org.sadun.util
Class ObjectLister

java.lang.Object
  org.sadun.util.ObjectLister

public class ObjectLister

extends java.lang.Object

A class to list the elements of an array or a collection/enumeration into a string, each element divided by a separtor, by invoking either the toString() method or a given method with no parameters (and returning a String).

The default list(array)method uses toString to describe each object; the list(array, method name) method attempts to locate a method with signature

  public String <method name>()
 

in each object in the array, and invokes it to describe each object.

For example, for the array String [] array { "Hello", "World" } invoking new ObjectLister().list(array); will produce "Hello, World".

For the array Thread [] array = { new Thread("Thread 1"), new Thread("Thread 2") }, invoking new ObjectLister().list(array, "getName"); will produce "Thread 1, Thread 2".

By default, the method to invoke is made accessible to the client code regardless of its protection status. Use setSetAccessible() to disable such behaviour. If disabled, the failOnUnaccessibleproperty may be used to cause the list to raise an excepion when a method is not accessible (by default, an explicit mention of the fact will appear in the list).

Author:

Cristiano Sadun

Field Summary

static char	DEFAULT_QUOTE_CHAR The default quote char, '"e;'
static java.lang.String	DEFAULT_SEPARATOR The default separator sequence ", "

Constructor Summary

ObjectLister()
Constructor for ObjectLister, which uses the default sequence DEFAULT_SEPARATORas separator.

ObjectLister(boolean useToStringIfNotFound)
Constructor for ObjectLister, which uses the default sequence DEFAULT_SEPARATORas separator.

ObjectLister(char quoteChar)
Constructor for ObjectLister, which uses the default sequence DEFAULT_SEPARATORas separator.

ObjectLister(java.lang.String separator)
Constructor for ObjectLister.

ObjectLister(java.lang.String separator, boolean useToStringIfNotFound)
Constructor for ObjectLister, which does not fail if the method to use is not accessible.

ObjectLister(java.lang.String separator, boolean useToStringIfNotFound, boolean failIfUnaccessible)
Constructor for ObjectLister.

ObjectLister(java.lang.String separator, char quoteChar)
Constructor for ObjectLister.

ObjectLister(java.lang.String separator, char quoteChar, boolean useToStringIfNotFound)
Constructor for ObjectLister, which does not fail if the method to use is not accessible.

ObjectLister(java.lang.String separator, char quoteChar, boolean useToStringIfNotFound, boolean failIfUnaccessible)
Constructor for ObjectLister.

Method Summary

static ObjectLister	getDefaultHTMLInstance() Return the default instance separating listed elements with a &ĝlt;br> HTML element
static ObjectLister	getInstance() Returns the default instance, which uses DEFAULT_SEPARATOR.
boolean	isFailOnUnaccessible()
boolean	isSetAccessible()
boolean	isUseToStringIfNotFound() Returns the useToStringIfNotFound.
java.lang.String	list(java.util.Collection coll) Invoke list() using the toString() method.
java.lang.String	list(java.util.Collection coll, java.lang.String methodToUse) Return a String containing a list of objects in the collection, obtained invoking the given method name on each element in the collection.
java.lang.String	list(java.util.Enumeration enum) Invoke list() using the toString() method.
java.lang.String	list(java.util.Enumeration enum, java.lang.String methodToUse) Return a String containing a list of objects in the enumeration, obtained invoking the given method name on each element in the enumeration.
java.lang.String	list(java.util.Iterator iterator) Invoke list() using the toString() method.
java.lang.String	list(java.util.Iterator iterator, java.lang.String methodToUse) Return a String containing a list of objects in the iterator, obtained invoking the given method name on each element.
java.lang.String	list(java.util.Map map) Invoke list()using the toString() method.
java.lang.String	list(java.util.Map map, java.lang.String methodToUse) Return a String containing a list of values in the map, obtained invoking the given method name on each element in the map.
java.lang.String	list(java.lang.Object[] array) Invoke list()using the toString() method.
java.lang.String	list(java.lang.Object[] array, java.lang.String methodToUse) Return a String containing a list of objects in the array, obtained invoking the given method name on each element in the array.
static void	main(java.lang.String[] args) A test method
void	println(java.util.Collection coll) Invoke list()and print the result on System.out.
void	println(java.util.Collection coll, java.lang.String methodToUse) Invoke list()and print the result on System.out.
void	println(java.util.Enumeration enum) Invoke list()and print the result on System.out.
void	println(java.util.Enumeration enum, java.lang.String methodToUse) Invoke list()and print the result on System.out.
void	println(java.util.Map map) Invoke list()and print the result on System.out.
void	println(java.util.Map map, java.lang.String methodToUse) Invoke list()and print the result on System.out.
void	println(java.lang.Object[] array) Invoke list()and print the result on System.out.
void	println(java.lang.Object[] array, java.lang.String methodToUse) Invoke list()and print the result on System.out.
void	setFailOnUnaccessible(boolean failOnUnaccessible)
void	setSetAccessible(boolean setAccessible)
void	setUseToStringIfNotFound(boolean useToStringIfNotFound) Sets the useToStringIfNotFound.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_QUOTE_CHAR

public static final char DEFAULT_QUOTE_CHAR

The default quote char, '"e;'

