SLF4JDelegatingLog (JULI-to-SLF4J Library 1.1.1 API)

java.lang.Object
- org.apache.juli.logging.impl.SLF4JDelegatingLog

All Implemented Interfaces:

Serializable, org.apache.juli.logging.Log
```
public class SLF4JDelegatingLog
extends Object
implements org.apache.juli.logging.Log, Serializable
```
A Log facade that can be plugged into the default Tomcat JULI logging system, and supports the SLF4J API to be on Tomcat system classpath and the SLF4J implementation to be on Tomcat common classpath.
The only supported SLF4J (backend) implementation is Logback.
This facade delegates to SeparateLogbackSupport the task of automatically bootstrapping Logback at the right time. For this bootstrap to run properly in multi-thraded environments, a global lock on this SLF4JDelegatingLog class is used.
The logging behaves differently before and after Logback bootstrap. (Here we refer to the “bootstrap” as being the Logback initialization, which happens during Catalina's startup, but is separate in concept.)
1. “Pre-bootstrap” time:
  Instances delegate to a PreBootstrapLoggers that store all pre-boostrap logging events in memory.
2. “Post-bootstrap” time:
  Instances delegate to underlying wrapped Loggers, as returned by the SLF4J API.
The pluggability of this class relies on an undocumented feature of LogFactory in the default JULI, which discovers Log implementation providers that expose a String-based constructor.
At pre-bootstrap time, all log events are stored in memory, because we assume that this stage will live a short time (typically less than 200ms) and log few messages (typically 64 messages).
Since version 1.0.1, this implementation properly supports the case were the underlying logger is a LocationAwareLogger.
Diagnostics can be activated by lowering their detail level with the org.apache.juli.logging.impl.SLF4JDelegatingLog.diagnostics system property. Reference values are those defined by the LocationAwareLogger interface. The default is LocationAwareLogger.WARN_INT, which only reports problems. Actual reporting is delegatedJ to SLF4, which outputs messages to the standard error stream.
Since:

1.0.0

Author:

Benjamin Gandon

See Also:

SeparateLogbackSupport, Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

static int diagnostics

protected String name
The logger's name.

Fields
Modifier and Type	Field and Description
`static int`	`diagnostics`
`protected String`	`name` The logger's name.

Constructor Summary

Constructors
Constructor and Description
`SLF4JDelegatingLog()` The default constructor is mandatory, as per the `ServiceLoader` specification.
`SLF4JDelegatingLog(String name)` This `String`-based constructor is required by the default "lean" JULI `LogFactory`, in order to accept this class a a `Log` implementation provider.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`debug(Object msg)` The implementation here converts the message to a string, and logs it as `DEBUG` level using the wrapped `Logger` instance.
`void`	`debug(Object msg, Throwable thrown)` The implementation here converts the message to a string, and logs it along with the given throwable as `DEBUG` level, using the wrapped `Logger` instance.
`void`	`error(Object msg)` The implementation here converts the message to a string, and logs it as `ERROR` level using the wrapped `Logger` instance.
`void`	`error(Object msg, Throwable thrown)` The implementation here converts the message to a string, and logs it along with the given throwable as `ERROR` level, using the wrapped `Logger` instance.
`void`	`fatal(Object msg)` The implementation here converts the message to a string, and logs it as `ERROR` level using the wrapped `Logger` instance, SLF4J has no `FATAL` level.
`void`	`fatal(Object msg, Throwable thrown)` The implementation here converts the message to a string, and logs it along with the given throwable as `ERROR` level, using the wrapped `Logger` instance, because SLF4J has no `FATAL` level.
`void`	`info(Object msg)` The implementation here converts the message to a string, and logs it as `INFO` level using the wrapped `Logger` instance.
`void`	`info(Object msg, Throwable thrown)` The implementation here converts the message to a string, and logs it along with the given throwable as `INFO` level, using the wrapped `Logger` instance.
`boolean`	`isDebugEnabled()` The implementation here delegates to the wrapped `Logger` instance.
`boolean`	`isErrorEnabled()` The implementation here delegates to the wrapped `Logger` instance.
`boolean`	`isFatalEnabled()` The implementation here delegates to the `isErrorEnabled` method of the wrapped `Logger` instance, because SLF4J has no `FATAL` level.
`boolean`	`isInfoEnabled()` The implementation here delegates to the wrapped `Logger` instance.
`boolean`	`isTraceEnabled()` The implementation here delegates to the wrapped `Logger` instance.
`boolean`	`isWarnEnabled()` The implementation here delegates to the wrapped `Logger` instance.
`protected Object`	`readResolve()` Replace the deserialized instance with a fresh new `SLF4JDelegatingLog` logger of the same name, so that it properly belong to the context of the applicable `LogManager`.
`void`	`trace(Object msg)` The implementation here converts the message to a string, and logs it as `TRACE` level using the wrapped `Logger` instance.
`void`	`trace(Object msg, Throwable thrown)` The implementation here converts the message to a string, and logs it along with the given throwable as `TRACE` level, using the wrapped `Logger` instance.
`void`	`warn(Object msg)` The implementation here converts the message to a string, and logs it as `WARN` level using the wrapped `Logger` instance.
`void`	`warn(Object msg, Throwable thrown)` The implementation here converts the message to a string, and logs it along with the given throwable as `WARN` level, using the wrapped `Logger` instance.

