org.djutils.exceptions.Try

public final class Try extends Object

The Try class has a number of static methods that make it easy to try-catch an exception for any Throwable class, including the standard Java exceptions and exceptions from libraries that are used in the project. Instead of:

 FileInputStream fis;
 try
 {
     fis = new FileInputStream(fileString);
 }
 catch (FileNotFoundException exception)
 {
     throw new IllegalArgumentException("File " + fileString + " is not a valid file.", exception);
 }
 try
 {
     fis.close();
 }
 catch (IOException exception)
 {
     throw new RuntimeException("Could not close the file.", exception);
 }

we can write:

 FileInputStream fis = Try.assign(() -> new FileInputStream(fileString), IllegalArgumentException.class,
         "File %s is not a valid file.", fileString);
 Try.execute(() -> fis.close(), "Could not close the file.");

The exception message can be formatted with additional arguments, such that the overhead of building the exception message only occurs if the exception condition is met. For each method there is a version without Throwable class, in which case a RuntimeException will be thrown.

Try is not suitable for try-with-resource statements.

Try also has a few methods to aid JUNIT tests: testFail(...) and testNotFail(...).

Copyright (c) 2016-2025 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See for project information https://djutils.org. The DJUTILS project is distributed under a three-clause BSD-style license, which can be found at https://djutils.org/docs/license.html.

Author:: Alexander Verbraeck, Peter Knoppers, Wouter Schakel

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

static interface

Try.Assignment<V>

Functional interface for calls to Try.assign(...).

static interface

Try.Execution

Functional interface for calls to Try.execute(...).
Method Summary

Modifier and Type

Method

Description

static <V, T extends Throwable> V

assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message)

Tries to return a value to assign.

static <V, T extends Throwable> V

assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message, Object arg)

Tries to return a value to assign.

static <V, T extends Throwable> V

assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message, Object arg1, Object arg2)

Tries to return a value to assign.

static <V, T extends Throwable> V

assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message, Object arg1, Object arg2, Object arg3)

Tries to return a value to assign.

static <V, T extends Throwable> V

assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message, Object arg1, Object arg2, Object arg3, Object... args)

Tries to return a value to assign.

static <V> V

assign(Try.Assignment<V> assignment, String message)

Tries to return a value to assign.

static <V> V

assign(Try.Assignment<V> assignment, String message, Object arg)

Tries to return a value to assign.

static <V> V

assign(Try.Assignment<V> assignment, String message, Object arg1, Object arg2)

Tries to return a value to assign.

static <V> V

assign(Try.Assignment<V> assignment, String message, Object arg1, Object arg2, Object arg3)

Tries to return a value to assign.

static <V> V

assign(Try.Assignment<V> assignment, String message, Object arg1, Object arg2, Object arg3, Object... args)

Tries to return a value to assign.

static <T extends Throwable> void

execute(Try.Execution execution, Class<T> throwableClass, String message)

Tries to execute.

static <T extends Throwable> void

execute(Try.Execution execution, Class<T> throwableClass, String message, Object arg)

Tries to execute.

static <T extends Throwable> void

execute(Try.Execution execution, Class<T> throwableClass, String message, Object arg1, Object arg2)

Tries to execute.

static <T extends Throwable> void

execute(Try.Execution execution, Class<T> throwableClass, String message, Object arg1, Object arg2, Object arg3)

Tries to execute.

static <T extends Throwable> void

execute(Try.Execution execution, Class<T> throwableClass, String message, Object arg1, Object arg2, Object arg3, Object... args)

Tries to execute.

static void

execute(Try.Execution execution, String message)

Tries to execute.

static void

execute(Try.Execution execution, String message, Object arg)

Tries to execute.

static void

execute(Try.Execution execution, String message, Object arg1, Object arg2)

Tries to execute.

static void

execute(Try.Execution execution, String message, Object arg1, Object arg2, Object arg3)

Tries to execute.

static void

execute(Try.Execution execution, String message, Object arg1, Object arg2, Object arg3, Object... args)

Tries to execute.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details
- assign
  
  public static <V> V assign(Try.Assignment<V> assignment, String message) throws RuntimeException
  
  Tries to return a value to assign. Will throw a RuntimeException if the try fails.
  
