org.apache.openejb.util.NetworkUtil Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.openejb.util;
import java.io.IOException;
import java.net.ServerSocket;
public final class NetworkUtil {
private NetworkUtil() {
// no-op
}
public static int getNextAvailablePort() {
return getNextAvailablePort(new int[]{0});
}
public static int getNextAvailablePort(int[] portList) {
int port;
ServerSocket s = null;
try {
s = create(portList);
port = s.getLocalPort();
s.close();
} catch (IOException ioe) {
port = -1;
}
return port;
}
private static ServerSocket create(int[] ports) throws IOException {
for (int port : ports) {
try {
return new ServerSocket(port);
} catch (IOException ex) {
continue; // try next port
}
}
// if the program gets here, no port in the range was found
throw new IOException("no free port found");
}
public static String getLocalAddress(String start, String end) {
return start + "localhost:" + getNextAvailablePort() + end;
}
}