org.scijava.util
Class ReflectedUniverse

java.lang.Object
  org.scijava.util.ReflectedUniverse

public class ReflectedUniverse
extends Object

A general-purpose reflection wrapper class.

Note: use of this class is discouraged in favor of compile-time (i.e., type-safe) dependency linkages. However, there are times when it proves very useful for writing blocks of reflected code in a more succinct way than you can do with the vanilla java.lang.reflect API. Of course, debugging such reflected code becomes much more difficult—caveat emptor!

Author:

Curtis Rueden

Constructor Summary

ReflectedUniverse()
Constructs a new reflected universe.

ReflectedUniverse(ClassLoader loader)
Constructs a new reflected universe that uses the given class loader.

ReflectedUniverse(URL[] urls)
Constructs a new reflected universe, with the given URLs representing additional search paths for imported classes (in addition to the CLASSPATH).

Method Summary

Object	exec(String command) Executes a command in the universe.
Object	getVar(String varName) Returns the value of a variable or field in the universe.
boolean	isAccessibilityIgnored() Gets whether access modifiers (protected, private, etc.) are ignored.
static boolean	isInstance(Class<?> c, Object o) Returns whether the given object is compatible with the specified class for the purposes of reflection.
static void	main(String[] args) Allows exploration of a reflected universe in an interactive environment.
void	setAccessibilityIgnored(boolean ignore) Sets whether access modifiers (protected, private, etc.) are ignored.
void	setVar(String varName, boolean b) Registers a variable of primitive type boolean in the universe.
void	setVar(String varName, byte b) Registers a variable of primitive type byte in the universe.
void	setVar(String varName, char c) Registers a variable of primitive type char in the universe.
void	setVar(String varName, double d) Registers a variable of primitive type double in the universe.
void	setVar(String varName, float f) Registers a variable of primitive type float in the universe.
void	setVar(String varName, int i) Registers a variable of primitive type int in the universe.
void	setVar(String varName, long l) Registers a variable of primitive type long in the universe.
void	setVar(String varName, Object obj) Registers a variable in the universe.
void	setVar(String varName, short s) Registers a variable of primitive type short in the universe.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReflectedUniverse

public ReflectedUniverse()

Constructs a new reflected universe.

ReflectedUniverse

public ReflectedUniverse(URL[] urls)

Constructs a new reflected universe, with the given URLs representing additional search paths for imported classes (in addition to the CLASSPATH).

ReflectedUniverse

public ReflectedUniverse(ClassLoader loader)

Constructs a new reflected universe that uses the given class loader.

Method Detail

isInstance

public static boolean isInstance(Class<?> c,
                                 Object o)

Returns whether the given object is compatible with the specified class for the purposes of reflection.

exec

public Object exec(String command)
            throws ReflectException

Executes a command in the universe. The following syntaxes are valid:

• import fully.qualified.package.ClassName
• var = new ClassName(param1, ..., paramN)
• var.method(param1, ..., paramN)
• var2 = var.method(param1, ..., paramN)
• ClassName.method(param1, ..., paramN)
• var2 = ClassName.method(param1, ..., paramN)
• var2 = var

Important guidelines:

• Any referenced class must be imported first using "import".
• Variables can be exported from the universe with getVar().
• Variables can be imported to the universe with setVar().
• Each parameter must be either:
  1. a variable in the universe
  2. a static or instance field (i.e., no nested methods)
  3. a string literal (remember to escape the double quotes)
  4. an integer literal
  5. a long literal (ending in L)
  6. a double literal (containing a decimal point)
  7. a boolean literal (true or false)
  8. the null keyword

Throws:

ReflectException

setVar

public void setVar(String varName,
                   Object obj)

Registers a variable in the universe.

setVar

public void setVar(String varName,
                   boolean b)

Registers a variable of primitive type boolean in the universe.

setVar

public void setVar(String varName,
                   byte b)

Registers a variable of primitive type byte in the universe.

setVar

public void setVar(String varName,
                   char c)

Registers a variable of primitive type char in the universe.

setVar

public void setVar(String varName,
                   double d)

Registers a variable of primitive type double in the universe.

setVar

public void setVar(String varName,
                   float f)

Registers a variable of primitive type float in the universe.

setVar

public void setVar(String varName,
                   int i)

Registers a variable of primitive type int in the universe.

setVar

public void setVar(String varName,
                   long l)

Registers a variable of primitive type long in the universe.

setVar

public void setVar(String varName,
                   short s)

Registers a variable of primitive type short in the universe.

getVar

public Object getVar(String varName)
              throws ReflectException

Returns the value of a variable or field in the universe. Primitive types will be wrapped in their Java Object wrapper classes.

Throws:

ReflectException

setAccessibilityIgnored

public void setAccessibilityIgnored(boolean ignore)

Sets whether access modifiers (protected, private, etc.) are ignored.

isAccessibilityIgnored

public boolean isAccessibilityIgnored()

Gets whether access modifiers (protected, private, etc.) are ignored.

main

public static void main(String[] args)
                 throws IOException

Allows exploration of a reflected universe in an interactive environment.

Throws:

IOException