Cannot resolve symbol: class OracleDriver

Attempting to compile a servlet on Apache Server using same jdeveloper jdbc libraries:
classes12.jar & nls_charset12.jar
Error message:
$compilejava2.sh ProdJobs
ProdJobs.java:361: cannot resolve symbol
symbol : class OracleDriver
location: package driver
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
Am I missing something else?
Jeffrey

Enter this code into your program and then put the Oracle jar file that contains the driver in your run-time classpath.
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
catch(ClassNotFoundException cnfe) {
// driver not found
}The effect of this is that the classloader will load the Oracle driver for you then call it's static initiailizer that does a bunch of magic that results in the Java runtime knowing that there's a JDBC driver out there.
It is a little weird - but that's the way it works.

Similar Messages

PLEASE HELP: cannot resolve symbol class

it's showing me the error on the following lines 7 and 9
it says cannot resolve symbol class Name and cannot resolve symbol class Phone
I also have a package name addressBook and it contains two files Entry.java and Address.java
Here is the code:
import java.io.*;
import addressBook.*;
public class AddressDr
     public static void main(String[] args)throws IOException
          Name name;
          Address address;
          Phone phone;
          Entry entry;
          String first, last, middle, street, city, state, zip;
          int areaCode, number;
          BufferedReader in;
          in=new BufferedReader(new InputStreamReader(System.in));
          PrintWriter outFile;
          outFile=new PrintWriter(new FileWriter("Entries"));
          System.out.println("Quit entered fot the first name ends the " + "application.");
          System.out.print("Enter first name: ");
          first=in.readLine();
          while (first.compareTo("Quit") !=0)
               System.out.print("Enter last name: ");
               last=in.readLine();
               System.out.print("Enter middle name: ");
               middle=in.readLine();
               name=new Name(first, last, middle);
               System.out.print("Enter street address: ");
               street=in.readLine();
               System.out.print("Enter city: ");
               city=in.readLine();
               System.out.print("Enter state: ");
               state=in.readLine();
               System.out.print("Enter ZIP code: ");
               zip=in.readLine();
               address=new Address(street, city, state, zip);
               System.out.print("Enter areaCode: ");
               areaCode = Integer.parseInt(in.readLine());
               System.out.print("Enter number: ");
               number=Integer.parseInt(in.readLine());
               phone=new Phone(areaCode, number);
               entry= new Entry(name, address, phone);
               entry.writeToFile(outFile);
               System.out.print("Enter first name: ");
               first=in.readLine();
          outFile.close();
}

OK. Here is how I did it.
I have AddressDr which is Address driver.
I have two files Address and Entry which in package addressBook.
AddressDr:
import java.io.*;
import addressBook.*;
public class AddressDr
     public static void main(String[] args)throws IOException
          Name name;
          Address address;
          Phone phone;
          Entry entry;
          String first, last, middle, street, city, state, zip;
          int areaCode, number;
          BufferedReader in;
          in=new BufferedReader(new InputStreamReader(System.in));
          PrintWriter outFile;
          outFile=new PrintWriter(new FileWriter("Entries"));
          System.out.println("Quit entered fot the first name ends the " + "application.");
          System.out.print("Enter first name: ");
          first=in.readLine();
          while (first.compareTo("Quit") !=0)
               System.out.print("Enter last name: ");
               last=in.readLine();
               System.out.print("Enter middle name: ");
               middle=in.readLine();
               name=new Name(first, last, middle);
               System.out.print("Enter street address: ");
               street=in.readLine();
               System.out.print("Enter city: ");
               city=in.readLine();
               System.out.print("Enter state: ");
               state=in.readLine();
               System.out.print("Enter ZIP code: ");
               zip=in.readLine();
               address=new Address(street, city, state, zip);
               System.out.print("Enter areaCode: ");
               areaCode = Integer.parseInt(in.readLine());
               System.out.print("Enter number: ");
               number=Integer.parseInt(in.readLine());
               phone=new Phone(areaCode, number);
               entry= new Entry(name, address, phone);
               entry.writeToFile(outFile);
               System.out.print("Enter first name: ");
               first=in.readLine();
          outFile.close();
Entry:
package addressBook;
import java.io.*;
public class Entry
     Name name;
     Address address;
     Phone phone;
public Entry(Name newName, Address newAddress, Phone phoneNumber)
     name = newName;
     address = newAddress;
     phone = phoneNumber;
public Name knowName()
     return name;
public Address knowAddress()
     return address;
public Phone knowPhone()
     return phone;
public void writeToFile(PrintWriter outFile)
     outFile.println(name.knowFirstName());
     outFile.println(name.knowLastName());
     outFile.println(name.knowMiddleName());
     oufFile.println(address.knowStreet());
     outFile.println(address.knowState());
     outFile.println(address.knowCity());
     outFile.println(address.knowZip());
     outFile.println(phone.knowAreaCode());
     outFile.println(phone.knowDigits());
Address:
package addressBook;
public class Address
     String street;
     String city;
     String state;
     String zipCode;
     public Address(String newStreet, String newCity, String newState, String zip)
          street=newStreet;
          city=newCity;
          state=newState;
          zipCode=zip;
     public String knowStreet()
          return street;
     public String knowCity()
          return city;
     public String knowState()
          return state;
     public String knowZip()
          return zipCode;
}

