| method not give me right result how pass code from applet to class [message #212855] |
Mon, 08 January 2007 10:22  |
mfa786
Messages: 210
Registered: February 2006
Location: karachi
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Senior Member |
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hi master
sir my meed is i pass code from appletd and call class method that return me title as per code
i am use this code
""method not give me right result how pass code from applet to class""
===================
sir see my code in java class
public String mfa3(String s){
String mfatt ="lkjldsf";
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@fahim:1521:aamir","muhammad","mfa786");
Statement stmt = conn.createStatement();
ResultSet rset = stmt.executeQuery("select title,accid from chartofacc where accid=s");
while (rset.next())
mfatt= rset.getString("accid");
}
catch(Exception e){
e.printStackTrace();
}
return mfatt;
}
==================
and this is in applet
private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {
// Add your handling code here:
jTextField5.setText(testcall.mfa3((String)jTextField2.getText()));
}
when i press button then give me this error
object created
java.security.AccessControlException: access denied (java.util.PropertyPermission oracle.jserver.version read)
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:269)
at java.security.AccessController.checkPermission(AccessController.java:401)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:524)
at java.lang.SecurityManager.checkPropertyAccess(SecurityManager.java:1276)
at java.lang.System.getProperty(System.java:573)
at oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java)
at java.sql.DriverManager.getConnection(DriverManager.java:512)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at testclass.mfa3(testclass.java:57)
at testapp.jButton5ActionPerformed(testapp.java:114)
at testapp.access$400(testapp.java:11)
at testapp$5.actionPerformed(testapp.java:98)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1786)
at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1839)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
system not give me result
sir please give me idea
thaning you
aamir
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| Re: method not give me right result how pass code from applet to class [message #213094 is a reply to message #212959] |
Tue, 09 January 2007 08:23  |
kmmfoo
Messages: 38
Registered: June 2005
Location: massachusetts
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Member |
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The idea is that you want the variable "query" to be a string that contains a correctly-formatted sql query, right? so if you had four or five different variables to put into the query, you would just build that string.
Let's take it in steps.
Step 1, assume it's just a string. To put a string into a query, you would surround it with single quotes, right? So for example, if you had a variable "s" that contained a string, you would add it to a query like this:
query = "select title,accid from chartofacc where accid='" +
s + "'";
Do you see what that is doing?
Step 2, do you see the problem with that previous example? The problem is, if the string inside variable "s" contains a single-quote character, it would create a malformed query.
For example, assume it contained the string "don't do this". The query would look like
select title,accid from chartofacc where accid='don't do this'
which is a bad query. So if we want to fix that problem, we would have to double any single-quote characters inside our strings. That is usually done with the regex function "String.replaceAll()", as in my example.
However, it gets very complicated to do that all the time, so what many people do is to create a local private function to do that replacement, and call the local private function.
But even that approach becomes tedious, which is why Java contains a "PreparedStatement" method, which does all of this for you. If you are interested you could look that up in the documentation.
Hope this helps.
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