Print all exception java

Class Throwable

The Throwable class is the superclass of all errors and exceptions in the Java language. Only objects that are instances of this class (or one of its subclasses) are thrown by the Java Virtual Machine or can be thrown by the Java throw statement. Similarly, only this class or one of its subclasses can be the argument type in a catch clause. For the purposes of compile-time checking of exceptions, Throwable and any subclass of Throwable that is not also a subclass of either RuntimeException or Error are regarded as checked exceptions.

Instances of two subclasses, Error and Exception , are conventionally used to indicate that exceptional situations have occurred. Typically, these instances are freshly created in the context of the exceptional situation so as to include relevant information (such as stack trace data).

A throwable contains a snapshot of the execution stack of its thread at the time it was created. It can also contain a message string that gives more information about the error. Over time, a throwable can suppress other throwables from being propagated. Finally, the throwable can also contain a cause: another throwable that caused this throwable to be constructed. The recording of this causal information is referred to as the chained exception facility, as the cause can, itself, have a cause, and so on, leading to a «chain» of exceptions, each caused by another.

One reason that a throwable may have a cause is that the class that throws it is built atop a lower layered abstraction, and an operation on the upper layer fails due to a failure in the lower layer. It would be bad design to let the throwable thrown by the lower layer propagate outward, as it is generally unrelated to the abstraction provided by the upper layer. Further, doing so would tie the API of the upper layer to the details of its implementation, assuming the lower layer’s exception was a checked exception. Throwing a «wrapped exception» (i.e., an exception containing a cause) allows the upper layer to communicate the details of the failure to its caller without incurring either of these shortcomings. It preserves the flexibility to change the implementation of the upper layer without changing its API (in particular, the set of exceptions thrown by its methods).

A second reason that a throwable may have a cause is that the method that throws it must conform to a general-purpose interface that does not permit the method to throw the cause directly. For example, suppose a persistent collection conforms to the Collection interface, and that its persistence is implemented atop java.io . Suppose the internals of the add method can throw an IOException . The implementation can communicate the details of the IOException to its caller while conforming to the Collection interface by wrapping the IOException in an appropriate unchecked exception. (The specification for the persistent collection should indicate that it is capable of throwing such exceptions.)

A cause can be associated with a throwable in two ways: via a constructor that takes the cause as an argument, or via the initCause(Throwable) method. New throwable classes that wish to allow causes to be associated with them should provide constructors that take a cause and delegate (perhaps indirectly) to one of the Throwable constructors that takes a cause. Because the initCause method is public, it allows a cause to be associated with any throwable, even a «legacy throwable» whose implementation predates the addition of the exception chaining mechanism to Throwable .

By convention, class Throwable and its subclasses have two constructors, one that takes no arguments and one that takes a String argument that can be used to produce a detail message. Further, those subclasses that might likely have a cause associated with them should have two more constructors, one that takes a Throwable (the cause), and one that takes a String (the detail message) and a Throwable (the cause).

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What are the different ways to print an exception message in java?

Print Exceptions in Java There are three methods to print exception messages in Java. Since Throwable is the base class for all exceptions and errors, we can use these three methods on any exception object.

Different Ways to Print Exception Messages in Java

In Java, there are three methods to print exception information. All of them are present in the Throwable class. Since Throwable is the base class for all exceptions and errors, we can use these three methods on any exception object.

Method s t o Print Exceptions in Java

There are three methods to print exception messages in Java. These are:

1. java.lang.Throwable.printStackTrace() method:

By using this method, we will get the name(e.g., java.lang.ArithmeticException) and description(e.g., / by zero) of an exception separated by a colon, and the stack trace (wherein the code, that exception has occurred) in the next line.

public void printStackTrace()

Java

Runtime Exception:

java.lang.ArithmeticException: / by zero at Test.main(Test.java:9)

java.lang.ArithmeticException: / by zero

2. toString() method :

Using this method will only get the name and description of an exception. Note that this method is overridden in the Throwable class.

Java

java.lang.ArithmeticException: / by zero

3. java.lang.Throwable.getMessage() method:

Using this method, we will only get a description of an exception.

Java

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Different Ways to Print Exception Messages in Java, Methods to Print Exceptions in Java. There are three methods to print exception messages in Java. These are: 1. java.lang.Throwable.printStackTrace() method: By using this method, we will get the name(e.g., java.lang.ArithmeticException) and description(e.g., / by zero) of …

What are the different ways to print an exception message in java?