  Type Parameters:
  
  V - value type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  message - the message to use in the throwable
  
  Returns:
  
  value to assign
  
  Throws:
  
  RuntimeException - on failed Try
- assign
  
  public static <V> V assign(Try.Assignment<V> assignment, String message, Object arg) throws RuntimeException
  
  Tries to return a value to assign. Will throw a RuntimeException if the try fails.
  
  Type Parameters:
  
  V - value type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  message - the message to use in the throwable, with formatting identifier
  
  arg - value to use for the formatting identifier
  
  Returns:
  
  value to assign
  
  Throws:
  
  RuntimeException - on failed Try
- assign
  
  public static <V> V assign(Try.Assignment<V> assignment, String message, Object arg1, Object arg2) throws RuntimeException
  
  Tries to return a value to assign. Will throw a RuntimeException if the try fails.
  
  Type Parameters:
  
  V - value type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  Returns:
  
  value to assign
  
  Throws:
  
  RuntimeException - on failed Try
- assign
  
  public static <V> V assign(Try.Assignment<V> assignment, String message, Object arg1, Object arg2, Object arg3) throws RuntimeException
  
  Tries to return a value to assign. Will throw a RuntimeException if the try fails.
  
  Type Parameters:
  
  V - value type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  arg3 - 3rd value to use for the formatting identifiers
  
  Returns:
  
  value to assign
  
  Throws:
  
  RuntimeException - on failed Try
- assign
  
  public static <V> V assign(Try.Assignment<V> assignment, String message, Object arg1, Object arg2, Object arg3, Object... args) throws RuntimeException
  
  Tries to return a value to assign. Will throw a RuntimeException if the try fails.
  
  Type Parameters:
  
  V - value type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  arg3 - 3rd value to use for the formatting identifiers
  
  args - potential 4th and further values to use for the formatting identifiers
  
  Returns:
  
  value to assign
  
  Throws:
  
  RuntimeException - on failed Try
- assign
  
  public static <V, T extends Throwable> V assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message) throws T
  
  Tries to return a value to assign. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  V - value type
  
  T - throwable type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable
  
  Returns:
  
  value to assign
  
  Throws:
  
  T - throwable on failed Try
- assign
  
  public static <V, T extends Throwable> V assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message, Object arg) throws T
  
  Tries to return a value to assign. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  V - value type
  
  T - throwable type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable, with formatting identifier
  
  arg - value to use for the formatting identifier
  
  Returns:
  
  value to assign
  
  Throws:
  
  T - throwable on failed Try
- assign
  
  public static <V, T extends Throwable> V assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message, Object arg1, Object arg2) throws T
  
  Tries to return a value to assign. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  V - value type
  
  T - throwable type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  Returns:
  
  value to assign
  
  Throws:
  
  T - throwable on failed Try
- assign
  
  public static <V, T extends Throwable> V assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message, Object arg1, Object arg2, Object arg3) throws T
  
  Tries to return a value to assign. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  V - value type
  
  T - throwable type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  arg3 - 3rd value to use for the formatting identifiers
  
  Returns:
  
  value to assign
  
  Throws:
  
  T - throwable on failed Try
- assign
  
  public static <V, T extends Throwable> V assign(Try.Assignment<V> assignment, Class<T> throwableClass, String message, Object arg1, Object arg2, Object arg3, Object... args) throws T
  
  Tries to return a value to assign. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  V - value type
  
  T - throwable type
  
  Parameters:
  
  assignment - functional interface to assign value
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  arg3 - 3rd value to use for the formatting identifiers
  
  args - potential 4th and further values to use for the formatting identifiers
  
  Returns:
  
  value to assign
  
  Throws:
  
  T - throwable on failed Try
- execute
  
  public static void execute(Try.Execution execution, String message) throws RuntimeException
  
  Tries to execute. Will throw a RuntimeException if the try fails.
  
