org.wildfly.galleon.plugin.PropertyReplacer Maven / Gradle / Ivy
/*
* Copyright 2016-2018 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.wildfly.galleon.plugin;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.nio.file.Files;
import java.nio.file.Path;
/**
* Utility that copies content from reader to writer replacing the properties.
*
* @author Alexey Loubyansky
*/
public class PropertyReplacer {
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;
public static void copy(final Path src, final Path target, PropertyResolver resolver, String failureReplacement) throws IOException {
if(!Files.exists(target.getParent())) {
Files.createDirectories(target.getParent());
}
try(BufferedReader reader = Files.newBufferedReader(src);
BufferedWriter writer = Files.newBufferedWriter(target)) {
copy(reader, writer, resolver, failureReplacement);
}
}
public static void copy(final Reader reader, Writer writer, PropertyResolver properties,
String failureReplacement) throws IOException {
int state = INITIAL;
final StringBuilder buf = new StringBuilder();
int ch = reader.read();
while (ch >= 0) {
switch (state) {
case INITIAL: {
switch (ch) {
case '$': {
state = GOT_DOLLAR;
break;
}
default: {
writer.write(ch);
}
}
break;
}
case GOT_DOLLAR: {
switch (ch) {
case '$': {
// escaped $
buf.setLength(0);
writer.write(ch);
state = INITIAL;
break;
}
case '{': {
state = GOT_OPEN_BRACE;
break;
}
default: {
// invalid; emit and resume
writer.append('$');
writer.write(ch);
buf.setLength(0);
state = INITIAL;
}
}
break;
}
case GOT_OPEN_BRACE: {
switch (ch) {
case '}':
case ',': {
final String name = buf.toString();
if ("/".equals(name)) {
writer.append(File.separatorChar);
state = ch == '}' ? INITIAL : RESOLVED;
} else {
final String val = properties.resolveProperty(name);
if (val != null) {
writer.write(val);
state = ch == '}' ? INITIAL : RESOLVED;
} else if (ch == ',') {
state = DEFAULT;
} else {
if(failureReplacement != null) {
writer.write(failureReplacement);
state = ch == '}' ? INITIAL : RESOLVED;
} else {
throw new IllegalStateException("Failed to resolve property: " + buf);
}
}
}
buf.setLength(0);
break;
}
default: {
buf.appendCodePoint(ch);
}
}
break;
}
case RESOLVED: {
if (ch == '}') {
state = INITIAL;
}
break;
}
case DEFAULT: {
if (ch == '}') {
state = INITIAL;
final String val = properties.resolveProperty(buf.toString());
if (val != null) {
writer.write(val);
} else {
writer.write(buf.toString());
}
} else {
buf.appendCodePoint(ch);
}
break;
}
default:
throw new IllegalStateException("Unexpected char seen: " + ch);
}
ch = reader.read();
}
switch (state) {
case GOT_DOLLAR: {
writer.append('$');
break;
}
case DEFAULT: {
writer.write(buf.toString());
break;
}
case GOT_OPEN_BRACE: {
throw new IllegalStateException("Incomplete expression: " + buf.toString());
}
}
}
}