu:,ND
* The hasPrePage to set. |6!L\/}M%
*/ /Gvd5
publicvoid setHasPrePage(boolean hasPrePage){ ;}4^WzmK^(
this.hasPrePage = hasPrePage; @Q%<~b[y
} (!0fmL
tl^![Z
/** #pr{tL
* @return Returns the totalPage. y\zRv(T=
* OpFm:j3
*/ B-W8Zq#4>
publicint getTotalPage(){ L%
`lC]
return totalPage; !uSG 1j"y
} 'ARbJ1a
D\k'Eez
/** mcq.*at
* @param totalPage PiF &0;
* The totalPage to set. agj_l}=gO
*/ 6 B*,Mu4A
publicvoid setTotalPage(int totalPage){ 4Bk9d\z
this.totalPage = totalPage; C(}N*e1
} w=QW8q?
KYR64[1
} ##BfI`FJ
_7b' i6-
\&b1%Asyz
UQ}#=[)2e
sU0W)c;
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 V~fPp"F
pd}Cg'}X
个PageUtil,负责对Page对象进行构造: 1)hO!%
java代码: tPaNhm[-q7
=_Ip0FfK!
ayrCLv
/*Created on 2005-4-14*/ 1`)e}p&
package org.flyware.util.page; +{au$v}
I8Q!`KJ
import org.apache.commons.logging.Log; oe,yCdPs
import org.apache.commons.logging.LogFactory; Xhp={p;
^~7ouA
/** 9z kRwrQ
* @author Joa f]48>LRE8
* PdSYFJM
*/ Z\>mAtm
publicclass PageUtil { D2]i*gs
dZ`c
privatestaticfinal Log logger = LogFactory.getLog _p;=]#+c&
E~`l/ W
(PageUtil.class); ,dXJCX8so
{P'^X+B0*
/** xP-\)d-.aN
* Use the origin page to create a new page 36UUt!}p
* @param page U5yBU9\G
* @param totalRecords EGxCNB
* @return bE6bx6=u
*/ 'J_`CS
publicstatic Page createPage(Page page, int $d5}OI"g
!![HR6"Q
totalRecords){ ?g9oiOhnG
return createPage(page.getEveryPage(), x*!%o(G
OQiyAyX
page.getCurrentPage(), totalRecords); DdCNCXU
} 8 t`lRWJ
7&
'p"hF
/** 85qD~o?O
* the basic page utils not including exception d[`vd^hI
+'{d^-( (
handler GUC.t7!
* @param everyPage ^T*'B-`C7X
* @param currentPage `Jn2(+
* @param totalRecords y&6 pc
* @return page (D2N_l(`<
*/ .O6(QI*
publicstatic Page createPage(int everyPage, int %/w%A:y#&
jJyS^*.X
currentPage, int totalRecords){ )8%m|v#W
everyPage = getEveryPage(everyPage); nd~O*-uYg
currentPage = getCurrentPage(currentPage); A5go)~x\
int beginIndex = getBeginIndex(everyPage, ne
8rF.D
6)yi^v
currentPage); T&^b~T(y
int totalPage = getTotalPage(everyPage, ).IK[5Q`
odKdpa
Zc[
totalRecords); `y$@zT?j
boolean hasNextPage = hasNextPage(currentPage, szGGw
Y(F>;/AA
totalPage); eS/Au[wS
boolean hasPrePage = hasPrePage(currentPage); "Z)zKg
!OV+=Rwdx
returnnew Page(hasPrePage, hasNextPage, e#!p6+#"
everyPage, totalPage, 2?@Ozr2Uh
currentPage, `J%35
AmB*4p5b
beginIndex); WSbD."p<
} [oOV@GE
a/xnf<(H
privatestaticint getEveryPage(int everyPage){ "f:_(np,
return everyPage == 0 ? 10 : everyPage; Ou{VDE
} zg$NrI&
/ "@cv{
privatestaticint getCurrentPage(int currentPage){ =F09@C,
return currentPage == 0 ? 1 : currentPage; 5xhYOwQBo
} R5=M{
6"yIk4u:
privatestaticint getBeginIndex(int everyPage, int Y2$xlqQd"
`\yQn7 Oq
currentPage){ Qv]>L4PO
return(currentPage - 1) * everyPage; ),XDY_9K
} rmeGk&*R8
v9"03=h
privatestaticint getTotalPage(int everyPage, int !q 9PO
RV),E:?
totalRecords){ xwojjiV
int totalPage = 0; oZ>2Tt%
Rw^X5ByJE
if(totalRecords % everyPage == 0) a xz-H`oq4
totalPage = totalRecords / everyPage; X*t2h3"}
else -nqq;|%
totalPage = totalRecords / everyPage + 1 ; 3&zcdwPj
|?t}7V#[
return totalPage; {_ {zs!r
} vngn^2
g\pLQH
privatestaticboolean hasPrePage(int currentPage){ }pKKNZ`[
return currentPage == 1 ? false : true; R%6KxN)+@
} GHpP
*x
6|QIzs<Z-X
privatestaticboolean hasNextPage(int currentPage, )i<Qg.@MX
>[S\NAE>
int totalPage){ $:D\yZ,
return currentPage == totalPage || totalPage == > ,x``-
p8MN>pLP%
0 ? false : true; 9\>{1"a
} Sb^o`~ Eh
^1bM=9]F0
XA\wZV
|{
} ?u>A2Vc!
