Host (Apache Tomcat 8.0.53 API Documentation)

All Superinterfaces:

Container, Lifecycle

All Known Implementing Classes:

StandardHost
```
public interface Host
extends Container
```
A Host is a Container that represents a virtual host in the Catalina servlet engine. It is useful in the following types of scenarios:
- You wish to use Interceptors that see every single request processed by this particular virtual host.
- You wish to run Catalina in with a standalone HTTP connector, but still want support for multiple virtual hosts.
In general, you would not use a Host when deploying Catalina connected to a web server (such as Apache), because the Connector will have utilized the web server's facilities to determine which Context (or perhaps even which Wrapper) should be utilized to process this request.
The parent Container attached to a Host is generally an Engine, but may be some other implementation, or may be omitted if it is not necessary.
The child containers attached to a Host are generally implementations of Context (representing an individual servlet context).
Author:

Craig R. McClanahan

Nested Class Summary
- Nested classes/interfaces inherited from interface org.apache.catalina.Lifecycle
  Lifecycle.SingleUse

Field Summary

Fields
Modifier and Type	Field and Description
`static java.lang.String`	`ADD_ALIAS_EVENT` The ContainerEvent event type sent when a new alias is added by `addAlias()`.
`static java.lang.String`	`REMOVE_ALIAS_EVENT` The ContainerEvent event type sent when an old alias is removed by `removeAlias()`.

Fields inherited from interface org.apache.catalina.Container
ADD_CHILD_EVENT, ADD_VALVE_EVENT, REMOVE_CHILD_EVENT, REMOVE_VALVE_EVENT

Fields inherited from interface org.apache.catalina.Lifecycle
AFTER_DESTROY_EVENT, AFTER_INIT_EVENT, AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_DESTROY_EVENT, BEFORE_INIT_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addAlias(java.lang.String alias)` Add an alias name that should be mapped to this same Host.
`java.lang.String[]`	`findAliases()` Return the set of alias names for this Host.
`java.lang.String`	`getAppBase()` Return the application root for this Host.
`java.io.File`	`getAppBaseFile()` Return an absolute `File` for the appBase of this Host.
`boolean`	`getAutoDeploy()` Return the value of the auto deploy flag.
`java.io.File`	`getConfigBaseFile()` Return a default configuration path of this Host.
`java.lang.String`	`getConfigClass()` Return the Java class name of the context configuration class for new web applications.
`boolean`	`getCreateDirs()` Returns true if the Host will attempt to create directories for appBase and xmlBase unless they already exist.
`java.lang.String`	`getDeployIgnore()` Return the regular expression that defines the files and directories in the host's appBase that will be ignored by the automatic deployment process.
`java.util.regex.Pattern`	`getDeployIgnorePattern()` Return the compiled regular expression that defines the files and directories in the host's appBase that will be ignored by the automatic deployment process.
`boolean`	`getDeployOnStartup()` Return the value of the deploy on startup flag.
`java.util.concurrent.ExecutorService`	`getStartStopExecutor()` Return the executor that is used for starting and stopping contexts.
`boolean`	`getUndeployOldVersions()` Returns true of the Host is configured to automatically undeploy old versions of applications deployed using parallel deployment.
`java.lang.String`	`getXmlBase()` Return the XML root for this Host.
`void`	`removeAlias(java.lang.String alias)` Remove the specified alias name from the aliases for this Host.
`void`	`setAppBase(java.lang.String appBase)` Set the application root for this Host.
`void`	`setAutoDeploy(boolean autoDeploy)` Set the auto deploy flag value for this host.
`void`	`setConfigClass(java.lang.String configClass)` Set the Java class name of the context configuration class for new web applications.
`void`	`setCreateDirs(boolean createDirs)` Should the Host attempt to create directories for xmlBase and appBase upon startup.
`void`	`setDeployIgnore(java.lang.String deployIgnore)` Set the regular expression that defines the files and directories in the host's appBase that will be ignored by the automatic deployment process.
`void`	`setDeployOnStartup(boolean deployOnStartup)` Set the deploy on startup flag value for this host.
`void`	`setUndeployOldVersions(boolean undeployOldVersions)` Set to true if the Host should automatically undeploy old versions of applications deployed using parallel deployment.
`void`	`setXmlBase(java.lang.String xmlBase)` Set the Xml root for this Host.

Methods inherited from interface org.apache.catalina.Lifecycle
addLifecycleListener, destroy, findLifecycleListeners, getState, getStateName, init, removeLifecycleListener, start, stop

- Field Detail
  - ADD_ALIAS_EVENT
```
static final java.lang.String ADD_ALIAS_EVENT
```
    The ContainerEvent event type sent when a new alias is added by addAlias().
    
    See Also:
    Constant Field Values
  - REMOVE_ALIAS_EVENT
```
static final java.lang.String REMOVE_ALIAS_EVENT
```
    The ContainerEvent event type sent when an old alias is removed by removeAlias().
    
