Package com.alibaba.dcm.internal

Class InetAddressCacheUtilCommons

java.lang.Object

com.alibaba.dcm.internal.InetAddressCacheUtilCommons

public class InetAddressCacheUtilCommons
extends Object

Util class to manipulate dns cache.

Since:

1.6.0

Author:

Jerry Lee (oldratlee at gmail dot com)

Field Summary

Fields

Modifier and Type	Field	Description
static long	NEVER_EXPIRATION	We never really have "never".

Constructor Summary

Constructors

Constructor	Description
InetAddressCacheUtilCommons()

Method Summary

Modifier and Type	Method	Description
static int	getDnsCachePolicy()
static int	getDnsNegativeCachePolicy()
static void	setDnsCachePolicy(int cacheSeconds)	Set JVM DNS cache policy
static void	setDnsNegativeCachePolicy(int negativeCacheSeconds)	Set JVM DNS negative cache policy

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NEVER_EXPIRATION

public static final long NEVER_EXPIRATION

We never really have "never".

Long.MAX_VALUE(~9e18) nanoseconds is ~292 years.

Long.MAX_VALUE / 1e9 / 3600 / 24 / 365 ~= 292.47.

See Also:

Constant Field Values

Constructor Detail

InetAddressCacheUtilCommons

public InetAddressCacheUtilCommons()

Method Detail

setDnsCachePolicy

public static void setDnsCachePolicy(int cacheSeconds)
                              throws NoSuchFieldException,
                                     IllegalAccessException

Set JVM DNS cache policy

Parameters:

cacheSeconds - set default dns cache time. Special input case:

• -1 means never expired.(In effect, all negative value)
• 0 never cached.

Throws:

NoSuchFieldException

IllegalAccessException

See Also:

InetAddressCachePolicy, InetAddressCachePolicy.cachePolicy

getDnsCachePolicy

public static int getDnsCachePolicy()

setDnsNegativeCachePolicy

public static void setDnsNegativeCachePolicy(int negativeCacheSeconds)
                                      throws NoSuchFieldException,
                                             IllegalAccessException

Set JVM DNS negative cache policy

Parameters:

negativeCacheSeconds - set default dns cache time. Special input case:

• -1 means never expired.(In effect, all negative value)
• 0 never cached.

Throws:

NoSuchFieldException

IllegalAccessException

See Also:

InetAddressCachePolicy, InetAddressCachePolicy.negativeCachePolicy

getDnsNegativeCachePolicy

public static int getDnsNegativeCachePolicy()