一 开发环境
*~g!KH ] Elicpse+Struts Studio+SqlServer2000+Tomcat。
nO%)Hu 5~]w-20; 二 开发思路
Nl43K2@f 既然讲的是Struts,那自然离不了MVC,分页显示也是如此。
bl<.$SmCY hB DT0 1 建立适当的模型组件,对应你要查询数据库中的表。这部分由我们熟悉的javaBean来充当。并在其中建立数据库查询方法,该方法需要一个java.sql.Conntection类型的参数,并返回一个ArrayList。在本例中为 Book.java
,p@\HvP|B cxBWGP 2 建立分页所需要的模型组件,也是由javaBean来充当,通过由Book中提供的ArrayList来构造。本例中为 PageBean.java.。
Ho.ev66 %z; o5 3建立控制器组件,这部分由Struts 中的Action来实现。主要负责将实例化Book,并利用返回的ArrayList对象,构造PageBean。以及接收由视图传递而来的action参数。从而在PageBean对象中调用不同的方法,该方法返回Book[] 对象。最后将 Book[]和PageBean放入request中。本例中为PageListAction.java。
N%< k[4 AD3G[\Qlm 4建立视图组件,这部分由jsp来充当,为了不出现java 代码,我们使用Struts提供的标签库,主要负责从request中取出刚刚放入的对象,通过反复调用PageListAction以及action参数,而实现分页显示。本例中为pagetest.jsp.
ZO,s^0gR 5 建立并配置struts-config.xml。
U/pD:y.M 6 建立数据库。
TrZL_n'r n=3\#gl 三 实例代码
}QlE&{A 1 Book.java
l3U0Ff5y) BxP1g gi package bean;
E 1e{{8 import java.sql.*;
+J@oD7[$ import java.util.ArrayList;
O!mo[u>t /**
D>Uz_A:-h * Struts分页显示数据Bean,对应数据库中Book表
WoH*{u */
"`K y"Kb public class Book {
24Mf7Xi6K private String bookname; //书名
*H6Mb YEF private String author; //作者
|{mq'M mR private String price; //价格
;Zn@}rPV ;e$Ks( public Book(String name,String author,String price){
L!D2dsKf^ this.bookname=name;
OedSR?#5q. this.author=author;
hv<J40eB? this.price=price;
FEaO(]BFqe }
G$w<&O d-juM]thZ public String getAuthor() {
Pu5)Xog{^ return author;
Da+ 6c }
]&HxN5u +3L4# public void setAuthor(String author) {
lQgX&z this.author = author;
G_Zja1\ }
CV$ dlAi H |:#o#8; public String getBookname() {
ozmFWfo;} return bookname;
$cI(0w_ }
2 5 r6u~ :hANTH8 public void setBookname(String bookname) {
hrVRe d2 this.bookname = bookname;
_j)hx8TEkb }
(=2v: [ wZ%#8hp public String getPrice(){
)eSj^w!p return this.price;
6r"BFcE/ }
^_h&U4dmg S6Z"N"<4 public void setPrice(String price){
|;y/rI{h- this.price=price;
h: b0T{_h }
e_*>FU[u)X b@RT)}g + public static ArrayList getAllBook(Connection connection){
4Zh[s&PU String sql="select * from book";
THhNp3C|4 ArrayList arrayList = new ArrayList();
0<O/9H?g,' try{
M,qG,({{ Statement statement = connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
mM]k%7 ResultSet resultSet = statement.executeQuery(sql);
=\{GwVv System.out.println("BookBean 数据查询已完成!");
Qr0o?L@2 while(resultSet.next())
LwS V.? {
f$`H {2 String name = resultSet.getString("name");
<x+p)6IM] String author = resultSet.getString("author");
l+U~Uc String price = resultSet.getString("price");
ne+3kVs System.out.println("开始数据封装:name="+name+"author="+author+"price="+price);
hujd}{OS" Book book = new Book(name,author,price);
m""fM! arrayList.add(book);
p|/@$3 }
6zM?"| connection.close();
xWX|?=0 resultSet.close();
sBgF]w J@ }catch(SQLException e)
SQ"09^h {
8,ij+9 System.out.println("数据库异常"+e.toString());
lZm+_uFzy }
K'X: rBl ( Sp1nF return arrayList;
q ^}j* }
0Zk6>ee }
