Can we call a method from a adapter class?

Hi
I have added KeyAdapter class to a textfield now i want to call a method in the outer class from inside the adapter class. I tried but its showing some error,
public class A
A()
TF1.addKeyListener(new KeyAdapter()
public void keyReleased(KeyEvent e)
A a=new A();
ec.chkSalary();
chkSalary()
can i call the method like this?

yeah.. i got it.. i just passed that KeyEvent object to the method
but i did declare that as a char in that method like,
chkSalary(e) // e is the KeyEvent reference
and the method is
chk(char e);
thats it.
thank you yaar.

Similar Messages

Calling a method from a super class

Hello, I'm trying to write a program that will call a method from a super class. This program is the test program, so should i include extends in the class declaration? Also, what code is needed for the call? Just to make things clear the program includes three different types of object classes and one abstract superclass and the test program which is what im having problems with. I try to use the test program to calculate somthing for each of them using the abstract method in the superclass, but its overridden for each of the three object classes. Now to call this function what syntax should I include? the function returns a double. Thanks.

Well, this sort of depends on how the methods are overridden.
public class SuperFoo {
public void foo() {
     //do something;
public void bar(){
     //do something
public class SubFoo extends SuperFoo {
   public void foo() {
      //do something different that overrides foo()
   public void baz() {
      bar(); //calls superclass method
      foo(); //calls method in this (sub) class
      super.foo(); //calls method in superclass
}However, if you have a superclass with an abstract method, then all the subclasses implement that same method with a relevant implementation. Since the parent method is abstract, you can't make a call to it (it contains no implementation, right?).

Calling a method from an abstract class in a seperate class

I am trying to call the getID() method from the Chat class in the getIDs() method in the Outputter class. I would usually instantiate with a normal class but I know you cant instantiate the method when using abstract classes. I've been going over and over my theory and have just become more confused??
Package Chatroom
public abstract class Chat
   private String id;
   public String getID()
      return id;
   protected void setId(String s)
      id = s;
   public abstract void sendMessageToUser(String msg);
Package Chatroom
public class Outputter
public String[] getIDs()
     // This is where I get confused. I know you can't instantiate the object like:
        Chat users=new Chat();
        users.getID();
I have the two classes in the package and you need to that to be able to use a class' methods in another class.
Please help me :(

I have just looked over my program and realised my class names are not the most discriptive, so I have renamed them to give you a clearer picture.
package Chatroom
public abstract class Chatter
private String id;
public String getID()
return id;
protected void setId(String s)
id = s;
I am trying to slowly build a chatroom on my own. The Chatter class is a class that will be used to represent a single logged in user and the user is given an ID when he logs in through the setId and getID() methods.
package Chatroom;
import java.util.Vector;
public class Broadcaster
private Vector<Chatter> chatters = new Vector<Chatter>();
public String[] getIDs()
// code here
The Broadcaster class will keep a list of all logged-in users keeps a list of all the chats representing logged-in users, which it stores in a Vector.I am trying to use the getIDs() method to return an array of Strings comprising the IDs of all logged-in users, which is why im trying to use the getID() method from the Chat class.
I apologise if I come across as clueless, it's just I have been going through books for about 4 hours now and I have just totally lossed all my bearings

How to call a method from a separate class using IBAction

I can't work out how to call a method form an external class with IBAction.
//This Works 1
-(void)addCard:(MyiCards *)card{
[card insertNewCardIntoDatabase];
//This works 2
-(IBAction) addNewCard:(id)sender{
//stuff -- I want to call [card insertNewCardIntoDatabase];
I have tried tons of stuff here, but nothing is working. When i build this I get no errors or warnings, but trying to call the method in anyway other that what is there, i get errors.

Can you explain more about what you are trying to do? IBAction is just a 'hint' to Interface Builder. It's just a void method return. And it's unclear what method is where from your code snippet below. is addNewCard: in another class? And if so, does it have a reference to the 'card' object you are sending the 'insertNewCardIntoDatabase' message? Some more details would help.
Cheers,
George

Need help calling a method from an immutable class

I'm having difficulties in calling a method from my class called Cabin to my main. Here's the code in my main              if(this is where i want my method hasKitchen() from my Cabin class)
                    System.out.println("There is a kitchen.");
               else
                    System.out.println("There is not a kitchen.");
               }and here's my method from my Cabin class:public boolean hasKitchen()
     return kitchen;
}

You should first have an instance of Cabin created by using
   Cabin c = ....
   if (c.hasKitchen()) {
     System.out.println("There is a kitchen.");
   } else {
        System.out.println("There is not a kitchen.");
   }

Calling a method from a different class?

