DatagramSocketClient

java.lang.Object
- com.fr.ftp.DatagramSocketClient

```
public abstract class DatagramSocketClient
extends java.lang.Object
```
The DatagramSocketClient provides the basic operations that are required of client objects accessing datagram sockets. It is meant to be subclassed to avoid having to rewrite the same code over and over again to open a socket, close a socket, set timeouts, etc. Of special note is the setDatagramSocketFactory method, which allows you to control the type of DatagramSocket the DatagramSocketClient creates for network communications. This is especially useful for adding things like proxy support as well as better support for applets. For example, you could create a DatagramSocketFactory that requests browser security capabilities before creating a socket. All classes derived from DatagramSocketClient should use the _socketFactory_ member variable to create DatagramSocket instances rather than instantiating them by directly invoking a constructor. By honoring this contract you guarantee that a user will always be able to provide his own Socket implementations by substituting his own SocketFactory.

另请参阅:
DatagramSocketFactory

字段概要

字段
限定符和类型	字段和说明
`protected boolean`	`_isOpen_` A status variable indicating if the client's socket is currently open.
`protected java.net.DatagramSocket`	`_socket_` The datagram socket used for the connection.
`protected DatagramSocketFactory`	`_socketFactory_` The datagram socket's DatagramSocketFactory.
`protected int`	`_timeout_` The timeout to use after opening a socket.

构造器概要

构造器
构造器和说明

DatagramSocketClient()
Default constructor for DatagramSocketClient.

构造器
构造器和说明
`DatagramSocketClient()` Default constructor for DatagramSocketClient.

方法概要

方法
限定符和类型	方法和说明
`void`	`close()` Closes the DatagramSocket used for the connection.
`java.nio.charset.Charset`	`getCharset()` Gets the charset.
`java.lang.String`	`getCharsetName()` Gets the charset name.
`int`	`getDefaultTimeout()` Returns the default timeout in milliseconds that is used when opening a socket.
`java.net.InetAddress`	`getLocalAddress()` Returns the local address to which the client's socket is bound.
`int`	`getLocalPort()` Returns the port number of the open socket on the local host used for the connection.
`int`	`getSoTimeout()` Returns the timeout in milliseconds of the currently opened socket.
`boolean`	`isOpen()` Returns true if the client has a currently open socket.
`void`	`open()` Opens a DatagramSocket on the local host at the first available port.
`void`	`open(int port)` Opens a DatagramSocket on the local host at a specified port.
`void`	`open(int port, java.net.InetAddress laddr)` Opens a DatagramSocket at the specified address on the local host at a specified port.
`void`	`setCharset(java.nio.charset.Charset charset)` Sets the charset.
`void`	`setDatagramSocketFactory(DatagramSocketFactory factory)` Sets the DatagramSocketFactory used by the DatagramSocketClient to open DatagramSockets.
`void`	`setDefaultTimeout(int timeout)` Set the default timeout in milliseconds to use when opening a socket.
`void`	`setSoTimeout(int timeout)` Set the timeout in milliseconds of a currently open connection.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - _timeout_
```
protected int _timeout_
```
    The timeout to use after opening a socket.
  - _socket_
```
protected java.net.DatagramSocket _socket_
```
    The datagram socket used for the connection.
  - _isOpen_
```
protected boolean _isOpen_
```
    A status variable indicating if the client's socket is currently open.
  - _socketFactory_
```
protected DatagramSocketFactory _socketFactory_
```
    The datagram socket's DatagramSocketFactory.
- 构造器详细资料
  - DatagramSocketClient
```
public DatagramSocketClient()
```
    Default constructor for DatagramSocketClient. Initializes _socket_ to null, _timeout_ to 0, and _isOpen_ to false.
- 方法详细资料
  - open
```
public void open()
          throws java.net.SocketException
```
    Opens a DatagramSocket on the local host at the first available port. Also sets the timeout on the socket to the default timeout set by setDefaultTimeout() .
    _isOpen_ is set to true after calling this method and _socket_ is set to the newly opened socket.
    
    抛出:
    
    java.net.SocketException - If the socket could not be opened or the timeout could not be set.
  - open
```
public void open(int port)
          throws java.net.SocketException
```
    Opens a DatagramSocket on the local host at a specified port. Also sets the timeout on the socket to the default timeout set by setDefaultTimeout() .
    _isOpen_ is set to true after calling this method and _socket_ is set to the newly opened socket.
    
