org.apache.calcite.util

Class Template

java.lang.Object

java.text.Format

java.text.MessageFormat

org.apache.calcite.util.Template

All Implemented Interfaces:

Serializable, Cloneable

public class Template
extends MessageFormat

String template.

It is extended from MessageFormat to allow parameters to be substituted by name as well as by position.

The following example, using MessageFormat, yields "Happy 64th birthday, Ringo!":

MessageFormat f = new MessageFormat("Happy {0,number}th birthday, {1}!");
Object[] args = {64, "Ringo"};
System.out.println(f.format(args);

Here is the same example using a Template and named parameters:

Template f = new Template("Happy {age,number}th birthday, {name}!");
Map<Object, Object> args = new HashMap<Object, Object>();
args.put("age", 64);
args.put("name", "Ringo");
System.out.println(f.format(args);

Using a Template you can also use positional parameters:

Template f = new Template("Happy {age,number}th birthday, {name}!");
Object[] args = {64, "Ringo"};
System.out.println(f.format(args);

Or a hybrid; here, one argument is specified by name, another by position:

Template f = new Template("Happy {age,number}th birthday, {name}!");
Map<Object, Object> args = new HashMap<Object, Object>();
args.put(0, 64);
args.put("name", "Ringo");
System.out.println(f.format(args);

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.text.MessageFormat

MessageFormat.Field

Field Summary

Fields

Modifier and Type	Field and Description
private List<String>	parameterNames

Constructor Summary

Constructors

Modifier	Constructor and Description
private	Template(String pattern, List<String> parameterNames, Locale locale)

Method Summary

Modifier and Type	Method and Description
String	format(Map<Object,Object> argMap) Formats a set of arguments to produce a string.
static String	formatByName(String pattern, Map<Object,Object> argMap) Creates a Template with the given pattern and uses it to format the given arguments.
private Object	getArg(Map<Object,Object> argMap, int ordinal) Returns the value of the ordinalth argument.
List<String>	getParameterNames() Returns the names of the parameters, in the order that they appeared in the template string.
private static void	makeFormat(StringBuilder[] segments, List<String> parameterNames) Called when a complete parameter has been seen.
static Template	of(String pattern) Creates a Template for the default locale and the specified pattern.
static Template	of(String pattern, Locale locale) Creates a Template for the specified locale and pattern.
private static String	process(String pattern, List<String> parameterNames) Parses the pattern, populates the parameter names, and returns the pattern with parameter names converted to parameter ordinals.

Methods inherited from class java.text.MessageFormat

applyPattern, clone, equals, format, format, format, formatToCharacterIterator, getFormats, getFormatsByArgumentIndex, getLocale, hashCode, parse, parse, parseObject, setFormat, setFormatByArgumentIndex, setFormats, setFormatsByArgumentIndex, setLocale, toPattern

Methods inherited from class java.text.Format

format, parseObject

Methods inherited from class java.lang.Object

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

Field Detail

parameterNames

private final List<String> parameterNames

Constructor Detail

Template

private Template(String pattern,
                 List<String> parameterNames,
                 Locale locale)

Method Detail

of

public static Template of(String pattern)

Creates a Template for the default locale and the specified pattern.

Parameters:

pattern - the pattern for this message format

Throws:

IllegalArgumentException - if the pattern is invalid

of

public static Template of(String pattern,
                          Locale locale)

Creates a Template for the specified locale and pattern.

Parameters:

pattern - the pattern for this message format

locale - the locale for this message format

Throws:

IllegalArgumentException - if the pattern is invalid

process

private static String process(String pattern,
                              List<String> parameterNames)

Parses the pattern, populates the parameter names, and returns the pattern with parameter names converted to parameter ordinals.

To ensure that the same parsing rules apply, this code is copied from MessageFormat.applyPattern(String) but with different actions when a parameter is recognized.

Parameters:

pattern - Pattern

parameterNames - Names of parameters (output)

Returns:

Pattern with named parameters substituted with ordinals

makeFormat

private static void makeFormat(StringBuilder[] segments,
                               List<String> parameterNames)

Called when a complete parameter has been seen.

Parameters:

segments - Comma-separated segments of the parameter definition

parameterNames - List of parameter names seen so far

format

public String format(Map<Object,Object> argMap)

Formats a set of arguments to produce a string.

Arguments may appear in the map using named keys (of type String), or positional keys (0-based ordinals represented either as type String or Integer).

Parameters:

argMap - A map containing the arguments as (key, value) pairs

Returns:

Formatted string.

Throws:

IllegalArgumentException - if the Format cannot format the given object

getArg

private Object getArg(Map<Object,Object> argMap,
                      int ordinal)

Returns the value of the ordinalth argument.

Parameters:

argMap - Map of argument values

ordinal - Ordinal of argument

Returns:

Value of argument

formatByName

public static String formatByName(String pattern,
                                  Map<Object,Object> argMap)

Creates a Template with the given pattern and uses it to format the given arguments. This is equivalent to

Template(pattern).format(java.util.Map<java.lang.Object, java.lang.Object>)(args)

Throws:

IllegalArgumentException - if the pattern is invalid, or if an argument in the arguments array is not of the type expected by the format element(s) that use it.

getParameterNames

public List<String> getParameterNames()

Returns the names of the parameters, in the order that they appeared in the template string.

Returns:

List of parameter names