Cannot resolve symbol class graphics

does anyone know what the error
cannot resolve symbol class graphics means?
with this code i can't seem to call the graphics method to draw the line....any reason why?
import javax.swing.*;
import java.*;
public class LineDraw extends JFrame {
    public static void main(String[] args) {
        LineDraw ld = new LineDraw();
        ld.setSize(500,500);
        ld.setVisible(true);
        ld.enterVariables();
    public void init(){
    private int x1;
    private int x2;
    private int y1;
    private int y2;
    public void paint(Graphics g) {
        g.GetGraphics(g);
        super.paintComponent(g);
        g.drawLine(x1, y1, x2, y2);
    public void enterVariables() {
        x1 = Integer.parseInt(JOptionPane.showInputDialog("Enter x1:"));
        y1 = Integer.parseInt(JOptionPane.showInputDialog("Enter y1:"));
        x2 = Integer.parseInt(JOptionPane.showInputDialog("Enter x2:"));
        y2 = Integer.parseInt(JOptionPane.showInputDialog("Enter y2:"));
        repaint();
}

well the exact error message is ...by the way now that i think about it
if the graphics method shoudl not be part of the JFrame class then what method would i use to draw 2D Graphics?
--------------------Configuration: <Default>--------------------
C:\Documents and Settings\c1s5\My Documents\LineDraw.java:21: cannot resolve symbol
symbol : class Graphics
location: class LineDraw
public void paint(Graphics g)
^
1 error
Process completed.
and the exact code is
import javax.swing.*;
import java.*;
public class LineDraw extends JFrame {
    public static void main(String[] args) {
        LineDraw ld = new LineDraw();
        ld.setSize(1024,500);
        ld.setVisible(true);
        ld.enterVariables();
    private int x1;
    private int x2;
    private int y1;
    private int y2;
    public void paint(Graphics g)
        super.paintComponent(g);
        g.drawLine(x1, y1, x2, y2);
    public void enterVariables() {
        x1 = Integer.parseInt(JOptionPane.showInputDialog("Enter x1:"));
        y1 = Integer.parseInt(JOptionPane.showInputDialog("Enter y1:"));
        x2 = Integer.parseInt(JOptionPane.showInputDialog("Enter x2:"));
        y2 = Integer.parseInt(JOptionPane.showInputDialog("Enter y2:"));
        repaint();
}

Cannot resolve symbol class Scanner (Error)

For whatever reason I get the error message "cannot resolve symbol class Scanner" when trying to run this:
import java.io.*;
import java.util.*;
public class NameReversal
     public static void main(String args[])
          System.out.print("Enter your name: ");
          Scanner Reader = new Scanner(System.in);
          String first = Reader.next();
          String finl = Reader.next();
          int z = first.length();
          int v = finl.length();
          int y = z-1;
          int f = y-1;
          for(int i = y; i>=0; z--)
          System.out.print(first.charAt(1));
          System.out.print(" ");
          for(int p = f; p >= 0; p--)
          System.out.println(finl.charAt(p));
}

The Scanner class is in the JDK version 1.5 or later. You must be using an earlier version.

Cannot resolve symbol: class EJBObject

Using javac I get this compile error on this file Calculator.java
Calculator.java:1: cannot resolve symbol
symbol : class EJBObject
location: package ejb
import javax.ejb.EJBObject;
^
Calculator.java:5: cannot resolve symbol
symbol : class EJBObject
location: interface Calculator
public interface Calculator extends EJBObject {
Source code for Calculator.java
import javax.ejb.EJBObject;
import java.rmi.*;
public interface Calculator extends EJBObject {
public long add (int x, int y) throws RemoteException;
public long subtract (int x, int y) throws RemoteException;

This code is from a book, so I will assume its a classpath problem. My
classpath looks like:
"C\QTJava.zip".;%J2EE_HOME%\lib\j2ee.jar;%J2EE_HOME%\lib\locale
Also the following enviorment varibales have been set to:
J2EE_HOME
C:\Development\Java\j2sdkee1.3.1
JAVA_HOME
C:\Development\Java\jdk1.3.1
Path
%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;C:\Program Files\Common Files\Adaptec Shared\System;%JAVA_HOME%\bin;%J2EE_HOME%\bin
I can run j2EE, like "j2EE -verbose" (no problems)
also run cloudscape, like "cloudscape -start" (no problems)
also can run deploytool, like "deploytool" (no problems, & deploy sample ear files from cd book)
Your help is appreicated.

