com.sun.mail.util.logging

Class MailHandler

java.lang.Object

java.util.logging.Handler

com.sun.mail.util.logging.MailHandler

public class MailHandler
extends java.util.logging.Handler

Handler that formats log records as an email message.

This Handler will store a fixed number of log records used to generate a single email message. When the internal buffer reaches capacity, all log records are formatted and placed in an email which is sent to an email server. The code to manually setup this handler can be as simple as the following:

      Properties props = new Properties();
      props.put("mail.smtp.host", "my-mail-server");
      props.put("mail.to", "me@example.com");
      props.put("verify", "local");
      MailHandler h = new MailHandler(props);
      h.setLevel(Level.WARNING);
 

Configuration: The LogManager should define at least one or more recipient addresses and a mail host for outgoing email. The code to setup this handler via the logging properties can be as simple as the following:

      #Default MailHandler settings.
      com.sun.mail.util.logging.MailHandler.mail.smtp.host = my-mail-server
      com.sun.mail.util.logging.MailHandler.mail.to = me@example.com
      com.sun.mail.util.logging.MailHandler.level = WARNING
      com.sun.mail.util.logging.MailHandler.verify = local
 

For a custom handler, e.g. com.foo.MyHandler, the properties would be:

      #Subclass com.foo.MyHandler settings.
      com.foo.MyHandler.mail.smtp.host = my-mail-server
      com.foo.MyHandler.mail.to = me@example.com
      com.foo.MyHandler.level = WARNING
      com.foo.MyHandler.verify = local
 

All mail properties documented in the Java Mail API cascade to the LogManager by prefixing a key using the fully qualified class name of this MailHandler or the fully qualified derived class name dot mail property. If the prefixed property is not found, then the mail property itself is searched in the LogManager. By default each MailHandler is initialized using the following LogManager configuration properties where refers to the fully-qualified class name of the handler. If properties are not defined, or contain invalid values, then the specified default values are used.

• <handler-name>.attachment.filters a comma separated list of Filter class names used to create each attachment. The literal null is reserved for attachments that do not require filtering. (default is no filters)
• <handler-name>.attachment.formatters a comma separated list of Formatter class names used to create each attachment. (default is no attachments)
• <handler-name>.attachment.names a comma separated list of names or Formatter class names of each attachment. The attachment file names must not contain any line breaks. (default is no attachments names)
• <handler-name>.authenticator name of an javax.mail.Authenticator class used to provide login credentials to the email server or string literal that is the password used with the default user name. (default is null)
• <handler-name>.capacity the max number of LogRecord objects include in each email message. (defaults to 1000)
• <handler-name>.comparator name of a Comparator class used to sort the published LogRecord objects prior to all formatting. (defaults to null meaning records are unsorted).
• <handler-name>.comparator.reverse a boolean true to reverse the order of the specified comparator or false to retain the original order. (defaults to false)
• <handler-name>.encoding the name of the Java character set to use for the email message. (defaults to null, the default platform encoding).
• <handler-name>.errorManager name of an ErrorManager class used to handle any configuration or mail transport problems. (defaults to java.util.logging.ErrorManager)
• <handler-name>.filter name of a Filter class used for the body of the message. (defaults to null, allow all records)
• <handler-name>.formatter name of a Formatter class used to format the body of this message. (defaults to java.util.logging.SimpleFormatter)
• <handler-name>.level specifies the default level for this Handler (defaults to Level.WARNING).
• <handler-name>.mail.bcc a comma separated list of addresses which will be blind carbon copied. Typically, this is set to the recipients that may need to be privately notified of a log message or notified that a log message was sent to a third party such as a support team. The empty string can be used to specify no blind carbon copied address. (defaults to null, none)
• <handler-name>.mail.cc a comma separated list of addresses which will be carbon copied. Typically, this is set to the recipients that may need to be notified of a log message but, are not required to provide direct support. The empty string can be used to specify no carbon copied address. (defaults to null, none)
• <handler-name>.mail.from a comma separated list of addresses which will be from addresses. Typically, this is set to the email address identifying the user running the application. The empty string can be used to override the default behavior and specify no from address. (defaults to the local address)
• <handler-name>.mail.host the host name or IP address of the email server. (defaults to null, use default Java Mail behavior)
• <handler-name>.mail.reply.to a comma separated list of addresses which will be reply-to addresses. Typically, this is set to the recipients that provide support for the application itself. The empty string can be used to specify no reply-to address. (defaults to null, none)
• <handler-name>.mail.to a comma separated list of addresses which will be send-to addresses. Typically, this is set to the recipients that provide support for the application, system, and/or supporting infrastructure. The empty string can be used to specify no send-to address which overrides the default behavior. (defaults to local address.)
• <handler-name>.mail.sender a single address identifying sender of the email; never equal to the from address. Typically, this is set to the email address identifying the application itself. The empty string can be used to specify no sender address. (defaults to null, none)
• <handler-name>.subject the name of a Formatter class or string literal used to create the subject line. The empty string can be used to specify no subject. The subject line must not contain any line breaks. (defaults to the empty string)
• <handler-name>.pushFilter the name of a Filter class used to trigger an early push. (defaults to null, no early push)
• <handler-name>.pushLevel the level which will trigger an early push. (defaults to Level.OFF, only push when full)
• <handler-name>.verify used to verify all of the Handler properties prior to a push. If set to a value of limited then the Handler will verify minimal local machine settings. If set to a value of local the Handler will verify all of settings of the local machine. If set to a value of remote, the Handler will verify all local settings and try to establish a connection with the email server. If the value is not set, equal to an empty string, or equal to the literal null then no settings are verified prior to a push. If this Handler is only implicitly closed by the LogManager, then verification should be turned on. (defaults to null, no verify).

