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CoherenceTM v3.3 Copyright© 2000-2007 by Oracle Corporation |
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java.lang.Objectcom.tangosol.util.Base
com.tangosol.util.extractor.AbstractExtractor
com.tangosol.util.extractor.KeyExtractor
public class KeyExtractor
The KeyExtractor is a special purpose ValueExtractor implementation that
serves as an indicator that a query should be run against the key objects
rather than the values. The major difference between the KeyExtractor and a
standard ReflectionExtractor
is that when used in various
EntryFilter
implementations it forces
the evaluation of entry keys rather than entry values.
KeyExtractor extractor = new KeyExtractor("getLastName"); Set setKeys = cache.keySet(new EqualsFilter(extractor, "Smith"));
Field Summary | |
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protected ValueExtractor |
m_extractor
The underlying ValueExtractor. |
Constructor Summary | |
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KeyExtractor()
Default constructor (necessary for the ExternalizableLite interface). |
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KeyExtractor(String sMethod)
Construct a KeyExtractor for a specified method name. |
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KeyExtractor(ValueExtractor extractor)
Construct a KeyExtractor based on a specified ValueExtractor. |
Method Summary | |
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boolean |
equals(Object o)
Compare the KeyExtractor with another object to determine equality. |
Object |
extract(Object oTarget)
Extract the value from the passed object. The returned value may be null. For intrinsic types, the returned value is expected to be a standard wrapper type in the same manner that reflection works; for example, int would be returned as a java.lang.Integer. |
ValueExtractor |
getExtractor()
Obtain the underlying ValueExtractor. |
int |
hashCode()
Determine a hash value for the KeyExtractor object according to the general Object.hashCode() contract. |
void |
readExternal(DataInput in)
Restore the contents of this object by loading the object's state from the passed DataInput object. |
void |
readExternal(PofReader in)
Restore the contents of a user type instance by reading its state using the specified PofReader object. |
String |
toString()
Return a human-readable description for this KeyExtractor. |
void |
writeExternal(DataOutput out)
Save the contents of this object by storing the object's state into the passed DataOutput object. |
void |
writeExternal(PofWriter out)
Save the contents of a POF user type instance by writing its state using the specified PofWriter object. |
Methods inherited from class com.tangosol.util.extractor.AbstractExtractor |
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compare, compareEntries |
Field Detail |
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protected ValueExtractor m_extractor
Constructor Detail |
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public KeyExtractor()
public KeyExtractor(ValueExtractor extractor)
extractor
- the underlying ValueExtractorpublic KeyExtractor(String sMethod)
sMethod
- a method name to construct an underlying
ReflectionExtractor
for;
this parameter can also be a dot-delimited sequence
of method names which would result in a KeyExtractor
based on the ChainedExtractor
that is based on
an array of corresponding ReflectionExtractor objectsMethod Detail |
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public Object extract(Object oTarget)
extract
in interface ValueExtractor
extract
in class AbstractExtractor
oTarget
- an Object to retrieve the value from
public ValueExtractor getExtractor()
public boolean equals(Object o)
equals
in interface ValueExtractor
equals
in interface Comparator
o
- the reference object with which to compare
public int hashCode()
Object.hashCode()
contract.
hashCode
in interface ValueExtractor
public String toString()
toString
in interface ValueExtractor
public void readExternal(DataInput in) throws IOException
readExternal
in interface ExternalizableLite
in
- the DataInput stream to read data from in order to restore
the state of this object
IOException
- if an I/O exception occurs
NotActiveException
- if the object is not in its initial
state, and therefore cannot be deserialized intopublic void writeExternal(DataOutput out) throws IOException
writeExternal
in interface ExternalizableLite
out
- the DataOutput stream to write the state of this object to
IOException
- if an I/O exception occurspublic void readExternal(PofReader in) throws IOException
readExternal
in interface PortableObject
in
- the PofReader from which to read the object's state
IOException
- if an I/O error occurspublic void writeExternal(PofWriter out) throws IOException
writeExternal
in interface PortableObject
out
- the PofWriter to which to write the object's state
IOException
- if an I/O error occurs
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CoherenceTM v3.3 Copyright© 2000-2007 by Oracle Corporation |
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