Cannot resolve symbol : class odbc ERROR

Hi Helper
I am trying to compile a the following and I am getting the error
C:\jdk\websiter>javac MainServlet.java
MainServlet.java:86: cannot resolve symbol
symbol : class odbc
location: package jdbc
Class.forName(sun.jdbc.odbc.JdbcOdbcDriver);
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
import java.io.*;
import java.util.*;
* This is the servlet to send the user the names of all the sites present in the database
public class MainServlet extends HttpServlet implements ServletConstants
Connection m_con;
PreparedStatement m_pstmt;
ResultSet m_res;
Vector m_vecsiteName;
public void Init(ServletConfig config) throws ServletException {
     super.init(config);
}// end of init()
public void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
          m_vecsiteName = new Vector();
     try {
     Class.forName(sun.jdbc.odbc.JdbcOdbcDriver);
m_con = DriverManager.getConnection("jdbc:odbc:sitewd", "", "");
How can i fix it? thanks
VT

Replace the Statement
Class.forName(sun.jdbc.odbc.JdbcOdbcDriver);
as
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

Error:cannot resolve Symbol class"name"

when I have compiled Bean class named SlBean which has primary class named pk, I recevied following error message(I compiled pk class without error) :
cannot resolve symbol
symbol : class pk
location: class SlBean
public pk ejbCreate(

Sorry , its not classpath problem. You have to simply import the pk class if its in any package. I am assuming you have packaged your pk class with ejb jar file.
for eg. if your class is
package abc.xyz
public class pk
then in your bean class import
import abc.xyz.pk;
--Ashwani

Cannot resolve symbol - class FileInputStream

I am getting the above error when I compile this following method; I get it in the first line of code.
Anyone know why?
private String readAndProcessData(FileInputStream stream)
      InputStreamReader iStrReader = new InputStreamReader(stream);
      BufferedReader reader = new BufferedReader(iStrReader);
      try
         output.setText("");
         String data=reader.readLine();
         while (data!= null){
              output.append(data + "\n");
              data=reader.readLine();}
      catch(IOException e)
         messageBox("Error in file input:\n" + e.toString());
[code/]

I am already doing this in another class which is linked to this one.
I have three classes and java.io is imported in the Inteface, and this method is in the model class.

Cannot resolve symbol: class NamespaceContext

I get the following error when I compile
import javax.xml.namespace.NamespaceContext;
I have added jar files come with jwsdp-1.3

It's a bit old, but for the records:
The NamespaceContext class is in the jaxp-api.jar which is located here: jwsdp-1.6\jaxp\lib
As the time of this writing, 1.6 is the current version ;)

Cannot resolve symbol : class InputStream

I had and environment in which this code compiled. Then I installed Java Communications API. After fooling around to get that to work, I find that I get this error when compiling. What did I do to cause this? what jar file might be missing?

InputStream is in java.io.
If you deleted a jar file in your jre/bin/lib folder there
would problably be a lot more errors then this.The possible
files are jce.jar,jsse.jar,jaws.jar,rt.jar,or sunrsasign.jar.
Although i'm not certain this is correct.If one of those files
are missing that's your problem, if not,I don't know sorry.