xv*X GhL# Fzi p p -~ 2 PageBean.java
Qe'Mci6D package page;
/{=w&zy3 import bean.Book;
v&!DjD( import java.util.*;
p$J>/!] /**
n4T( * Struts分页显示逻辑Bean
dfA6:K/aK */
^dlzKLid public class PageBean {
)fn?, *Zn5 :oa0P"N int currentPage=1; //当前页
:,Af85c public int totalPages=0; //总页数
Z.WS FY int pageRecorders=5;//每页5条数据
qtUc]( int totalRows=0; //总数据数
)B~Phc+(f int pageStartRow=0;//每页的起始数
.9/@"mm int pageEndRow=0; //每页显示数据的终止数
3#Ap-',&K boolean hasNextPage=false; //是否有下一页
DJN!#k boolean hasPreviousPage=false; //是否有前一页
{ &XKaK1 ArrayList arrayList;
4|R<}}_ ,o Iterator it;
9nQ?NzmiKt public PageBean(){}
$:Tz& mW>/ H public PageBean(ArrayList arrayList){
@G2*}%Ny4 this.arrayList=arrayList;
}yd/w[]4 totalRows=arrayList.size();
SZ} it=arrayList.iterator();
<R_<y} hasPreviousPage=false;
8nr~lUK' currentPage=1;
fKtS?oc] if((totalRows%pageRecorders)==0)
W^o&*6 L {
4*(I]Se totalPages=totalRows/pageRecorders;
da^x kV}/ }
w&r. else
L>67t}Y: {
{b:Lq tg totalPages=totalRows/pageRecorders+1;
oFpPP]OGT" }
A!S@NL( ;16U8 if(currentPage>=totalPages)
u*w}}bPn {
C,&3 j ?|X hasNextPage=false;
s h+;~ }
,}yKJ63 else
N cw15p#oS {
SUQcmzBh y hasNextPage=true;
M.n0ST`I- }
wB7Vz!i@ `ZAkTd0x oN;fbUD if(totalRows<pageRecorders)
w#pe&Z {
OOE f+I this.pageStartRow=0;
]`MsHub? this.pageEndRow=totalRows;
zm[V<-s2l }
!gOS7.(. else
m^O@exD8 {
Z-_@UsGY> this.pageStartRow=0;
;NWuCOb:G this.pageEndRow=pageRecorders;
a8W to;C\ }
+K"N.LmD i 'W5!fp| }
kK1X.]m{ NX8X#c'?I^ /**
lV,|3J= * @return Returns the currentPage.
]t/;Z7J] */
:3 >w :LB public String getCurrentPage() {
AL 8E&|s return this.toString(currentPage);
$b M{34 }
F-2l /**
ol?0CI"2? * @param currentPage The currentPage to set.
7\o *7B */
SInrW[t!b public void setCurrentPage(int currentPage) {
|! >`+'Q this.currentPage = currentPage;
udGb*a* }
tY[q~')F /**
O.B7E|H * @return Returns the pageRecorders.
QgwH[{^] */
XzEfhLt3c public int getPageRecorders() {
?4m |3:f return pageRecorders;
QYqbTZNW_, }
TyQA3hj /**
T:7CE> * @param pageRecorders The pageRecorders to set.
WLzJy_j7 */
bohC"EK` public void setPageRecorders(int pageRecorders) {
a$Jhs}|y this.pageRecorders = pageRecorders;
"QhNro^ }
<'+UF1 /**
6';![dB * @return Returns the pageEndRow.
z+8-NV */
HJeXzbAf public int getPageEndRow() {
H@xz$X~ return pageEndRow;
dm-7F> }
?VBw_~3xa /**
}lG"B,X * @return Returns the pageStartRow.
}:~YCC.U# */
MV~bE public int getPageStartRow() {
cutH}PQe return pageStartRow;
0vba6o }
Co7: YA;s /**
[+P]m]-Jr~ * @return Returns the totalPages.
i'%|l^L */
`CxDOa6;q public String getTotalPages() {
Z] RG*_ /zK9!/=Lv return this.toString(totalPages);
a3j;XZ }
UXp73* /**
Y &! JW1 * @return Returns the totalRows.
C(w=_vd4 */
V^BZ`{q| public String getTotalRows() {
[ + / u return this.toString(totalRows);
6)z]\ + }
D@!+Z7ouV /**
g'RHw]FlE * @return Returns the hasNextPage.
