@@ -24,50 +24,97 @@ import org.apache.tools.ant.taskdefs.condition.Condition;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.net.URL;
import java.net.MalformedURLException;
import java.io.IOException;
/**
* Test for a host being reachable using ICMP "ping" packets.
* Ping packets are very reliable for assessing reachability in a LAN or WAN,
* but they do not get through any well-configured firewall.
*
* <p/>
* This condition turns unknown host exceptions into false conditions. This is
* because on a laptop, DNS is one of the first services when the network goes; you
* are implicitly offline.
* <p/>
* If a URL is supplied instead of a host, the hostname is extracted
* and used in the test - all other parts of the URL are discarded.
* <p/>
* The test may not work through firewalls, that is, something may be reachable
* using a protocol such as HTTP, while the lower level ICMP packets get dropped
* on the floor. Similarly, a host may detected as reachable with ICMP, but
* not reachable on other ports (i.e. port 80), because of firewalls.
* <p/>
* Requires Java1.5+ to work
*
* @ant.condition name="isreachable"
* @since Ant1.7
*/
public class IsPingable extends ProjectComponent implements Condition {
public class IsPingable extends ProjectComponent implements Condition {
private String host;
/** The default timeout. */
private String url;
/**
* The default timeout.
*/
public static final int DEFAULT_TIMEOUT = 30;
private int timeout = DEFAULT_TIMEOUT;
/** Error when no hostname is defined */
/**
* Error when no hostname is defined
*/
public static final String ERROR_NO_HOSTNAME = "No hostname defined";
/** Error when invalid timeout value is defined */
/**
* Error when invalid timeout value is defined
*/
public static final String ERROR_BAD_TIMEOUT = "Invalid timeout value";
/** Unknown host message is seen. */
/**
* Unknown host message is seen.
*/
public static final String ERROR_UNKNOWN_HOST = "Unknown host:";
/** Network error message is seen. */
/**
* Network error message is seen.
*/
public static final String ERROR_ON_NETWORK = "network error to ";
public static final String ERROR_BOTH_TARGETS = "Both url and host have been specified";
/**
* The host to ping.
*
* @param host the host to ping.
*/
public void setHost(String host) {
this.host = host;
}
/**
* A URL to extract the hostname from
*
* @param url
*/
public void setUrl(String url) {
this.url = url;
}
/**
* Timeout for the reachability test -in seconds.
*
* @param timeout the timeout in seconds.
*/
public void setTimeout(int timeout) {
this.timeout = timeout;
}
/**
* emptyness test
*
* @param string param to check
* @return true if it is empty
*/
private boolean empty(String string) {
return string == null || string.length() == 0;
}
/**
* Is this condition true?
*
@@ -76,21 +123,39 @@ public class IsPingable extends ProjectComponent implements Condition {
* if an error occurs
*/
public boolean eval() throws BuildException {
if (host == null || host.length() == 0 ) {
if (empty(host) && empty(url) ) {
throw new BuildException(ERROR_NO_HOSTNAME);
}
if (timeout < 0) {
throw new BuildException(ERROR_BAD_TIMEOUT);
}
String target = host;
if (!empty(url)) {
if (!empty(host)) {
throw new BuildException(ERROR_BOTH_TARGETS);
}
try {
//get the host of a url
URL realURL = new URL(url);
target = realURL.getHost();
} catch (MalformedURLException e) {
throw new BuildException("Bad URL " + url, e);
}
}
try {
InetAddress address = InetAddress.getByName(host);
return address.isReachable(timeout * 1000);
log("Probing host " + target, Project.MSG_VERBOSE);
InetAddress address = InetAddress.getByName(target);
log("Host address =" + address.getHostAddress(),
Project.MSG_VERBOSE);
final boolean reachable = address.isReachable(timeout * 1000);
log("host is " + (reachable ? "" : "not") + " reachable",
Project.MSG_VERBOSE);
return reachable;
} catch (UnknownHostException e) {
log(ERROR_UNKNOWN_HOST + host, Project.MSG_VERBOSE);
log(ERROR_UNKNOWN_HOST + target );
return false;
} catch (IOException e) {
log(ERROR_ON_NETWORK + host + ": " + e.toString(),
Project.MSG_VERBOSE);
log(ERROR_ON_NETWORK + target + ": " + e.toString());
return false;
}
}
Steve Loughran