SCJP 5.0 Objectives
Section 1: Declarations, Initialization and Scoping
- Develop code that declares classes (including abstract and all
forms of nested classes), interfaces, and enums, and includes the
appropriate use of package and import statements (including static
- Develop code that declares an interface. Develop code that
implements or extends one or more interfaces. Develop code that
declares an abstract class. Develop code that extends an abstract class.
- Develop code that declares, initializes, and uses primitives,
arrays, enums, and objects as static, instance, and local variables.
Also, use legal identifiers for variable names.
- Develop code that declares both static and non-static methods, and
- if appropriate - use method names that adhere to the JavaBeans naming
standards. Also develop code that declares and uses a variable-length
- Given a code example, determine if a method is correctly overriding
or overloading another method, and identify legal return values
(including covariant returns), for the method.
- Given a set of classes and superclasses, develop constructors for
one or more of the classes. Given a class declaration, determine if a
default constructor will be created, and if so, determine the behavior
of that constructor. Given a nested or non-nested class listing, write
code to instantiate the class.
Section 2: Flow Control
- Develop code that implements an if or switch statement; and identify legal argument types for these statements.
- Develop code that implements all forms of loops and iterators,
including the use of for, the enhanced for loop (for-each), do, while,
labels, break, and continue; and explain the values taken by loop
counter variables during and after loop execution.
- Develop code that makes use of assertions, and distinguish appropriate from inappropriate uses of assertions.
- Develop code that makes use of exceptions and exception handling
clauses (try, catch, finally), and declares methods and overriding
methods that throw exceptions.
- Recognize the effect of an exception arising at a specified point
in a code fragment. Note that the exception may be a runtime exception,
a checked exception, or an error.
- Recognize situations that will result in any of the following being
IllegalArgumentException, IllegalStateException, NullPointerException,
NumberFormatException, AssertionError, ExceptionInInitializerError,
StackOverflowError or NoClassDefFoundError. Understand which of these
are thrown by the virtual machine and recognize situations in which
others should be thrown programatically.
Section 3: API Contents
- Develop code that uses the primitive wrapper classes (such as
Boolean, Character, Double, Integer, etc.), and/or autoboxing &
unboxing. Discuss the differences between the String, StringBuilder,
and StringBuffer classes.
- Given a scenario involving navigating file systems, reading from
files, or writing to files, develop the correct solution using the
following classes (sometimes in combination), from java.io:
BufferedReader,BufferedWriter, File, FileReader, FileWriter and
- Develop code that serializes and/or de-serializes objects using the
following APIs from java.io: DataInputStream, DataOutputStream,
FileInputStream, FileOutputStream, ObjectInputStream,
ObjectOutputStream and Serializable.
- Use standard J2SE APIs in the java.text package to correctly format
or parse dates, numbers, and currency values for a specific locale;
and, given a scenario, determine the appropriate methods to use if you
want to use the default locale or a specific locale. Describe the
purpose and use of the java.util.Locale class.
- Write code that uses standard J2SE APIs in the java.util and
java.util.regex packages to format or parse strings or streams. For
strings, write code that uses the Pattern and Matcher classes and the
String.split method. Recognize and use regular expression patterns for
matching (limited to: . (dot), * (star), + (plus), ?, \d, \s, \w, ,
()). The use of *, +, and ? will be limited to greedy quantifiers, and
the parenthesis operator will only be used as a grouping mechanism, not
for capturing content during matching. For streams, write code using
the Formatter and Scanner classes and the PrintWriter.format/printf
methods. Recognize and use formatting parameters (limited to: %b, %c,
%d, %f, %s) in format strings.
Section 4: Concurrency
- Write code to define, instantiate, and start new threads using both java.lang.Thread and java.lang.Runnable.
- Recognize the states in which a thread can exist, and identify ways in which a thread can transition from one state to another.
- Given a scenario, write code that makes appropriate use of object
locking to protect static or instance variables from concurrent access
- Given a scenario, write code that makes appropriate use of wait, notify, or notifyAll.
- Develop code that implements tight encapsulation, loose coupling, and high cohesion in classes, and describe the benefits.
- Given a scenario, develop code that demonstrates the use of
polymorphism. Further, determine when casting will be necessary and
recognize compiler vs. runtime errors related to object reference
- Explain the effect of modifiers on inheritance with respect to
constructors, instance or static variables, and instance or static
- Given a scenario, develop code that declares and/or invokes
overridden or overloaded methods and code that declares and/or invokes
superclass, overridden, or overloaded constructors.
- Develop code that implements "is-a" and/or "has-a" relationships.
Section 6: Collections / Generics
- Given a design scenario, determine which collection classes
and/or interfaces should be used to properly implement that design,
including the use of the Comparable interface.
- Distinguish between correct and incorrect overrides of
corresponding hashCode and equals methods, and explain the difference
between == and the equals method.
- Write code that uses the generic versions of the Collections API,
in particular, the Set, List, and Map interfaces and implementation
classes. Recognize the limitations of the non-generic Collections API
and how to refactor code to use the generic versions.
- Develop code that makes proper use of type parameters in
class/interface declarations, instance variables, method arguments, and
return types; and write generic methods or methods that make use of
wildcard types and understand the similarities and differences between
these two approaches.
- Use capabilities in the java.util package to write code to
manipulate a list by sorting, performing a binary search, or converting
the list to an array. Use capabilities in the java.util package to
write code to manipulate an array by sorting, performing a binary
search, or converting the array to a list. Use the java.util.Comparator
and java.lang.Comparable interfaces to affect the sorting of lists and
arrays. Furthermore, recognize the effect of the "natural ordering" of
primitive wrapper classes and java.lang.String on sorting.
Section 7: Fundamentals
- Given a code example and a scenario, write code that uses the
appropriate access modifiers, package declarations, and import
statements to interact with (through access or inheritance) the code in
- Given an example of a class and a command-line, determine the expected runtime behavior.
- Determine the effect upon object references and primitive values
when they are passed into methods that perform assignments or other
modifying operations on the parameters.
- Given a code example, recognize the point at which an object
becomes eligible for garbage collection, and determine what is and is
not guaranteed by the garbage collection system. Recognize the
behaviors of System.gc and finalization.
- Given the fully-qualified name of a class that is deployed inside
and/or outside a JAR file, construct the appropriate directory
structure for that class. Given a code example and a classpath,
determine whether the classpath will allow the code to compile
- Write code that correctly applies the appropriate operators
including assignment operators (limited to: =, +=, -=), arithmetic
operators (limited to: +, -, *, /, %, ++, --), relational operators
(limited to: <, <=, >, >=, ==, !=), the instanceof
operator, logical operators (limited to: &, |, ^, !, &&,
||), and the conditional operator ( ? : ), to produce a desired result.
Write code that determines the equality of two objects or two