FileHandler Class
Definition
Important
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Simple file logging Handler.
[Android.Runtime.Register("java/util/logging/FileHandler", DoNotGenerateAcw=true)]
public class FileHandler : Java.Util.Logging.StreamHandler[<Android.Runtime.Register("java/util/logging/FileHandler", DoNotGenerateAcw=true)>]
type FileHandler = class
inherit StreamHandler- Inheritance
- Attributes
Remarks
Simple file logging Handler.
The FileHandler can either write to a specified file, or it can write to a rotating set of files.
For a rotating set of files, as each file reaches a given size limit, it is closed, rotated out, and a new file opened. Successively older files are named by adding "0", "1", "2", etc. into the base filename.
By default buffering is enabled in the IO libraries but each log record is flushed out when it is complete.
By default the XMLFormatter class is used for formatting.
<b>Configuration:</b> By default each FileHandler is initialized using the following LogManager configuration properties where <handler-name> refers to the fully-qualified class name of the handler. If properties are not defined (or have invalid values) then the specified default values are used. <ul> <li> <handler-name>.level specifies the default level for the Handler (defaults to Level.ALL). </li> <li> <handler-name>.filter specifies the name of a Filter class to use (defaults to no Filter). </li> <li> <handler-name>.formatter specifies the name of a Formatter class to use (defaults to java.util.logging.XMLFormatter) </li> <li> <handler-name>.encoding the name of the character set encoding to use (defaults to the default platform encoding). </li> <li> <handler-name>.limit specifies an approximate maximum amount to write (in bytes) to any one file. If this is zero, then there is no limit. (Defaults to no limit). </li> <li> <handler-name>.count specifies how many output files to cycle through (defaults to 1). </li> <li> <handler-name>.pattern specifies a pattern for generating the output file name. See below for details. (Defaults to "%h/java%u.log"). </li> <li> <handler-name>.append specifies whether the FileHandler should append onto any existing files (defaults to false). </li> </ul>
For example, the properties for FileHandler would be: <ul> <li> java.util.logging.FileHandler.level=INFO </li> <li> java.util.logging.FileHandler.formatter=java.util.logging.SimpleFormatter </li> </ul>
For a custom handler, e.g. com.foo.MyHandler, the properties would be: <ul> <li> com.foo.MyHandler.level=INFO </li> <li> com.foo.MyHandler.formatter=java.util.logging.SimpleFormatter </li> </ul>
A pattern consists of a string that includes the following special components that will be replaced at runtime: <ul> <li> "/" the local pathname separator </li> <li> "%t" the system temporary directory </li> <li> "%h" the value of the "user.home" system property </li> <li> "%g" the generation number to distinguish rotated logs </li> <li> "%u" a unique number to resolve conflicts </li> <li> "%%" translates to a single percent sign "%" </li> </ul> If no "%g" field has been specified and the file count is greater than one, then the generation number will be added to the end of the generated filename, after a dot.
Thus for example a pattern of "%t/java%g.log" with a count of 2 would typically cause log files to be written on Solaris to /var/tmp/java0.log and /var/tmp/java1.log whereas on Windows 95 they would be typically written to C:\TEMP\java0.log and C:\TEMP\java1.log
Generation numbers follow the sequence 0, 1, 2, etc.
Normally the "%u" unique field is set to 0. However, if the FileHandler tries to open the filename and finds the file is currently in use by another process it will increment the unique number field and try again. This will be repeated until FileHandler finds a file name that is not currently in use. If there is a conflict and no "%u" field has been specified, it will be added at the end of the filename after a dot. (This will be after any automatically added generation number.)
Thus if three processes were all trying to log to fred%u.%g.txt then they might end up using fred0.0.txt, fred1.0.txt, fred2.0.txt as the first file in their rotating sequences.
Note that the use of unique ids to avoid conflicts is only guaranteed to work reliably when using a local disk file system.
Added in 1.4.
Java documentation for java.util.logging.FileHandler.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.
Constructors
| FileHandler() |
Construct a default |
| FileHandler(IntPtr, JniHandleOwnership) |
A constructor used when creating managed representations of JNI objects; called by the runtime. |
| FileHandler(String, Boolean) |
Initialize a |
| FileHandler(String, Int32, Int32, Boolean) |
Initialize a |
| FileHandler(String, Int32, Int32) |
Initialize a |
| FileHandler(String) |
Initialize a |
Properties
| Class |
Returns the runtime class of this |
| Encoding |
Return the character encoding for this |
| ErrorManager |
Retrieves the ErrorManager for this Handler. -or- Define an ErrorManager for this Handler. (Inherited from Handler) |
| Filter |
Get the current |
| Formatter |
Return the |
| Handle |
The handle to the underlying Android instance. (Inherited from Object) |
| JniIdentityHashCode | (Inherited from Object) |
| JniPeerMembers | |
| Level |
Get the log level specifying which messages will be
logged by this |
| PeerReference | (Inherited from Object) |
| ThresholdClass |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
| ThresholdType |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
Methods
| Clone() |
Creates and returns a copy of this object. (Inherited from Object) |
| Close() |
Close the current output stream. (Inherited from StreamHandler) |
| Dispose() | (Inherited from Object) |
| Dispose(Boolean) | (Inherited from Object) |
| Equals(Object) |
Indicates whether some other object is "equal to" this one. (Inherited from Object) |
| Flush() |
Flush any buffered messages. (Inherited from StreamHandler) |
| GetHashCode() |
Returns a hash code value for the object. (Inherited from Object) |
| IsLoggable(LogRecord) |
Check if this |
| JavaFinalize() |
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object) |
| Notify() |
Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object) |
| NotifyAll() |
Wakes up all threads that are waiting on this object's monitor. (Inherited from Object) |
| Publish(LogRecord) |
Format and publish a |
| ReportError(String, Exception, Int32) |
Protected convenience method to report an error to this Handler's ErrorManager. (Inherited from Handler) |
| SetHandle(IntPtr, JniHandleOwnership) |
Sets the Handle property. (Inherited from Object) |
| SetOutputStream(Stream) |
Change the output stream. (Inherited from StreamHandler) |
| ToArray<T>() | (Inherited from Object) |
| ToString() |
Returns a string representation of the object. (Inherited from Object) |
| UnregisterFromRuntime() | (Inherited from Object) |
| Wait() |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object) |
| Wait(Int64, Int32) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
| Wait(Int64) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
Explicit Interface Implementations
| IJavaPeerable.Disposed() | (Inherited from Object) |
| IJavaPeerable.DisposeUnlessReferenced() | (Inherited from Object) |
| IJavaPeerable.Finalized() | (Inherited from Object) |
| IJavaPeerable.JniManagedPeerState | (Inherited from Object) |
| IJavaPeerable.SetJniIdentityHashCode(Int32) | (Inherited from Object) |
| IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates) | (Inherited from Object) |
| IJavaPeerable.SetPeerReference(JniObjectReference) | (Inherited from Object) |
Extension Methods
| JavaCast<TResult>(IJavaObject) |
Performs an Android runtime-checked type conversion. |
| JavaCast<TResult>(IJavaObject) | |
| GetJniTypeName(IJavaPeerable) | |