Android Network Programming API notes-java.net package APIs

Android Network programming package: 9 packets, 20 interfaces, 103 categories, 6 enumeration, 14 exceptions;

--Java package: Java.net package (6 interfaces, 34 categories, 2 enumeration, 12 exceptions );

--Android package: Android.net package (1 interface, 19 classes, 3 enumeration, 1 exception), android.net. http packet (6 types), android.net. nsd package (3 interfaces, 2 categories), android.net. rtp (class 4), android.net. sip package (1 interface, 9 categories, 1 exception), android.net. wifi package (16 categories, 1 enumeration), android.net. wifi. p2p package (9 interfaces, 7 categories), android.net. wifi. p2p. nsd package (6 categories );

ContentHandlerFactory: This interface defines the content processing program factory;

DatagramSocketImplFactory: This interface defines the factory for implementing user datagram;

FileNameMap: DefinedIng between file names and MIME Type stringsInterface;

SocketImplFactory: Define the socket implementation factory;

SocketOptions: DefinitionObtain the method for setting SOCKET optionsInterface;

URLStreamHandlerFactory: Defines the URL stream protocol handler factory;

1. ContentHandlerFactory

Function: Defines the content processing program factory. The implementation class of this interface is responsible for ing the MIME type to the ContentHandler instance object;

MIME parsing:

--Extension: Multipurpose Internet Mail Extentions multi-purpose Internet Mail Extension type;

--Function: Use Program B to open A file with the extension A. When the file with the extension A is accessed, the browser will automatically call program B to open the file with the extension;

--Usage: Mostly used to associate custom file suffix file opening methods and media file opening methods;

Interface Environment: URLStreamHandler uses the method implemented by this interface to create the ContentHandler of the MIME Type;

Interface Method Parsing:

ContentHandler createContentHandler(String mimetype)

-- Function: Create a New ContentHandler. The ContentHandler can read objects from URLStreamHandler;

2. DatagramSocketImplFactory

Function: Defines the factory used for data PACKET socket implementation;

Interface Environment: Assumramsocket uses this interface to create a socket instance;

Interface Method Parsing:

DatagramSocketImpl createDatagramSocketImpl()

-- Function: Create an DatagramSocketImpl instance object;

3. FileNameMap

Function:File NameAndMIME Type stringInterfaces required for ing between them;

Interface Method Parsing:

String getContentTypeFor(String fileName)

-- Function: Gets the MIME Type string of the specified file name;

4. SocketImplFactory

Function: Defines the socket implementation factory;

Environment: Socket and ServerSocket use the method defined by this interface to create a Socket instance;

Method Analysis:

SocketImpl createSocketImpl()

-- Function: Create a new socket instance;

5. SocketOptions

Function: DefinedSet to getMethod of socket options;

Interface Environment: SocketImpl and DatagramSocketImpl implement this interface. subclasses of these two classes should rewrite this interface to support the options of subclass of the two classes;

(1) constant field Parsing

IP_MULTICAST_IF: Sets an outgoing interface (eth0, eth1, wlan0, etc.) for sending multicast packets );

--Environment:Multiple Network InterfacesIn general, in this case, the application does not use the default system interface, but uses other interfaces;

IP Multicast: One host (Multicast Source) simultaneously sends the same data to multiple hosts;

IP-MULTICAST_IF2: Works the same as IP_MULTICAST_IF, but supports IPv4 IPv6.Version 1.4Start to support;

IF_MULTICAST_LOOP: Used to start or disable multicast datagram sending. The default status is start;

IP_TOS: InIP Address HeaderSet tcp udp datagramService TypeOrTraffic Field;

TOS (Type Of Service): The packet forwarding priority in the network area. The following is a common constant service type in a single byte;

--IPTOS_LOWDELAY: Minimize latency;

--IPTOS_THROUGHPUT: Optimized throughput;

--IPTOS_RELIABILITY: Reliability optimization;

