org.apache.poi.util

Interface POILogger

All Known Implementing Classes:

CommonsLogger, NullLogger, SLF4JLogger, SystemOutLogger

@Internal
public interface POILogger

A logger interface that strives to make it as easy as possible for developers to write log calls, while simultaneously making those calls as cheap as possible by performing lazy evaluation of the log message. A logger can be selected via system properties, e.g. -Dorg.apache.poi.util.POILogger=org.apache.poi.util.SystemOutLogger The following Logger-implementations are provided:

• NullLogger
• CommonsLogger
• SystemOutLogger

(一个记录器接口，它努力使开发人员尽可能轻松地编写日志调用，同时通过对日志消息执行惰性评估，使这些调用尽可能便宜。可以通过系统属性选择记录器，例如 -Dorg.apache.poi.util.POILogger=org.apache.poi.util.SystemOutLogger 提供以下记录器实现： NullLogger CommonsLogger SystemOutLogger)

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEBUG
static int	ERROR
static int	FATAL
static int	INFO
static int	WARN

Method Summary

Modifier and Type	Method and Description
void	_log(int level, java.lang.Object obj1) Log a message - belongs to the SPI, usually not called from user code (记录消息 - 属于 SPI，通常不从用户代码调用)
void	_log(int level, java.lang.Object obj1, java.lang.Throwable exception) Log a message - belongs to the SPI, usually not called from user code (记录消息 - 属于 SPI，通常不从用户代码调用)
boolean	check(int level) Check if a logger is enabled to log at the specified level This allows code to avoid building strings or evaluating functions in the arguments to log. (检查是否启用了记录器以在指定级别记录这允许代码避免在要记录的参数中构建字符串或评估函数。)
void	initialize(java.lang.String cat) Initialize the Logger - belongs to the SPI, called from the POILogFactory (初始化 Logger - 属于 SPI，从 POILogFactory 调用)
default void	log(int level, java.lang.Object... objs) Log a message. (记录一条消息。)

Field Detail

DEBUG

static final int DEBUG

See Also:

Constant Field Values

INFO

static final int INFO

See Also:

Constant Field Values

WARN

static final int WARN

See Also:

Constant Field Values

ERROR

static final int ERROR

See Also:

Constant Field Values

FATAL

static final int FATAL

See Also:

Constant Field Values

Method Detail

initialize

void initialize(java.lang.String cat)

Initialize the Logger - belongs to the SPI, called from the POILogFactory (初始化 Logger - 属于 SPI，从 POILogFactory 调用)

Parameters:

cat - the String that defines the log (cat - 定义日志的字符串)

_log

@Internal
void _log(int level,
                    java.lang.Object obj1)

Log a message - belongs to the SPI, usually not called from user code (记录消息 - 属于 SPI，通常不从用户代码调用)

Parameters:

level - One of DEBUG, INFO, WARN, ERROR, FATAL (level - DEBUG、INFO、WARN、ERROR、FATAL 之一)

obj1 - The object to log. This is converted to a string. (obj1 - 要记录的对象。这将转换为字符串。)

_log

@Internal
void _log(int level,
                    java.lang.Object obj1,
                    java.lang.Throwable exception)

Log a message - belongs to the SPI, usually not called from user code (记录消息 - 属于 SPI，通常不从用户代码调用)

Parameters:

level - One of DEBUG, INFO, WARN, ERROR, FATAL (level - DEBUG、INFO、WARN、ERROR、FATAL 之一)

obj1 - The object to log. This is converted to a string. (obj1 - 要记录的对象。这将转换为字符串。)

exception - An exception to be logged (exception - 要记录的异常)

check

boolean check(int level)

Check if a logger is enabled to log at the specified level This allows code to avoid building strings or evaluating functions in the arguments to log. An example:

 if (logger.check(POILogger.INFO)) {
     logger.log(POILogger.INFO, "Avoid concatenating ", " strings and evaluating ", functions());
 }
 

(检查是否启用了记录器以在指定级别记录这允许代码避免在要记录的参数中构建字符串或评估函数。一个例子： if (logger.check(POILogger.INFO)) { logger.log(POILogger.INFO, "避免连接", "字符串和评估", functions()); })

Parameters:

level - One of DEBUG, INFO, WARN, ERROR, FATAL (level - DEBUG、INFO、WARN、ERROR、FATAL 之一)

log

default void log(int level,
                 java.lang.Object... objs)

Log a message. Lazily appends Object parameters together. If the last parameter is a Throwable it is logged specially. (记录一条消息。懒惰地将对象参数附加在一起。如果最后一个参数是 Throwable，则专门记录它。)

Parameters:

level - One of DEBUG, INFO, WARN, ERROR, FATAL (level - DEBUG、INFO、WARN、ERROR、FATAL 之一)

objs - the objects to place in the message (objs - 放置在消息中的对象)