NoClassDeffounderror
I am very new to java,
I am getting the following errrors for almost allthe programs i type..
error:exception in thread"main" java.def.NoClassDeffounderror:table1
where table1 is the name of the file.
here is the program :
import java.io.*;
import java.lang.*;
class table1 extends Thread
{
int m,n,i,sum;
public void getData(int X1)throws IOException
{
DataInputStream din=new DataInputStream(System.in);
System.out.println("enter the table no1");
m=Integer.parseInt(din.readLine());
n=X1;
}
public void run()
{
for(i=1;i<=n;i++)
{
sum=i*m;
System.out.print(i+"*"+m+"="+sum+"\t");
yield();
}
}
}
class table2 extends Thread
{
int m1,n1,j,sum1;
public void getData1(int X1)throws IOException
{
DataInputStream din=new DataInputStream(System.in);
System.out.println("enter the table no2");
m1=Integer.parseInt(din.readLine());
n1=X1;
}
public void run()
{
for(j=1;j<=n1;j++)
{
sum1=j*m1;
System.out.print(j+"*"+m1+"="+sum1);
System.out.println("");
yield();
}
}
}
when i try executing it.. i get this error:
class multi is public, should be declared in a file named multi.java
when i further try to execute it by using java table1.. i get the following error:
exception in thread"main" java.def.NoClassDeffounderror:table1
i do not know where i am going wrong.. I use DOS for execution.. i have saved the files in the following loacation: program files/java/jdk1.6.0_01/bin
and i type javac filename.classand then java filename
this worked for some programs like this one:
import java.io.*;
import java.lang.*;
import java.lang.String.*;
class Matrix
{
public static void main(String args[])throws IOException
{
try
{
int a[][],b[][],c[][],i,j,r1,r2,c1,c2,k=0;
a=new int[10][10];
b=new int[10][10];
c=new int[10][10];
DataInputStream din=new DataInputStream(System.in);
System.out.println("Enter first matrix row,col");
r1=Integer.parseInt(din.readLine());
c1=Integer.parseInt(din.readLine());
System.out.println("Enter second matrix row,col");
r2=Integer.parseInt(din.readLine());
c2=Integer.parseInt(din.readLine());
if(c1==r2)
{
System.out.println("enter the first matrix:");
for(i=0;i<=r1;i++)
{
for(j=0;j<=r1;j++)
a[j]=Integer.parseInt(din.readLine());
}
System.out.println("enter the second matrix");
for(i=0;i<r2;i++)
{
for(j=0;j<=c2;j++)
b[j]=Integer.parseInt(din.readLine());
}
for(i=0;i<=r1;i++)
{
for(j=0;j<=c2;j++)
{
c[j]=0;
for(k=0;k<r2;k++)
{
c[j]=c[j]+a[k]*b[k][j];
}
}
}
System.out.println("\t Resultant matrix:");
for(i=0;i<r2;i++)
{
for(j=0;j<c2;j++)
System.out.print(c[j]+"");
System.out.print("");
}
}
else
throw new IllegalAccessException("demo");
}
catch(Exception e)
{
System.out.println("illegal rows and cols");
}
}
}
but it is giving errors for some programs like this first one..can you please help
thankyou
>
[3541 byte] By [
shw123a] at [2007-11-27 3:04:40]
I'm also pretty new to Java, but I think you forgot to declare the "main"- Method in your code. As far as I know, only classes with a "main"-method can be executed by the Java-VM.I didn't see this line in your code:public static void main(String args[])
You will get the NoClassDef Exception. Because in your code no main method exists.
If you want to run your program , it should have a main method
import java.io.*;
import java.lang.*;
class table1 extends Thread
{
int m,n,i,sum;
public static void main(String[] args) {
//TODO
}
public void getData(int X1)throws IOException
{
DataInputStream din=new DataInputStream(System.in);
System.out.println("enter the table no1");
m=Integer.parseInt(din.readLine());
n=X1;
}
public void run()
{
for(i=1;i<=n;i++)
{
sum=i*m;
System.out.print(i+"*"+m+"="+sum+"\t");
yield();
}
}
}
I guess your multi.java has the main method but you did not declare the file with public access specifier.