    See Also:
    Constant Field Values
- Method Detail
  - getXmlBase
```
java.lang.String getXmlBase()
```
    Return the XML root for this Host. This can be an absolute pathname, a relative pathname, or a URL. If null, defaults to ${catalina.base}/conf/<engine name>/<host name> directory
  - setXmlBase
```
void setXmlBase(java.lang.String xmlBase)
```
    Set the Xml root for this Host. This can be an absolute pathname, a relative pathname, or a URL. If null, defaults to ${catalina.base}/conf/<engine name>/<host name> directory
    
    Parameters:
    xmlBase - The new XML root
  - getConfigBaseFile
```
java.io.File getConfigBaseFile()
```
    Return a default configuration path of this Host. The file will be canonical if possible.
  - getAppBase
```
java.lang.String getAppBase()
```
    Return the application root for this Host. This can be an absolute pathname, a relative pathname, or a URL.
  - getAppBaseFile
```
java.io.File getAppBaseFile()
```
    Return an absolute File for the appBase of this Host. The file will be canonical if possible. There is no guarantee that that the appBase exists.
  - setAppBase
```
void setAppBase(java.lang.String appBase)
```
    Set the application root for this Host. This can be an absolute pathname, a relative pathname, or a URL.
    
    Parameters:
    appBase - The new application root
  - getAutoDeploy
```
boolean getAutoDeploy()
```
    Return the value of the auto deploy flag. If true, it indicates that this host's child webapps should be discovered and automatically deployed dynamically.
  - setAutoDeploy
```
void setAutoDeploy(boolean autoDeploy)
```
    Set the auto deploy flag value for this host.
    
    Parameters:
    autoDeploy - The new auto deploy flag
  - getConfigClass
```
java.lang.String getConfigClass()
```
    Return the Java class name of the context configuration class for new web applications.
  - setConfigClass
```
void setConfigClass(java.lang.String configClass)
```
    Set the Java class name of the context configuration class for new web applications.
    
    Parameters:
    configClass - The new context configuration class
  - getDeployOnStartup
```
boolean getDeployOnStartup()
```
    Return the value of the deploy on startup flag. If true, it indicates that this host's child webapps should be discovered and automatically deployed.
  - setDeployOnStartup
```
void setDeployOnStartup(boolean deployOnStartup)
```
    Set the deploy on startup flag value for this host.
    
    Parameters:
    deployOnStartup - The new deploy on startup flag
  - getDeployIgnore
```
java.lang.String getDeployIgnore()
```
    Return the regular expression that defines the files and directories in the host's appBase that will be ignored by the automatic deployment process.
  - getDeployIgnorePattern
```
java.util.regex.Pattern getDeployIgnorePattern()
```
    Return the compiled regular expression that defines the files and directories in the host's appBase that will be ignored by the automatic deployment process.
  - setDeployIgnore
```
void setDeployIgnore(java.lang.String deployIgnore)
```
    Set the regular expression that defines the files and directories in the host's appBase that will be ignored by the automatic deployment process.
  - getStartStopExecutor
```
java.util.concurrent.ExecutorService getStartStopExecutor()
```
    Return the executor that is used for starting and stopping contexts. This is primarily for use by components deploying contexts that want to do this in a multi-threaded manner.
  - getCreateDirs
```
boolean getCreateDirs()
```
    Returns true if the Host will attempt to create directories for appBase and xmlBase unless they already exist.
    
    Returns:
    true if the Host will attempt to create directories
  - setCreateDirs
```
void setCreateDirs(boolean createDirs)
```
    Should the Host attempt to create directories for xmlBase and appBase upon startup.
    
    Parameters:
    createDirs - The new value for this flag
  - getUndeployOldVersions
```
boolean getUndeployOldVersions()
```
    Returns true of the Host is configured to automatically undeploy old versions of applications deployed using parallel deployment. This only takes effect is getAutoDeploy() also returns true.
  - setUndeployOldVersions
```
void setUndeployOldVersions(boolean undeployOldVersions)
```
    Set to true if the Host should automatically undeploy old versions of applications deployed using parallel deployment. This only takes effect if getAutoDeploy() returns true.
  - addAlias
```
void addAlias(java.lang.String alias)
```
    Add an alias name that should be mapped to this same Host.
    
    Parameters:
    alias - The alias to be added
  - findAliases
```
java.lang.String[] findAliases()
```
    Return the set of alias names for this Host. If none are defined, a zero length array is returned.
  - removeAlias
```
void removeAlias(java.lang.String alias)
```
    Remove the specified alias name from the aliases for this Host.
    
    Parameters:
    alias - Alias name to be removed

Interface Host

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.catalina.Lifecycle

Field Summary

Fields inherited from interface org.apache.catalina.Container

Fields inherited from interface org.apache.catalina.Lifecycle

Method Summary

Methods inherited from interface org.apache.catalina.Container

Methods inherited from interface org.apache.catalina.Lifecycle

Field Detail

ADD_ALIAS_EVENT

REMOVE_ALIAS_EVENT

Method Detail

getXmlBase

setXmlBase

getConfigBaseFile

getAppBase

getAppBaseFile

setAppBase

getAutoDeploy

setAutoDeploy

getConfigClass

setConfigClass

getDeployOnStartup

setDeployOnStartup

getDeployIgnore

getDeployIgnorePattern

setDeployIgnore

getStartStopExecutor

getCreateDirs

setCreateDirs

getUndeployOldVersions

setUndeployOldVersions

addAlias

findAliases

removeAlias