  Normalization: The error manager, filters, and formatters when loaded from the LogManager are converted into canonical form inside the MailHandler. The pool of interned values is limited to each MailHandler object such that no two MailHandler objects created by the LogManager will be created sharing identical error managers, filters, or formatters. If a filter or formatter should not be interned then it is recommended to retain the identity equals and identity hashCode methods as the implementation. For a filter or formatter to be interned the class must implement the equals and hashCode methods. The recommended code to use for stateless filters and formatters is:

   public boolean equals(Object obj) {
       return obj == null ? false : obj.getClass() == getClass();
   }
  
   public int hashCode() {
       return 31 * getClass().hashCode();
   }
   

  Sorting: All LogRecord objects are ordered prior to formatting if this Handler has a non null comparator. Developers might be interested in sorting the formatted email by thread id, time, and sequence properties of a LogRecord. Where as system administrators might be interested in sorting the formatted email by thrown, level, time, and sequence properties of a LogRecord. If comparator for this handler is null then the order is unspecified.

  Formatting: The main message body is formatted using the Formatter returned by getFormatter(). Only records that pass the filter returned by getFilter() will be included in the message body. The subject Formatter will see all LogRecord objects that were published regardless of the current Filter. The MIME type of the message body can be overridden by adding a MIME entry using the simple class name of the body formatter as the file extension. The MIME type of the attachments can be overridden by changing the attachment file name extension or by editing the default MIME entry for a specific file name extension.

  Attachments: This Handler allows multiple attachments per each email. The attachment order maps directly to the array index order in this Handler with zero index being the first attachment. The number of attachment formatters controls the number of attachments per email and the content type of each attachment. The attachment filters determine if a LogRecord will be included in an attachment. If an attachment filter is null then all records are included for that attachment. Attachments without content will be omitted from email message. The attachment name formatters create the file name for an attachment. Custom attachment name formatters can be used to generate an attachment name based on the contents of the attachment.

  Push Level and Push Filter: The push method, push level, and optional push filter can be used to conditionally trigger a push at or prior to full capacity. When a push occurs, the current buffer is formatted into an email and is sent to the email server. If the push method, push level, or push filter trigger a push then the outgoing email is flagged as high importance with urgent priority.

  Buffering: Log records that are published are stored in an internal buffer. When this buffer reaches capacity the existing records are formatted and sent in an email. Any published records can be sent before reaching capacity by explictly calling the flush, push, or close methods. If a circular buffer is required then this handler can be wrapped with a MemoryHandler typically with an equivalent capacity, level, and push level.