See Also:

Constant Field Values

DEFAULT_SEPARATOR

public static final java.lang.String DEFAULT_SEPARATOR

The default separator sequence ", "

See Also:

Constant Field Values

Constructor Detail

ObjectLister

public ObjectLister(java.lang.String separator,
                    char quoteChar,
                    boolean useToStringIfNotFound,
                    boolean failIfUnaccessible)

Constructor for ObjectLister.

Parameters:

separator - the separator to use

quoteChar - the quotation charachter to use. If 0, no quotes are used.

useToStringIfNotFound - if true, when {@link #list(java.lang.Object[], java.lang.String)

failIfUnaccessible - if true an exception is thrown if the method to use for listing is not accessible. list(array, method name)} is invoked, toString() will be used if the given method is not found in an object in the array to list. If false an exception will be raised.

ObjectLister

public ObjectLister(java.lang.String separator,
                    boolean useToStringIfNotFound,
                    boolean failIfUnaccessible)

Constructor for ObjectLister.

Parameters:

separator - the separator to use

useToStringIfNotFound - if true, when {@link #list(java.lang.Object[], java.lang.String)

failIfUnaccessible - if true an exception is thrown if the method to use for listing is not accessible. list(array, method name)} is invoked, toString() will be used if the given method is not found in an object in the array to list. If false an exception will be raised.

ObjectLister

public ObjectLister(java.lang.String separator,
                    boolean useToStringIfNotFound)

Constructor for ObjectLister, which does not fail if the method to use is not accessible.

Parameters:

separator - the separator to use

useToStringIfNotFound - if true, when list(array, method name) is invoked, toString() will be used if the given method is not found in an object in the array to list. If false an exception will be raised.

ObjectLister

public ObjectLister(java.lang.String separator,
                    char quoteChar,
                    boolean useToStringIfNotFound)

Constructor for ObjectLister, which does not fail if the method to use is not accessible.

Parameters:

separator - the separator to use

quoteChar - the quotation charachter to use. If 0, no quotes are used.

useToStringIfNotFound - if true, when list(array, method name) is invoked, toString() will be used if the given method is not found in an object in the array to list. If false an exception will be raised.

ObjectLister

public ObjectLister(boolean useToStringIfNotFound)

Constructor for ObjectLister, which uses the default sequence DEFAULT_SEPARATORas separator.

Parameters:

useToStringIfNotFound - if true, when list(array, method name) is invoked, toString() will be used if the given method is not found in an object in the array to list. If false an exception will be raised.

ObjectLister

public ObjectLister(java.lang.String separator)

Constructor for ObjectLister. When list(array, method name) is invoked, toString() will be used if the given method is not found in an object in the array to list.

Parameters:

separator - the separator to use

ObjectLister

public ObjectLister(java.lang.String separator,
                    char quoteChar)

Constructor for ObjectLister. When list(array, method name) is invoked, toString() will be used if the given method is not found in an object in the array to list.

Parameters:

separator - the separator to use

quoteChar - the quotation charachter to use. If 0, no quotes are used.

ObjectLister

public ObjectLister()

Constructor for ObjectLister, which uses the default sequence DEFAULT_SEPARATORas separator. When list(array, method name) is invoked, toString() will be used if the given method is not found in an object in the array to list.

ObjectLister

public ObjectLister(char quoteChar)

Constructor for ObjectLister, which uses the default sequence DEFAULT_SEPARATORas separator. When list(array, method name) is invoked, toString() will be used if the given method is not found in an object in the array to list.

Parameters:

quoteChar - the quotation charachter to use. If 0, no quotes are used.

Method Detail

list

public java.lang.String list(java.lang.Object[] array,
                             java.lang.String methodToUse)

Return a String containing a list of objects in the array, obtained invoking the given method name on each element in the array.

The method must return a String and have no parameters.

Parameters:

array - the array to list

methodToUse - the name of the method to use

Returns:

a String containing a list of objects in the array

Throws:

java.lang.RuntimeException - if a method with the given name, which returns a String and has no parameter is not available in the objects of the array.

list

public java.lang.String list(java.lang.Object[] array)

Invoke list()using the toString() method.

Returns:

a string listing the array

list

public java.lang.String list(java.util.Collection coll,
                             java.lang.String methodToUse)

Return a String containing a list of objects in the collection, obtained invoking the given method name on each element in the collection.