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

- Field Detail
  - diagnostics
```
public static volatile int diagnostics
```
  - name
```
protected String name
```
    The logger's name.
- Constructor Detail
  - SLF4JDelegatingLog
```
public SLF4JDelegatingLog()
```
    The default constructor is mandatory, as per the ServiceLoader specification.
    This will construct an unusable Log, though.
  - SLF4JDelegatingLog
```
public SLF4JDelegatingLog(String name)
```
    This String-based constructor is required by the default "lean" JULI LogFactory, in order to accept this class a a Log implementation provider.
    
    Parameters:
    
    name - the name of the logger to create.
    
    See Also:
    
    LogFactory.LogFactory()
- Method Detail
  - isTraceEnabled
```
public boolean isTraceEnabled()
```
    The implementation here delegates to the wrapped Logger instance.
    
    Specified by:
    
    isTraceEnabled in interface org.apache.juli.logging.Log
    
    Returns:
    
    true if the wrapped logger isTraceEnabled, or false otherwise.
  - isDebugEnabled
```
public boolean isDebugEnabled()
```
    The implementation here delegates to the wrapped Logger instance.
    
    Specified by:
    
    isDebugEnabled in interface org.apache.juli.logging.Log
    
    Returns:
    
    true if the wrapped logger isDebugEnabled, or false otherwise.
  - isInfoEnabled
```
public boolean isInfoEnabled()
```
    The implementation here delegates to the wrapped Logger instance.
    
    Specified by:
    
    isInfoEnabled in interface org.apache.juli.logging.Log
    
    Returns:
    
    true if the wrapped logger isInfoEnabled, or false otherwise.
  - isWarnEnabled
```
public boolean isWarnEnabled()
```
    The implementation here delegates to the wrapped Logger instance.
    
    Specified by:
    
    isWarnEnabled in interface org.apache.juli.logging.Log
    
    Returns:
    
    true if the wrapped logger isWarnEnabled, or false otherwise.
  - isErrorEnabled
```
public boolean isErrorEnabled()
```
    The implementation here delegates to the wrapped Logger instance.
    
    Specified by:
    
    isErrorEnabled in interface org.apache.juli.logging.Log
    
    Returns:
    
    true if the wrapped logger isErrorEnabled, or false otherwise.
  - isFatalEnabled
```
public boolean isFatalEnabled()
```
    The implementation here delegates to the isErrorEnabled method of the wrapped Logger instance, because SLF4J has no FATAL level.
    
