/*
* 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.harmony.luni.net;
import java.net.Proxy;
import java.net.ProxySelector;
import java.net.URI;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.List;
public class NetUtil {
/**
* Answers whether to use a SOCKS proxy.
*
* @param proxy java.net.Proxy <code>proxy</code> is used to determine
* whether using SOCKS proxy.
* @return true if only the type of <code>proxy</code> is
* Proxy.Type.SOCKS.
*/
public static boolean usingSocks(Proxy proxy) {
if (null != proxy && Proxy.Type.SOCKS == proxy.type()) {
return true;
}
return false;
}
/**
* Answer whether to prefer IPV6 address
*
* @return boolean
*/
public static boolean preferIPv6Addresses() {
final Action a = new Action("java.net.preferIPv6Addresses");//$NON-NLS-1$
return AccessController.doPrivileged(a).booleanValue();
}
/**
* Answer whether to prefer IPV4 stack
*
* @return boolean
*/
public static boolean preferIPv4Stack() {
final Action a = new Action("java.net.preferIPv4Stack");//$NON-NLS-1$
return AccessController.doPrivileged(a).booleanValue();
}
/**
* Gets proxy list according to the URI by system ProxySelector.
*
* @param uri
* @return a list of proxy for the URI. Returns null if no proxy is
* available.
*/
public static List<Proxy> getProxyList(URI uri) {
// use system default selector to get proxy list
ProxySelector selector = ProxySelector.getDefault();
if (null == selector) {
return null;
}
return selector.select(uri);
}
private static final class Action implements PrivilegedAction<Boolean> {
private final String propertyName;
Action(String propertyName) {
super();
this.propertyName = propertyName;
}
public Boolean run() {
if (Boolean.getBoolean(propertyName)) {
return Boolean.TRUE;
}
return Boolean.FALSE;
}
}
static void intToBytes(int value, byte bytes[], int start) {
/*
* Shift the int so the current byte is right-most Use a byte mask of
* 255 to single out the last byte.
*/
bytes[start] = (byte) ((value >> 24) & 255);
bytes[start + 1] = (byte) ((value >> 16) & 255);
bytes[start + 2] = (byte) ((value >> 8) & 255);
bytes[start + 3] = (byte) (value & 255);
}
static int bytesToInt(byte bytes[], int start) {
/*
* First mask the byte with 255, as when a negative signed byte converts
* to an integer, it has bits on in the first 3 bytes, we are only
* concerned about the right-most 8 bits. Then shift the rightmost byte
* to align with its position in the integer.
*/
int value = ((bytes[start + 3] & 255)) | ((bytes[start + 2] & 255) << 8)
| ((bytes[start + 1] & 255) << 16) | ((bytes[start] & 255) << 24);
return value;
}
}