  Parameters:
  
  execution - functional interface to execute
  
  message - the message to use in the throwable
  
  Throws:
  
  RuntimeException - on failed Try
- execute
  
  public static void execute(Try.Execution execution, String message, Object arg) throws RuntimeException
  
  Tries to execute. Will throw a RuntimeException if the try fails.
  
  Parameters:
  
  execution - functional interface to execute
  
  message - the message to use in the throwable, with formatting identifier
  
  arg - value to use for the formatting identifier
  
  Throws:
  
  RuntimeException - on failed Try
- execute
  
  public static void execute(Try.Execution execution, String message, Object arg1, Object arg2) throws RuntimeException
  
  Tries to execute. Will throw a RuntimeException if the try fails.
  
  Parameters:
  
  execution - functional interface to execute
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  Throws:
  
  RuntimeException - on failed Try
- execute
  
  public static void execute(Try.Execution execution, String message, Object arg1, Object arg2, Object arg3) throws RuntimeException
  
  Tries to execute. Will throw a RuntimeException if the try fails.
  
  Parameters:
  
  execution - functional interface to execute
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  arg3 - 3rd value to use for the formatting identifiers
  
  Throws:
  
  RuntimeException - on failed Try
- execute
  
  public static void execute(Try.Execution execution, String message, Object arg1, Object arg2, Object arg3, Object... args) throws RuntimeException
  
  Tries to execute. Will throw a RuntimeException if the try fails.
  
  Parameters:
  
  execution - functional interface to execute
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  arg3 - 3rd value to use for the formatting identifiers
  
  args - potential 4th and further values to use for the formatting identifiers
  
  Throws:
  
  RuntimeException - on failed Try
- execute
  
  public static <T extends Throwable> void execute(Try.Execution execution, Class<T> throwableClass, String message) throws T
  
  Tries to execute. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  T - throwable type
  
  Parameters:
  
  execution - functional interface to execute
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable
  
  Throws:
  
  T - throwable on failed Try
- execute
  
  public static <T extends Throwable> void execute(Try.Execution execution, Class<T> throwableClass, String message, Object arg) throws T
  
  Tries to execute. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  T - throwable type
  
  Parameters:
  
  execution - functional interface to execute
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable, with formatting identifier
  
  arg - value to use for the formatting identifier
  
  Throws:
  
  T - throwable on failed Try
- execute
  
  public static <T extends Throwable> void execute(Try.Execution execution, Class<T> throwableClass, String message, Object arg1, Object arg2) throws T
  
  Tries to execute. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  T - throwable type
  
  Parameters:
  
  execution - functional interface to execute
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  Throws:
  
  T - throwable on failed Try
- execute
  
  public static <T extends Throwable> void execute(Try.Execution execution, Class<T> throwableClass, String message, Object arg1, Object arg2, Object arg3) throws T
  
  Tries to execute. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  T - throwable type
  
  Parameters:
  
  execution - functional interface to execute
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  arg3 - 3rd value to use for the formatting identifiers
  
  Throws:
  
  T - throwable on failed Try
- execute
  
  public static <T extends Throwable> void execute(Try.Execution execution, Class<T> throwableClass, String message, Object arg1, Object arg2, Object arg3, Object... args) throws T
  
  Tries to execute. Will throw a specified Throwable if the try fails.
  
  Type Parameters:
  
  T - throwable type
  
  Parameters:
  
  execution - functional interface to execute
  
  throwableClass - class of the throwable to throw
  
  message - the message to use in the throwable, with formatting identifiers
  
  arg1 - 1st value to use for the formatting identifiers
  
  arg2 - 2nd value to use for the formatting identifiers
  
  arg3 - 3rd value to use for the formatting identifiers
  
  args - potential 4th and further values to use for the formatting identifiers
  
  Throws:
  
  T - throwable on failed Try

Class Try

Nested Class Summary

Method Summary

Methods inherited from class java.lang.Object

Method Details

assign

assign

assign

assign

assign

assign

assign

assign

assign

assign

execute

execute

execute

execute

execute

execute

execute

execute

execute

execute