Cannot reslove symbol class Date

I am trying to get a clock to show the time in my program. However, when I try to compile the program a "cannot resolve symbol class Date" error appears. I can't figure out where the problem in my program is. Here is my source code. I would appreciate any help.
import javax.swing.*;
import java.io.*;
import java.lang.*;
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
//import java.util.*;
import java.math.*;
public class store
public static void main(String[] args)
String dataInput;
     dataInput = JOptionPane.showInputDialog(null, "Input item data: ");
JOptionPane.showMessageDialog(null, "" + dataInput);
EasyReader console = new EasyReader();
int i, j, k, inum, icom, min, nswaps; inum = 0; boolean swap = false;
double num[] = new double[100]; double dsum, T;
     do
     System.out.println(); System.out.println("Command Menu"); System.out.println();
     System.out.println("1 = Display the data");
System.out.println("2 = Bubble Sort the numbers");
System.out.println("3 = Selection Sort the numbers");
System.out.println("4 = Insertion Sort the numbers");
System.out.println("5 = Binary Search for a number");
System.out.println("0 = Exit the program"); System.out.println();
System.out.print("Enter Command - ");
icom = console.readInt(); System.out.println();
switch (icom)
case 1: // Display the data
               Display(inum, num);
               break;
case 2: // Bubble sort
               nswaps = 0;
               for (i = 0; i < (inum-1); i++ )
          for (j = (i+1); j < inum; j++)
                    if (num[i] > num[j])
                              T = num;
                         num[i] = num[j];
                         num[j] = T;
                         nswaps++;
               System.out.println("The number of swaps was - " + nswaps);
               Display(inum, num);
               break;
case 3: // Selection sort
               nswaps = 0;
               for (i = 0; i < inum - 1; i++) {
          min = i; swap = false;
for (j = i + 1; j < inum; j++)
     if (num[j] < num[min]) { min = j; swap = true; }
if (swap) {T = num[min];
          num[min] = num[i];
                    num[i] = T;
                    nswaps++;}
               System.out.println("The number of swaps was - " + nswaps);
               Display(inum, num);
               break;
case 4: // Selection sort
               nswaps = 0;
               for (i = 1; i < inum; i++)
               j = i; T = num[i];
                    while ((j > 0) && (T < num[j-1]))
          num[j] = num[j-1]; j--; nswaps++;
               num[j] = T; nswaps++;
               System.out.println("The number of swaps was - " + nswaps);
               Display(inum, num);
               break;
case 5: // Binary Search
               System.out.println("Your numbers will be sorted first");
               System.out.println();
               for (i = 1; i < inum; i++)
               j = i; T = num[i];
                    while ((j > 0) && (T < num[j-1]))
          num[j] = num[j-1]; j--;
               num[j] = T;
               System.out.print("Enter the number to locate - ");
               T = console.readDouble(); nswaps = 0; System.out.println();
               int left = 0, right = inum, middle; k = -1;
               while (left <= right)
                    middle = (left + right) / 2;
                    if (T > num[middle]) {left = middle + 1; nswaps++;}
                    else if (T < num[middle]) {right = middle - 1; nswaps++;}
                    else { k = middle; break; }
               if (k == -1) System.out.println("Your number was not located in the array");
               else System.out.println("Your number " + T + " is in position " + (k+1));
               System.out.println();
               System.out.println(nswaps + " comparisons were needed to search for your number");
               Display(inum, num);
               break;
     } while (icom != 0);
     public static void Display(int inum, double num[])
          {     int k;
               System.out.println();
               System.out.println("");
               System.out.println();
          for (k = 0; k < inum; k++)
          System.out.println((k+1) + " - " + num[k]);
     return;
class Clock extends Thread
     //A Canvas that will display the current time on the calculator
     Canvas Time;
     //A Date object that will access the current time
     private Date now;
     //A string to hold the current time
     private String currentTime;
     //The constructor for Clock, accepting a Label as an argument
     public Clock(Canvas _Time)
          Time = Time;          //Time is passed by reference, so Time
                                   //now refers to the same Canvas
          start();               //start this thread
     //The overriden run method of this thread
     public void run()
          //while this thread exists
          while (true)
               try
                    draw_clock();          //calls the draw_clock method
                    sleep(1000);          //puts this thread to sleep for one
                                             //second
               //catches an InterruptedException that the sleep() method might throw
               catch (InterruptedException e) { suspend(); }
               //catches a NullPointerException and suspends the thread if one occurs
               catch (NullPointerException e) { suspend(); }
     //A method to draw the current time onto the Time Canvas on the applet
     public void draw_clock()
          try
               //Obtains the Graphics object from the Canvas Time so that it can
               //be manipulated directly
               Graphics g = Time.getGraphics();
               g.setColor(Color.gray);          //sets the color of the Graphics object
                                                  //to gray for the rectangle background
               g.fillRect(0,0,165,25);          //fills the Canvas area with a rectangle
                                                  //starting at 0,0 coordinates of the Canvas
                                                  //and extending to the length and width
               g.setColor(Color.orange);     //sets the color of the Graphics object
                                                  //to orange for the text color
               get_the_time();                    //calls the get_the_time() method
               //calls the drawString method of the Graphics object g, which will
               //draw a string to the screen
               //Accepts a string and two integers to represent the coordinates
               g.drawString("Current Time - " + currentTime, 0, 17);
          //catches a NullPointerException and suspends the thread if one occurs
          catch (NullPointerException e) { suspend(); }
     //A method to obtain the current time, accurate to the second
     public void get_the_time()
          //creates a new Date object for "now" every time this is called
          now = new Date( );
          //integers to hold the hours, minutes and seconds of the current time
          int a = now.getHours();
          int b = now.getMinutes();
          int c = now.getSeconds();
          if (a == 0) a = 12;          //if hours are zero, set them to twelve
          if (a > 12) a = a -12;     //if hours are greater than twelve, make a
                                        //conversion to civilian time, as opposed to
                                        //24-hour time
          if ( a < 10)               //if hours are less than 10
               //sets the currentTime string to 0, appends a's value and a
               //colon
               currentTime = "0" + a + ":" ;
          else
               //otherwise set currentTime string to "a", append a colon
               currentTime = a +":";
          if (b < 10)                    //if minutes are less than ten
               //append a zero to string currentTime, then append "b" and a colon
               currentTime = currentTime + "0" + b + ":" ;
          else
               //otherwise append "b" and a colon to currentTime string
               currentTime = currentTime + b + ":" ;
          if (c < 10)                    //if seconds are less than ten
               //append a zero to string currentTime, then append "c" and a colon
               currentTime = currentTime + "0" + c ;
          else
               //otherwise append "c" to currentTime string
               currentTime = currentTime + c;
}          //end of the Clock class

