程序包 cn.taketoday.util

类 StopWatch

java.lang.Object

cn.taketoday.util.StopWatch

public class StopWatch
extends Object

Simple stop watch, allowing for timing of a number of tasks, exposing total running time and running time for each named task.

Conceals use of System.nanoTime(), improving the readability of application code and reducing the likelihood of calculation errors.

Note that this object is not designed to be thread-safe and does not use synchronization.

This class is normally used to verify performance during proof-of-concept work and in development, rather than as part of production applications.

running time is tracked and reported in nanoseconds. the default time unit for String renderings is seconds with decimal points in nanosecond precision. Custom renderings with specific time units can be requested through prettyPrint(TimeUnit).

从以下版本开始:

3.0

作者:

Rod Johnson, Juergen Hoeller, Sam Brannen, Harry Yang

另请参阅:

• start()
• stop()
• shortSummary()
• prettyPrint()

嵌套类概要

嵌套类

修饰符和类型	类	说明
static final class	StopWatch.TaskInfo	Nested class to hold data about one task executed within the StopWatch.

字段概要

字段

修饰符和类型	字段	说明
private String	currentTaskName	Name of the current task.
private final String	id	Identifier of this StopWatch.
private StopWatch.TaskInfo	lastTaskInfo
private long	startTimeNanos	Start time of the current task.
private int	taskCount
private ArrayList<StopWatch.TaskInfo>	taskList
private long	totalTimeNanos	Total running time.

构造器概要

构造器

构造器	说明
StopWatch()	Construct a new StopWatch.
StopWatch(String id)	Construct a new StopWatch with the given id.

方法概要

修饰符和类型	方法	说明
String	currentTaskName()	Get the name of the currently running task, if any.
String	getId()	Get the id of this StopWatch, as specified on construction.
String	getLastTaskName()	Get the name of the last task.
long	getLastTaskTimeMillis()	Get the time taken by the last task in milliseconds.
long	getLastTaskTimeNanos()	Get the time taken by the last task in nanoseconds.
int	getTaskCount()	Get the number of tasks timed.
StopWatch.TaskInfo[]	getTaskInfo()	Get an array of the data for tasks performed.
double	getTotalTime(TimeUnit timeUnit)	Get the total time for all tasks in the requested time unit (with decimal points in nanosecond precision).
long	getTotalTimeMillis()	Get the total time for all tasks in milliseconds.
long	getTotalTimeNanos()	Get the total time for all tasks in nanoseconds.
double	getTotalTimeSeconds()	Get the total time for all tasks in seconds.
boolean	isRunning()	Determine whether this StopWatch is currently running.
StopWatch.TaskInfo	lastTaskInfo()	Get the last task as a StopWatch.TaskInfo object.
String	prettyPrint()	Generate a table describing all tasks performed in seconds (with decimal points in nanosecond precision).
String	prettyPrint(TimeUnit timeUnit)	Generate a table describing all tasks performed in the requested time unit (with decimal points in nanosecond precision).
void	setKeepTaskList(boolean keepTaskList)	Configure whether the StopWatch.TaskInfo array is built over time.
String	shortSummary()	Get a short description of the total running time in seconds.
void	start()	Start an unnamed task.
void	start(String taskName)	Start a named task.
void	stop()	Stop the current task.
String	toString()	Generate an informative string describing all tasks performed in seconds.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

字段详细资料

id

private final String id

Identifier of this StopWatch.

Handy when we have output from multiple stop watches and need to distinguish between them in log or console output.

taskList

@Nullable
private ArrayList<StopWatch.TaskInfo> taskList

startTimeNanos

private long startTimeNanos

Start time of the current task.

currentTaskName

@Nullable
private String currentTaskName

Name of the current task.

lastTaskInfo

@Nullable
private StopWatch.TaskInfo lastTaskInfo

taskCount

private int taskCount

totalTimeNanos

private long totalTimeNanos

Total running time.

构造器详细资料

StopWatch

public StopWatch()

Construct a new StopWatch.

Does not start any task.

StopWatch

public StopWatch(String id)

Construct a new StopWatch with the given id.

The id is handy when we have output from multiple stop watches and need to distinguish between them.

Does not start any task.

参数:

id - identifier for this stop watch

方法详细资料

getId

public String getId()

Get the id of this StopWatch, as specified on construction.