    参数:
    port - The port to use for the socket.
    
    抛出:
    
    java.net.SocketException - If the socket could not be opened or the timeout could not be set.
  - open
```
public void open(int port,
        java.net.InetAddress laddr)
          throws java.net.SocketException
```
    Opens a DatagramSocket at the specified address on the local host at a specified port. Also sets the timeout on the socket to the default timeout set by setDefaultTimeout() .
    _isOpen_ is set to true after calling this method and _socket_ is set to the newly opened socket.
    
    参数:
    port - The port to use for the socket.
    laddr - The local address to use.
    
    抛出:
    
    java.net.SocketException - If the socket could not be opened or the timeout could not be set.
  - close
```
public void close()
```
    Closes the DatagramSocket used for the connection. You should call this method after you've finished using the class instance and also before you call open() again. _isOpen_ is set to false and _socket_ is set to null.
  - isOpen
```
public boolean isOpen()
```
    Returns true if the client has a currently open socket.
    
    返回:
    True if the client has a currently open socket, false otherwise.
  - setDefaultTimeout
```
public void setDefaultTimeout(int timeout)
```
    Set the default timeout in milliseconds to use when opening a socket. After a call to open, the timeout for the socket is set using this value. This method should be used prior to a call to open() and should not be confused with setSoTimeout() which operates on the currently open socket. _timeout_ contains the new timeout value.
    
    参数:
    timeout - The timeout in milliseconds to use for the datagram socket connection.
  - getDefaultTimeout
```
public int getDefaultTimeout()
```
    Returns the default timeout in milliseconds that is used when opening a socket.
    
    返回:
    The default timeout in milliseconds that is used when opening a socket.
  - setSoTimeout
```
public void setSoTimeout(int timeout)
                  throws java.net.SocketException
```
    Set the timeout in milliseconds of a currently open connection. Only call this method after a connection has been opened by open().
    
    参数:
    timeout - The timeout in milliseconds to use for the currently open datagram socket connection.
    
    抛出:
    
    java.net.SocketException - if an error setting the timeout
  - getSoTimeout
```
public int getSoTimeout()
                 throws java.net.SocketException
```
    Returns the timeout in milliseconds of the currently opened socket. If you call this method when the client socket is not open, a NullPointerException is thrown.
    
    返回:
    The timeout in milliseconds of the currently opened socket.
    
    抛出:
    
    java.net.SocketException - if an error getting the timeout
  - getLocalPort
```
public int getLocalPort()
```
    Returns the port number of the open socket on the local host used for the connection. If you call this method when the client socket is not open, a NullPointerException is thrown.
    
    返回:
    The port number of the open socket on the local host used for the connection.
  - getLocalAddress
```
public java.net.InetAddress getLocalAddress()
```
    Returns the local address to which the client's socket is bound. If you call this method when the client socket is not open, a NullPointerException is thrown.
    
    返回:
    The local address to which the client's socket is bound.
  - setDatagramSocketFactory
```
public void setDatagramSocketFactory(DatagramSocketFactory factory)
```
    Sets the DatagramSocketFactory used by the DatagramSocketClient to open DatagramSockets. If the factory value is null, then a default factory is used (only do this to reset the factory after having previously altered it).
    
    参数:
    factory - The new DatagramSocketFactory the DatagramSocketClient should use.
  - getCharsetName
```
public java.lang.String getCharsetName()
```
    Gets the charset name.
    
    返回:
    the charset name.
    从以下版本开始:
    
    3.3 TODO Will be deprecated once the code requires Java 1.6 as a mininmum
  - getCharset
```
public java.nio.charset.Charset getCharset()
```
    Gets the charset.
    
    返回:
    the charset.
    从以下版本开始:
    
    3.3
  - setCharset
```
public void setCharset(java.nio.charset.Charset charset)
```
    Sets the charset.
    
    参数:
    charset - the charset.
    从以下版本开始:
    
    3.3

类 DatagramSocketClient

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

_timeout_

_socket_

_isOpen_

_socketFactory_

构造器详细资料

DatagramSocketClient

方法详细资料

open

open

open

close

isOpen

setDefaultTimeout

getDefaultTimeout

setSoTimeout

getSoTimeout

getLocalPort

getLocalAddress

setDatagramSocketFactory

getCharsetName

getCharset

setCharset