Ok..
I been trying for hours... but im stumped.
How can I get this to work?
(Note: I cut this code down from over 600+ lines of code.. I left in a REALLY raw framework that shows where the basic problem is.)
public class Client extends JPanel implements Runnable {
// variable declarations...
    Socket connection;
    BufferedReader fromServer;
    PrintWriter toServer;
    public Client(){
// GUI creation...
// Create the login JFrame
    Login login = new Login()
    public void connect(){
    try {
            //Attempt to connect to the server
            connection = new Socket(ip,port);
            fromServer = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            toServer = new PrintWriter(connection.getOutputStream());
            //Launch a thread here to read incoming messages from the server
            //so I dont block on reading
            new Thread (this).start();
    } catch (Exception e) {
        e.printStackTrace();
    public void run(){
        // This keeps reading lines from the server
        String s;
        try {
            //Read messages sent from the server - add them to chat window
            while ((s=fromServer.readLine()) != null) {
            txtChat.append(s);
        } catch (Exception e) {}
    public static void main(String args[]){
        // some init frame stuff
        frame = new JFrame();
        frame.getContentPane().add(new Client(),BorderLayout.CENTER);
     frame.setVisible(true);
class Login extends JFrame {
    JPanel pane;
    public Login() {
     super("Login");
     pane = new JPanel();
     JButton cmdConnect = new JButton("Connect");
        pane.add(cmdConnect);
     setContentPane(pane);
     setSize(300,300);
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     cmdConnect.addActionListener(new ActionListener(){
         public void actionPerformed(ActionEvent ae){
          // I want to connect to the server when this button is pressed.
          // How can I call the connect method in the Client class?
}

Your posted code shows Login as an inner class. So one way to solve your problem is.
1. Make an instance variable to hold the instance. For example, after "PrintWriter toServer;" add "private Client client;"
2. In the Client constructor, add a line "client = this;"
3. In the Login actionPerformed(), use "client.connect();"
Another way is to have Login keep a reference to the Client that created it.
1. Add an instance variable to Login "private Client client;"
2. Change the Login constructor "public Login(Client c) {"
3. Add a line in the constructor "client = c;"
4. In the actionPerformed() "client.connect();"

Problems calling a method from a different class

Like many programmers, I'm having a go at making my own chat room. All has been going well so far, however I am having trouble calling the method which connects the client to the server, from the method which actually starts the server.
The method for starting the server:
public static void serverStart () throws IOException {
        new Thread () {
        public void run() {
            try {
                ServerSocket serverSock = new ServerSocket (client.serverPort);
            while (true) {
                Socket serverClient = serverSock.accept ();
                ChatHandler handler = new ChatHandler(serverClient);
                handler.start ();
            } catch (IOException ex) {
                connectTo.handleIOException(ex);
        }.start();
        try {
            connectTo.start();
        } catch (IOException ex) {
            connectTo.handleIOException(ex);
    }The part of interest is the "connectTo.start()" line, as this is the one which calls a method in the class connectToMethod which tells the client to connect to this newly started server. Now for the client connection code:
public synchronized void start () throws IOException {
      if (listener == null) {
          Socket socket = new Socket (client.serverAddr, client.serverPort);
          try {
              dataIn = new DataInputStream
                      (new BufferedInputStream (socket.getInputStream ()));
              dataOut = new DataOutputStream
                      (new BufferedOutputStream (socket.getOutputStream ()));
          } catch (IOException ex) {
          socket.close ();
          throw ex;
      listener = new Thread (this);
      listener.start ();
}Now when the server starts, it should automatically start the connection method "start()" and connect to itself. However I am getting a NullPointerException error at the line "connectTo.start();" from the server code. The server and connection client actually work separately, just not when I try to connect from the server itself. I have tried a few ways of getting around this problem, all without success. If anyone could give some input on what might be wrong, or a possible way to fix it, I'd be very grateful.

Sorry, connectTo comes from:
connectToMethod connectTo = new
connectToMethod();
That doesn't necessarily mean this variable reference is the same one as in the code where the NullPointerException was thrown though.
Or the exception was thrown inside the start() method. The runtime isn't lying to you. You have a null reference (pointer) where it says you do.