%*OQH?pyx}
0zE(:K
Iz8gZ:rd0
2E0oLl[
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。 |eqp3@Y1E
|y4j:`@.
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 /L=Y8tDt
as"@E>a
做法如下: _|7bpt9
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 mXI'=Vo!S
6L3i
的信息,和一个结果集List: <sG}[:v
java代码: dst!VO:
M
{dwlW`{
$pauPEe
/*Created on 2005-6-13*/ e6Kyu*
package com.adt.bo; QObHW[:F
5ljEh -
import java.util.List; V`}u:t7r
@zT2!C?^L
import org.flyware.util.page.Page; }$#PIyz
W8M(@*
T
/** Z<#h$XUA
* @author Joa Lc0=5]D
*/ ?N&s.
publicclass Result { 1ezBnZJg
T3PwM2em_`
private Page page; d?aZk-|c
,3W,M=j)
private List content; Y?:"nhN
<MJ-w1A
/** *9(E0"
* The default constructor 3-BC4y/
*/ DK1{Z;Z
public Result(){ _% i!LyG
super(); E+J +fi
} (?ZS9&y}
Tj6kCB
/** p5J!j I=
* The constructor using fields mp8Zb&Ggb
* ~R~eQ=8
* @param page ]3uj~la
* @param content C)ic;!$Qhb
*/ V6_~"pRR=
public Result(Page page, List content){ L&&AK`Ur3l
this.page = page; <GSp%r
this.content = content;
_+}f@&"
} oo|Nu+
;#=y5Q4
/** '`j MNKn\
* @return Returns the content. OV`li#H
*/ J:G{
publicList getContent(){ W&7(
return content; 9]:F!d/
} fvj
yh{U!hG
/** AsR}qqG
* @return Returns the page. ]j]<CqG
*/ 0@RVM|
public Page getPage(){ L$ZsNs+
return page; [ ^gb6W9Y
} o90[,
N'Vj& DWC
/** r`e6B!p
* @param content ?=b#H6vs
* The content to set. )NO,G
*/ W
Haf}.V
public void setContent(List content){ AI-ZZ6lzR
this.content = content; fJ+4H4K
} lXXWQ=
M,we,!B0
/** !\\OMAf7
* @param page zIr4!|X
* The page to set. G6s3\de#U
*/ |Rz}bsrZ
publicvoid setPage(Page page){ #I#_gjJkx
this.page = page; Z<'iT%6+r
} S$/SFB$)~W
} 60l!3o"p!
MHS|gR.c
dRUmC H
k0D):
B.~[m}
2. 编写业务逻辑接口,并实现它(UserManager, (/7cXd@\6
YD#L@:&gv
UserManagerImpl) ?O0,)hro
java代码: ~J
>Jd
_)6r@fZ.p
r(<91~Ww
/*Created on 2005-7-15*/ 3gv?rJV
package com.adt.service; r9p ((ir
I_|W'%N]
import net.sf.hibernate.HibernateException; &_' evZ8
V!s#xXD }
import org.flyware.util.page.Page; ,My'_"S?
p4P"U
import com.adt.bo.Result; MRzY<MD
yO@@-)$[y
/** &D&U!3~(
* @author Joa 5kCXy$"%
*/ nLR
publicinterface UserManager { %
@!hf!
>RrG&Wv59
public Result listUser(Page page)throws gp+@+i>b+[
;X+cS,h
HibernateException; O7p=|F"
oo1h"[
} U"Y/PBs,
'tt4"z2
zL3I!& z2
TRr%]qd{Hr
e@PY(#ru
java代码: u ^M'[<{
9TEAM<b;
J\Tu=f)
/*Created on 2005-7-15*/ vnqLcNB H
package com.adt.service.impl; 3bHB$n
(W#^-*$R
import java.util.List; rpEN\S%7P
E9]*!^=/
import net.sf.hibernate.HibernateException; PR%n>a#
9 $^b^It
import org.flyware.util.page.Page; eL
[.;_
import org.flyware.util.page.PageUtil; $ )6x3&]P
7_J0[C!G
import com.adt.bo.Result; }/jWa|)f
import com.adt.dao.UserDAO; gI/(hp3ob
import com.adt.exception.ObjectNotFoundException; {uxTgX
import com.adt.service.UserManager; I(j$^DA.
