# Signer
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
Deprecated in[API level 3](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
Summary:[Ctors](https://developer.android.com/reference/java/security/Signer#pubctors)\|[Protected Ctors](https://developer.android.com/reference/java/security/Signer#proctors)\|[Methods](https://developer.android.com/reference/java/security/Signer#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/java/security/Signer#inhmethods)
# Signer
`
public
abstract
class
Signer
`
`
``
extends `[Identity](https://developer.android.com/reference/java/security/Identity)`
``
`
|---|---|----------------------|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) |||
| ↳ | [java.security.Identity](https://developer.android.com/reference/java/security/Identity) ||
| | ↳ | java.security.Signer |
*** ** * ** ***
**This class was deprecated in API level 3.**
This class is deprecated and subject to removal in a future version of Java SE. It has been replaced by`java.security.KeyStore`, the`java.security.cert`package, and`java.security.Principal`.
This class is used to represent an Identity that can also digitally sign data.
The management of a signer's private keys is an important and sensitive issue that should be handled by subclasses as appropriate to their intended use.
**See also:**
- [Identity](https://developer.android.com/reference/java/security/Identity)
## Summary
| ### Public constructors ||
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ` `[Signer](https://developer.android.com/reference/java/security/Signer#Signer(java.lang.String))`(`[String](https://developer.android.com/reference/java/lang/String)` name) ` Creates a signer with the specified identity name. |
| ` `[Signer](https://developer.android.com/reference/java/security/Signer#Signer(java.lang.String,%20java.security.IdentityScope))`(`[String](https://developer.android.com/reference/java/lang/String)` name, `[IdentityScope](https://developer.android.com/reference/java/security/IdentityScope)` scope) ` Creates a signer with the specified identity name and scope. |
| ### Protected constructors ||
|-----------------------------------------------------------------------------------------------------------|---|
| ` `[Signer](https://developer.android.com/reference/java/security/Signer#Signer())`() ` Creates a signer. |
| ### Public methods ||
|-----------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` `[PrivateKey](https://developer.android.com/reference/java/security/PrivateKey) | ` `[getPrivateKey](https://developer.android.com/reference/java/security/Signer#getPrivateKey())`() ` Returns this signer's private key. |
| ` final void` | ` `[setKeyPair](https://developer.android.com/reference/java/security/Signer#setKeyPair(java.security.KeyPair))`(`[KeyPair](https://developer.android.com/reference/java/security/KeyPair)` pair) ` Sets the key pair (public key and private key) for this signer. |
| ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/java/security/Signer#toString())`() ` Returns a string of information about the signer. |
| ### Inherited methods |
|-----------------------|---|
| From class` `[java.security.Identity](https://developer.android.com/reference/java/security/Identity)` ` |-----------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` void` | ` `[addCertificate](https://developer.android.com/reference/java/security/Identity#addCertificate(java.security.Certificate))`(`[Certificate](https://developer.android.com/reference/java/security/Certificate)` certificate) ` Adds a certificate for this identity. | | ` `[Certificate[]](https://developer.android.com/reference/java/security/Certificate) | ` `[certificates](https://developer.android.com/reference/java/security/Identity#certificates())`() ` Returns a copy of all the certificates for this identity. | | ` final boolean` | ` `[equals](https://developer.android.com/reference/java/security/Identity#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` identity) ` Tests for equality between the specified object and this identity. | | ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[getInfo](https://developer.android.com/reference/java/security/Identity#getInfo())`() ` Returns general information previously specified for this identity. | | ` final `[String](https://developer.android.com/reference/java/lang/String) | ` `[getName](https://developer.android.com/reference/java/security/Identity#getName())`() ` Returns this identity's name. | | ` `[PublicKey](https://developer.android.com/reference/java/security/PublicKey) | ` `[getPublicKey](https://developer.android.com/reference/java/security/Identity#getPublicKey())`() ` Returns this identity's public key. | | ` final `[IdentityScope](https://developer.android.com/reference/java/security/IdentityScope) | ` `[getScope](https://developer.android.com/reference/java/security/Identity#getScope())`() ` Returns this identity's scope. | | ` int` | ` `[hashCode](https://developer.android.com/reference/java/security/Identity#hashCode())`() ` Returns a hashcode for this identity. | | ` boolean` | ` `[identityEquals](https://developer.android.com/reference/java/security/Identity#identityEquals(java.security.Identity))`(`[Identity](https://developer.android.com/reference/java/security/Identity)` identity) ` Tests for equality between the specified identity and this identity. | | ` void` | ` `[removeCertificate](https://developer.android.com/reference/java/security/Identity#removeCertificate(java.security.Certificate))`(`[Certificate](https://developer.android.com/reference/java/security/Certificate)` certificate) ` Removes a certificate from this identity. | | ` void` | ` `[setInfo](https://developer.android.com/reference/java/security/Identity#setInfo(java.lang.String))`(`[String](https://developer.android.com/reference/java/lang/String)` info) ` Specifies a general information string for this identity. | | ` void` | ` `[setPublicKey](https://developer.android.com/reference/java/security/Identity#setPublicKey(java.security.PublicKey))`(`[PublicKey](https://developer.android.com/reference/java/security/PublicKey)` key) ` Sets this identity's public key. | | ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/java/security/Identity#toString())`() ` Returns a short string describing this identity, telling its name and its scope (if any). | | ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/java/security/Identity#toString(boolean))`(boolean detailed) ` Returns a string representation of this identity, with optionally more details than that provided by the`toString`method without any arguments. | ||