The method must return a String and have no parameters.

Parameters:

coll - the collection to list

methodToUse - the name of the method to use

Returns:

a String containing a list of objects in the collection

Throws:

java.lang.RuntimeException - if a method with the given name, which returns a String and has no parameter is not available in the objects of the collection.

list

public java.lang.String list(java.util.Collection coll)

Invoke list() using the toString() method.

Returns:

a string listing the collection

list

public java.lang.String list(java.util.Iterator iterator,
                             java.lang.String methodToUse)

Return a String containing a list of objects in the iterator, obtained invoking the given method name on each element.

The method must return a String and have no parameters.

Parameters:

iterator - the iterator to be listed

methodToUse - the name of the method to use

Returns:

a String containing a list of objects in the collection

Throws:

java.lang.RuntimeException - if a method with the given name, which returns a String and has no parameter is not available in the objects of the collection.

list

public java.lang.String list(java.util.Iterator iterator)

Invoke list() using the toString() method.

Parameters:

iterator - the iterator to be listed

Returns:

a string listing the collection

list

public java.lang.String list(java.util.Enumeration enum,
                             java.lang.String methodToUse)

Return a String containing a list of objects in the enumeration, obtained invoking the given method name on each element in the enumeration.

The method must return a String and have no parameters.

Parameters:

enum - the enumeration to list

methodToUse - the name of the method to use

Returns:

a String containing a list of objects in the enumeration

Throws:

java.lang.RuntimeException - if a method with the given name, which returns a String and has no parameter is not available in the objects of the enumeration.

list

public java.lang.String list(java.util.Enumeration enum)

Invoke list() using the toString() method.

Parameters:

enum - the enumeration to be listed

Returns:

a string listing the enumeration

println

public void println(java.lang.Object[] array,
                    java.lang.String methodToUse)

Invoke list()and print the result on System.out.

Parameters:

array - see list()

methodToUse - see list()

println

public void println(java.lang.Object[] array)

Invoke list()and print the result on System.out.

Parameters:

array - see list()

println

public void println(java.util.Collection coll,
                    java.lang.String methodToUse)

Invoke list()and print the result on System.out.

Parameters:

coll - see list()

methodToUse - see list()

println

public void println(java.util.Collection coll)

Invoke list()and print the result on System.out.

Parameters:

coll - see list()

println

public void println(java.util.Enumeration enum,
                    java.lang.String methodToUse)

Invoke list()and print the result on System.out.

Parameters:

enum - see list()

methodToUse - see list()

println

public void println(java.util.Enumeration enum)

Invoke list()and print the result on System.out.

Parameters:

enum - see list()

println

public void println(java.util.Map map,
                    java.lang.String methodToUse)

Invoke list()and print the result on System.out.

Parameters:

map - see list()

methodToUse - see list()

println

public void println(java.util.Map map)

Invoke list()and print the result on System.out.

list

public java.lang.String list(java.util.Map map,
                             java.lang.String methodToUse)

Return a String containing a list of values in the map, obtained invoking the given method name on each element in the map.

The method must return a String and have no parameters.

Parameters:

map - the map to list

methodToUse - the name of the method to use

Returns:

a String containing a list of values in the map

Throws:

java.lang.RuntimeException - if a method with the given name, which returns a String and has no parameter is not available in the objects of the map.

list

public java.lang.String list(java.util.Map map)

Invoke list()using the toString() method.

Returns:

a string listing the map

isUseToStringIfNotFound

public boolean isUseToStringIfNotFound()

Returns the useToStringIfNotFound.

Returns:

boolean

setUseToStringIfNotFound

public void setUseToStringIfNotFound(boolean useToStringIfNotFound)

Sets the useToStringIfNotFound.

Parameters:

useToStringIfNotFound - The useToStringIfNotFound to set

getInstance

public static ObjectLister getInstance()

Returns the default instance, which uses DEFAULT_SEPARATOR.

Returns:

ObjectLister the default object lister.

main

public static void main(java.lang.String[] args)
                 throws java.lang.NoSuchMethodException,
                        java.lang.reflect.InvocationTargetException

A test method

Throws:

java.lang.NoSuchMethodException

java.lang.reflect.InvocationTargetException

isSetAccessible

public boolean isSetAccessible()

Returns:

setSetAccessible

public void setSetAccessible(boolean setAccessible)

Parameters:

setAccessible -

isFailOnUnaccessible

public boolean isFailOnUnaccessible()

Returns:

setFailOnUnaccessible

public void setFailOnUnaccessible(boolean failOnUnaccessible)

Parameters:

failOnUnaccessible -

getDefaultHTMLInstance

public static ObjectLister getDefaultHTMLInstance()

Return the default instance separating listed elements with a &ĝlt;br> HTML element

Returns: