Logger (emma 2.1.3 API)

java.lang.Object
- com.vladium.logging.Logger

所有已实现的接口:

ILogLevels
```
public final class Logger
extends Object
implements ILogLevels
```
A simple Java version-independent logging framework. Each Logger is also an immutable context that encapsulates configuration elements like the logging verbosity level etc. In general, a Logger is looked up as an inheritable thread-local piece of data. This decouples classes and logging configurations in a way that seems difficult with log4j.
Note that a given class is free to cache its context in an instance field if the class is instantiated and used only on a single thread (or a set of threads that are guaranteed to share the same logging context). [This is different from the usual log4j pattern of caching a logger in a class static field]. In other cases (e.g., the instrumentation runtime), it makes more sense to scope a context to a single method invocation.
Every log message is structured as follows:
1. message is prefixed with the prefix string set in the Logger if that is not null;
2. if the calling class could be identified and it supplied the calling method name, the calling method is identified with all name components that are not null;
3. caller-supplied message is logged, if not null;
4. caller-supplied Throwable is dumped starting with a new line, if not null.
MT-safety: a given Logger instance will not get corrupted by concurrent usage from multiple threads and guarantees that data written to the underlying PrintWriter in a single log call will be done in one atomic print() step.
作者:

(C) 2001, Vlad Roubtsov

另请参阅:

ILogLevels

字段概要
- 从接口继承的字段 com.vladium.logging.ILogLevels
  ALL, ALL_STRING, INFO, INFO_STRING, NONE, NONE_STRING, QUIET_STRING, SEVERE, SEVERE_STRING, SILENT_STRING, TRACE1, TRACE1_STRING, TRACE2, TRACE2_STRING, TRACE3, TRACE3_STRING, VERBOSE, VERBOSE_STRING, WARNING, WARNING_STRING

方法概要

所有方法静态方法实例方法具体方法
限定符和类型	方法和说明
`boolean`	`atINFO()` A convenience method equivalent to isLoggable(INFO).
`boolean`	`atTRACE1()` A convenience method equivalent to isLoggable(TRACE1).
`boolean`	`atTRACE2()` A convenience method equivalent to isLoggable(TRACE2).
`boolean`	`atTRACE3()` A convenience method equivalent to isLoggable(TRACE3).
`boolean`	`atVERBOSE()` A convenience method equivalent to isLoggable(VERBOSE).
`static Logger`	`create(int level, PrintWriter out, String prefix, Set classMask)`
`static Logger`	`create(int level, PrintWriter out, String prefix, Set classMask, Logger base)` This works as a cloning creator of sorts.
`static Logger`	`getLogger()` Returns the current top of the thread-local logger stack or the static Logger instance scoped to Logger.class if the stack is empty.
`PrintWriter`	`getWriter()` Provides direct access to the PrintWriter used by this Logger.
`void`	`info(String msg)` A convenience method to log 'msg' from an anonymous calling method at INFO level.
`boolean`	`isLoggable(int level)` A quick method to determine if logging is enabled at a given level.
`void`	`log(int level, String msg, boolean logCaller)` Logs 'msg' from an unnamed calling method.
`void`	`log(int level, String method, String msg, boolean logCaller)` Logs 'msg' from a given calling method.
`void`	`log(int level, String method, String msg, Throwable throwable)` Logs 'msg' from a given calling method followed by the 'throwable' stack trace dump.
`void`	`log(int level, String msg, Throwable throwable)` Logs 'msg' from an unnamed calling method followed by the 'throwable' stack trace dump.
`static void`	`pop(Logger ctx)` Requiring a context parameter here helps enforce correct push/pop nesting in the caller code.
`static void`	`push(Logger ctx)`
`static int`	`stringToLevel(String level)`
`void`	`trace1(String method, String msg)` A convenience method equivalent to log(TRACE1, method, msg).
`void`	`trace2(String method, String msg)` A convenience method equivalent to log(TRACE2, method, msg).
`void`	`trace3(String method, String msg)` A convenience method equivalent to log(TRACE3, method, msg).
`void`	`verbose(String msg)` A convenience method to log 'msg' from an anonymous calling method at VERBOSE level.
`void`	`warning(String msg)` A convenience method to log 'msg' from an anonymous calling method at WARNING level.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 方法详细资料
  - create
```
public static Logger create(int level,
                            PrintWriter out,
                            String prefix,
                            Set classMask)
```
  - create
```
public static Logger create(int level,
                            PrintWriter out,
                            String prefix,
                            Set classMask,
                            Logger base)
```
    This works as a cloning creator of sorts.
    