返回:

the id (empty String by default)

另请参阅:

• StopWatch(String)

setKeepTaskList

public void setKeepTaskList(boolean keepTaskList)

Configure whether the StopWatch.TaskInfo array is built over time.

Set this to false when using a StopWatch for millions of tasks; otherwise, the TaskInfo structure will consume excessive memory.

Default is true.

start

public void start()
           throws IllegalStateException

Start an unnamed task.

The results are undefined if stop() or timing methods are called without invoking this method first.

抛出:

IllegalStateException

另请参阅:

• start(String)
• stop()

start

public void start(String taskName)
           throws IllegalStateException

Start a named task.

The results are undefined if stop() or timing methods are called without invoking this method first.

参数:

taskName - the name of the task to start

抛出:

IllegalStateException

另请参阅:

• start()
• stop()

stop

public void stop()
          throws IllegalStateException

Stop the current task.

The results are undefined if timing methods are called without invoking at least one pair of start() / stop() methods.

抛出:

IllegalStateException

另请参阅:

• start()
• start(String)

isRunning

public boolean isRunning()

Determine whether this StopWatch is currently running.

另请参阅:

• currentTaskName()

currentTaskName

@Nullable
public String currentTaskName()

Get the name of the currently running task, if any.

另请参阅:

• isRunning()

lastTaskInfo

public StopWatch.TaskInfo lastTaskInfo()
                                throws IllegalStateException

Get the last task as a StopWatch.TaskInfo object.

抛出:

IllegalStateException - if no tasks have run yet

getLastTaskName

public String getLastTaskName()
                       throws IllegalStateException

Get the name of the last task.

抛出:

IllegalStateException

另请参阅:

• StopWatch.TaskInfo.getTaskName()

getLastTaskTimeNanos

public long getLastTaskTimeNanos()
                          throws IllegalStateException

Get the time taken by the last task in nanoseconds.

抛出:

IllegalStateException

另请参阅:

• StopWatch.TaskInfo.getTimeNanos()

getLastTaskTimeMillis

public long getLastTaskTimeMillis()
                           throws IllegalStateException

Get the time taken by the last task in milliseconds.

抛出:

IllegalStateException

另请参阅:

• StopWatch.TaskInfo.getTimeMillis()

getTaskInfo

public StopWatch.TaskInfo[] getTaskInfo()

Get an array of the data for tasks performed.

另请参阅:

• setKeepTaskList(boolean)

getTaskCount

public int getTaskCount()

Get the number of tasks timed.

getTotalTimeNanos

public long getTotalTimeNanos()

Get the total time for all tasks in nanoseconds.

另请参阅:

• getTotalTime(TimeUnit)

getTotalTimeMillis

public long getTotalTimeMillis()

Get the total time for all tasks in milliseconds.

另请参阅:

• getTotalTime(TimeUnit)

getTotalTimeSeconds

public double getTotalTimeSeconds()

Get the total time for all tasks in seconds.

另请参阅:

• getTotalTime(TimeUnit)

getTotalTime

public double getTotalTime(TimeUnit timeUnit)

Get the total time for all tasks in the requested time unit (with decimal points in nanosecond precision).

参数:

timeUnit - the unit to use

另请参阅:

• getTotalTimeNanos()
• getTotalTimeMillis()
• getTotalTimeSeconds()

prettyPrint

public String prettyPrint()

Generate a table describing all tasks performed in seconds (with decimal points in nanosecond precision).

For custom reporting, call getTaskInfo() and use the data directly.

另请参阅:

• prettyPrint(TimeUnit)
• getTotalTimeSeconds()
• StopWatch.TaskInfo.getTimeSeconds()

prettyPrint

public String prettyPrint(TimeUnit timeUnit)

Generate a table describing all tasks performed in the requested time unit (with decimal points in nanosecond precision).

For custom reporting, call getTaskInfo() and use the data directly.

参数:

timeUnit - the unit to use for rendering total time and task time

另请参阅:

• prettyPrint()
• getTotalTime(TimeUnit)
• StopWatch.TaskInfo.getTime(TimeUnit)

shortSummary

public String shortSummary()

Get a short description of the total running time in seconds.

另请参阅:

• prettyPrint()
• prettyPrint(TimeUnit)

toString

public String toString()

Generate an informative string describing all tasks performed in seconds.

覆盖:

toString 在类中 Object

另请参阅:

• prettyPrint()
• prettyPrint(TimeUnit)