Wow.
1) Please in future use the code tags to format code you post so that it doesn't think you have italics in your code and render it largely1 unreadable. Read this
http://forum.java.sun.com/help.jspa?sec=formatting
2) You commented out the import of java.util which is the problem you are complaining about.
3) Are you planning to stick all the code you ever write into the one source file? Why is all this stuff rammed together. Yoinks.

Cannot resolve symbol--Shape

I am having a problem with the following code in InheritanceDemo.java.
public void paint(Graphics g)
numShapes = shapeList.size();
for (int i = 0;i < numShapes; i++)
Shape s = (Shape)shapeList.get(i);
s.draw(g);
It is giving me errors on s.draw(g). It's pointing to the period after the s and says "cannot resolve symbol", Class Shape.
My Shape.java looks like the following:
import java.awt.*;
abstract class Shape {
abstract void paint(Graphics g);
Can anyone tell me what I've done incorrectly?

Okay, I think I understand. You're importing java.awt.*, so when you say Shape it thinks you mean java.awt.Shape.
(Solution 1) Change the classname Shape to one which doesn't already exist in the Java class library.
(Solution 2) Only import the classes you need, not *.
(Solution 3) Add an explicit "import Shape;" below the rest of the import statements to override

Visual Studio 2012 cannot resolve symbol or Errors control is not a member of class

Visual Studio 2012 Web Site Project (Note not a Web application, so there are not Designer.vb files) > Site works perfectly fine and using IIS and attaching to IIS to debug code.
However, if I try to build the site inside of Visual Studio I am getting lots of Errors ‘pnlName’ is not a member of ‘Page_Name’ In the code behind I am getting errors ‘Cannot resolve symbol ‘pnlName’
.ascx Page
<li style="margin-right:0;" id="pnlName" runat="server"><a href="/cart" title="Checkout" class="global-checkout">Checkout</a></li>
.ascx.vb page
Me.pnlName.Attributes.Remove("style")
I have cleaned, rebuild and nothing gets rid of these errors, but again the site works as designed, but I would like to launch and debug inside of Visual Studio.
Moojjoo MCP, MCTS
MCP Virtual Business Card
http://moojjoo.blogspot.com

Cor,
What I am stating is this is a solution using the Web Site Project instead of a
Web Application Project.
Web Site projects do not require Designer.vb files, Web Application Projects add Designer.vb files in the solution.
Background: I have been hired to support a very successful e-commerce site that was built by a 3rd party vendor (I had no input on the contract or specification, because I would have went with
MVC). The site works 100% correctly, however from my 2003 - 2015 experience with Visual Studio and Web Development being in Web Forms and MVC I have always built ASP.NET Solutions using the Web Application Project Templates, which compiles the code down
to .dlls.
A Web Site project does not compile the code, but simply uses the .vb files and they have to be migrated to the server with the .aspx files. http://msdn.microsoft.com/en-us/library/dd547590%28v=vs.110%29.aspx
Currently the only way I can debug this Solution is to attach to the w3wp.exe process running locally on my work station.
The Solution is comprised of two Web Sites, which I cannot get it to compile because of the following errors -
'webServerControlName' is not a member of '(Protected Code Behind Class Name)' I am reaching out to the MSDN community to see if anyone has experienced this issue with
Web Site Projects.
I hope that clears up the Project Type question.
Moojjoo MCP, MCTS
MCP Virtual Business Card
http://moojjoo.blogspot.com