I am sorry i dint paste the last part of the program..:
public class multi
{
public static void main(String args[])throws IOException
{
int n;
DataInputStream din=new DataInputStream(System.in);
table1 obj1=new table1();
table2 obj2=new table2();
System.out.println("Enter how many rows?");
n=Integer.parseInt(din.readLine());
obj1.getData(n);
obj2.getData1(n);
obj1.start();
obj2.start();
}
}
so the whole program is:
import java.io.*;
import java.lang.*;
class table1 extends Thread
{
int m,n,i,sum;
public void getData(int X1)throws IOException
{
DataInputStream din=new DataInputStream(System.in);
System.out.println("enter the table no1");
m=Integer.parseInt(din.readLine());
n=X1;
}
public void run()
{
for(i=1;i<=n;i++)
{
sum=i*m;
System.out.print(i+"*"+m+"="+sum+"\t");
yield();
}
}
}
class table2 extends Thread
{
int m1,n1,j,sum1;
public void getData1(int X1)throws IOException
{
DataInputStream din=new DataInputStream(System.in);
System.out.println("enter the table no2");
m1=Integer.parseInt(din.readLine());
n1=X1;
}
public void run()
{
for(j=1;j<=n1;j++)
{
sum1=j*m1;
System.out.print(j+"*"+m1+"="+sum1);
System.out.println("");
yield();
}
}
}
public class multi
{
public static void main(String args[])throws IOException
{
int n;
DataInputStream din=new DataInputStream(System.in);
table1 obj1=new table1();
table2 obj2=new table2();
System.out.println("Enter how many rows?");
n=Integer.parseInt(din.readLine());
obj1.getData(n);
obj2.getData1(n);
obj1.start();
obj2.start();
}
}
the code public static void main(String args[]) is there in the public class multi..
public class multi
{
public static void main(String args[])
{
try {
int n;
DataInputStream din=new DataInputStream(System.in);
table1 obj1=new table1();
table2 obj2=new table2();
System.out.println("Enter how many rows?");
n=Integer.parseInt(din.readLine());
obj1.getData(n);
obj2.getData1(n);
obj1.start();
obj2.start();
} catch(Exception e) {
SOP(e.getMessage());
}
}
}
I tried the code but then it gives the following error: class multi is public,should be declared in a file named mulit.javaplus it gives this error too:cannot find symbolsymbol:method SOP(java.lang.string)location:class multiSOP(e.getMessage());
Well from the book where i copied this code.. the following was written before the start of the program:
Step1: class tab1 which is the subclass of Thread
data members-m,n,i,sum
Override run Method which prints the multiplication table
Step2 class tab2 which is the subclass of Thread
data members-m,n,i,sum
Override run Method which prints the multiplication table
step3:In main class create object for tab1 and tab2
step5:start the threads
I do not knw how to do this exactly with the given program.can you help
i guess , you have misunderstood the line.SOP stands for System.out.println(e.getMessage());try the following command in your command window.javac multi.java if you get any error post your full error message. Your program works in my system
Oh yes i dint understand that:) .. now after the correction made.. i tried the command you mentioned:javac multi.java
i get the following errors:
multi.java:3:cannot find symbol
symbol:class IOException
location:class multi
DataInputStream din=new DataInputStream(System.in);[there is a upper arrow mard below the D of the DataInputStream]
\table1.java :48:class multi is public,shoudl be declared in the file named multi.java
public class multi[there is an upper arrow uncer "c" of class multi]
note:.\table1.java uses or overrides a depriciated API
note:recomplie with -XLint:depreciation for details.
4 errors
i have reformatted your code below. try the following
table1.java
import java.io.*;
import java.lang.*;
class table1 extends Thread
{
int m,n,i,sum;
public void getData(int X1)throws IOException
{
DataInputStream din=new DataInputStream(System.in);
System.out.println("enter the table no1");
m=Integer.parseInt(din.readLine());
n=X1;
}
public void run()
{
for(i=1;i<=n;i++)
{
sum=i*m;
System.out.print(i+"*"+m+"="+sum+"\t");
yield();
}
}
}
table2.java
import java.io.DataInputStream;
import java.io.IOException;
class table2 extends Thread
{
int m1,n1,j,sum1;
public void getData1(int X1)throws IOException
{
DataInputStream din=new DataInputStream(System.in);
System.out.println("enter the table no2");
m1=Integer.parseInt(din.readLine());
n1=X1;
}
public void run()
{
for(j=1;j<=n1;j++)
{
sum1=j*m1;
System.out.print(j+"*"+m1+"="+sum1);
System.out.println("");
yield();
}
}
}
multi.java
import java.io.DataInputStream;
import java.io.IOException;
public class multi
{
public static void main(String args[])throws IOException
{
int n;
DataInputStream din=new DataInputStream(System.in);
table1 obj1=new table1();
table2 obj2=new table2();
System.out.println("Enter how many rows?");
n=Integer.parseInt(din.readLine());
obj1.getData(n);
obj2.getData1(n);
obj1.start();
obj2.start();
}
}
Try the above code. and compile each file in command line using javac
