Package org.springframework.util
Class SocketUtils
java.lang.Object
org.springframework.util.SocketUtils
Simple utility methods for working with network sockets — for example,
for finding available ports on
localhost
.
Within this class, a TCP port refers to a port for a ServerSocket
;
whereas, a UDP port refers to a port for a DatagramSocket
.
- Since:
- 4.0
- Author:
- Sam Brannen, Ben Hale, Arjen Poutsma, Gunnar Hillert, Gary Russell
-
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final int
The default maximum value for port ranges used when finding an available socket port.static final int
The default minimum value for port ranges used when finding an available socket port. -
Constructor Summary
ConstructorsConstructorDescriptionAlthoughSocketUtils
consists solely of static utility methods, this constructor is intentionallypublic
. -
Method Summary
Modifier and TypeMethodDescriptionstatic int
static int
findAvailableTcpPort
(int minPort) Find an available TCP port randomly selected from the range [minPort
, 65535].static int
findAvailableTcpPort
(int minPort, int maxPort) Find an available TCP port randomly selected from the range [minPort
,maxPort
].findAvailableTcpPorts
(int numRequested) findAvailableTcpPorts
(int numRequested, int minPort, int maxPort) Find the requested number of available TCP ports, each randomly selected from the range [minPort
,maxPort
].static int
static int
findAvailableUdpPort
(int minPort) Find an available UDP port randomly selected from the range [minPort
, 65535].static int
findAvailableUdpPort
(int minPort, int maxPort) Find an available UDP port randomly selected from the range [minPort
,maxPort
].findAvailableUdpPorts
(int numRequested) findAvailableUdpPorts
(int numRequested, int minPort, int maxPort) Find the requested number of available UDP ports, each randomly selected from the range [minPort
,maxPort
].
-
Field Details
-
PORT_RANGE_MIN
public static final int PORT_RANGE_MINThe default minimum value for port ranges used when finding an available socket port.- See Also:
-
PORT_RANGE_MAX
public static final int PORT_RANGE_MAXThe default maximum value for port ranges used when finding an available socket port.- See Also:
-
-
Constructor Details
-
SocketUtils
public SocketUtils()AlthoughSocketUtils
consists solely of static utility methods, this constructor is intentionallypublic
.Rationale
Static methods from this class may be invoked from within XML configuration files using the Spring Expression Language (SpEL) and the following syntax.
If this constructor were<bean id="bean1" ... p:port="#{T(org.springframework.util.SocketUtils).findAvailableTcpPort(12000)}" />
private
, you would be required to supply the fully qualified class name to SpEL'sT()
function for each usage. Thus, the fact that this constructor ispublic
allows you to reduce boilerplate configuration with SpEL as can be seen in the following example.<bean id="socketUtils" class="org.springframework.util.SocketUtils" /> <bean id="bean1" ... p:port="#{socketUtils.findAvailableTcpPort(12000)}" /> <bean id="bean2" ... p:port="#{socketUtils.findAvailableTcpPort(30000)}" />
-
-
Method Details
-
findAvailableTcpPort
public static int findAvailableTcpPort()- Returns:
- an available TCP port number
- Throws:
IllegalStateException
- if no available port could be found
-
findAvailableTcpPort
public static int findAvailableTcpPort(int minPort) Find an available TCP port randomly selected from the range [minPort
, 65535].- Parameters:
minPort
- the minimum port number- Returns:
- an available TCP port number
- Throws:
IllegalStateException
- if no available port could be found
-
findAvailableTcpPort
public static int findAvailableTcpPort(int minPort, int maxPort) Find an available TCP port randomly selected from the range [minPort
,maxPort
].- Parameters:
minPort
- the minimum port numbermaxPort
- the maximum port number- Returns:
- an available TCP port number
- Throws:
IllegalStateException
- if no available port could be found
-
findAvailableTcpPorts
Find the requested number of available TCP ports, each randomly selected from the range [1024, 65535].- Parameters:
numRequested
- the number of available ports to find- Returns:
- a sorted set of available TCP port numbers
- Throws:
IllegalStateException
- if the requested number of available ports could not be found
-
findAvailableTcpPorts
Find the requested number of available TCP ports, each randomly selected from the range [minPort
,maxPort
].- Parameters:
numRequested
- the number of available ports to findminPort
- the minimum port numbermaxPort
- the maximum port number- Returns:
- a sorted set of available TCP port numbers
- Throws:
IllegalStateException
- if the requested number of available ports could not be found
-
findAvailableUdpPort
public static int findAvailableUdpPort()- Returns:
- an available UDP port number
- Throws:
IllegalStateException
- if no available port could be found
-
findAvailableUdpPort
public static int findAvailableUdpPort(int minPort) Find an available UDP port randomly selected from the range [minPort
, 65535].- Parameters:
minPort
- the minimum port number- Returns:
- an available UDP port number
- Throws:
IllegalStateException
- if no available port could be found
-
findAvailableUdpPort
public static int findAvailableUdpPort(int minPort, int maxPort) Find an available UDP port randomly selected from the range [minPort
,maxPort
].- Parameters:
minPort
- the minimum port numbermaxPort
- the maximum port number- Returns:
- an available UDP port number
- Throws:
IllegalStateException
- if no available port could be found
-
findAvailableUdpPorts
Find the requested number of available UDP ports, each randomly selected from the range [1024, 65535].- Parameters:
numRequested
- the number of available ports to find- Returns:
- a sorted set of available UDP port numbers
- Throws:
IllegalStateException
- if the requested number of available ports could not be found
-
findAvailableUdpPorts
Find the requested number of available UDP ports, each randomly selected from the range [minPort
,maxPort
].- Parameters:
numRequested
- the number of available ports to findminPort
- the minimum port numbermaxPort
- the maximum port number- Returns:
- a sorted set of available UDP port numbers
- Throws:
IllegalStateException
- if the requested number of available ports could not be found
-