org.apache.juneau.utils

Class Args

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap<K,V>

java.util.LinkedHashMap<String,Object>

org.apache.juneau.ObjectMap

org.apache.juneau.utils.Args

All Implemented Interfaces:

Serializable, Cloneable, Map<String,Object>

public final class Args
extends ObjectMap

Utility class to make it easier to work with command-line arguments pass in through a main(String[] args) method.

Used to parse command-line arguments of the form "[zero or more main arguments] [zero or more optional arguments]".

The format of a main argument is a token that does not start with '-'.

The format of an optional argument is "-argName [zero or more tokens]".

Command-line examples

• java com.sample.MyClass mainArg1
• java com.sample.MyClass mainArg1 mainArg2
• java com.sample.MyClass mainArg1 -optArg1
• java com.sample.MyClass -optArg1
• java com.sample.MyClass mainArg1 -optArg1 optArg1Val
• java com.sample.MyClass mainArg1 -optArg1 optArg1Val1 optArg1Val2
• java com.sample.MyClass mainArg1 -optArg1 optArg1Val1 -optArg1 optArg1Val2

Example:

// Main method with arguments public static void main(String[] args) { // Wrap in Args Args a = new Args(args); // One main argument // a1 String a1 = a.getArg(0); // "a1" String a2 = a.getArg(1); // null // Two main arguments // a1 a2 String a1 = a.getArg(0); // "a1" String a2 = a.getArg(1); // "a2" // One main argument and one optional argument with no value // a1 -a2 String a1 = a.getArg(0); boolean hasA2 = a.hasArg("a2"); // true boolean hasA3 = a.hasArg("a3"); // false // One main argument and one optional argument with one value // a1 -a2 v2 String a1 = a.getArg(0); String a2 = a.getArg("a2"); // "v2" String a3 = a.getArg("a3"); // null // One main argument and one optional argument with two values // a1 -a2 v2a v2b String a1 = a.getArg(0); List<String> a2 = a.getArgs("a2"); // Contains ["v2a","v2b"] List<String> a3 = a.getArgs("a3"); // Empty list // Same as previous, except specify optional argument name multiple times // a1 -a2 v2a -a2 v2b String a1 = a.getArg(0); List<String> a2 = a.getArgs("a2"); // Contains ["v2a","v2b"] }

Main arguments are available through numeric string keys (e.g. "0", "1", ...). So you could use the ObjectMap API to convert main arguments directly to POJOs, such as an Enum

// Get 1st main argument as an Enum MyEnum e = a.get(MyEnum.class, "0"); // Get 1st main argument as an integer int i = a.get(int.class, "0");

Equivalent operations are available on optional arguments through the getArg(Class, String) method.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Field Summary

Fields inherited from class org.apache.juneau.ObjectMap

EMPTY_MAP

Constructor Summary

Constructors

Constructor and Description
Args(String args) Constructor.
Args(String[] args) Constructor.

Method Summary

Modifier and Type	Method and Description
<T> T	getArg(Class<T> c, String name) Returns the optional argument value converted to the specified object type.
String	getArg(int i) Returns main argument at the specified index, or null if the index is out of range.
String	getArg(String name) Returns the optional argument value, or blank if the optional argument was not specified.
List<String>	getArgs(String name) Returns the optional argument values as a list of strings.
boolean	hasArg(int i) Returns true if argument exists at specified index.

Methods inherited from class org.apache.juneau.ObjectMap

append, appendAll, cast, cast, containsKey, containsOuterKey, deleteAt, entrySet, exclude, find, find, findBoolean, findInt, findKeyIgnoreCase, findList, findLong, findMap, findObjectList, findObjectMap, findString, get, get, get, getAt, getAt, getBeanSession, getBoolean, getBoolean, getClassMeta, getFirstKey, getInt, getInt, getList, getList, getList, getLong, getLong, getMap, getMap, getMap, getObjectList, getObjectList, getObjectMap, getObjectMap, getString, getString, getStringArray, getStringArray, getSwapped, getWithDefault, getWithDefault, getWithDefault, include, keySet, postAt, putAt, putIfEmpty, putIfNull, putJson, removeAll, removeAll, removeWithDefault, serializeTo, setBeanSession, setInner, toString, toString

Methods inherited from class java.util.LinkedHashMap

clear, containsValue, forEach, getOrDefault, removeEldestEntry, replaceAll, values

Methods inherited from class java.util.HashMap

clone, compute, computeIfAbsent, computeIfPresent, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, size

Methods inherited from class java.util.AbstractMap

equals, hashCode

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, equals, hashCode, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, size

Constructor Detail

Args

public Args(String[] args)

Constructor.

Parameters:

args - Arguments passed in through a main(String[] args) method.

Args

public Args(String args)

Constructor.

Parameters:

args - Arguments passed in as a raw command line.

Method Detail

getArg

public String getArg(int i)

Returns main argument at the specified index, or null if the index is out of range.

Can be used in conjunction with hasArg(int) to check for existence of arg.

// Check for no arguments if (! args.hasArg(0)) printUsageAndExit(); // Get the first argument String firstArg = args.getArg(0);

Since main arguments are stored as numeric keys, this method is essentially equivalent to...

// Check for no arguments if (! args.containsKey("0")) printUsageAndExit(); // Get the first argument String firstArg = args.getString("0");

Parameters:

i - The index position of the main argument (zero-indexed).

Returns:

The main argument value, or "" if argument doesn't exist at that position.

hasArg

public boolean hasArg(int i)

Returns true if argument exists at specified index.

Parameters:

i - The zero-indexed position of the argument.

Returns:

true if argument exists at specified index.

getArg

public String getArg(String name)

Returns the optional argument value, or blank if the optional argument was not specified.

If the optional arg has multiple values, returns values as a comma-delimited list.

Parameters:

name - The optional argument name.

Returns:

The optional argument value, or blank if the optional argument was not specified.

getArg

public <T> T getArg(Class<T> c,
                    String name)

Returns the optional argument value converted to the specified object type.

If the optional arg has multiple values, returns only the first converted value.

Example:

// Command: java com.sample.MyClass -verbose true -debug 5 boolean b = args.getArg(boolean.class, "verbose"); int i = args.getArg(int.class, "debug");

Type Parameters:

T - The class type to convert the value to.

Parameters:

c - The class type to convert the value to.

name - The optional argument name.

Returns:

The optional argument value, or blank if the optional argument was not specified.

getArgs

public List<String> getArgs(String name)

Returns the optional argument values as a list of strings.

Example:

// Command: java com.sample.MyClass -extraArgs foo bar baz List<String> l1 = args.getArgs("extraArgs"); // ['foo','bar','baz'] List<String> l2 = args.getArgs("nonExistentArgs"); // An empty list

Parameters:

name - The optional argument name.

Returns:

The optional argument values, or an empty list if the optional argument was not specified.