>|mZu)HIY;
/** xrkR)~ E
* @author Joa +5GPU 9k
*/ ~DS.b-E
publicclass UserManagerImpl implements UserManager { v3wq-
|g"K7XfM4
private UserDAO userDAO; ED>P>Gg
Us_1 #$p,
/** +mYK
* @param userDAO The userDAO to set. T-x}o
*/ Kp19dp}'b
publicvoid setUserDAO(UserDAO userDAO){ #P
{|7}jk
this.userDAO = userDAO; x#hSN|'"
} [J55%N;#1
TV/ EC#48
/* (non-Javadoc) BC#O.93`
* @see com.adt.service.UserManager#listUser (~fv;}}v
aJ[|80U
(org.flyware.util.page.Page) I~nz~U:ak
*/ Lzx2An@R
public Result listUser(Page page)throws T&j:gg
^_BjO(b'e
HibernateException, ObjectNotFoundException { 4h
T!DS
int totalRecords = userDAO.getUserCount(); cGlpJ)'-{
if(totalRecords == 0) 8YQ7XB
throw new ObjectNotFoundException `chD*@76I
=&m;5R
("userNotExist"); I/u>Gt
page = PageUtil.createPage(page, totalRecords); B?4Iu)bCxI
List users = userDAO.getUserByPage(page); 5>hXqNjP2
returnnew Result(page, users); @QE&D+NS
} VFKFO9
D58RHgY[
} /h@3R[k
5yjG\~
w"L]?#
#X0Xc2}{f
_/YM@%d
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 xl9S=^`=
tjQ6[`
询,接下来编写UserDAO的代码: FM|3'a-z
3. UserDAO 和 UserDAOImpl: KGmAnN
java代码: gL`aLg_
/x\~5cC
V5gr-^E
/*Created on 2005-7-15*/ _>_"cKS
package com.adt.dao; `rV-,-r@
^?|d< J:{
import java.util.List; U|8?$/*\
|o@U
L
import org.flyware.util.page.Page; #k,.xMJ~
0n\AUgVPF
import net.sf.hibernate.HibernateException; ZuKOscVS#T
OF,_6"m
/** [MD"JW?4B
* @author Joa AqHGBH0
*/ w*X(bua@
publicinterface UserDAO extends BaseDAO { ):fu]s"
<v?2p{U%
publicList getUserByName(String name)throws y2 R\SL,
H|/"'t
OZ
HibernateException; VO /b&%
]`|;ZQiD
publicint getUserCount()throws HibernateException; bD?gwhAKA
8t|?b
publicList getUserByPage(Page page)throws ! vuun |
6XnUs1O
HibernateException; 'r1X6?dJ
:_Iz(
2hV
} u/xP$
2iC BF-,
T
"#DhEM
?QtM|e
]C{N4Ni^Z
java代码: .N7&Jy
E+/XKF
tH:?aP*2
/*Created on 2005-7-15*/ EJNHZ<
package com.adt.dao.impl; V0n8fez
b
$QwzL/a
import java.util.List; O2xqNQ`d
n^nQrRIp
import org.flyware.util.page.Page; (%G>TV
_qH]OSo
import net.sf.hibernate.HibernateException; JURg=r]LI
import net.sf.hibernate.Query;
iF_u/#
YoZd,} i
import com.adt.dao.UserDAO; C~PP}|<~V
%&J`mq
/** #%{
* @author Joa w^:@g~
*/ 5i'KGL
public class UserDAOImpl extends BaseDAOHibernateImpl "2 D{X
h;mOfF
implements UserDAO { '-#gQxIpD
*z]P|_:&G
/* (non-Javadoc) @6-3D/=
* @see com.adt.dao.UserDAO#getUserByName S_s;foT
L!fIAd`
(java.lang.String) @P h'!
*/ s"~,Zzy@j
publicList getUserByName(String name)throws 4C3i
u,~+ho@
HibernateException { ^ '_Fd
String querySentence = "FROM user in class a(uQGyr[k1
?OGs+G
com.adt.po.User WHERE user.name=:name"; M>i *e
Query query = getSession().createQuery 4-9cp=\PE
"&\(:#L
(querySentence); \aN5:Yy
query.setParameter("name", name); .tsXQf
return query.list(); }:*?w>=
} Xd.y or
COd~H
/* (non-Javadoc) -L2?Tap
* @see com.adt.dao.UserDAO#getUserCount()
U^-RyE!}
*/ r
l;Y7l
publicint getUserCount()throws HibernateException { COD^osM@
int count = 0; 8jiBLZkRf
String querySentence = "SELECT count(*) FROM k8cR`5@PK
5nK|0vv%2
user in class com.adt.po.User"; 89W8cJ$yW
Query query = getSession().createQuery mn(MgJKQ\
ANR611-a
(querySentence); ) P|/<>z
count = ((Integer)query.iterate().next V1A7hRjxvG
yK mHTjX=
()).intValue(); 3Q,p,
return count; k1LbWR1%wB
} hJX;/~L
% QaWg2Y=
/* (non-Javadoc) R^.c
* @see com.adt.dao.UserDAO#getUserByPage /q!_f!<q4x
EPM(hxCIQ
(org.flyware.util.page.Page) WK.,q>#
*/ nVGOhYn
publicList getUserByPage(Page page)throws \_+Af`
7j"B-k#
HibernateException { F^!mgU X
String querySentence = "FROM user in class u@zT~\ h*
"T} HH
com.adt.po.User"; M[e{(iQ:
Query query = getSession().createQuery GF0Utp:Zf;
rNgAzH
(querySentence); ~\zIb/ #
query.setFirstResult(page.getBeginIndex()) D~TK'&