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/AlgorithmParametersSpi#pubctors) \| [Protected Methods](https://developer.android.com/reference/java/security/AlgorithmParametersSpi#promethods) \| [Inherited Methods](https://developer.android.com/reference/java/security/AlgorithmParametersSpi#inhmethods)

# AlgorithmParametersSpi


`
public


abstract
class
AlgorithmParametersSpi
`


`

extends https://developer.android.com/reference/java/lang/Object


`

`


`

|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | java.security.AlgorithmParametersSpi |

<br />

*** ** * ** ***

This class defines the *Service Provider Interface* (**SPI** )
for the `AlgorithmParameters` class, which is used to manage
algorithm parameters.

All the abstract methods in this class must be implemented by each
cryptographic service provider who wishes to supply parameter management
for a particular algorithm.
**See also:**

- `https://developer.android.com/reference/java/security/AlgorithmParameters`
- `https://developer.android.com/reference/java/security/spec/AlgorithmParameterSpec`
- `https://developer.android.com/reference/java/security/spec/DSAParameterSpec`

## Summary

| ### Public constructors ||
|---|---|
| ` https://developer.android.com/reference/java/security/AlgorithmParametersSpi#AlgorithmParametersSpi()() ` |

| ### Protected methods ||
|---|---|
| ` abstract byte[]` | ` https://developer.android.com/reference/java/security/AlgorithmParametersSpi#engineGetEncoded(java.lang.String)(https://developer.android.com/reference/java/lang/String format) ` Returns the parameters encoded in the specified format. |
| ` abstract byte[]` | ` https://developer.android.com/reference/java/security/AlgorithmParametersSpi#engineGetEncoded()() ` Returns the parameters in their primary encoding format. |
| ` abstract <T extends https://developer.android.com/reference/java/security/spec/AlgorithmParameterSpec> T` | ` https://developer.android.com/reference/java/security/AlgorithmParametersSpi#engineGetParameterSpec(java.lang.Class<T>)(https://developer.android.com/reference/java/lang/Class<T> paramSpec) ` Returns a (transparent) specification of this parameters object. |
| ` abstract void` | ` https://developer.android.com/reference/java/security/AlgorithmParametersSpi#engineInit(byte[],%20java.lang.String)(byte[] params, https://developer.android.com/reference/java/lang/String format) ` Imports the parameters from `params` and decodes them according to the specified decoding format. |
| ` abstract void` | ` https://developer.android.com/reference/java/security/AlgorithmParametersSpi#engineInit(java.security.spec.AlgorithmParameterSpec)(https://developer.android.com/reference/java/security/spec/AlgorithmParameterSpec paramSpec) ` Initializes this parameters object using the parameters specified in `paramSpec`. |
| ` abstract void` | ` https://developer.android.com/reference/java/security/AlgorithmParametersSpi#engineInit(byte[])(byte[] params) ` Imports the specified parameters and decodes them according to the primary decoding format for parameters. |
| ` abstract https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/security/AlgorithmParametersSpi#engineToString()() ` Returns a formatted string describing the parameters. |

| ### Inherited methods |
|---|---|
| From class ` https://developer.android.com/reference/java/lang/Object ` |---|---| | ` https://developer.android.com/reference/java/lang/Object` | ` https://developer.android.com/reference/java/lang/Object#clone()() ` Creates and returns a copy of this object. | | ` boolean` | ` https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) ` Indicates whether some other object is "equal to" this one. | | ` void` | ` 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 https://developer.android.com/reference/java/lang/Class<?>` | ` https://developer.android.com/reference/java/lang/Object#getClass()() ` Returns the runtime class of this `Object`. | | ` int` | ` https://developer.android.com/reference/java/lang/Object#hashCode()() ` Returns a hash code value for the object. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#notify()() ` Wakes up a single thread that is waiting on this object's monitor. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#notifyAll()() ` Wakes up all threads that are waiting on this object's monitor. | | ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/lang/Object#toString()() ` Returns a string representation of the object. | | ` final void` | ` 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` | ` 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` | ` 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

### AlgorithmParametersSpi

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public AlgorithmParametersSpi ()
```

<br />

<br />

## Protected methods

### engineGetEncoded

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
protected abstract byte[] engineGetEncoded (String format)
```

Returns the parameters encoded in the specified format.
If `format` is null, the
primary encoding format for parameters is used. The primary encoding
format is ASN.1, if an ASN.1 specification for these parameters
exists.

<br />

| Parameters ||
|---|---|
| `format` | `String`: the name of the encoding format. <br /> |

| Returns ||
|---|---|
| `byte[]` | the parameters encoded using the specified encoding scheme. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | on encoding errors. |

### engineGetEncoded

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
protected abstract byte[] engineGetEncoded ()
```

Returns the parameters in their primary encoding format.
The primary encoding format for parameters is ASN.1, if an ASN.1
specification for this type of parameters exists.

<br />

| Returns ||
|---|---|
| `byte[]` | the parameters encoded using their primary encoding format. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | on encoding errors. |

### engineGetParameterSpec

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
protected abstract T engineGetParameterSpec (Class<T> paramSpec)
```

Returns a (transparent) specification of this parameters
object.
`paramSpec` identifies the specification class in which
the parameters should be returned. It could, for example, be
`DSAParameterSpec.class`, to indicate that the
parameters should be returned in an instance of the
`DSAParameterSpec` class.

<br />

| Parameters ||
|---|---|
| `paramSpec` | `Class`: the specification class in which the parameters should be returned. <br /> |

| Returns ||
|---|---|
| `T` | the parameter specification. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/security/spec/InvalidParameterSpecException` | if the requested parameter specification is inappropriate for this parameter object. |

### engineInit

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
protected abstract void engineInit (byte[] params, 
                String format)
```

Imports the parameters from `params` and
decodes them according to the specified decoding format.
If `format` is null, the
primary decoding format for parameters is used. The primary decoding
format is ASN.1, if an ASN.1 specification for these parameters
exists.

<br />

| Parameters ||
|---|---|
| `params` | `byte`: the encoded parameters. <br /> |
| `format` | `String`: the name of the decoding format. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | on decoding errors |

### engineInit

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
protected abstract void engineInit (AlgorithmParameterSpec paramSpec)
```

Initializes this parameters object using the parameters
specified in `paramSpec`.

<br />

| Parameters ||
|---|---|
| `paramSpec` | `AlgorithmParameterSpec`: the parameter specification. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/security/spec/InvalidParameterSpecException` | if the given parameter specification is inappropriate for the initialization of this parameter object. |

### engineInit

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
protected abstract void engineInit (byte[] params)
```

Imports the specified parameters and decodes them
according to the primary decoding format for parameters.
The primary decoding format for parameters is ASN.1, if an ASN.1
specification for this type of parameters exists.

<br />

| Parameters ||
|---|---|
| `params` | `byte`: the encoded parameters. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | on decoding errors |

### engineToString

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
protected abstract String engineToString ()
```

Returns a formatted string describing the parameters.

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/String` | a formatted string describing the parameters. <br /> |