Getting error message Cannot Resolve Symbol when trying to compile a class

Hello All -
I am getting an error message cannot resolve symbol while trying to compile a java class that calls another java class in the same package. The called class compiles fine, but the calling class generates
the following error message:
D:\Apache Tomcat 4.0\webapps\examples\WEB-INF\classes\cal>javac
ConnectionPool.java
ConnectionPool.java:158: cannot resolve symbol
symbol : class PooledConnection
location: class cal.ConnectionPool
private void addConnection(PooledConnection value) {
^
ConnectionPool.java:144: cannot resolve symbol
symbol : class PooledConnection
location: class cal.ConnectionPool
PooledConnection pcon = new PooledConnection(con);
^
ConnectionPool.java:144: cannot resolve symbol
symbol : class PooledConnection
location: class cal.ConnectionPool
PooledConnection pcon = new PooledConnection(con);
The code is listed as follows for PooledConnection.java (it compiles fine)
package cal;
import java.sql.*;
public class PooledConnection {
// Real JDBC Connection
private Connection connection = null;
// boolean flag used to determine if connection is in use
private boolean inuse = false;
// Constructor that takes the passed in JDBC Connection
// and stores it in the connection attribute.
public PooledConnection(Connection value) {
if ( value != null ) {
connection = value;
// Returns a reference to the JDBC Connection
public Connection getConnection() {
// get the JDBC Connection
return connection;
// Set the status of the PooledConnection.
public void setInUse(boolean value) {
inuse = value;
// Returns the current status of the PooledConnection.
public boolean inUse() {
return inuse;
// Close the real JDBC Connection
public void close() {
try {
connection.close();
catch (SQLException sqle) {
System.err.println(sqle.getMessage());
Now the code for ConnectionPool.java class that gives the cannot
resolve symbol error
package cal;
import java.sql.*;
import java.util.*;
public class ConnectionPool {
// JDBC Driver Name
private String driver = null;
// URL of database
private String url = null;
// Initial number of connections.
private int size = 0;
// Username
private String username = new String("");
// Password
private String password = new String("");
// Vector of JDBC Connections
private Vector pool = null;
public ConnectionPool() {
// Set the value of the JDBC Driver
public void setDriver(String value) {
if ( value != null ) {
driver = value;
// Get the value of the JDBC Driver
public String getDriver() {
return driver;
// Set the URL Pointing to the Datasource
public void setURL(String value ) {
if ( value != null ) {
url = value;
// Get the URL Pointing to the Datasource
public String getURL() {
return url;
// Set the initial number of connections
public void setSize(int value) {
if ( value > 1 ) {
size = value;
// Get the initial number of connections
public int getSize() {
return size;
// Set the username
public void setUsername(String value) {
if ( value != null ) {
username = value;
// Get the username
public String getUserName() {
return username;
// Set the password
public void setPassword(String value) {
if ( value != null ) {
password = value;
// Get the password
public String getPassword() {
return password;
// Creates and returns a connection
private Connection createConnection() throws Exception {
Connection con = null;
// Create a Connection
con = DriverManager.getConnection(url,
username, password);
return con;
// Initialize the pool
public synchronized void initializePool() throws Exception {
// Check our initial values
if ( driver == null ) {
throw new Exception("No Driver Name Specified!");
if ( url == null ) {
throw new Exception("No URL Specified!");
if ( size < 1 ) {
throw new Exception("Pool size is less than 1!");
// Create the Connections
try {
// Load the Driver class file
Class.forName(driver);
// Create Connections based on the size member
for ( int x = 0; x < size; x++ ) {
Connection con = createConnection();
if ( con != null ) {
// Create a PooledConnection to encapsulate the
// real JDBC Connection
PooledConnection pcon = new PooledConnection(con);
// Add the Connection to the pool.
addConnection(pcon);
catch (Exception e) {
System.err.println(e.getMessage());
throw new Exception(e.getMessage());
// Adds the PooledConnection to the pool
private void addConnection(PooledConnection value) {
// If the pool is null, create a new vector
// with the initial size of "size"
if ( pool == null ) {
pool = new Vector(size);
// Add the PooledConnection Object to the vector
pool.addElement(value);
public synchronized void releaseConnection(Connection con) {
// find the PooledConnection Object
for ( int x = 0; x < pool.size(); x++ ) {
PooledConnection pcon =
(PooledConnection)pool.elementAt(x);
// Check for correct Connection
if ( pcon.getConnection() == con ) {
System.err.println("Releasing Connection " + x);
// Set its inuse attribute to false, which
// releases it for use
pcon.setInUse(false);
break;
// Find an available connection
public synchronized Connection getConnection()
throws Exception {
PooledConnection pcon = null;
// find a connection not in use
for ( int x = 0; x < pool.size(); x++ ) {
pcon = (PooledConnection)pool.elementAt(x);
// Check to see if the Connection is in use
if ( pcon.inUse() == false ) {
// Mark it as in use
pcon.setInUse(true);
// return the JDBC Connection stored in the
// PooledConnection object
return pcon.getConnection();
// Could not find a free connection,
// create and add a new one
try {
// Create a new JDBC Connection
Connection con = createConnection();
// Create a new PooledConnection, passing it the JDBC
// Connection
pcon = new PooledConnection(con);
// Mark the connection as in use
pcon.setInUse(true);
// Add the new PooledConnection object to the pool
pool.addElement(pcon);
catch (Exception e) {
System.err.println(e.getMessage());
throw new Exception(e.getMessage());
// return the new Connection
return pcon.getConnection();
// When shutting down the pool, you need to first empty it.
public synchronized void emptyPool() {
// Iterate over the entire pool closing the
// JDBC Connections.
for ( int x = 0; x < pool.size(); x++ ) {
System.err.println("Closing JDBC Connection " + x);
PooledConnection pcon =
(PooledConnection)pool.elementAt(x);
// If the PooledConnection is not in use, close it
if ( pcon.inUse() == false ) {
pcon.close();
else {
// If it is still in use, sleep for 30 seconds and
// force close.
try {
java.lang.Thread.sleep(30000);
pcon.close();
catch (InterruptedException ie) {
System.err.println(ie.getMessage());
I am using Sun JDK Version 1.3.0_02" and Apache/Tomcat 4.0. Both the calling and the called class are in the same directory.
Any help would be greatly appreciated.
tnx..
addi

