org.eclipse.tycho.extras.docbundle.PackageNameMatcher Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2015 VDS Rail and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Enrico De Fent - initial API and implementation (see bug 459214)
*******************************************************************************/
package org.eclipse.tycho.extras.docbundle;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
import org.apache.commons.lang3.StringUtils;
/**
* An utility class for filtering package names.
*/
public class PackageNameMatcher {
/**
* Compiles the given list of package name specification strings into a matching object.
*
*
* If the list is empty, the resulting object will never match any package name, which means
* that {@link #matches(String)} will always return false.
*
*
* @param specs
* The list of package name specifications. For details on specification syntax see
* {@link #compile(String)}.
* @return A new matching object.
* @throws IllegalArgumentException
* Thrown if the given argument is null or if any of the strings in the
* list is an invalid package name specification.
*/
public static PackageNameMatcher compile(final List specs) {
if (specs == null) {
throw new IllegalArgumentException("null package name specifications");
}
final List list = new ArrayList<>();
for (String part : specs) {
list.add(buildPattern(part));
}
return new PackageNameMatcher(list);
}
private static Pattern buildPattern(final String spec) {
if (StringUtils.isEmpty(spec)) {
throw new IllegalArgumentException("empty package name");
}
final StringBuilder regex = new StringBuilder();
for (int idx = 0; idx < spec.length(); idx++) {
char ch = spec.charAt(idx);
if (ch == '*') {
regex.append(".*");
} else if (ch == '.') {
regex.append("\\.");
} else if (idx == 0 && !Character.isJavaIdentifierStart(ch)) {
throw new IllegalArgumentException("invalid package name: " + spec);
} else if (!Character.isJavaIdentifierPart(ch)) {
throw new IllegalArgumentException("invalid package name: " + spec);
} else {
regex.append(ch);
}
}
try {
return Pattern.compile(regex.toString());
} catch (PatternSyntaxException e) {
throw new IllegalArgumentException("invalid package specification: " + spec, e);
}
}
private final List patterns;
private final String description;
/**
* Constructs a new object which matches against the given patterns.
*
* @param patterns
*/
private PackageNameMatcher(List patterns) {
this.patterns = patterns;
this.description = buildDescription();
}
private String buildDescription() {
final StringBuilder sb = new StringBuilder();
for (int idx = 0; idx < patterns.size(); idx++) {
sb.append('"').append(patterns.get(idx).pattern()).append('"');
if (idx < patterns.size() - 1) {
sb.append(", ");
}
}
return sb.toString();
}
/**
* Returns true if the given package name matches against any of the patterns in this matcher.
*
* @return Always false if the given package name is null or an empty
* string.
*/
public boolean matches(String packageName) {
if (StringUtils.isEmpty(packageName)) {
return false;
}
for (Pattern pattern : patterns) {
if (pattern.matcher(packageName).matches()) {
return true;
}
}
return false;
}
@Override
public String toString() {
return String.format("%s[%s]", getClass().getSimpleName(), description);
}
}