R-sqE^{Ef */
F=>&|5 public boolean isHasNextPage() {
;U:ExDOd return hasNextPage;
OJ3E7%SR }
*EQFyD /**
gfd~ $4B * @param hasNextPage The hasNextPage to set.
)x~a)qf$)c */
T9{_9kB'? public void setHasNextPage(boolean hasNextPage) {
JsN/"r?5 this.hasNextPage = hasNextPage;
(WzFjjY3 }
dPkuU2 I /**
kB,nnX * @return Returns the hasPreviousPage.
(t0[m~~F6 */
w*I1$lZ public boolean isHasPreviousPage() {
a7_ >n) return hasPreviousPage;
r2$i[6@?b) }
j\m`HGZ /**
y=- V@P] * @param hasPreviousPage The hasPreviousPage to set.
x<`uN_a0Gr */
apUj;giq1 public void setHasPreviousPage(boolean hasPreviousPage) {
b;)xgz~a this.hasPreviousPage = hasPreviousPage;
+(o[R KA }
zhHei?I public Book[] getNextPage(){
t^R,G7K= ^{jUO j/ currentPage=currentPage+1;
biDY|l U System.out.println("PageBean.getNextPage()正在执行;");
@nj*<2 System.out.println("参数currentPage="+currentPage);
Ow{e6?uJ XZ~ly/(A if((currentPage-1)>0)
*\Q;AB {
$?3=|zDC}{ hasPreviousPage=true;
~Dfz*/GVW }
lcFhC2. else
(TA:I3' {
#W}JiH(T hasPreviousPage=false;
+3;&^[@hf }
t+GBz%6f6 %u 6#}#) if(currentPage>=totalPages)
iT HrC,rt {
_r5?/Yevs9 hasNextPage=false;
Ag[R=o] }
|Imf1{7]8 else
v ,W4xrN6+ {
dW a#pVyT+ hasNextPage=true;
- S{ p }
8xguAY] System.out.println("参数hasNextPage="+hasNextPage);
.9!enM9] System.out.println("准备执行PageBean.getBooks()");
fY v5RT\~ Book[] books=getBooks();
O'C (e62 this.description();
Ns4$+J(pt /F k* aI return books;
Lyr9&%R> }
4j&A$8Uo ["e?O zj public Book[] getPreviouspage(){
fki\&L s3: currentPage=currentPage-1;
@Y) w'_| 9kr_(jAw if(currentPage==0){currentPage=1;}
#lP=ht?>A xXi"l895 if(currentPage>=totalPages)
*({"Y.$h$R {
dO?.Td hasNextPage=false;
OjU.h/$ }
2Y011IJ S else
9J< z0IS {
sMf4sJPK hasNextPage=true;
M"dYKT"0 }
G^k72B5 if((currentPage-1)>0)
{W b*U {
`i\mz)dx1 hasPreviousPage=true;
`PDLS =W }
:rQ]3;y else
IhdZ"P[-< {
La ;R,SrG hasPreviousPage=false;
vH7H4e.r }
*6bV8>_K Book[] books=getBooks();
->$-&`'i this.description();
ef]G:5O return books;
#$I qcW@` }
;\zsWW"No =$}!8pyc public Book[] getBooks(){
F>EK5IJ System.out.println("pageBean.getBooks()开始执行;");
q=EtGO B*jM.U< skHR j if(currentPage*pageRecorders<totalRows){//判断是否为最后一页
bXVsF3Mso pageEndRow=currentPage*pageRecorders;
CD (wH&t pageStartRow=pageEndRow-pageRecorders;
YF;@){}BqC }
g#]&?le: else{
Po78I4id pageEndRow=totalRows;
V+FE}JJ`| pageStartRow=pageRecorders*(totalPages-1);
kmQGR S& }
\}MZe{ Book[] books=new Book[pageEndRow-pageStartRow+1];
Q7)$[EAJ2 V!gl<-B System.out.println("pageStartRow="+pageStartRow);
A0*$r w2 System.out.println("pageEndRow="+pageEndRow);
VH15-m int j=0;
WHi}p&RD for(int i=pageStartRow;i<pageEndRow;i++)
r$!"k< {
<<gx [)W BO+FD)Fj Book book=(Book)arrayList.get(i);
JAj6$P1 books[j++]=book;
[D_T+AU0p F=dv1pYu }
Dk/GqeX System.out.println("要显示的页面数据已经封装,具体信息如下:");
#d#/nIi ] this.description();
z!oP &${i return books;
\Zp9) y }
pDFY.WYW< fQ*m2uu public String toString(int temp)
_3w |r5 {
,f.KY(4- String str=Integer.toString(temp);
nB Ne!c return str;
n%keldsBF }
>ebBnQ}Y) tk>dwxry public void description()
+ kE3+ {
