First of the Java1.5 extensions. Closest j2se has for detecting offline state, though I note J2ME and JavaWebStart have offline tests.

Needs tests.


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@276928 13f79535-47bb-0310-9956-ffa450edef68

build.xml

@@ -152,6 +152,12 @@
     </or>
   </selector>
 
+  <selector id="needs.jdk1.5+">
+    <or>
+      <filename name="${ant.package}/taskdefs/condition/IsPingable*"/>
+    </or>
+  </selector>
+  
   <!-- classes that should be present in Sun based JVMs, but not in
        Kaffe for example -->
   <selector id="needs.sun.tools">
@@ -637,6 +643,7 @@
           <or>
             <selector refid="needs.jdk1.3+" unless="jdk1.3+"/>
             <selector refid="needs.jdk1.4+" unless="jdk1.4+"/>
+            <selector refid="needs.jdk1.5+" unless="jdk1.5+"/>
             <selector refid="needs.sun.tools" unless="sun.tools.present"/>
             <selector refid="needs.sun.uue" unless="sunuue.present"/>
             <selector refid="needs.sun.b64" unless="base64.present"/>

src/main/org/apache/tools/ant/taskdefs/condition/IsPingable.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright  2004 The Apache Software Foundation
+ *
+ *  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.apache.tools.ant.taskdefs.condition;
+
+import org.apache.tools.ant.ProjectComponent;
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.Project;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+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.
+ *
+ * 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.
+ * Requires Java1.5+ to work
+ * @since Ant1.7
+ */
+public class IsPingable extends ProjectComponent implements Condition  {
+
+    private String host;
+    public static final int DEFAULT_TIMEOUT = 30;
+    private int timeout=DEFAULT_TIMEOUT;
+    public static final String ERROR_NO_HOSTNAME = "No hostname defined";
+    public static final String ERROR_BAD_TIMEOUT = "Invalid timeout value";
+    public static final String ERROR_UNKNOWN_HOST = "Unknown host:";
+    public static final String ERROR_ON_NETWORK = "network error to ";
+
+    /**
+     * the host to ping
+     * @param host
+     */
+    public void setHost(String host) {
+        this.host = host;
+    }
+
+    /**
+     * timeout for the reachability test -in seconds
+     * @param timeout
+     */
+    public void setTimeout(int timeout) {
+        this.timeout = timeout;
+    }
+
+    /**
+     * Is this condition true?
+     *
+     * @return true if the condition is true
+     * @throws org.apache.tools.ant.BuildException
+     *          if an error occurs
+     */
+    public boolean eval() throws BuildException {
+        if(host==null && host.length()==0) {
+            throw new BuildException(ERROR_NO_HOSTNAME);
+        }
+        if(timeout<0) {
+            throw new BuildException(ERROR_BAD_TIMEOUT);
+        }
+        try {
+            InetAddress address=InetAddress.getByName(host);
+            return address.isReachable(timeout*1000);
+        } catch (UnknownHostException e) {
+            log(ERROR_UNKNOWN_HOST+host,Project.MSG_VERBOSE);
+            return false;
+        } catch (IOException e) {
+            log(ERROR_ON_NETWORK + host +": "+e.toString(),
+                    Project.MSG_VERBOSE);
+            return false;
+        }
+    }
+}