How can i call a method from the a subdirectory using packages

This is my directory structure:
java
--p1
--One.java
--p2
--Two.java
package java.p1;
import p2.Two;
public class One
     public static void main(String args[])
          Two obj = new Two();
          obj.p();
package java.p2;
public class Two
     public void p()
          System.out.println("p method");
ERRORS !!
C:\Documents and Settings\ashutosh\Desktop\java\p1\One.java:3: package p2 does not exist
import p2.Two;
          ^
C:\Documents and Settings\ashutosh\Desktop\java\p1\One.java:9: cannot find symbol
symbol : class Two
location: class java.p1.One
          Two obj = new Two();
                ^
C:\Documents and Settings\ashutosh\Desktop\java\p1\One.java:9: cannot find symbol
symbol : class Two
location: class java.p1.One
          Two obj = new Two();
                              ^Help me out. Thanks.

jinchuriki123 wrote:
This is my directory structure:
java
--p1
--One.java
--p2
--Two.java
package java.p1;
import p2.Two;
public class One
     public static void main(String args[])
          Two obj = new Two();
          obj.p();
package java.p2;
public class Two
     public void p()
          System.out.println("p method");
ERRORS !!
C:\Documents and Settings\ashutosh\Desktop\java\p1\One.java:3: package p2 does not exist
import p2.Two;
^
C:\Documents and Settings\ashutosh\Desktop\java\p1\One.java:9: cannot find symbol
symbol : class Two
location: class java.p1.One
          Two obj = new Two();
^
C:\Documents and Settings\ashutosh\Desktop\java\p1\One.java:9: cannot find symbol
symbol : class Two
location: class java.p1.One
          Two obj = new Two();
^Help me out. Thanks.You don't have a class p2.Two, You do have a class java.p2.Two. Package paths aren't relative.
Also, it's recommended not to use package names containing "java" or "javax" (or is it illegal to do so?). Change your package & folder names.
db

How to Call a method from a separate class...?

Hi there...
I have a class name HMSCon which has a method named con...
method con is the one the loads the jdbc driver and establishes the connection....Now!I have a separate class file named TAQueries,this is where i am going to write my SQL Statements...any idea how to use my variables from HMSCon to my TAQueries class???
here's my code:
public class HMSCon{
public static void con(){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
String url="jdbc:odbc:;DRIVER=Microsoft Access Driver (*.mdb);DBQ=" +
"E:/samer/HardwareMonitoringSystem/src/hms/pkg/hmsData.mdb";
Connection cn = DriverManager.getConnection(url,"Admin", "asian01");
}catch(Exception s){
System.err.print(s);}
here's my seperate class file TAQueries,i put an error message below..
class TAInfoQueries{
public void insertNewTA(String TAID,String Fname,String Mname, String Lname,String Age,
String Bdate,String Haddress,String ContactNo){
// Statement stmt=cn.createStatement(); ERROR: Cannot find symbol cn.
// stmt.executeUpdate("INSERT INTO TechnicalAssistants VALUES('sdfas','sdfsdf','sdfdsf','sdfdsf',3,04/13/04,'asdf','asdfsdf')");
// stmt.close();
}

You can try the below code, but it's a bad idea to use staitc member for connection:(
public class HMSCon{
static Connection cn;
static{
con();
public static void con(){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
String url="jdbc:odbc:;DRIVER=Microsoft Access Driver (*.mdb);DBQ=" +
"E:/samer/HardwareMonitoringSystem/src/hms/pkg/hmsData.mdb";
cn = DriverManager.getConnection(url,"Admin", "asian01");
}catch(Exception s){
System.err.print(s);}
here's my seperate class file TAQueries,i put an error message below..
class TAInfoQueries{
public void insertNewTA(String TAID,String Fname,String Mname, String Lname,String Age,
String Bdate,String Haddress,String ContactNo){
// Statement stmt=HMSCon.cn.createStatement(); ERROR: Cannot find symbol cn.
// stmt.executeUpdate("INSERT INTO TechnicalAssistants VALUES('sdfas','sdfsdf','sdfdsf','sdfdsf',3,04/13/04,'asdf','asdfsdf')");
// stmt.close();
}

How can I disable a method from a direved class

I am extended TreeSet for an assigment with some new functionality.
This new class is rbTree.
I need to disable all of the old functions so that if a user creates a new rbTree he will only be able to use the methods defined in rbTree.
rbTree uses some of treeSets methods using super.
I now how to just overwrite them but I think I should let the user know those methods are unsupported, by throwing an exception. I can't throw any exceptions because most of treeSets methods don't.
I know there is an easy way to do this, and I don't think I should just leave them blank.
Any ideas?
thanks in advance
-Marc

