AlertMessage (bitcoinj-core 0.16-SNAPSHOT API)

java.lang.Object
- org.bitcoinj.core.Message
- - org.bitcoinj.core.AlertMessage

```
public class AlertMessage
extends Message
```
Alerts are signed messages that are broadcast on the peer-to-peer network if they match a hard-coded signing key. The private keys are held by a small group of core Bitcoin developers, and alerts may be broadcast in the event of an available upgrade or a serious network problem. Alerts have an expiration time, data that specifies what set of software versions it matches and the ability to cancel them by broadcasting another type of alert.
The right course of action on receiving an alert is usually to either ensure a human will see it (display on screen, log, email), or if you decide to use alerts for notifications that are specific to your app in some way, to parse it. For example, you could treat it as an upgrade notification specific to your app. Satoshi designed alerts to ensure that software upgrades could be distributed independently of a hard-coded website, in order to allow everything to be purely peer-to-peer. You don't have to use this of course, and indeed it often makes more sense not to.

Before doing anything with an alert, you should check isSignatureValid().

Instances of this class are not safe for use by multiple threads.

Field Summary
- Fields inherited from class org.bitcoinj.core.Message
  cursor, length, MAX_SIZE, offset, params, payload, recached, serializer, UNKNOWN_LENGTH

Constructor Summary

Constructors
Constructor and Description

AlertMessage(NetworkParameters params, byte[] payloadBytes)

Constructors
Constructor and Description
`AlertMessage(NetworkParameters params, byte[] payloadBytes)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`long`	`getCancel()` A marker that results in any alerts with an ID lower than this value to be considered cancelled.
`java.lang.String`	`getComment()` This field is unused.
`java.util.Date`	`getExpiration()` The time at which the alert ceases to be relevant.
`long`	`getId()` The numeric identifier of this alert.
`long`	`getMaxVer()` The inclusive upper bound on software versions considered for the purposes of this alert.
`long`	`getMinVer()` The inclusive lower bound on software versions that are considered for the purposes of this alert.
`long`	`getPriority()` Provides an integer ordering amongst simultaneously active alerts.
`java.util.Date`	`getRelayUntil()` The time at which the alert should stop being broadcast across the network.
`java.lang.String`	`getReserved()` This field is never used.
`java.lang.String`	`getStatusBar()` A string that is intended to display in the status bar of Bitcoin Core's GUI client.
`long`	`getVersion()`
`boolean`	`isSignatureValid()` Returns true if the digital signature attached to the message verifies.
`protected void`	`parse()`
`void`	`setCancel(long cancel)`
`void`	`setComment(java.lang.String comment)`
`void`	`setExpiration(java.util.Date expiration)`
`void`	`setId(long id)`
`void`	`setMaxVer(long maxVer)`
`void`	`setMinVer(long minVer)`
`void`	`setPriority(long priority)`
`void`	`setRelayUntil(java.util.Date relayUntil)`
`void`	`setReserved(java.lang.String reserved)`
`void`	`setStatusBar(java.lang.String statusBar)`
`java.lang.String`	`toString()`

Methods inherited from class org.bitcoinj.core.Message
adjustLength, bitcoinSerialize, bitcoinSerialize, bitcoinSerializeToStream, getHash, getMessageSize, getParams, hasMoreBytes, isCached, isRecached, readByte, readByteArray, readBytes, readHash, readInt64, readStr, readUint32, readUint64, readVarInt, readVarInt, setSerializer, unCache, unsafeBitcoinSerialize

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - AlertMessage
```
public AlertMessage(NetworkParameters params,
                    byte[] payloadBytes)
             throws ProtocolException
```
    Throws:
    
    ProtocolException
- Method Detail
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - parse
```
protected void parse()
              throws ProtocolException
```
    Specified by:
    
    parse in class Message
    
    Throws:
    
    ProtocolException
  - isSignatureValid
```
public boolean isSignatureValid()
```
    Returns true if the digital signature attached to the message verifies. Don't do anything with the alert if it doesn't verify, because that would allow arbitrary attackers to spam your users.
  - getRelayUntil
```
public java.util.Date getRelayUntil()
```
    The time at which the alert should stop being broadcast across the network. Note that you can still receive the alert after this time from other nodes if the alert still applies to them or to you.
  - setRelayUntil
```
public void setRelayUntil(java.util.Date relayUntil)
```
  - getExpiration
```
public java.util.Date getExpiration()
```
    The time at which the alert ceases to be relevant. It should not be presented to the user or app administrator after this time.
  - setExpiration
```
public void setExpiration(java.util.Date expiration)
```
  - getId
```
public long getId()
```
    The numeric identifier of this alert. Each alert should have a unique ID, but the signer can choose any number. If an alert is broadcast with a cancel field higher than this ID, this alert is considered cancelled.
    
    Returns:
    
    uint32
  - setId
```
public void setId(long id)
```
  - getCancel
```
public long getCancel()
```
    A marker that results in any alerts with an ID lower than this value to be considered cancelled.
    
    Returns:
    
    uint32
  - setCancel
```
public void setCancel(long cancel)
```
  - getMinVer
```
public long getMinVer()
```
    The inclusive lower bound on software versions that are considered for the purposes of this alert. Bitcoin Core compares this against a protocol version field, but as long as the subVer field is used to restrict it your alerts could use any version numbers.
    
    Returns:
    
    uint32
  - setMinVer
```
public void setMinVer(long minVer)
```
  - getMaxVer
```
public long getMaxVer()
```
    The inclusive upper bound on software versions considered for the purposes of this alert. Bitcoin Core compares this against a protocol version field, but as long as the subVer field is used to restrict it your alerts could use any version numbers.
  - setMaxVer
```
public void setMaxVer(long maxVer)
```
  - getPriority
```
public long getPriority()
```
    Provides an integer ordering amongst simultaneously active alerts.
    
    Returns:
    
    uint32
  - setPriority
```
public void setPriority(long priority)
```
  - getComment
```
public java.lang.String getComment()
```
    This field is unused. It is presumably intended for the author of the alert to provide a justification for it visible to protocol developers but not users.
  - setComment
```
public void setComment(java.lang.String comment)
```
  - getStatusBar
```
public java.lang.String getStatusBar()
```
    A string that is intended to display in the status bar of Bitcoin Core's GUI client. It contains the user-visible message. English only.
  - setStatusBar
```
public void setStatusBar(java.lang.String statusBar)
```
  - getReserved
```
public java.lang.String getReserved()
```
    This field is never used.
  - setReserved
```
public void setReserved(java.lang.String reserved)
```
  - getVersion
```
public long getVersion()
```

Class AlertMessage

Field Summary

Fields inherited from class org.bitcoinj.core.Message

Constructor Summary

Method Summary

Methods inherited from class org.bitcoinj.core.Message

Methods inherited from class java.lang.Object

Constructor Detail

AlertMessage

Method Detail

toString

parse

isSignatureValid

getRelayUntil

setRelayUntil

getExpiration

setExpiration

getId

setId

getCancel

setCancel

getMinVer

setMinVer

getMaxVer

setMaxVer

getPriority

setPriority

getComment

setComment

getStatusBar

setStatusBar

getReserved

setReserved

getVersion