Thankyou so much .. now it executes! ill try the rest of the programs now..thankyou once again:)
Hi i have another problem come up with a program where i have to use inheritance:
the instructions told:
design a class named Account
Data members:accno,name,branch name and balance
methods: getdetails()
putdetails()
design a class named Transaction which extends from the class Account data members: ttype,amount and cur_bal
methods: doTransaction()
printAll()
in the main method,create and object for the class Transaction and call the methods
what i did was:
created Account.java:
import java.io.*;
class Account
{
int acc_no;
String name;
String branch_name;
protected float old_bal;
protected static DataInputStream din=new DataInputStream(System.in);
void get_details()throws IOException
{
System.out.print("Enter Name:");
name=din.readLine( );
System.out.print("Enter Account no");
acc_no=Integer.parseInt(din.readLine());
System.out.print("Enter Branch Name.:");
branch_name=din.readLine( );
do
{
System.out.print("Enter Balance Amount(minimum2000):");
old_bal=Float.parseFloat(din.readline( ));
}
while(old_bal<=2000);
}
void put_details()
{
System.out.println("state Bank of india");
System.out.println("Chidambaram");
System.out.println("-");
System.out.println("AccountNo.:"+acc_no);
System.out.println("Name :"+name);
System.out.println("Branch name:"+branch_name);
System.out.println("oldBalance:"+old_bal);
}
}
created Transaction.java:
import java.io.DataInputStream;
import java.io.IOException;
class Transaction extends Account
{
String ttype;
float amount,cur_bal;
void Do Transaction()throws IOException
{
System.out.print("Enter Transaction code(D04-Deposit,W04-Withdraw:");
ttype=din.readLine();
System.out.print("Enter Transaction Amount:");
amount=Float.parseFloat(din.readLine());
if(ttype.equalsIgnoreCase("D04"))
cur_bal=old_bal+amount;
elseif(ttype.equalsIgnoreCase("W04"))
if(old-bal-amount>=2000)
cur_bal=old_bal-amount
else
{
System.out.println("Minimum amount must be 2000");
cur_bal=old_bal;
}
else
System.out.println("Invalid Transition");
cur_bal=old_bal;
}
}
void print All()
{
put_details();
if(cur_bal==old_bal)
System.out.println("No transactions");
else
{
System.out.println("Transaction Type:"+ttype);
System.out.println("Transaction amount:"+amount);
System.out.println("Current Balance:"+cur_bal);
}
}}
then created Bank.java:
import java.io.DataInputStream;
import java.io.IOException;
public class Bank
{
public static void main(String args[])throws IOException
{
Transaction T =new Transaction();
T.get_details();
T.do Transaction();
T.printAll();
}
}
and then complied each of them.. but am getting erors:
for bank.java i get:
identifier expected
T.do Transaction();[ iget an upper arrow mark below "d" and after the ";"]
for Account.java i get:
cannot find symbol:method readLine()
i get an upper arrow mark just below the dot of (din.readline( ));
and i get lots of errors in Transaction
can you help
Your method name is Do Transaction, but you have called T.do Transaction();. It is not a good practice for giving names. I have modified your method name in the following code snippet
void doTransaction()throws IOException // here i have changed the method name
{
System.out.print("Enter Transaction code(D04-Deposit,W04-Withdraw:");
ttype=din.readLine();
System.out.print("Enter Transaction Amount:");
amount=Float.parseFloat(din.readLine());
if(ttype.equalsIgnoreCase("D04"))
cur_bal=old_bal+amount;
elseif(ttype.equalsIgnoreCase("W04"))
if(old-bal-amount>=2000)
cur_bal=old_bal-amount
else
{
System.out.println("Minimum amount must be 2000");
cur_bal=old_bal;
}
else
System.out.println("Invalid Transition");
cur_bal=old_bal;
}
}
Use code tags next time
or Account.java i get:
cannot find symbol:method readLine()
i get an upper arrow mark just below the dot of (din.readline( ));
You have written
old_bal=Float.parseFloat(din.readline( ));
readline should be readLine()
I found few errors in your Transaction.java. I have modified the file below
class Transaction extends Account
{
String ttype;
float amount,cur_bal;
void doTransaction()throws IOException
{
System.out.print("Enter Transaction code(D04-Deposit,W04-Withdraw:");
ttype=din.readLine();
System.out.print("Enter Transaction Amount:");
amount=Float.parseFloat(din.readLine());
if(ttype.equalsIgnoreCase("D04")) {
cur_bal=old_bal+amount;
} else if(ttype.equalsIgnoreCase("W04")) {
if((old_bal-amount) >= 2000)
cur_bal=old_bal - amount;
else
{
System.out.println("Minimum amount must be 2000");
cur_bal=old_bal;
}
} else {
System.out.println("Invalid Transition");
cur_bal=old_bal;
}
}
void printAll()
{
put_details();
if(cur_bal==old_bal)
System.out.println("No transactions");
else
{
System.out.println("Transaction Type:"+ttype);
System.out.println("Transaction amount:"+amount);
System.out.println("Current Balance:"+cur_bal);
}
}}
.
The changes are obvious so you dont need any explanation for these changes.
Use code tags next time.or read Formatting tips before posting your question