  Error Handling: If the transport of an email message fails, the email is converted to a raw string and is then passed as the msg parameter to reportError along with the exception describing the cause of the failure. This allows custom error managers to store, reconstruct, and resend the original MimeMessage. The message parameter string is not a raw email if it starts with value returned from Level.SEVERE.getName(). Custom error managers can use the following test to determine if the msg parameter from this handler is a raw email:

   public void error(String msg, Exception ex, int code) {
        if (msg == null || msg.length() == 0 || msg.startsWith(Level.SEVERE.getName())) {
            super.error(msg, ex, code);
        } else {
            //The 'msg' parameter is a raw email.
        }
   }
   

Since:

JavaMail 1.4.3

Constructor Summary

Constructors

Constructor and Description
MailHandler() Creates a MailHandler that is configured by the LogManager configuration properties.
MailHandler(int capacity) Creates a MailHandler that is configured by the LogManager configuration properties but overrides the LogManager capacity with the given capacity.
MailHandler(java.util.Properties props) Creates a mail handler with the given mail properties.

Method Summary

Modifier and Type	Method and Description
void	close() Prevents any other records from being published.
void	flush() Pushes any buffered records to the email server as normal priority.
java.util.logging.Filter[]	getAttachmentFilters() Gets the attachment filters.
java.util.logging.Formatter[]	getAttachmentFormatters() Gets the attachment formatters.
java.util.logging.Formatter[]	getAttachmentNames() Gets the attachment name formatters.
Authenticator	getAuthenticator() Gets the Authenticator used to login to the email server.
int	getCapacity() Gets the number of log records the internal buffer can hold.
java.util.Comparator<? super java.util.logging.LogRecord>	getComparator() Gets the comparator used to order all LogRecord objects prior to formatting.
java.util.Properties	getMailProperties() Gets a copy of the mail properties used for the session.
java.util.logging.Filter	getPushFilter() Gets the push filter.
java.util.logging.Level	getPushLevel() Gets the push level.
java.util.logging.Formatter	getSubject() Gets the formatter used to create the subject line.
boolean	isLoggable(java.util.logging.LogRecord record) Check if this Handler would actually log a given LogRecord into its internal buffer.
void	publish(java.util.logging.LogRecord record) Stores a LogRecord in the internal buffer.
void	push() Pushes any buffered records to the email server as high importance with urgent priority.
void	setAttachmentFilters(java.util.logging.Filter... filters) Sets the attachment filters.
void	setAttachmentFormatters(java.util.logging.Formatter... formatters) Sets the attachment Formatter object for this handler.
void	setAttachmentNames(java.util.logging.Formatter... formatters) Sets the attachment file name formatters.
void	setAttachmentNames(java.lang.String... names) Sets the attachment file name for each attachment.
void	setAuthenticator(Authenticator auth) Sets the Authenticator used to login to the email server.
void	setAuthenticator(char... password) Sets the Authenticator used to login to the email server.
void	setComparator(java.util.Comparator<? super java.util.logging.LogRecord> c) Sets the comparator used to order all LogRecord objects prior to formatting.
void	setLevel(java.util.logging.Level newLevel) Set the log level specifying which message levels will be logged by this Handler.
void	setMailProperties(java.util.Properties props) Sets the mail properties used for the session.
void	setPushFilter(java.util.logging.Filter filter) Sets the push filter.
void	setPushLevel(java.util.logging.Level level) Sets the push level.
void	setSubject(java.util.logging.Formatter format) Sets the subject formatter for email.
void	setSubject(java.lang.String subject) Sets a literal string for the email subject.

Methods inherited from class java.util.logging.Handler

getEncoding, getErrorManager, getFilter, getFormatter, getLevel, setEncoding, setErrorManager, setFilter, setFormatter

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MailHandler

public MailHandler()

Creates a MailHandler that is configured by the LogManager configuration properties.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

MailHandler

public MailHandler(int capacity)

Creates a MailHandler that is configured by the LogManager configuration properties but overrides the LogManager capacity with the given capacity.

Parameters:

capacity - of the internal buffer.

Throws:

java.lang.IllegalArgumentException - if capacity less than one.

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

MailHandler

public MailHandler(java.util.Properties props)

Creates a mail handler with the given mail properties. The key/value pairs are defined in the Java Mail API documentation. This Handler will also search the LogManager for defaults if needed.

Parameters:

props - a non null properties object.

Throws:

java.lang.NullPointerException - if props is null.

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

Method Detail

isLoggable

public boolean isLoggable(java.util.logging.LogRecord record)

Check if this Handler would actually log a given LogRecord into its internal buffer.

This method checks if the LogRecord has an appropriate level and whether it satisfies any Filter including any attachment filters. However it does not check whether the LogRecord would result in a "push" of the buffer contents.

Overrides:

isLoggable in class java.util.logging.Handler

Parameters:

record - a LogRecord

Returns:

true if the LogRecord would be logged.

publish

public void publish(java.util.logging.LogRecord record)

Stores a LogRecord in the internal buffer.

