Log4j2 (Groovy 6.0.0-RC-2)

groovy.util.logging.Log4j2

```
@Documented
@Retention(RetentionPolicy.SOURCE)
@Target(ElementType.TYPE)
public @interface Log4j2
```
This local transform adds a logging ability to your program using Log4j2 logging. Every method call on an unbound variable named log will be mapped to a call to the logger. For this a log field will be inserted in the class. If the field already exists the usage of this transform will cause a compilation error. The method name will be used to determine what to call on the logger.
```
 log.name(exp)
 
```
is mapped to
```
 if (log.isNameEnabled() {
    log.name(exp)
 }
```
Here name is a placeholder for info, debug, warning, error, etc. If the expression exp is a constant or only a variable access the method call will not be transformed. But this will still cause a call on the injected logger.
Since:
2.2.0

Element Summary

Optional Element Summary
Type	Name and Description
`String`	`category` Returns the logger category name.
`Class<? extends LogASTTransformation.LoggingStrategy>`	`loggingStrategy` Returns the logging strategy implementation used by this transform.
`boolean`	`staticLocation` Whether logging statements hand Log4j 2 their source location, computed at compile time, instead of leaving it to be found by walking the stack at run time.
`String`	`value` Returns the injected logger field name.
`String`	`visibilityId` If specified, must match the "id" attribute in a VisibilityOptions annotation to enable a custom visibility.

Inherited Methods Summary

Inherited Methods
Methods inherited from class	Name
`class Object`	`equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- Element Detail
  - public String category
    
    Returns the logger category name. Defaults to LogASTTransformation.DEFAULT_CATEGORY_NAME, which uses the host class name.
    Returns:
    the logger category name
    Default:
    LogASTTransformation.DEFAULT_CATEGORY_NAME
  - public Class<? extends LogASTTransformation.LoggingStrategy> loggingStrategy
    
    Returns the logging strategy implementation used by this transform. Defaults to Log4j2LoggingStrategy.
    Returns:
    the logging strategy type
    Default:
    Log4j2LoggingStrategy.class
  - public boolean staticLocation
    
    Whether logging statements hand Log4j 2 their source location, computed at compile time, instead of leaving it to be found by walking the stack at run time. With true, log.info(msg) becomes log.atInfo().withLocation(location).log(msg), where location is a StackTraceElement for the statement held in a synthetic static field of the annotated class, naming the class, the enclosing method, the source file and the line of the statement. That location is correct however the call is dispatched -- through the Groovy runtime on a JVM, or inside a GraalVM native image, where stack walking otherwise reports runtime frames -- and it spares Log4j 2 the stack walk that %C, %M, %F and %L patterns need.
    Requires the LogBuilder API (Log4j 2.13 or later) on the compile classpath; compilation fails otherwise. Argument types are unknown when the transform runs, so a Marker first argument or a Throwable last argument is recognised, at run time, when it is passed as a variable (the usual log.error("...", e) shape); other expressions in those positions are logged as message parameters. Statements inside a closure name the enclosing method rather than the closure's doCall. Only statements made through the injected logger field are rewritten.
    Returns:
    true to supply locations at compile time
    Since:
    6.0.0
    Default:
    false
  - public String value
    
    Returns the injected logger field name. Defaults to "log".
    Returns:
    the logger field name
    Default:
    "log"
  - public String visibilityId
    
    If specified, must match the "id" attribute in a VisibilityOptions annotation to enable a custom visibility.
    Since:
    3.0.0
    Default:
    Undefined.STRING

Summary:
Optional

| Detail:
Element

[Java] Annotation Type Log4j2

Element Summary

Inherited Methods Summary

Element Detail

public String category

public Class<? extends LogASTTransformation.LoggingStrategy> loggingStrategy

public boolean staticLocation

public String value

public String visibilityId