# SystemProperty
Date: 2012-02-24

## com.google.appengine.api.utils
Class SystemProperty

    java.lang.Object
      com.google.appengine.api.utils.SystemProperty

Direct Known Subclasses:
  SystemProperty.Environment

    public class SystemProperty

extends java.lang.Object

Global system properties which are set by App Engine.

Example code:

     if (SystemProperty.environment.value() == SystemProperty.Environment.Value.Production) {
       // do something that's production-only
     }
     String version = SystemProperty.version.get();

Nested Class Summary
`static class` `SystemProperty.Environment` The current executing environment.

Field Summary
`static SystemProperty` `applicationId` The application identifier for the current application.
`static SystemProperty` `applicationVersion` The major version number for the currently running version of the application plus a timestamp at which it was deployed.
`static SystemProperty.Environment` `environment` The current executing environment.
`static SystemProperty` `instanceReplicaId` Deprecated. Use `com.google.appengine.api.servers.ServerService#getCurrentInstance()`
`static SystemProperty` `version` The current executing runtime version.

Method Summary
`java.lang.String` `get()` Gets the value of the system property.
`java.lang.String` `key()` The key for the system property.
`void` `set(java.lang.String value)` Sets the value of the system property.

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

Field Detail

### environment

    public static final SystemProperty.Environment environment

  The current executing environment. Has the key, `"com.google.appengine.runtime.environment"`. Has the values `"Production"` and `"Development"`.

### version

    public static final SystemProperty version

  The current executing runtime version. Has the key, `"com.google.appengine.runtime.version"`. A Version value is composed of period-separated integers, for example, "1.2.8".

### applicationId

    public static final SystemProperty applicationId

  The application identifier for the current application. Has the key, `"com.google.appengine.application.id"`.

### applicationVersion

    public static final SystemProperty applicationVersion

  The major version number for the currently running version of the application plus a timestamp at which it was deployed. Has the key, `"com.google.appengine.application.version"`.

### instanceReplicaId

    @Deprecated
    public static final SystemProperty instanceReplicaId

  Deprecated. Use `com.google.appengine.api.servers.ServerService#getCurrentInstance()`

Method Detail

### key

    public java.lang.String key()

  The key for the system property.

### get

    public java.lang.String get()

  Gets the value of the system property. Equivalent to `System.getProperty(key())`.

### set

    public void set(java.lang.String value)

  Sets the value of the system property. Equivalent to `System.setProperty(key(), value)`.