O=9#]!(] B_~{3#@ String description="共有数据数:"+this.getTotalRows()+
sV#MZ$A '*p5zQcI "共有页数: "+this.getTotalPages() +
marY$D Wk~'6KyqJR "当前页数为:"+this.getCurrentPage()+
e?\hlucsua p>kP,E?? " 是否有前一页: "+this.isHasPreviousPage() +
:X5ru; M;#j"I " 是否有下一页:"+this.isHasNextPage()+
QYhDVu"K h TLf y " 开始行数:"+this.getPageStartRow()+
.;rS7+SK oO>tvtR " 终止行数:"+this.getPageEndRow();
B|]b&zK~ oD6vbJh{ System.out.println(description);
yZh} lV-S m? -rPn=# }
bS^7~f }
vqrq/sI: s() ]C[C 3 PageListAction.java
^ "{2l- package page;
-AA~&kOdJ import org.apache.struts.action.*;
~Fmhc$2Z3< import javax.servlet.http.*;
4AL2NFD import comm.Constants;
EnG9GD{`j R^tp/]x import bean.Book;
|eE{gCI1 import java.util.*;
>"!k8}K5}U import javax.sql.DataSource;
?|W$U v ${-uB . O?& ~j public class PageListAction extends Action {
E$/ZGkN> /Fe^k] k_A public PageListAction(){}
y.yy=\FN ArrayList arrayList=new ArrayList();
E4-c`O(Ldo PageBean pb;
)V;vYB3x) _S!Sgsr? public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {
[:[kI<b9s String action;
[a2f=<E{f action=request.getParameter("action");
h"j;r/CE? if(action==null || action.equals("null")){ //第一次读取数据
&iy,J,G< try{
sLwIO+J( DataSource datasource=this.getDataSource(request,Constants.DATASOURCE_KEY);
/04 \ arrayList=Book.getAllBook(datasource.getConnection());
I5iI8{G System.out.println("第一步,数据已经成功传递到Action,action="+action);
C a7@ q }catch(Exception e){
7t>(C f e.printStackTrace();
eJTIn - System.out.println("数据库连接出现异常");
nV5T6kqV }
m|g@V]-> wp $&*qD pb=new PageBean(arrayList);
x}IAM$ YY Book[] books=pb.getBooks();
%T/w={K pb.description();
$p``7{'ed request.setAttribute("result",books);
|<3Q^>K' request.setAttribute("page",pb);
*R q{SE WIl2}&A"0 }
)F , else
u*PD^ P+s {
aiCE-n) if(action=="nextPage" || action.equals("nextPage"))
Nj)yG] {
a p X System.out.println("参数action="+action);
COkb8kzU6 System.out.println("函数pb.getNextPage()准备执行");
#_9:fDX Book[]books=pb.getNextPage();
t} H1v request.setAttribute("page",pb);
VO%- request.setAttribute("result",books);
oXJ?Pua }
SePvM if(action=="previousPage" || action.equals("previousPage"))
?dGmqJ {
gH .U~w3 System.out.println("参数action="+action);
vWDo tn System.out.println("函数pb.getPreviouspage()准备执行");
R='VywD Book[] books=pb.getPreviouspage();
En2&i.K8 request.setAttribute("page",pb);
*YYgqQ> request.setAttribute("result",books);
SR`J/[R,< ]shCi }
8Y&T6Dl }
O^2O uo return (mapping.findForward("success"));
gKNw(sUTl }
0g:f XV }
eH.^ri 7f[y<t 4 pagetest.jsp
u7;m9:- <%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
p ~$- 7e <%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
hG?eF2F, <%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
EmRq sS <%@ page contentType="text/html; charset=gb2312" language="java"%>
4S)q- A a`v/8=IL0o <html:html locale="true">
v*s.0y k <head>
$)U${Vg"<- <meta http-equiv="Content-Type" content="text/html; charset=gb2312">
~MMR&*W:V? </head>
<I|:I,;u <body>
DzV-g h h10$,O <table border="1">
Cc:u deXf <tr><th>书名</th><th>作者</th><th>价格</th></tr>
6 .i3u) <logic:present name="result">
