Which class is the wait() method defined in?

Learn Java programming

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Java arithmetic

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Java operators

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Class relationships and references

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Handling exceptions

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Variable scope

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Java utility applications

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Java applications

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Concurrent programming features

• What is a thread? (stub article)

Threads and runnable types

• How does the run() method in Runnable work? (stub article)

Thread management methods

• Which class is the wait() method defined in? (stub article)
• Why are there separate wait and sleep methods? (stub article)

Multi-threaded design questions

• Do I need to use synchronized on setValue(int)? (stub article)
• How do I create a Runnable with inheritance? (stub article)
• Which has priority with a static synchronized thread? (stub article)

Multiple inheritance

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• Is multiple interface inheritance better than extending a class? (stub article)

Java inheritance principles

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• How does inheritance avoid duplication? (stub article)

Extending classes

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Overridden methods

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• How can I find the inherited attributes of a class? (stub article)

Techniques for overridden superclasses

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• How can I get the superclass to call back to a method in the subclass? (stub article)

Java visibility modifiers

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The static main method

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• What does public static void main(String[]) mean? (stub article)
• Can you give an example of overloading the main()? (stub article)

Main method arguments

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Calling the main method

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• How can I make an interactive command line interface? (stub article)

Interface concepts

• What is the difference between abstract classes and interfaces? (stub article)

Interface usage

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• Can you give an example of multiple inheritance with interfaces? (stub article)
• What are the rules for passing subclasses for method arguments? (stub article)

How to define an interface

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How to implement an interface

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• This code seems to be instantiating an interface! (stub article)

Marker interfaces

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Language features

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• What are Java types are available? (stub article)
• What's the difference between checked and un-checked exceptions? (stub article)
• What is dynamic method dispatch? (stub article)

Design concepts

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• Is println() overloading or overriding? (stub article)
• What are keywords and reserved words? (stub article)

Design patterns

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• How do I format my price correctly? (stub article)
• What is a factory method? (stub article)
• How should I create an immutable class? (stub article)
• What are adapters in Java? (stub article)

The Java API

• When is hashCode() used? (stub article)
• What is a NullPointerException in Java? (stub article)
• How can I create a constructor to equate two other objects? (stub article)
• How do I draw a Rectangle on a Graphics instance? (stub article)

Java jargon explained

• What is the difference between the JVM, JRE and JDK? (stub article)
• What is the difference between heavyweight and lightweight components? (stub article)

Class loading

• How can I get a class reference without using new operator? (stub article)
• What's the difference between the Class.forName() method and the new operator? (stub article)
• How can I implement the Class.forName() scheme? (stub article)
• How can I cast an unknown sub-class returned by newInstance()? (stub article)
• Is Class.forName() runtime polymorphism? (stub article)
• How does Class.forName(dbDriver) work with DriverManager.getConnection? (stub article)

The String class

• Why is the String class declared final? (stub article)

String methods and operators

• The == operator doesn't match strings correctly! (stub article)
• How can you say the + operator is not overloaded in Java! (stub article)
• How can I reverse the characters in a string? (stub article)

String buffers and tokenizers

• Why don't two StringBuffers match? (stub article)
• How can I pad a StringBuffer? (stub article)
• What is a StringTokenizer for? (stub article)
• How can I get a person's initials from their full name? (stub article)

Regular expressions

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Getting started with JDBC

• How do I use JDBC with Microsoft SQLServer? (stub article)

Java SQL API

• What's the difference between Statement and PreparedStatement? (stub article)
• How can I insert multiple records at a time? (stub article)
• Why it is better to use PreparedStatement? (stub article)

JDBC techniques

• How do you make a database insert using JDBC? (stub article)
• How can I use system variables to make a database connection? (stub article)

JDBC problems

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SQL queries

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• What is a database view? (stub article)

Understanding constructors

• How do I invoke a constructor? (stub article)
• How can I call a constructor from a constructor? (stub article)
• Is it OK to tag inline method calls on constructors? (stub article)

Object methods

• How does an object call an inner class method? (stub article)

Object design

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• Can objects be used in place of arrays? (stub article)
• What's the difference between equals and ==? (stub article)

Static variables

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• I get "non-static variable this cannot be referenced from a static context"! (stub article)

The static modifier

• What is the difference between static and final keywords? (stub article)

Abstract class design and use

• Why use an abstract class instead of an interface? (stub article)
• What's the use of concrete methods in abstract classes? (stub article)

Abstract method design constraints

• Can you show some static calls to abstract classes? (stub article)

Abstract classes and methods

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• Can you give an example of an abstract class? (stub article)

Compiler concepts

• Which class should be compiled first? (stub article)

Compiler commands

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• What do I type at the command line to compile Hello.java? (stub article)
• Where is my compiled class file? (stub article)
• How can I ensure my compiler will locate the SAX package? (stub article)

Compiler diagnostics

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• What are undefined and undeclared variables? (stub article)

Development environment

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• How do I set environment variables on Windows XP? (stub article)
• How do I configure EditPlus to compile Java and capture output? (stub article)

Storage structures

• What is the difference between Hashtable and HashMap? (stub article)

Working with dates and calendars

• How do I insert slashes in a date? (stub article)
• How can I convert a String into a Date object? (stub article)
• How can I get the difference between two dates in days? (stub article)
• Why isn't my custom Calendar class called? (stub article)

Read and write files

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• How can I generate an array from a list? (stub article)

File system navigation

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• How can I get the path to an installed program? (stub article)
• How do I limit the scope of a file chooser? (stub article)

Java Web clients

• How can I download a Web page and write it to a file? (stub article)
• My Java Web client gets the wrong site! (stub article)
• How can I set a code name identifier for my feed reader? (stub article)

Java networking API

• How do I get the registered domain name from a URL? (stub article)
• How do I get a domain name from an IP address? (stub article)

Servlet concepts

• How does the JVM execute a servlet compared with a regular Java class? (stub article)

Servlet programming

• Can I use a normal class to handle my requests? (stub article)
• Can I use a constructor in my servlet? (stub article)

Servlet start up

• How do I compile a servlet? (stub article)
• Why won't my servlet compile? (stub article)
• What is the difference between JAR and WAR files? (stub article)

Servlet techniques

• What is URL-rewriting? (stub article)
• What's the difference between forward, include and redirection? (stub article)

General container questions

• Is the session ID stored in the servlet or container? (stub article)

Web application configuration

• What is a servlet URL mapping? (stub article)
• How do I load a servlet at start-up? (stub article)
• How can I create database connections for all servlets? (stub article)