/*
* JBoss, Home of Professional Open Source.
* Copyright 2012, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.as.test.shared;
import java.io.File;
import java.util.Properties;
/**
* Parses a string and replaces any references to system properties or environment variables in the string
*
* @author Jaikiran Pai (copied from JBoss DMR project)
* @author <a href="mailto:david.lloyd@redhat.com">David M. Lloyd</a>
*/
public class PropertiesValueResolver {
private static final int INITIAL = 0;
private static final int GOT_DOLLAR = 1;
private static final int GOT_OPEN_BRACE = 2;
private static final int RESOLVED = 3;
private static final int DEFAULT = 4;
/**
* Replace properties of the form:
* <code>${<i><[env.]name>[</i>,<i><[env.]name2>[</i>,<i><[env.]name3>...]][</i>:<i><default>]</i>}</code>
*
* @param value - either a system property or environment variable reference
* @return the value of the system property or environment variable referenced if
* it exists
*/
public static String replaceProperties(final String value) {
return replaceProperties(value, System.getProperties());
}
/**
* Replace properties of the form:
* <code>${<i><[env.]name>[</i>,<i><[env.]name2>[</i>,<i><[env.]name3>...]][</i>:<i><default>]</i>}</code>
*
* @param value - either a system property or environment variable reference
* @return the value of the system property or environment variable referenced if
* it exists
*/
public static String replaceProperties(final String value, final Properties properties) {
final StringBuilder builder = new StringBuilder();
final int len = value.length();
int state = INITIAL;
int start = -1;
int nameStart = -1;
String resolvedValue = null;
for (int i = 0; i < len; i = value.offsetByCodePoints(i, 1)) {
final int ch = value.codePointAt(i);
switch (state) {
case INITIAL: {
switch (ch) {
case '$': {
state = GOT_DOLLAR;
continue;
}
default: {
builder.appendCodePoint(ch);
continue;
}
}
// not reachable
}
case GOT_DOLLAR: {
switch (ch) {
case '$': {
builder.appendCodePoint(ch);
state = INITIAL;
continue;
}
case '{': {
start = i + 1;
nameStart = start;
state = GOT_OPEN_BRACE;
continue;
}
default: {
// invalid; emit and resume
builder.append('$').appendCodePoint(ch);
state = INITIAL;
continue;
}
}
// not reachable
}
case GOT_OPEN_BRACE: {
switch (ch) {
case ':':
case '}':
case ',': {
final String name = value.substring(nameStart, i).trim();
if ("/".equals(name)) {
builder.append(File.separator);
state = ch == '}' ? INITIAL : RESOLVED;
continue;
} else if (":".equals(name)) {
builder.append(File.pathSeparator);
state = ch == '}' ? INITIAL : RESOLVED;
continue;
}
// First check for system property, then env variable
String val = (String) properties.get(name);
if (val == null && name.startsWith("env."))
val = System.getenv(name.substring(4));
if (val != null) {
builder.append(val);
resolvedValue = val;
state = ch == '}' ? INITIAL : RESOLVED;
continue;
} else if (ch == ',') {
nameStart = i + 1;
continue;
} else if (ch == ':') {
start = i + 1;
state = DEFAULT;
continue;
} else {
throw new IllegalStateException("Failed to resolve expression: " + value.substring(start - 2, i + 1));
}
}
default: {
continue;
}
}
// not reachable
}
case RESOLVED: {
if (ch == '}') {
state = INITIAL;
}
continue;
}
case DEFAULT: {
if (ch == '}') {
state = INITIAL;
builder.append(value.substring(start, i));
}
continue;
}
default:
throw new IllegalStateException("Unexpected char seen: " + ch);
}
}
switch (state) {
case GOT_DOLLAR: {
builder.append('$');
break;
}
case DEFAULT: {
builder.append(value.substring(start - 2));
break;
}
case GOT_OPEN_BRACE: {
// We had a reference that was not resolved, throw ISE
if (resolvedValue == null)
throw new IllegalStateException("Incomplete expression: " + builder.toString());
break;
}
}
return builder.toString();
}
}