b] =dI{ <logic:iterate id="book" name="result" type="bean.Book" >
Z0Tm 0v <logic:present name="book">
f8u3v 'qY <tr>
,xp8! B <td><bean:write name="book" property="bookname" /></td>
%/O%|x_O <td> <bean:write name="book" property="author" /></td>
z\0*OFK)~ <td><bean:write name="book" property="price" /></td>
2 Y G_(9 </tr>
9g8XGzX </logic:present>
G{vzJ(x<< </logic:iterate>
^LAHA-:3: </logic:present>
xFK#L{u_R </table>
_vrRGpO4 <logic:equal name="page" property="hasNextPage" value="true">
#r|[b&.~]a <html:link page="/page.do?action=nextPage">nextPage</html:link>
T'5zP1:R-A </logic:equal>
\.^w;Y{% s <logic:equal name="page" property="hasPreviousPage" value="true">
08yD,jFitP <html:link page="/page.do?action=previousPage">PreviousPage</html:link>
8Y;th;5 </logic:equal>
$4J~E@i] 共有数据总数<bean:write name="page" property="totalRows"/>;
fQ8]C,~M 共分<bean:write name="page" property="totalPages"/>页,当前是第
Jy@m <bean:write name="page" property="currentPage"/>页
a+^^WH ? </body>
fob^[ 4 </html:html>
sHCwD| Y][D=K[ 5 struts-config.xml
z>Opyp{4 <?xml version="1.0" encoding="ISO-8859-1" ?>
ns,hD\< .'(wHR%S_r <!DOCTYPE struts-config PUBLIC
B5XF0s" "-//Apache Software Foundation//DTD Struts Configuration 1.1//EN"
(Pu2_<yC "
http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">
_ +\{ON lN= C3 <struts-config>
&xoMq rWw\ <data-sources>
tTOv:YO? <data-source key="dataSource" type="org.apache.commons.dbcp.BasicDataSource">
Jz\KD4~ <set-property property="driverClassName" value="com.microsoft.jdbc.sqlserver.SQLServerDriver"/>
mrFy~J&T <set-property property="url" value="jdbc:microsoft:sqlserver://127.0.0.1:1433;DatabaseName=eBookStore;SelectMethod=cursor"/>
PF0S7E' <set-property property="username" value="limq"/>
k7sr[7]7] <set-property property="password" value="1"/>
__W(/@ <set-property property="maxActive" value="10"/>
RX$$EJxZuV <set-property property="maxWait" value="5000"/>
\U]@q, <set-property property="defaultAutoCommit" value="true"/>
YOL_2]LX <set-property property="defaultReadOnly" value="false"/>
JkW8X \w </data-source>
a*>;-JDr </data-sources>
&'s|~F 4r. <form-beans>
=": E<^V_ </form-beans>
( yXX_'Y <global-forwards>
&KSpW(/ </global-forwards>
Ux}W2G.)O <action-mappings>
biOEj)M <action path="/page" type="page.PageListAction" scope="request">
H\|O. Zqh <forward name="success" path="/pagetest.jsp"/>
nSqxOi% </action>
wo16r|%4X </action-mappings>
{F]=FRW4jy <controller>
f V6hiRv </controller>
/-O2Iv# </struts-config>
v'7^MHyS\` Qlexd*-, 6 建立eBookStore数据库,以及表book(name,author,parce);其中数据的配置可以根据你的不同情况在struts-config.xml中而定。
8(?<C|~ Z@MF<FxP` 7 Constants.java
.| ^ekOC 2yQ-8qH package comm;
;KcRW%Z ,2;VETs /**
C6fW-wH" * this interface provides the constant string for applicator constant
7n^[$]nm */
v4? $Ga public class Constants {
TvA -=+n /**
j'b?$8t * name of the User Object in HttpSession
'' t@'$ */
,JL\\ 8~ public static String USER_KEY="user";
;u*C/xZ] /**
uX/S$ ftVA * dataSource name
pC,-*U= */
`&X-ZL)^tB public static String DATASOURCE_KEY="dataSource";
51&x5>D5 }