How could Java classes direct program messages to the system console, but error messages, say to a file?

Java Interview Questions and Answers (part 1)

(Continued from previous question...)

7. How could Java classes direct program messages to the system console, but error messages, say to a file?

The class System has a variable out that represents the standard output, and the variable err that represents the standard error device. By default, they both point at the system console. This how the standard output could be re-directed:
Stream st = new Stream(new FileOutputStream("output.txt")); System.setErr(st); System.setOut(st);

(Continued on next question...)

Other Interview Questions

• What's Java?
• What does a well-written OO program look like?
• Can you have virtual functions in Java?
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• What is similarities/difference between an Abstract class and Interface?
• How to define an Abstract class?
• How to define an Interface?
• If a class is located in a package, what do you need to change in the OS environment to be able to use it?
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• How many methods in the Externalizable interface?
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• What modifiers may be used with an inner class that is a member of an outer class?
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• What is the purpose of the System class?
• What is the purpose of the finally clause of a try-catch-finally statement?
• What is the Locale class?
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• What are peerless components?
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• What classes of exceptions may be caught by a catch clause?
• What is the difference between throw and throws keywords?
• If a class is declared without any access modifiers, where may the class be accessed?
• What is the Map interface?
• Does a class inherit the constructors of its superclass?
• Name primitive Java types.
• Which class should you use to obtain design information about an object?
• How can a GUI component handle its own events?
• How are the elements of a GridBagLayout organized?
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• What are the problems faced by Java programmers who don't use layout managers?
• What is the difference between static and non-static variables?
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• What is the purpose of the File class?
• Why would you use a synchronized block vs. synchronized method?
• What restrictions are placed on method overriding?
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• What is the Set interface?
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