# X509EncodedKeySpec
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
Summary:[Ctors](https://developer.android.com/reference/java/security/spec/X509EncodedKeySpec#pubctors)\|[Methods](https://developer.android.com/reference/java/security/spec/X509EncodedKeySpec#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/java/security/spec/X509EncodedKeySpec#inhmethods)
# X509EncodedKeySpec
`
public
class
X509EncodedKeySpec
`
`
``
extends `[EncodedKeySpec](https://developer.android.com/reference/java/security/spec/EncodedKeySpec)`
``
`
|---|---|---------------------------------------|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) |||
| ↳ | [java.security.spec.EncodedKeySpec](https://developer.android.com/reference/java/security/spec/EncodedKeySpec) ||
| | ↳ | java.security.spec.X509EncodedKeySpec |
*** ** * ** ***
This class represents the ASN.1 encoding of a public key, encoded according to the ASN.1 type`SubjectPublicKeyInfo`. The`SubjectPublicKeyInfo`syntax is defined in the X.509 standard as follows:
```
SubjectPublicKeyInfo ::= SEQUENCE {
algorithm AlgorithmIdentifier,
subjectPublicKey BIT STRING }
```
**See also:**
- [Key](https://developer.android.com/reference/java/security/Key)
- [KeyFactory](https://developer.android.com/reference/java/security/KeyFactory)
- [KeySpec](https://developer.android.com/reference/java/security/spec/KeySpec)
- [EncodedKeySpec](https://developer.android.com/reference/java/security/spec/EncodedKeySpec)
- [PKCS8EncodedKeySpec](https://developer.android.com/reference/java/security/spec/PKCS8EncodedKeySpec)
## Summary
| ### Public constructors ||
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ` `[X509EncodedKeySpec](https://developer.android.com/reference/java/security/spec/X509EncodedKeySpec#X509EncodedKeySpec(byte[]))`(byte[] encodedKey) ` Creates a new`X509EncodedKeySpec`with the given encoded key. |
| ` `[X509EncodedKeySpec](https://developer.android.com/reference/java/security/spec/X509EncodedKeySpec#X509EncodedKeySpec(byte[],%20java.lang.String))`(byte[] encodedKey, `[String](https://developer.android.com/reference/java/lang/String)` algorithm) ` Creates a new`X509EncodedKeySpec`with the given encoded key. |
| ### Public methods ||
|-----------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` byte[]` | ` `[getEncoded](https://developer.android.com/reference/java/security/spec/X509EncodedKeySpec#getEncoded())`() ` Returns the key bytes, encoded according to the X.509 standard. |
| ` final `[String](https://developer.android.com/reference/java/lang/String) | ` `[getFormat](https://developer.android.com/reference/java/security/spec/X509EncodedKeySpec#getFormat())`() ` Returns the name of the encoding format associated with this key specification. |
| ### Inherited methods |
|-----------------------|---|
| From class` `[java.security.spec.EncodedKeySpec](https://developer.android.com/reference/java/security/spec/EncodedKeySpec)` ` |--------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[getAlgorithm](https://developer.android.com/reference/java/security/spec/EncodedKeySpec#getAlgorithm())`() ` Returns the name of the algorithm of the encoded key. | | ` byte[]` | ` `[getEncoded](https://developer.android.com/reference/java/security/spec/EncodedKeySpec#getEncoded())`() ` Returns the encoded key. | | ` abstract `[String](https://developer.android.com/reference/java/lang/String) | ` `[getFormat](https://developer.android.com/reference/java/security/spec/EncodedKeySpec#getFormat())`() ` Returns the name of the encoding format associated with this key specification. | ||
| From class` `[java.lang.Object](https://developer.android.com/reference/java/lang/Object)` ` |--------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` `[Object](https://developer.android.com/reference/java/lang/Object) | ` `[clone](https://developer.android.com/reference/java/lang/Object#clone())`() ` Creates and returns a copy of this object. | | ` boolean` | ` `[equals](https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` obj) ` Indicates whether some other object is "equal to" this one. | | ` void` | ` `[finalize](https://developer.android.com/reference/java/lang/Object#finalize())`() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ` final `[Class](https://developer.android.com/reference/java/lang/Class)`` | ` `[getClass](https://developer.android.com/reference/java/lang/Object#getClass())`() ` Returns the runtime class of this`Object`. | | ` int` | ` `[hashCode](https://developer.android.com/reference/java/lang/Object#hashCode())`() ` Returns a hash code value for the object. | | ` final void` | ` `[notify](https://developer.android.com/reference/java/lang/Object#notify())`() ` Wakes up a single thread that is waiting on this object's monitor. | | ` final void` | ` `[notifyAll](https://developer.android.com/reference/java/lang/Object#notifyAll())`() ` Wakes up all threads that are waiting on this object's monitor. | | ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/java/lang/Object#toString())`() ` Returns a string representation of the object. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long,%20int))`(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long))`(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait())`() ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*. | ||
## Public constructors
### X509EncodedKeySpec
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public X509EncodedKeySpec (byte[] encodedKey)
```
Creates a new`X509EncodedKeySpec`with the given encoded key.
| Parameters ||
|--------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `encodedKey` | `byte`: the key, which is assumed to be encoded according to the X.509 standard. The contents of the array are copied to protect against subsequent modification.
|
| Throws ||
|------------------------------------------------------------------------------------------------|------------------------|
| [NullPointerException](https://developer.android.com/reference/java/lang/NullPointerException) | if`encodedKey`is null. |
### X509EncodedKeySpec
Added in[API level 35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public X509EncodedKeySpec (byte[] encodedKey,
String algorithm)
```
Creates a new`X509EncodedKeySpec`with the given encoded key. This constructor is useful when subsequent callers of the`X509EncodedKeySpec`object might not know the algorithm of the key.
| Parameters ||
|--------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `encodedKey` | `byte`: the key, which is assumed to be encoded according to the X.509 standard. The contents of the array are copied to protect against subsequent modification.
|
| `algorithm` | `String`: the algorithm name of the encoded public key See the KeyFactory section in the[Java Security Standard Algorithm Names Specification](https://docs.oracle.com/en/java/javase/17/docs/specs/security/standard-names.html#keyfactory-algorithms)for information about standard algorithm names.
|
| Throws ||
|--------------------------------------------------------------------------------------------------------|--------------------------------------|
| [NullPointerException](https://developer.android.com/reference/java/lang/NullPointerException) | if`encodedKey`or`algorithm`is null. |
| [IllegalArgumentException](https://developer.android.com/reference/java/lang/IllegalArgumentException) | if`algorithm`is the empty string`""` |
## Public methods
### getEncoded
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public byte[] getEncoded ()
```
Returns the key bytes, encoded according to the X.509 standard.
| Returns ||
|----------|--------------------------------------------------------------------------------------------|
| `byte[]` | the X.509 encoding of the key. Returns a new array each time this method is called.
|
### getFormat
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public final String getFormat ()
```
Returns the name of the encoding format associated with this key specification.
| Returns ||
|--------------------------------------------------------------------|-----------------------------|
| [String](https://developer.android.com/reference/java/lang/String) | the string`"X.509"`.
|