Java Basics 112– Java Stack Trace
STEPS
1) Open Startup Project
Continue from the previous tutorial or create a new project as follows.
Project Name: errorhandling
Main Class Name: errorhandling .errorChecking
2) Begin with Startup Codes.
2-1) Replace the generated codes with the following codes (which has discarded all comments and unnecessary codes).
package errorhandling;
public class errorChecking {
public static void main(String[] args) {
System.out.println("Starting Main method");
m1();
System.out.println("End Main method");
}
static void m1() {
System.out.println("Method One - m1");
m2();
}
static void m2() {
System.out.println("Method One - m2");
}
}
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2-2) Run.
3) Edit the Method m2 so that it contains errors
3-1) Paste the codes to method m2.
package errorhandling;
public class errorChecking {
public static void main(String[] args) {
System.out.println("Starting Main method");
m1();
System.out.println("End Main method");
}
static void m1() {
System.out.println("Method One - m1");
m2();
}
static void m2() {
int x = 10;
int y = 0;
double z = x / y;
System.out.println(z);
System.out.println("Method Two - m2");
}
}
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3-2) Run.
4) Edit method m1 so that it contains TRY…CATCH block.
4-1) Add the codes.
package errorhandling;
public class errorChecking {
public static void main(String[] args) {
System.out.println("Starting Main method");
m1();
System.out.println("End Main method");
}
static void m1() {
try {
System.out.println("Method One - m1");
m2();
} catch (ArithmeticException err) {
System.out.println(err.getMessage());
}
}
static void m2() {
int x = 10;
int y = 0;
double z = x / y;
System.out.println(z);
System.out.println("Method Two - m2");
}
}
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4-2) Run.
Info:
If you see a stack trace in the Output window, just remember that first line is where the problem occurred; the rest of the lines, if any, are where the Exception was handed up the stack, usually finishing at the main method.
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REFERENCE
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