| 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*. | ||
| From interface` `[java.security.Principal](https://developer.android.com/reference/java/security/Principal)` ` |--------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` abstract boolean` | ` `[equals](https://developer.android.com/reference/java/security/Principal#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` another) ` Compares this principal to the specified object. | | ` abstract `[String](https://developer.android.com/reference/java/lang/String) | ` `[getName](https://developer.android.com/reference/java/security/Principal#getName())`() ` Returns the name of this principal. | | ` abstract int` | ` `[hashCode](https://developer.android.com/reference/java/security/Principal#hashCode())`() ` Returns a hashcode for this principal. | | ` default boolean` | ` `[implies](https://developer.android.com/reference/java/security/Principal#implies(javax.security.auth.Subject))`(`[Subject](https://developer.android.com/reference/javax/security/auth/Subject)` subject) ` Returns true if the specified subject is implied by this principal. | | ` abstract `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/java/security/Principal#toString())`() ` Returns a string representation of this principal. | ||
## Public constructors
### Signer
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public Signer (String name)
```
Creates a signer with the specified identity name.
| Parameters ||
|--------|-------------------------------------|
| `name` | `String`: the identity name.
|
### Signer
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public Signer (String name,
IdentityScope scope)
```
Creates a signer with the specified identity name and scope.
| Parameters ||
|---------|----------------------------------------------------|
| `name` | `String`: the identity name.
|
| `scope` | `IdentityScope`: the scope of the identity.
|
| Throws ||
|--------------------------------------------------------------------------------------------------------|------------------------------------------------------------------|
| [KeyManagementException](https://developer.android.com/reference/java/security/KeyManagementException) | if there is already an identity with the same name in the scope. |
## Protected constructors
### Signer
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
protected Signer ()
```
Creates a signer. This constructor should only be used for serialization.
## Public methods
### getPrivateKey
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public PrivateKey getPrivateKey ()
```
Returns this signer's private key.
First, if there is a security manager, its`checkSecurityAccess`method is called with`"getSignerPrivateKey"`as its argument to see if it's ok to return the private key.
| Returns ||
|--------------------------------------------------------------------------------|------------------------------------------------------------------------------------|
| [PrivateKey](https://developer.android.com/reference/java/security/PrivateKey) | this signer's private key, or null if the private key has not yet been set.
|
| Throws ||
|------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------|
| [SecurityException](https://developer.android.com/reference/java/lang/SecurityException) | if a security manager exists and its`checkSecurityAccess`method doesn't allow returning the private key. |
**See also:**
- [SecurityManager.checkSecurityAccess(String)](https://developer.android.com/reference/java/lang/SecurityManager#checkSecurityAccess(java.lang.String))
### setKeyPair
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public final void setKeyPair (KeyPair pair)
```
Sets the key pair (public key and private key) for this signer.
First, if there is a security manager, its`checkSecurityAccess`method is called with`"setSignerKeyPair"`as its argument to see if it's ok to set the key pair.
| Parameters ||
|--------|--------------------------------------------|
| `pair` | `KeyPair`: an initialized key pair.
|
| Throws ||
|--------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------|
| [InvalidParameterException](https://developer.android.com/reference/java/security/InvalidParameterException) | if the key pair is not properly initialized. |
| [KeyException](https://developer.android.com/reference/java/security/KeyException) | if the key pair cannot be set for any other reason. |
| [SecurityException](https://developer.android.com/reference/java/lang/SecurityException) | if a security manager exists and its`checkSecurityAccess`method doesn't allow setting the key pair. |
**See also:**
- [SecurityManager.checkSecurityAccess(String)](https://developer.android.com/reference/java/lang/SecurityManager#checkSecurityAccess(java.lang.String))
### toString
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public String toString ()
```
Returns a string of information about the signer.
| Returns ||
|--------------------------------------------------------------------|--------------------------------------------------|
| [String](https://developer.android.com/reference/java/lang/String) | a string of information about the signer.
|