Is ConnectionPool in this "cal" package as well as PooledConnection? From the directory you are compiling from it appears that it is. If it is, then you are compiling it incorrectly. To compile ConnectionPool (and PooledConnection similarly), you must change the current directory to the one that contains cal and type
javac cal/ConnectionPool.

Class error - cannot resolve symbol "MyDocumentListener"

Hello,
this is a groaner I'm sure, but I don't see the problem.
Newbie-itis probably ...
I'm not concerned with what the class does, but it would be nice for the silly thing to compile!
What the heck am I missing for "MyDocumentListener" ?
C:\divelog>javac -classpath C:\ CenterPanel.java
CenterPanel.java:53: cannot resolve symbol
symbol : class MyDocumentListener
location: class divelog.CenterPanel
MyDocumentListener myDocumentListener = new MyDocumentListener(); // define the listener class
^
CenterPanel.java:53: cannot resolve symbol
symbol : class MyDocumentListener
location: class divelog.CenterPanel
MyDocumentListener myDocumentListener = new MyDocumentListener(); // define the listener class
^
2 errors
package divelog;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.lang.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.filechooser.*;
import javax.swing.text.*;
public class CenterPanel extends JPanel implements ActionListener
{ // Opens class
static private final String newline = "\n";
private JTextArea comments;
private JScrollPane scrollpane;
private JButton saveButton, openButton;
private JLabel whiteshark;
private Box box;
private BufferedReader br ;
private String str;
private JTextArea instruct;
private File defaultDirectory = new File("C://divelog");
private File fileDirectory = null;
private File currentFile= null;
public CenterPanel()
{ // open constructor CenterPanel
setBackground(Color.white);
comments = new JTextArea("Enter comments, such as " +
"location, water conditions, sea life you observed," +
" and problems you may have encountered.", 15, 10);
comments.setLineWrap(true);
comments.setWrapStyleWord(true);
comments.setEditable(true);
comments.setFont(new Font("Times-Roman", Font.PLAIN, 14));
// add a document listener for changes to the text,
// query before opening a new file to decide if we need to save changes.
MyDocumentListener myDocumentListener = new MyDocumentListener(); // define the listener class
comments.getDocument().addDocumentListener(myDocumentListener); // create the reference for the class
// ------ Document listener class -----------
class MyDocumentListener implements DocumentListener {
public void insertUpdate(DocumentEvent e) {
Calculate(e);
public void removeUpdate(DocumentEvent e) {
Calculate(e);
public void changedUpdate(DocumentEvent e) {
private void Calculate(DocumentEvent e) {
// do something here
scrollpane = new JScrollPane(comments);
scrollpane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
saveButton = new JButton("Save Comments", new ImageIcon("images/Save16.gif"));
saveButton.addActionListener( this );
saveButton.setToolTipText("Click this button to save the current file.");
openButton = new JButton("Open File...", new ImageIcon("images/Open16.gif"));
openButton.addActionListener( this );
openButton.setToolTipText("Click this button to open a file.");
whiteshark = new JLabel("", new ImageIcon("images/gwhite.gif"), JLabel.CENTER);
Box boxH;
boxH = Box.createHorizontalBox();
boxH.add(openButton);
boxH.add(Box.createHorizontalStrut(15));
boxH.add(saveButton);
box = Box.createVerticalBox();
box.add(scrollpane);
box.add(Box.createVerticalStrut(10));
box.add(boxH);
box.add(Box.createVerticalStrut(15));
box.add(whiteshark);
add(box);
} // closes constructor CenterPanel
public void actionPerformed( ActionEvent evt )
{ // open method actionPerformed
JFileChooser jfc = new JFileChooser();
// these do not work !!
// -- set the file types to view --
// ExtensionFileFilter filter = new ExtensionFileFilter();
// FileFilter filter = new FileFilter();
//filter.addExtension("java");
//filter.addExtension("txt");
//filter.setDescription("Text & Java Files");
//jfc.setFileFilter(filter);
     //Add a custom file filter and disable the default "Accept All" file filter.
jfc.addChoosableFileFilter(new JTFilter());
jfc.setAcceptAllFileFilterUsed(false);
// -- open the default directory --
// public void setCurrentDirectory(File dir)
// jfc.setCurrentDirectory(new File("C://divelog"));
jfc.setCurrentDirectory(defaultDirectory);