An exception is an issue (run time error) occurred during the execution of a program. When an exception occurred the program gets terminated abruptly and, the code past the line that generated the exception never gets executed.

Printing the Exception message

You can print the exception message in Java using one of the following methods which are inherited from Throwable class.

• printStackTrace() − This method prints the backtrace to the standard error stream.
• getMessage() − This method returns the detail message string of the current throwable object.
• toString() − This message prints the short description of the current throwable object.

Example

import java.util.Scanner; public class PrintingExceptionMessage < public static void main(String args[]) < Scanner sc = new Scanner(System.in); System.out.println("Enter first number: "); int a = sc.nextInt(); System.out.println("Enter second number: "); int b = sc.nextInt(); try < int c = a/b; System.out.println("The result is: "+c); >catch(ArithmeticException e) < System.out.println("Output of printStackTrace() method: "); e.printStackTrace(); System.out.println(" "); System.out.println("Output of getMessage() method: "); System.out.println(e.getMessage()); System.out.println(" "); System.out.println("Output of toString() method: "); System.out.println(e.toString()); >> >

Output

Enter first number: 10 Enter second number: 0 Output of printStackTrace() method: java.lang.ArithmeticException: / by zero Output of getMessage() method: / by zero Output of toString() method: java.lang.ArithmeticException: / by zero at PrintingExceptionMessage.main(PrintingExceptionMessage.java:11)

What are the different ways to print an exception, Printing the Exception message You can print the exception message in Java using one of the following methods which are inherited from …

Print all variables in Java exception? [duplicate]

I frequently write java code on Apache Spark for ETL job, usually on cloudera cdh cluster with every data source set up. The data I’m processing is usually dirty. For example for zip code, I was thinking I could use an integer to represent it but there could exists some record like «85281-281» and we couldn’t parse it as a integer. Thus an exception is thrown and the program halt with a bunch of stack trace.

Previously I have to write the code based on my assumption, run it on the cluster, failed with a huge bunch of stack trace. Including the line number that throws the exception. But it is really time consuming to find the root cause especially I don’t the specific line of the data.

So I’m think the following:

1. The code shouldn’t stop when errors occurs. This is easy, use Java’s exception handling system can easily achieve this.
2. I want to know the variables content in current stack which cause the error, so that I could find the root cause of the input (specific line in the input). Not just the line number that throws the exception. For example NullPointerException, I want to know the raw input data, which specific line in the input file caused this.

We have e.printStackTrace() to show the all function call in the stack trace. Can we do it better by also showing the content on top of the current stack? Just like a debugger do?

Of course I would manually print out all variables by hand coding. But I just want to know if there is a specific function that a debugger would use to show those variables.

For example, if you have the following code

final String line = . // get next line processLine(line); 

you could transform it to

final String line = . // get next line try < processLine(line); >catch (RuntimeException e) < System.out.println(String.format("Oh no, an exception! The line was '%s'", line); e.printStackTrace(); // . any recovery logic >

You could catch not just RuntimeException’s, but other exceptions as well. You could also log to some logger and not to console.

Print all variables in Java exception?, Including the line number that throws the exception. But it is really time consuming to find the root cause especially I don’t the specific line of the …

How to print messages in Custom Exception?

I’m new to exceptions and am a bit confused at getMessage() and super(customMessage). Please forgive me if it sounds rather ridiculous.

Part of my try catch code is here:

try < sc.buyASong(); >catch (CardEmptyException e) < System.out.println("Caught error: " +e.getMessage() ); >catch (CardNotActivatedException e)

And I want to print «Caught error: Card not activated» or «Caught error: No more songs on the card». And my custom exception is like this

class CardNotActivatedException extends Exception < public CardNotActivatedException()< super("Card not activated"); >> class CardEmptyException extends Exception < public CardEmptyException()< super("No more songs on the card"); >> 

But when I run it, it prints

com.example.CardNotActivatedException: Card not activated 

and «Caught error: —-» is not printed out as well. Is there something that I am understanding wrongly? Because it looks like I am fundamentally wrong and I’m not quite sure where my misunderstanding is.

Are you sure you’re catching the CardEmptyException ? Did you forget to save your code?

Anyway, I suggest you change your approach, and use a constructor method receiving a String object. You can keep a default costructor with a default message, but also use somthing like this one:

public MyCustomException(String arg0)

Then, whenever you call this exception, you can call passa the message you want to.

Java — How to print messages in Custom Exception?, Anyway, I suggest you change your approach, and use a constructor method receiving a String object. You can keep a default costructor with a default …

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Print all exception java

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