org.apache.hadoop.metrics2.util

类 TryIterator<T>

java.lang.Object

org.apache.hadoop.metrics2.util.TryIterator<T>

类型参数:

T - the type of the iterator

所有已实现的接口:

Iterator<T>

public abstract class TryIterator<T>
extends Object
implements Iterator<T>

A base class for unmodifiable iterators (throws on remove) This class also makes writing filtering iterators easier, where the only way to discover the end of data is by trying to read it. The same applies to writing iterator wrappers around stream read calls. One only needs to implement the tryNext() method and call done() when done.

构造器概要

构造器

构造器和说明
TryIterator()

方法概要

方法

限定符和类型	方法和说明
T	current()
protected T	done() Implementations of tryNext() must call this method when there are no more elements left in the iteration.
boolean	hasNext()
T	next()
void	remove() Guaranteed to throw UnsupportedOperationException
protected abstract T	tryNext() Return the next element.

从类继承的方法 java.lang.Object

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

构造器详细资料

TryIterator

public TryIterator()

方法详细资料

tryNext

protected abstract T tryNext()

Return the next element. Must call done() when done, otherwise infinite loop could occur. If this method throws an exception, any further attempts to use the iterator would result in an IllegalStateException.

返回:

the next element if there is one or return done()

done

protected final T done()

Implementations of tryNext() must call this method when there are no more elements left in the iteration.

返回:

null as a convenience to implement tryNext()

hasNext

public final boolean hasNext()

指定者:

hasNext 在接口中 Iterator<T>

返回:

true if we have a next element or false otherwise.

next

public final T next()

指定者:

next 在接口中 Iterator<T>

返回:

the next element if we have one.

current

public final T current()

返回:

the current element without advancing the iterator

remove

public final void remove()

Guaranteed to throw UnsupportedOperationException

指定者:

remove 在接口中 Iterator<T>