jfc.setSize(400, 300);
jfc.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
Container parent = saveButton.getParent();
//========================= Test Button Actions ================================
//========================= Open Button ================================
if (evt.getSource() == openButton)
int choice = jfc.showOpenDialog(CenterPanel.this);
File file = jfc.getSelectedFile();
/* a: */
if (file != null && choice == JFileChooser.APPROVE_OPTION)
String filename = jfc.getSelectedFile().getAbsolutePath();
// -- compare the currentFile to the file chosen, alert of loosing any changes to currentFile --
// If (currentFile != filename)
// -- get the current directory name -------
// public File getCurrentDirectory( );
File f=new File(System.getProperty("user.dir"));
fileDirectory = jfc.getCurrentDirectory();
// -- remember the last directory used --
if (defaultDirectory != fileDirectory)
{defaultDirectory = fileDirectory;}
try
{ //opens try
comments.getLineCount( );
// -- clear the old data before importing the new file --
comments.selectAll();
comments.replaceSelection("");
// -- get the new data ---
br = new BufferedReader (new FileReader(file));
while ((str = br.readLine()) != null)
{//opens while
comments.append(str);
} //closes while
} // close try
catch (IOException ioe)
{ // open catch
comments.append(newline +"Open command not successful:" + ioe + newline);
} // close catch
// ---- display the values of the directory variables -----------------------
comments.append(
newline + "The f directory variable contains: " + f +
newline + "The fileDirectory variable contains: " + fileDirectory +
newline + "The defaultDirectory variable contains: " + defaultDirectory );
else
comments.append("Open command cancelled by user." + newline);
} //close if statement /* a: */
//========================= Save Button ================================
} else if (evt.getSource() == saveButton)
int choice = jfc.showSaveDialog(CenterPanel.this);
if (choice == JFileChooser.APPROVE_OPTION)
File fileName = jfc.getSelectedFile();
// -- get the current directory name -------
// public File getCurrentDirectory( );
File f=new File(System.getProperty("user.dir"));
fileDirectory = jfc.getCurrentDirectory();
// -- remember the last directory used --
if (defaultDirectory != fileDirectory)
{defaultDirectory = fileDirectory;}
//check for existing files. Warn users & ask if they want to overwrite
for(int i = 0; i < fileName.length(); i ++) {
File tmp = null;
tmp = (fileName);
if (tmp.exists()) // display pop-up alert
//public static int showConfirmDialog( Component parentComponent,
// Object message,
// String title,
// int optionType,
// int messageType,
// Icon icon);
int confirm = JOptionPane.showConfirmDialog(null,
fileName + " already exists on " + fileDirectory
+ "\n \nContinue?", // msg
"Warning! Overwrite File!", // title
JOptionPane.OK_CANCEL_OPTION, // buttons displayed
                    // JOptionPane.ERROR_MESSAGE
                    // JOptionPane.INFORMATION_MESSAGE
                    // JOptionPane.PLAIN_MESSAGE
                    // JOptionPane.QUESTION_MESSAGE
JOptionPane.WARNING_MESSAGE,
null);
if (confirm != JOptionPane.YES_OPTION)
{ //user cancels the file overwrite.
try {
jfc.cancelSelection();
break;
catch(Exception e) {}
// ----- Save the file if everything is OK ----------------------------
try
{ // opens try
BufferedWriter bw = new BufferedWriter(new FileWriter(fileName));
bw.write(comments.getText());
bw.flush();
bw.close();
comments.append( newline + newline + "Saving: " + fileName.getName() + "." + newline);
break;
} // closes try
catch (IOException ioe)
{ // open catch
comments.append(newline +"Save command unsuccessful:" + ioe + newline);
} // close catch
} // if exists
} //close for loop
else
comments.append("Save command cancelled by user." + newline);
} // end-if save button
} // close method actionPerformed
} //close constructor CenterPanel
} // Closes class CenterPanel

There is no way to be able to see MyDocumentListener class in the way you wrote. The reason is because MyDocumentListener class inside the constructor itself. MyDocumentListener class is an inner class, not suppose to be inside a constructor or a method. What you need to do is simple thing, just move it from inside the constructor and place it between two methods.
that's all folks
Qusay

Cannot resolve symbol: class OracleDriver

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