org.apache.hadoop.metrics2.util

类 Contracts

java.lang.Object

org.apache.hadoop.metrics2.util.Contracts

public class Contracts
extends Object

Utilities for programming by contract (preconditions, postconditions etc.)

方法概要

方法

限定符和类型	方法和说明
static double	checkArg(double arg, boolean expression, Object msg) Check an argument for false conditions
static float	checkArg(float arg, boolean expression, Object msg) Check an argument for false conditions
static int	checkArg(int arg, boolean expression, Object msg) Check an argument for false conditions
static long	checkArg(long arg, boolean expression, Object msg) Check an argument for false conditions
static <T> T	checkArg(T arg, boolean expression, Object msg) Check an argument for false conditions
static <T> T	checkNotNull(T ref, Object msg) Check that a reference is not null.
static void	checkState(boolean expression, Object msg) Check the state expression for false conditions

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

checkNotNull

public static <T> T checkNotNull(T ref,
                 Object msg)

Check that a reference is not null.

类型参数:

T - type of the reference

参数:

ref - the reference to check

msg - the error message

返回:

the checked reference for convenience

抛出:

NullPointerException - if ref is null

checkState

public static void checkState(boolean expression,
              Object msg)

Check the state expression for false conditions

参数:

expression - the boolean expression to check

msg - the error message if expression is false

抛出:

IllegalStateException - if expression is false

checkArg

public static <T> T checkArg(T arg,
             boolean expression,
             Object msg)

Check an argument for false conditions

类型参数:

T - type of the argument

参数:

arg - the argument to check

expression - the boolean expression for the condition

msg - the error message if expression is false

返回:

the argument for convenience

checkArg

public static int checkArg(int arg,
           boolean expression,
           Object msg)

Check an argument for false conditions

参数:

arg - the argument to check

expression - the boolean expression for the condition

msg - the error message if expression is false

返回:

the argument for convenience

checkArg

public static long checkArg(long arg,
            boolean expression,
            Object msg)

Check an argument for false conditions

参数:

arg - the argument to check

expression - the boolean expression for the condition

msg - the error message if expression is false

返回:

the argument for convenience

checkArg

public static float checkArg(float arg,
             boolean expression,
             Object msg)

Check an argument for false conditions

参数:

arg - the argument to check

expression - the boolean expression for the condition

msg - the error message if expression is false

返回:

the argument for convenience

checkArg

public static double checkArg(double arg,
              boolean expression,
              Object msg)

Check an argument for false conditions

参数:

arg - the argument to check

expression - the boolean expression for the condition

msg - the error message if expression is false

返回:

the argument for convenience