IsReachable (Apache Ant API)

java.lang.Object
- org.apache.tools.ant.ProjectComponent
- - org.apache.tools.ant.taskdefs.condition.IsReachable

All Implemented Interfaces:

java.lang.Cloneable, Condition
```
public class IsReachable
extends ProjectComponent
implements Condition
```
Test for a host being reachable using ICMP "ping" packets & echo operations. Ping packets are very reliable for assessing reachability in a LAN or WAN, but they do not get through any well-configured firewall. Echo (port 7) may.

This condition turns unknown host exceptions into false conditions. This is because on a laptop, DNS is one of the first services lost when the network goes; you are implicitly offline.

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.

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 be detected as reachable with ICMP, but not reachable on other ports (i.e. port 80), because of firewalls.

Since:

Ant 1.7

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`DEFAULT_TIMEOUT` The default timeout.
`static java.lang.String`	`ERROR_BAD_TIMEOUT` Error when invalid timeout value is defined
`static java.lang.String`	`ERROR_BAD_URL` Error message when an invalid url is used.
`static java.lang.String`	`ERROR_BOTH_TARGETS` Error message when url and host are specified.
`static java.lang.String`	`ERROR_NO_HOST_IN_URL` Error message when no hostname in url.
`static java.lang.String`	`ERROR_NO_HOSTNAME` Error when no hostname is defined
`static java.lang.String`	`ERROR_ON_NETWORK` Network error message is seen.
`static java.lang.String`	`METHOD_NAME` Deprecated. Since 1.9.14
`static java.lang.String`	`MSG_NO_REACHABLE_TEST` Error message when no reachably test avail.

Fields inherited from class org.apache.tools.ant.ProjectComponent
description, location, project

Constructor Summary

Constructors
Constructor and Description

IsReachable()

Constructors
Constructor and Description
`IsReachable()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`eval()` Evaluate the condition.
`void`	`setHost(java.lang.String host)` Set the host to ping.
`void`	`setTimeout(int timeout)` Set the timeout for the reachability test in seconds.
`void`	`setUrl(java.lang.String url)` Set the URL from which to extract the hostname.

Methods inherited from class org.apache.tools.ant.ProjectComponent
clone, getDescription, getLocation, getProject, log, log, setDescription, setLocation, setProject

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_TIMEOUT
```
public static final int DEFAULT_TIMEOUT
```
    The default timeout.
    
    See Also:
    
    Constant Field Values
  - ERROR_NO_HOSTNAME
```
public static final java.lang.String ERROR_NO_HOSTNAME
```
    Error when no hostname is defined
    
    See Also:
    
    Constant Field Values
  - ERROR_BAD_TIMEOUT
```
public static final java.lang.String ERROR_BAD_TIMEOUT
```
    Error when invalid timeout value is defined
    
    See Also:
    
    Constant Field Values
  - ERROR_ON_NETWORK
```
public static final java.lang.String ERROR_ON_NETWORK
```
    Network error message is seen.
    
    See Also:
    
    Constant Field Values
  - ERROR_BOTH_TARGETS
```
public static final java.lang.String ERROR_BOTH_TARGETS
```
    Error message when url and host are specified.
    
    See Also:
    
    Constant Field Values
  - MSG_NO_REACHABLE_TEST
```
public static final java.lang.String MSG_NO_REACHABLE_TEST
```
    Error message when no reachably test avail.
    
    See Also:
    
    Constant Field Values
  - ERROR_BAD_URL
```
public static final java.lang.String ERROR_BAD_URL
```
    Error message when an invalid url is used.
    
    See Also:
    
    Constant Field Values
  - ERROR_NO_HOST_IN_URL
```
public static final java.lang.String ERROR_NO_HOST_IN_URL
```
    Error message when no hostname in url.
    
    See Also:
    
    Constant Field Values
  - METHOD_NAME
```
@Deprecated
public static final java.lang.String METHOD_NAME
```
    Deprecated. Since 1.9.14
    
    The method name to look for in InetAddress
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - IsReachable
```
public IsReachable()
```
- Method Detail
  - setHost
```
public void setHost(java.lang.String host)
```
    Set the host to ping.
    
    Parameters:
    
    host - the host to ping.
  - setUrl
```
public void setUrl(java.lang.String url)
```
    Set the URL from which to extract the hostname.
    
    Parameters:
    
    url - a URL object.
  - setTimeout
```
public void setTimeout(int timeout)
```
    Set the timeout for the reachability test in seconds.
    
    Parameters:
    
    timeout - the timeout in seconds.
  - eval
```
public boolean eval()
             throws BuildException
```
    Evaluate the condition.
    
    Specified by:
    
    eval in interface Condition
    
    Returns:
    
    true if the condition is true.
    
    Throws:
    
    BuildException - if an error occurs

Class IsReachable

Field Summary

Fields inherited from class org.apache.tools.ant.ProjectComponent

Constructor Summary

Method Summary

Methods inherited from class org.apache.tools.ant.ProjectComponent

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_TIMEOUT

ERROR_NO_HOSTNAME

ERROR_BAD_TIMEOUT

ERROR_ON_NETWORK

ERROR_BOTH_TARGETS

MSG_NO_REACHABLE_TEST

ERROR_BAD_URL

ERROR_NO_HOST_IN_URL

METHOD_NAME

Constructor Detail

IsReachable

Method Detail

setHost

setUrl

setTimeout

eval