com.izforge.izpack.util

Class VariableSubstitutor

java.lang.Object

com.izforge.izpack.util.VariableSubstitutor

All Implemented Interfaces:

java.io.Serializable

public class VariableSubstitutor
extends java.lang.Object
implements java.io.Serializable

Substitutes variables occurring in an input stream or a string. This implementation supports a generic variable value mapping and escapes the possible special characters occurring in the substituted values. The file types specifically supported are plain text files (no escaping), Java properties files, and XML files. A valid variable name matches the regular expression [a-zA-Z][a-zA-Z0-9_]* and names are case sensitive. Variables are referenced either by $NAME or ${NAME} (the latter syntax being useful in situations like ${NAME}NOTPARTOFNAME). If a referenced variable is undefined then it is not substituted but the corresponding part of the stream is copied as is.

Author:

Johannes Lehtinen

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	bracesRequired Whether braces are required for substitution.
private static long	serialVersionUID
protected static int	TYPE_AT A constant for file type.
protected static int	TYPE_JAVA_PROPERTIES A constant for file type.
protected static int	TYPE_PLAIN A constant for file type.
protected static int	TYPE_SHELL A constant for file type.
protected static int	TYPE_XML A constant for file type.
protected static java.util.Map	typeNameToConstantMap A mapping of file type names to corresponding integer constants.
protected java.util.Properties	variables The variable value mappings

Constructor Summary

Constructors

Constructor and Description
VariableSubstitutor(java.util.Properties variables) Constructs a new substitutor using the specified variable value mappings.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	areBracesRequired() Get whether this substitutor requires braces.
protected java.lang.String	escapeSpecialChars(java.lang.String str, int type) Escapes the special characters in the specified string using file type specific rules.
protected int	getTypeConstant(java.lang.String type) Returns the internal constant for the specified file type.
void	setBracesRequired(boolean braces) Specify whether this substitutor requires braces.
int	substitute(java.io.InputStream in, java.io.OutputStream out, java.lang.String type, java.lang.String encoding) Substitutes the variables found in the specified input stream.
int	substitute(java.io.Reader reader, java.io.Writer writer, java.lang.String type) Substitutes the variables found in the data read from the specified reader.
java.lang.String	substitute(java.lang.String str, java.lang.String type) Substitutes the variables found in the specified string.

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

variables

protected transient java.util.Properties variables

The variable value mappings

bracesRequired

protected boolean bracesRequired

Whether braces are required for substitution.

TYPE_PLAIN

protected static final int TYPE_PLAIN

A constant for file type. Plain file.

See Also:

Constant Field Values

TYPE_JAVA_PROPERTIES

protected static final int TYPE_JAVA_PROPERTIES

A constant for file type. Java properties file.

See Also:

Constant Field Values

TYPE_XML

protected static final int TYPE_XML

A constant for file type. XML file.

See Also:

Constant Field Values

TYPE_SHELL

protected static final int TYPE_SHELL

A constant for file type. Shell file.

See Also:

Constant Field Values

TYPE_AT

protected static final int TYPE_AT

A constant for file type. Plain file with '@' start char.

See Also:

Constant Field Values

typeNameToConstantMap

protected static final java.util.Map typeNameToConstantMap

A mapping of file type names to corresponding integer constants.

Constructor Detail

VariableSubstitutor

public VariableSubstitutor(java.util.Properties variables)

Constructs a new substitutor using the specified variable value mappings. The environment hashtable is copied by reference. Braces are not required by default

Parameters:

variables - the map with variable value mappings

Method Detail

areBracesRequired

public boolean areBracesRequired()

Get whether this substitutor requires braces.

setBracesRequired

public void setBracesRequired(boolean braces)

Specify whether this substitutor requires braces.

substitute

public java.lang.String substitute(java.lang.String str,
                          java.lang.String type)
                            throws java.lang.IllegalArgumentException

Substitutes the variables found in the specified string. Escapes special characters using file type specific escaping if necessary.

Parameters:

str - the string to check for variables

type - the escaping type or null for plain

Returns:

the string with substituted variables

Throws:

java.lang.IllegalArgumentException - if unknown escaping type specified

substitute

public int substitute(java.io.InputStream in,
             java.io.OutputStream out,
             java.lang.String type,
             java.lang.String encoding)
               throws java.lang.IllegalArgumentException,
                      java.io.UnsupportedEncodingException,
                      java.io.IOException

Substitutes the variables found in the specified input stream. Escapes special characters using file type specific escaping if necessary.

Parameters:

in - the input stream to read

out - the output stream to write

type - the file type or null for plain

encoding - the character encoding or null for default

Returns:

the number of substitutions made

Throws:

java.lang.IllegalArgumentException - if unknown file type specified

java.io.UnsupportedEncodingException - if encoding not supported

java.io.IOException - if an I/O error occurs

substitute

public int substitute(java.io.Reader reader,
             java.io.Writer writer,
             java.lang.String type)
               throws java.lang.IllegalArgumentException,
                      java.io.IOException

Substitutes the variables found in the data read from the specified reader. Escapes special characters using file type specific escaping if necessary.

Parameters:

reader - the reader to read

writer - the writer used to write data out

type - the file type or null for plain

Returns:

the number of substitutions made

Throws:

java.lang.IllegalArgumentException - if unknown file type specified

java.io.IOException - if an I/O error occurs

getTypeConstant

protected int getTypeConstant(java.lang.String type)

Returns the internal constant for the specified file type.

Parameters:

type - the type name or null for plain

Returns:

the file type constant

escapeSpecialChars

protected java.lang.String escapeSpecialChars(java.lang.String str,
                                  int type)

Escapes the special characters in the specified string using file type specific rules.

Parameters:

str - the string to check for special characters

type - the target file type (one of TYPE_xxx)

Returns:

the string with the special characters properly escaped