The isLoggable method is called to check if the given log record is loggable. If the given record is loggable, it is copied into an internal buffer. Then the record's level property is compared with the push level. If the given level of the LogRecord is greater than or equal to the push level then the push filter is called. If no push filter exists, the push filter returns true, or the capacity of the internal buffer has been reached then all buffered records are formatted into one email and sent to the server.

Specified by:

publish in class java.util.logging.Handler

Parameters:

record - description of the log event.

push

public void push()

Pushes any buffered records to the email server as high importance with urgent priority. The internal buffer is then cleared. Does nothing if called from inside a push.

See Also:

flush()

flush

public void flush()

Pushes any buffered records to the email server as normal priority. The internal buffer is then cleared. Does nothing if called from inside a push.

Specified by:

flush in class java.util.logging.Handler

See Also:

push()

close

public void close()

Prevents any other records from being published. Pushes any buffered records to the email server as normal priority. The internal buffer is then cleared. Once this handler is closed it will remain closed.

If this Handler is only implicitly closed by the LogManager, then verification should be turned on.

Specified by:

close in class java.util.logging.Handler

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

See Also:

flush()

setLevel

public void setLevel(java.util.logging.Level newLevel)

Set the log level specifying which message levels will be logged by this Handler. Message levels lower than this value will be discarded.

Overrides:

setLevel in class java.util.logging.Handler

Parameters:

newLevel - the new value for the log level

Throws:

java.lang.NullPointerException - if newLevel is null.

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

getPushLevel

public final java.util.logging.Level getPushLevel()

Gets the push level. The default is Level.OFF meaning that this Handler will only push when the internal buffer is full.

Returns:

the push level.

setPushLevel

public final void setPushLevel(java.util.logging.Level level)

Sets the push level. This level is used to trigger a push so that all pending records are formatted and sent to the email server. When the push level triggers a send, the resulting email is flagged as high importance with urgent priority.

Parameters:

level - Level object.

Throws:

java.lang.NullPointerException - if level is null.

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.IllegalStateException - if called from inside a push.

getPushFilter

public final java.util.logging.Filter getPushFilter()

Gets the push filter. The default is null.

Returns:

the push filter or null.

setPushFilter

public final void setPushFilter(java.util.logging.Filter filter)

Sets the push filter. This filter is only called if the given LogRecord level was greater than the push level. If this filter returns true, all pending records are formatted and sent to the email server. When the push filter triggers a send, the resulting email is flagged as high importance with urgent priority.

Parameters:

filter - push filter or null

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.IllegalStateException - if called from inside a push.

getComparator

public final java.util.Comparator<? super java.util.logging.LogRecord> getComparator()

Gets the comparator used to order all LogRecord objects prior to formatting. If null then the order is unspecified.

Returns:

the LogRecord comparator.

setComparator

public final void setComparator(java.util.Comparator<? super java.util.logging.LogRecord> c)

Sets the comparator used to order all LogRecord objects prior to formatting. If null then the order is unspecified.

Parameters:

c - the LogRecord comparator.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.IllegalStateException - if called from inside a push.

getCapacity

public final int getCapacity()

Gets the number of log records the internal buffer can hold. When capacity is reached, Handler will format all LogRecord objects into one email message.

Returns:

the capacity.

getAuthenticator

public final Authenticator getAuthenticator()

Gets the Authenticator used to login to the email server.

Returns:

an Authenticator or null if none is required.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

setAuthenticator

public final void setAuthenticator(Authenticator auth)

Sets the Authenticator used to login to the email server.

Parameters:

auth - an Authenticator object or null if none is required.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.IllegalStateException - if called from inside a push.

setAuthenticator

public final void setAuthenticator(char... password)

Sets the Authenticator used to login to the email server.

Parameters:

password - a password or null if none is required.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.IllegalStateException - if called from inside a push.

Since:

JavaMail 1.4.6

See Also:

String.toCharArray()

setMailProperties

public final void setMailProperties(java.util.Properties props)

Sets the mail properties used for the session. The key/value pairs are defined in the Java Mail API documentation. This Handler will also search the LogManager for defaults if needed.

Parameters:

props - a non null properties object.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.NullPointerException - if props is null.

java.lang.IllegalStateException - if called from inside a push.

getMailProperties

public final java.util.Properties getMailProperties()

Gets a copy of the mail properties used for the session.