    参数:
    
    level -
    
    out -
    
    prefix -
    
    classMask -
    
    base -
    
    返回:
  - isLoggable
```
public final boolean isLoggable(int level)
```
    A quick method to determine if logging is enabled at a given level. This method acquires no monitors and should be used when calling one of log() or convenience logging methods directly incurs significant parameter construction overhead.
    
    另请参阅:
    
    ILogLevels
  - atINFO
```
public final boolean atINFO()
```
    A convenience method equivalent to isLoggable(INFO).
  - atVERBOSE
```
public final boolean atVERBOSE()
```
    A convenience method equivalent to isLoggable(VERBOSE).
  - atTRACE1
```
public final boolean atTRACE1()
```
    A convenience method equivalent to isLoggable(TRACE1).
  - atTRACE2
```
public final boolean atTRACE2()
```
    A convenience method equivalent to isLoggable(TRACE2).
  - atTRACE3
```
public final boolean atTRACE3()
```
    A convenience method equivalent to isLoggable(TRACE3).
  - warning
```
public final void warning(String msg)
```
    A convenience method to log 'msg' from an anonymous calling method at WARNING level.
    
    参数:
    
    msg - log message [ignored if null]
  - info
```
public final void info(String msg)
```
    A convenience method to log 'msg' from an anonymous calling method at INFO level.
    
    参数:
    
    msg - log message [ignored if null]
  - verbose
```
public final void verbose(String msg)
```
    A convenience method to log 'msg' from an anonymous calling method at VERBOSE level.
    
    参数:
    
    msg - log message [ignored if null]
  - trace1
```
public final void trace1(String method,
                         String msg)
```
    A convenience method equivalent to log(TRACE1, method, msg).
    
    参数:
    
    method - calling method name [ignored if null]
    
    msg - log message [ignored if null]
  - trace2
```
public final void trace2(String method,
                         String msg)
```
    A convenience method equivalent to log(TRACE2, method, msg).
    
    参数:
    
    method - calling method name [ignored if null]
    
    msg - log message [ignored if null]
  - trace3
```
public final void trace3(String method,
                         String msg)
```
    A convenience method equivalent to log(TRACE3, method, msg).
    
    参数:
    
    method - calling method name [ignored if null]
    
    msg - log message [ignored if null]
  - log
```
public final void log(int level,
                      String msg,
                      boolean logCaller)
```
    Logs 'msg' from an unnamed calling method.
    
    参数:
    
    level - level to log at [the method does nothing if this is less than the set level].
    
    msg - log message [ignored if null]
  - log
```
public final void log(int level,
                      String method,
                      String msg,
                      boolean logCaller)
```
    Logs 'msg' from a given calling method.
    
    参数:
    
    level - level to log at [the method does nothing if this is less than the set level].
    
    method - calling method name [ignored if null]
    
    msg - log message [ignored if null]
  - log
```
public final void log(int level,
                      String msg,
                      Throwable throwable)
```
    Logs 'msg' from an unnamed calling method followed by the 'throwable' stack trace dump.
    
    参数:
    
    level - level to log at [the method does nothing if this is less than the set level].
    
    msg - log message [ignored if null]
    
    throwable - to dump after message [ignored if null]
  - log
```
public final void log(int level,
                      String method,
                      String msg,
                      Throwable throwable)
```
    Logs 'msg' from a given calling method followed by the 'throwable' stack trace dump.
    
    参数:
    
    level - level to log at [the method does nothing if this is less than the set level].
    
    method - calling method name [ignored if null]
    
    msg - log message [ignored if null]
    
    throwable - to dump after message [ignored if null]
  - getWriter
```
public PrintWriter getWriter()
```
    Provides direct access to the PrintWriter used by this Logger.
    
    返回:
    
    print writer used by this logger [never null]
  - getLogger
```
public static Logger getLogger()
```
    Returns the current top of the thread-local logger stack or the static Logger instance scoped to Logger.class if the stack is empty.
    
    返回:
    
    current logger [never null]
  - push
```
public static void push(Logger ctx)
```
    参数:
    
    ctx - [may not be null]
  - pop
```
public static void pop(Logger ctx)
```
    Requiring a context parameter here helps enforce correct push/pop nesting in the caller code.
    
    参数:
    
    ctx - [may not be null]
  - stringToLevel
```
public static int stringToLevel(String level)
```

类 Logger

字段概要

从接口继承的字段 com.vladium.logging.ILogLevels

方法概要

从类继承的方法 java.lang.Object

方法详细资料

create

create

isLoggable

atINFO

atVERBOSE

atTRACE1

atTRACE2

atTRACE3

warning

info

verbose

trace1

trace2

trace3

log

log

log

log

getWriter

getLogger

push

pop

stringToLevel