| 发表于：2007-06-06 21:19:34 楼主 |
思路：通过applet输入sql代码并点击查询按钮来请求servlet响应，servlet通过访问指定数据库得到相应的查询记录并以resultset数据集对象回送给applet，applet以jtable格式显示查询记录。。
ide:jbuilder2006
数据库：mysql
服务器：tomcat5.5
帮忙看下为什么调不通。。。。。自己照着一个applet和servlet通信的例子改的。。大家有时间的话帮忙调下，看看问题在哪儿？共同进步，谢谢。
源代码如下：
applet：
package appletdemo;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.net.*;
import java.util.*;
import java.io.*;
import java.sql.*;
import com.sun.rowset.*;
import javax.swing.jscrollpane;
import javax.swing.jbutton;
import javax.swing.jtextarea;
import javax.swing.jtable;
import javax.swing.borderfactory;
import javax.swing.table.defaulttablemodel;
import com.borland.jbcl.layout.xylayout;
import com.borland.jbcl.layout.*;
public class applet1 extends applet {
boolean isstandalone = false;
borderlayout borderlayout1 = new borderlayout（);
jbutton jbutton1 = new jbutton（);
jtextarea jtextarea1 = new jtextarea（);
xylayout xylayout1 = new xylayout（);
hashtable hash = new hashtable（);
cachedrowsetimpl crsi;
jtable jtable = new jtable（);
defaulttablemodel dtm = new defaulttablemodel（);
jscrollpane jscrollpane1 = new jscrollpane（);
public void init（) {
try {
jbinit（);
} catch （exception e) {
e.printstacktrace（);
}
}
public void invoke（) {
try {
url url = new url（getcodebase（), "/servlet1 ");
urlconnection con = url.openconnection（);
con.setdooutput（true);
con.setusecaches（false);
con.setrequestproperty（ "content-type ", "application/octet-stream ");
objectoutputstream outstream = new objectoutputstream（con.
getoutputstream（));
hashtable setmsg = new hashtable（);
setmsg.put（ "action ", jtextarea1.gettext（));
outstream.writeobject（setmsg);
outstream.flush（);
outstream.close（);
objectinputstream instream = new objectinputstream（con.
getinputstream（));
cachedrowsetimpl crs = （cachedrowsetimpl) instream.readobject（);
crsi = crs;
} catch （exception e) {}
}
//component initialization
private void jbinit（) throws exception {
jbutton1.settext（ "查询 ");
jbutton1.addactionlistener（new applet1_jbutton1_actionadapter（this));
jtextarea1.setborder（borderfactory.createetchedborder（));
jtextarea1.settext（ "select * from test ");
this.setlayout（xylayout1);
jscrollpane1.setborder（borderfactory.createloweredbevelborder（));
this.add（jbutton1, new xyconstraints（142, 13, -1, -1));
this.add（jtextarea1, new xyconstraints（80, 48, 199, 25));
this.add（jscrollpane1, new xyconstraints（35, 85, 320, 183));
jtable.setmodel（dtm);
jscrollpane1.getviewport（).add（jtable);
}
public void jbutton1_actionperformed（actionevent e) {
this.invoke（);
resultset rs;
int columncount;
try {
rs = crsi.getoriginal（);
columncount = rs.getmetadata（).getcolumncount（);
for （int i = 1; i <= columncount; i++) {
dtm.addcolumn（rs.getmetadata（).getcolumnname（i));
}
string[] s = new string[columncount];
while （rs.next（)) {
for （int i = 1; i < columncount; i++) {
s[i - 1] = rs.getstring（i);
}
dtm.addrow（s);
}
} catch （exception ex) {
ex.printstacktrace（);
}
}
}
class applet1_jbutton1_actionadapter implements actionlistener {
private applet1 adaptee;
applet1_jbutton1_actionadapter（applet1 adaptee) {
this.adaptee = adaptee;
}
public void actionperformed（actionevent e) {
adaptee.jbutton1_actionperformed（e);
}
}
servlet代码：
package servletdemo;
import java.io.*;
import java.sql.*;
import com.sun.rowset.*;
import javax.servlet.*;
import java.util.*;
import javax.servlet.http.*;
public class servlet1 extends httpservlet {
private static final string content_type = "text/html; charset=gbk ";
string action = "succeed! ";
public void init（) throws servletexception {}
static {
try {
class.forname（ "com.mysql.jdbc.driver ");
} catch （exception e) {
e.printstacktrace（);
}
}
//process the http get request
public void doget（httpservletrequest req, httpservletresponse res) throws servletexception, ioexception {
objectinputstream in = new objectinputstream（req.getinputstream（));
hashtable getmsg = new hashtable（);
try {
getmsg = （hashtable) in.readobject（);
} catch （exception e) {}
try {
connection dbconn = drivermanager.getconnection（
"jdbc:mysql://localhost:3306/test ", "root ",
"password ");
statement stmt = dbconn.createstatement（);
resultset dbrest = stmt.ＥＸＥＣutequery（getmsg.tostring（));
cachedrowsetimpl crs = new cachedrowsetimpl（);
crs.populate（dbrest);
dbrest.close（);
stmt.close（);
dbconn.close（);
file: //传回对象给applet
res.setcontenttype（ "application/octet-stream ");
objectoutputstream oos = new objectoutputstream（res.getoutputstream（));
oos.writeobject（crs);
oos.close（);
} catch （exception exp) {
exp.printstacktrace（);
}
}
public void destroy（) {
}
} |
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