Returns:

a non null properties object.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

getAttachmentFilters

public final java.util.logging.Filter[] getAttachmentFilters()

Gets the attachment filters. If the attachment filter does not allow any LogRecord to be formatted, the attachment may be omitted from the email.

Returns:

a non null array of attachment filters.

setAttachmentFilters

public final void setAttachmentFilters(java.util.logging.Filter... filters)

Sets the attachment filters.

Parameters:

filters - a non null array of filters. A null index value is allowed. A null value means that all records are allowed for the attachment at that index.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.NullPointerException - if filters is null

java.lang.IndexOutOfBoundsException - if the number of attachment name formatters do not match the number of attachment formatters.

java.lang.IllegalStateException - if called from inside a push.

getAttachmentFormatters

public final java.util.logging.Formatter[] getAttachmentFormatters()

Gets the attachment formatters. This Handler is using attachments only if the returned array length is non zero.

Returns:

a non null array of formatters.

setAttachmentFormatters

public final void setAttachmentFormatters(java.util.logging.Formatter... formatters)

Sets the attachment Formatter object for this handler. The number of formatters determines the number of attachments per email. This method should be the first attachment method called. To remove all attachments, call this method with empty array.

Parameters:

formatters - a non null array of formatters.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.NullPointerException - if the given array or any array index is null.

java.lang.IllegalStateException - if called from inside a push.

getAttachmentNames

public final java.util.logging.Formatter[] getAttachmentNames()

Gets the attachment name formatters. If the attachment names were set using explicit names then the names can be returned by calling toString on each attachment name formatter.

Returns:

non null array of attachment name formatters.

setAttachmentNames

public final void setAttachmentNames(java.lang.String... names)

Sets the attachment file name for each attachment. The caller must ensure that the attachment file names do not contain any line breaks. This method will create a set of custom formatters.

Parameters:

names - an array of names.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.IndexOutOfBoundsException - if the number of attachment names do not match the number of attachment formatters.

java.lang.IllegalArgumentException - if any name is empty.

java.lang.NullPointerException - if any given array or name is null.

java.lang.IllegalStateException - if called from inside a push.

See Also:

Character.isISOControl(char), Character.isISOControl(int)

setAttachmentNames

public final void setAttachmentNames(java.util.logging.Formatter... formatters)

Sets the attachment file name formatters. The format method of each attachment formatter will see only the LogRecord objects that passed its attachment filter during formatting. The format method will typically return an empty string. Instead of being used to format records, it is used to gather information about the contents of an attachment. The getTail method should be used to construct the attachment file name and reset any formatter collected state. The formatter must ensure that the attachment file name does not contain any line breaks. The toString method of the given formatter should be overridden to provide a useful attachment file name, if possible.

Parameters:

formatters - and array of attachment name formatters.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.IndexOutOfBoundsException - if the number of attachment name formatters do not match the number of attachment formatters.

java.lang.NullPointerException - if any given array or name is null.

java.lang.IllegalStateException - if called from inside a push.

See Also:

Character.isISOControl(char), Character.isISOControl(int)

getSubject

public final java.util.logging.Formatter getSubject()

Gets the formatter used to create the subject line. If the subject was created using a literal string then the toString method can be used to get the subject line.

Returns:

the formatter.

setSubject

public final void setSubject(java.lang.String subject)

Sets a literal string for the email subject. The caller must ensure that the subject line does not contain any line breaks.

Parameters:

subject - a non null string.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.NullPointerException - if subject is null.

java.lang.IllegalStateException - if called from inside a push.

See Also:

Character.isISOControl(char), Character.isISOControl(int)

setSubject

public final void setSubject(java.util.logging.Formatter format)

Sets the subject formatter for email. The format method of the subject formatter will see all LogRecord objects that were published to this Handler during formatting and will typically return an empty string. This formatter is used to gather information to create a summary about what information is contained in the email. The getTail method should be used to construct the subject and reset any formatter collected state. The formatter must ensure that the subject line does not contain any line breaks. The toString method of the given formatter should be overridden to provide a useful subject, if possible.

Parameters:

format - the subject formatter.

Throws:

java.lang.SecurityException - if a security manager exists and the caller does not have LoggingPermission("control").

java.lang.NullPointerException - if format is null.

java.lang.IllegalStateException - if called from inside a push.

See Also:

Character.isISOControl(char), Character.isISOControl(int)