--IPTOS_MINCOST: Fill in the data, which can be transmitted at low speed, irrelevant;

SO_BINDADDR: Obtain the local address of the bound socket;

--The local socket address cannot be changed.: The socket is bound to a local address when it is created, so it cannot be changed;

--Default socket address: INADDR_ANY indicates any address of a multi-host (host with multiple IP addresses;

SO_REUSEADDR: Used only for MulticastSocket. This option is set by default for MulticastSocket, which is valid for DatagramSocketImpl;

SO_BROADCAST: Enable the processing capability to disable sending of broadcast messages;

--Use Cases: Datagram socket, supporting the network of the concept of broadcast message;

--Default settings: DatagramSocket starts this option by default;

SO_KEEPALIVE: This option is set for TCP Socket. If data is not transmitted through Socket within 2 hours, TCP will send the keepalive probe to the same body;

--Function: Checks whether the same-bit host crashes;

--Applicability: Valid only for TCP sockets;

--The same body uses the expected ACK response: The application is not notified. After no data is transmitted for the other two hours, TCP continues to send a probe;

--Same-bit response through RST: Notifies the local TCP same-bit host to crash and closes socket to restart the host;

--No response from the same-Bit Body: Directly close the socket;

SO_LINGER: The timeout value for closing the stay, that is, the waiting time after the TCP Socket closes;

--Enable non-0 timeout value: After close (), it is blocked until transmission and read/write confirmation are completed. If it times out, it will be forcibly closed through tcp rst;

--Enable 0 timeout value: After close (), it will be forced to close without any waiting;

SO_OOBINLINE: Whether to discard tcp emergency data received by the socket;

--Startup options: Tcp emergency data received by the socket is received through the socket input stream;

--Disable Option: The received tcp emergency data is directly discarded;

SO_RCVBUF (receive): Set NetworkInputThe buffer size;

--Set Method usage: Set through socketReceive dataThe size of the buffer used;

--Obtain method usage: Get socket settingsReceive dataBuffer size;

--Applicability: SocketImpl, DatagramSocketImpl;

SO_SNDBUF (send): Set NetworkOutputThe basic I/O buffer size prompt used;

--Set Method usage: Set through socketSend dataThe size of the buffer used;

--Obtain method usage: Get socket settingsSend dataBuffer size;

--Applicability: SocketImpl, DatagramSocketImpl;

SO_TIMEOUT: Set the timeout value for Socket blocking;

--Timeout operation: ServerSocket. accept (), SocketInputStream. read (), DatagramSocket. receive ();

--Set Time: This option is valid only when it is set before it is blocked. If it is blocked, the setting will not take effect for this blocking;

--Timeout Processing: If a timeout occurs, the blocking operation will continue, but InterruptedIOException will be thrown, and the Socket will not be closed;

--Applicability: This setting is valid for all Sockets (SocketImpl, DatagramSocketImpl;

TCP_NODELAY: Set the link of this parameter to disable the nagle algorithm;

Nagle algorithm analysis: Reduce the number of packages, which is used to increase the efficiency of network software and avoid the use of 40 bytes of header files for a packet containing only one byte;

(2) interface methods

void setOption(int optID, Object value) throws SocketException

-- Function: Enable/disable the specified option. If enabled, the value option is used;

--Option input error: If the format of the input value is incorrect, an error occurs;

--Input Basic Data Type: Uses Integer Boolean and Other encapsulation;

--Disable Option: New Boolean (false) can be used to disable any option. This option is enabled if other content is input;

--Exception: If the options match incorrectly or the socket is closed, a SocketException exception is reported;

Object getOption(int optID) throws SocketException

-- Function: Get the option value;

6. URLStreamHandlerFactory

Interface Function: Defines the factory of the URL stream protocol processing program. The URL class implements this interface to create URLStreamHandler for a specific protocol;

createURLStreamHandler URLStreamHandler createURLStreamHandler(String protocol)

-- Function: Create a New URLStreamHandler instance with the specified protocol;

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