If you have a new class that extends TreeSet that shouldn't expose any of the TreeSet methods, don't extend TreeSet. Prefer composition over inheritance. You can use a TreeSet as a private member within your class; e.g. your new class has-a TreeSet, rather than is-a TreeSet. This way you control which functionality of the TreeSet to use, but only expose your new methods.
Also, you should read and implement Code Conventions for the Java Programming Language - it will help you and others understand/maintain your code.
Example:import java.util.TreeSet;
public class RbTree
    private TreeSet set = new TreeSet();
     * only allow a specific type of object (my.pkg.MySpecialObject) to be added to the set.
    public add(MySpecialObject mso)
        set.add(mso);
    // other methods follow...
}

Help on Calling a method from another class

how can i call a method from another class.
Class A has 3 methods
i just want to call only one of these 3 methods into my another class.
How can I do that.

When i am trying this
A a=new A;
Its calling all the methods from class A. I just want
to call a specfic method.How can it be done?When i am trying this
A a=new A();
Its calling all the methods from class A. I just want to call a specfic method.How can it be done?

Calling Java Methods from Stored Procedures

Can I call Java Methods from Oracle Stored Procedures? I have a Java framework that logs events and would like to reuse it for logging events that occur in stored procedures.
null

You need to publish java class methods to plsql.
Attached below is some information.
Although both PL/SQL modules and Java classes are stored in the database
and are managed by many of the same mechanisms, each of them resides in
its own namespace. Therefore, Java methods are not accessible from SQL
and PL/SQL by default. In order to expose Java methods to the SQL and
PL/SQL engines, first publish that Java method to the SQL namespace using
a 'Call Spec'.
Note: A 'Call Spec' does not create an additional layer of
execution so there is no performance penalty incurred.
A 'Call Spec' is simply a syntactical mechanism used to
make a method known in the SQL namespace.
The SQL name established by the 'Call Spec' can be top-level or packaged.
The syntax differs only slightly and is consistent with that used for
PL/SQL procedures and packages. For more information on the exact
syntax, see the references listed in 'Related Topics'.
In general, a top-level procedure 'Call Spec' takes the form:
CREATE OR REPLACE PROCEDURE procname ( pname mode ptype, ... )
AS LANGUAGE JAVA NAME 'javaname ( javatype, ... )';
Where: procname is the SQL name you wish to publish
pname is the name for a parameter to procname
mode is the parameter mode (i.e. IN, OUT, IN OUT)
ptype is a valid SQL type (e.g. NUMBER, CHAR, etc.)
javaname is the fully qualified name of the Java method
javatype is a Java type for the corresponding parameter
Likewise, a top-level function 'Call Spec' takes the form:
CREATE OR REPLACE FUNCTION fname ( pname mode ptype, ... ) RETURN rtype
AS LANGUAGE JAVA NAME 'javaname ( javatype, ... ) return javatype';
Where: fname is the SQL name you wish to publish
rtype is the SQL return type of the function
Note: Within the NAME clause, everything within quotes is case
sensitive. For example, if the keyword 'return' is in all
CAPS, this Call Spec will not compile.
Other optional parts of this syntax have been omitted here for simplicity.
Additional examples in subsequent sections illustrate some of these options.
eg
CREATE PROCEDURE MyProc (rowcnt IN NUMBER, numrows OUT NUMBER)
AS LANGUAGE JAVA NAME 'MyClass.MyMethod(int, int[])';
There are several important things to note here:
1.) The 'Call Spec' for a JSP must be created in the same schema as the
corresponding Java class that implements that method.
2.) IN parameters are passed by value. This is the only parameter mode
available in Java. OUT parameters, therefore, must be passed as single
element arrays in order to emulate pass by reference.
3.) Parameter names do not need to match, but the number and types of
the parameters must match (with just one exception - see item 5 below).
Oracle 8i supports conversions between an assortment of SQL and Java.
See the references listed in 'Related Topics' for additional information.
4.) Primitive types (e.g. int, float, etc.) are not required to be fully
qualified with any package name. However, standard Java object types
(e.g. String, Integer, etc.) as well as any user defined object types
(e.g. like those generated by JPublisher) must be prefixed with a
corresponding package name (e.g. java.lang) if applicable.
5.) The 'main' method which takes a single String[] parameter can be
mapped to any PL/SQL procedure or function which takes some number
of VARCHAR2 or CHAR type IN parameters. For example, the java method:
public static void main ( String[] args ) { ... }
can be mapped to each of the following:
PROCEDURE MyProc2 ( arg1 IN CHAR ) ...
PROCEDURE MyProc3 ( arg1 IN CHAR, arg2 IN VARCHAR2 ) ...
PROCEDURE MyProc4 ( arg1 IN VARCHAR2, arg2 IN VARCHAR2 ) ...
and so forth. Parameters map to the corresponding element of the String
array (e.g. arg1 -> args[0], arg2 -> args[1], etc.).
null

How to call java method from C ?

