com.google.gwt.dev.util.arg.SourceLevel Maven / Gradle / Ivy
/*
* Copyright 2013 Google Inc.
*
* 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 com.google.gwt.dev.util.arg;
import com.google.gwt.thirdparty.guava.common.annotations.VisibleForTesting;
import com.google.gwt.util.tools.Utility;
/**
* Java source level compatibility constants. Java versions range from 1.0 to 1.7. Versions 1.6 and
* 1.7 are also referred as 6 and 7 respectively.
*
* Both names can be used indistinctly.
*/
public enum SourceLevel {
// Source levels must appear in ascending order for the default setting logic to work.
JAVA6("1.6", "6"),
JAVA7("1.7", "7");
/**
* The default java sourceLevel.
*/
public static final SourceLevel DEFAULT_SOURCE_LEVEL = getJvmBestMatchingSourceLevel();
private final String stringValue;
private final String altStringValue;
SourceLevel(String stringValue, String altStringValue) {
this.stringValue = stringValue;
this.altStringValue = altStringValue;
}
/**
* Returns a string value representation for the source level.
*/
public String getStringValue() {
return stringValue;
}
/**
* Returns an alternate string value representation for the source level.
*/
public String getAltStringValue() {
return altStringValue;
}
@Override
public String toString() {
return stringValue;
}
/**
* Returns the SourceLevel given the string or alternate string representation; returns {@code
* null} if none is found.
*/
public static SourceLevel fromString(String sourceLevelString) {
if (sourceLevelString == null) {
return null;
}
for (SourceLevel sourceLevel : SourceLevel.values()) {
if (sourceLevel.stringValue.equals(sourceLevelString) ||
sourceLevel.altStringValue.equals(sourceLevelString)) {
return sourceLevel;
}
}
return null;
}
private static SourceLevel getJvmBestMatchingSourceLevel() {
// If everything fails set default to JAVA7.
String javaSpecLevel = System.getProperty("java.specification.version");
return getBestMatchingVersion(javaSpecLevel);
}
@VisibleForTesting
public static SourceLevel getBestMatchingVersion(String javaVersionString) {
try {
// Find the first version that is less than or equal to javaSpecLevel by iterating in reverse
// order.
SourceLevel[] sourceLevels = SourceLevel.values();
for (int i = sourceLevels.length - 1; i >= 0; i--) {
if (Utility.versionCompare(javaVersionString, sourceLevels[i].stringValue) >= 0) {
// sourceLevel is <= javaSpecLevel, so keep this one.
return sourceLevels[i];
}
}
} catch (IllegalArgumentException e) {
// If the version can not be parsed fallback to JAVA7.
}
// If everything fails set default to JAVA7.
return JAVA7;
}
}