/*
* Copyright 2016 the original author or authors.
*
* 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.gradle.internal.jvm.inspection;
import org.gradle.api.GradleException;
import org.gradle.api.JavaVersion;
import org.gradle.api.UncheckedIOException;
import org.gradle.internal.io.NullOutputStream;
import org.gradle.internal.io.StreamByteBuffer;
import org.gradle.internal.jvm.JavaInfo;
import org.gradle.process.internal.ExecHandleBuilder;
import org.gradle.process.internal.ExecHandleFactory;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class DefaultJvmVersionDetector implements JvmVersionDetector {
private final ExecHandleFactory execHandleFactory;
public DefaultJvmVersionDetector(ExecHandleFactory execHandleFactory) {
this.execHandleFactory = execHandleFactory;
}
@Override
public JavaVersion getJavaVersion(JavaInfo jvm) {
return getJavaVersion(jvm.getJavaExecutable().getPath());
}
@Override
public JavaVersion getJavaVersion(String javaCommand) {
StreamByteBuffer buffer = new StreamByteBuffer();
ExecHandleBuilder builder = execHandleFactory.newExec();
builder.setWorkingDir(new File(".").getAbsolutePath());
builder.setCommandLine(javaCommand, "-version");
builder.setStandardOutput(NullOutputStream.INSTANCE);
builder.setErrorOutput(buffer.getOutputStream());
builder.build().start().waitForFinish().assertNormalExitValue();
return parseJavaVersionCommandOutput(javaCommand, new BufferedReader(new InputStreamReader(buffer.getInputStream())));
}
private JavaVersion parseJavaVersionCommandOutput(String javaExecutable, BufferedReader reader) {
try {
String versionStr = reader.readLine();
while (versionStr != null) {
Matcher matcher = Pattern.compile("(?:java|openjdk) version \"(.+?)\"").matcher(versionStr);
if (matcher.matches()) {
return JavaVersion.toVersion(matcher.group(1));
}
versionStr = reader.readLine();
}
} catch (IOException e) {
throw new UncheckedIOException(e);
}
throw new GradleException(String.format("Could not determine Java version using executable %s.", javaExecutable));
}
}