    Specified by:
    
    isFatalEnabled in interface org.apache.juli.logging.Log
    
    Returns:
    
    true if the wrapped logger isErrorEnabled, or false otherwise.
  - trace
```
public void trace(Object msg)
```
    The implementation here converts the message to a string, and logs it as TRACE level using the wrapped Logger instance.
    
    Specified by:
    
    trace in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
  - trace
```
public void trace(Object msg,
                  Throwable thrown)
```
    The implementation here converts the message to a string, and logs it along with the given throwable as TRACE level, using the wrapped Logger instance.
    
    Specified by:
    
    trace in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
    
    thrown - the throwable to log
  - debug
```
public void debug(Object msg)
```
    The implementation here converts the message to a string, and logs it as DEBUG level using the wrapped Logger instance.
    
    Specified by:
    
    debug in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
  - debug
```
public void debug(Object msg,
                  Throwable thrown)
```
    The implementation here converts the message to a string, and logs it along with the given throwable as DEBUG level, using the wrapped Logger instance.
    
    Specified by:
    
    debug in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
    
    thrown - the throwable to log
  - info
```
public void info(Object msg)
```
    The implementation here converts the message to a string, and logs it as INFO level using the wrapped Logger instance.
    
    Specified by:
    
    info in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
  - info
```
public void info(Object msg,
                 Throwable thrown)
```
    The implementation here converts the message to a string, and logs it along with the given throwable as INFO level, using the wrapped Logger instance.
    
    Specified by:
    
    info in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
    
    thrown - the throwable to log
  - warn
```
public void warn(Object msg)
```
    The implementation here converts the message to a string, and logs it as WARN level using the wrapped Logger instance.
    
    Specified by:
    
    warn in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
  - warn
```
public void warn(Object msg,
                 Throwable thrown)
```
    The implementation here converts the message to a string, and logs it along with the given throwable as WARN level, using the wrapped Logger instance.
    
    Specified by:
    
    warn in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
    
    thrown - the throwable to log
  - error
```
public void error(Object msg)
```
    The implementation here converts the message to a string, and logs it as ERROR level using the wrapped Logger instance.
    
    Specified by:
    
    error in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
  - error
```
public void error(Object msg,
                  Throwable thrown)
```
    The implementation here converts the message to a string, and logs it along with the given throwable as ERROR level, using the wrapped Logger instance.
    
    Specified by:
    
    error in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
    
    thrown - the throwable to log
  - fatal
```
public void fatal(Object msg)
```
    The implementation here converts the message to a string, and logs it as ERROR level using the wrapped Logger instance, SLF4J has no FATAL level.
    
    Specified by:
    
    fatal in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
  - fatal
```
public void fatal(Object msg,
                  Throwable thrown)
```
    The implementation here converts the message to a string, and logs it along with the given throwable as ERROR level, using the wrapped Logger instance, because SLF4J has no FATAL level.
    
    Specified by:
    
    fatal in interface org.apache.juli.logging.Log
    
    Parameters:
    
    msg - the message to log, to be converted to String
    
    thrown - the throwable to log
  - readResolve
```
protected Object readResolve()
                      throws ObjectStreamException
```
    Replace the deserialized instance with a fresh new SLF4JDelegatingLog logger of the same name, so that it properly belong to the context of the applicable LogManager.
    
    Returns:
    
    a homonymous logger that properly belongs to the context of the applicable log manager.
    
    Throws:
    
    ObjectStreamException - actually never thrown by this implementation.

Class SLF4JDelegatingLog

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

diagnostics

name

Constructor Detail

SLF4JDelegatingLog

SLF4JDelegatingLog

Method Detail

isTraceEnabled

isDebugEnabled

isInfoEnabled

isWarnEnabled

isErrorEnabled

isFatalEnabled

trace

trace

debug

debug

info

info

warn

warn

error

error

fatal

fatal

readResolve