Hello,
I try to call a native method from java which calls java method from the same class. Exception (noSuchMethodError) is thrown. Any ideas?
Thanx in advance !
here is the source of the native method :
JNIEXPORT jint JNICALL Java_TestDll_Proc_1Mul_1Int_1Var_1Var_1Stdcall (JNIEnv * env, jclass jcl, jint jarg1, jint jarg2) {
int arg1;
int arg2;
int arg3;
jint res;
char * ch = "test";
jfieldID fid;
jmethodID mid;
int (* procedure) (int *, int * ,int *);
int mch;
arg1 = (int )jarg1;
arg2 = (int )jarg2;
procedure = GetProcAddress(libraryHandle,"Proc_Mul_Int_Var_Var_Stdcall");
procedure(&arg1,&arg2,&arg3);
res = (jint) arg3;
printf("(*env)->GetMethodID(env, jcl, \"test\", \"()V\");\n");
mid = (*env)->GetMethodID(env, jcl, "test", "()V");
printf("(*env)->CallVoidMethod(env, jcl, mid);\n");
(*env)->CallVoidMethod(env, jcl, mid);
return res;
here is the source of the java file:
public class TestDll {
static {
System.loadLibrary("testdllwrap");
System.out.println("java: Library testdllwrap.dll loaded");
public TestDll() {
public native int Proc_Mul_Int_Var_Var_Stdcall(int jarg1, int jarg2);
public void test() {
System.out.println("java: test()");
public static void main(String[] args) {
TestDll access = new TestDll();
int a = 5;
int b = 6;
int c = 0;
System.out.println("Calling Proc_Mul_Int_Var_Var_Stdcall");
c = access.Proc_Mul_Int_Var_Var_Stdcall(a,b);
System.out.println("Java Result = " + c);

Something is wrong with the code you posted here.
Since your native method is not static, it should have the jobject instance as a parameter in the function prototype, not a jclass. Also, you should be calling CallObjectMethod with a jobject, not jclass.
Check out Jace at http://jace.reyelts.com/jace.
To call the java method you would do:
JNIEXPORT jint JNICALL Java_TestDll_Proc_1Mul_1Int_1Var_1Var_1Stdcall
(JNIEnv * env, jobject jTestDll, jint jarg1, jint jarg2) {
TestDll testDll( jTestDll );
testDll.test();
}God bless,
-Toby Reyelts

Calling a method in a different class?

How do you call a method from a differnt class into the class you are working on?

Class and method were just generic names. You should insert the names of your classes and methods.
class OtherClass {
    public static void one() {
        System.out.println("Static method")l;
    public void two() {
        System.out.println("Non-static method");
class MainClass {
    public static void main(String[] args) {
        OtherClass.one();
        OtherClass oc = new OtherClass();
        oc.two();
}

Can't add list element when calling a method from another class

I am trying to call a method in another class, which contains code listmodel.addElement("text"); to add an element into a list component made in that class.
I've put in System.out.println("passed"); in the method just to make sure if the method was being called properly and it displays normally.
I can change variables in the other class by calling the method with no problem. The only thing I can't do is get listmodel.addElement("text"); to add a new element in the list component by doing it this way.
I've called that method within it's class and it added the element with no problem. Does Java have limitations about what kind of code it can run from other classes? And if that's the case I'd really like to know just why.

There were no errors, just the element doesnt get added to the list by doing it this way
class showpanel extends JPanel implements ActionListener, MouseMotionListener {
       framepanel fp = new framepanel();
       --omitted--
     public void actionPerformed(ActionEvent e){
              if(e.getSource() == button1){
                   fp.addLayer();
/*is in a different class file*/
class framepanel extends JPanel implements ActionListener{
        --omitted--
     public void addLayer(){
          listmodel.addElement("Layer"+numLayer);
          numLayer++;
}

Can we call a method from a adapter class?

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