EnvHelppublic class EnvHelp extends Object
| Fields Summary |
|---|
| private static final String | DEFAULT_CLASS_LOADER Name of the attribute that specifies a default class loader
object.
The value associated with this attribute is a ClassLoader object | | private static final String | DEFAULT_CLASS_LOADER_NAME Name of the attribute that specifies a default class loader
ObjectName.
The value associated with this attribute is an ObjectName object | | public static final String | MAX_FETCH_NOTIFS Name of the attribute that specifies the maximum number of
notifications that a client will fetch from its server.. The
value associated with this attribute should be an
Integer object. The default value is 1000. | | public static final String | FETCH_TIMEOUT Name of the attribute that specifies the timeout for a
client to fetch notifications from its server. The value
associated with this attribute should be a Long
object. The default value is 60000 milleseconds. | | public static final String | DEFAULT_ORB | | public static final String | HIDDEN_ATTRIBUTESThe value of this attribute, if present, is a string specifying
what other attributes should not appear in
JMXConnectorServer.getAttributes(). It is a space-separated
list of attribute patterns, where each pattern is either an
attribute name, or an attribute prefix followed by a "*"
character. The "*" has no special significance anywhere except
at the end of a pattern. By default, this list is added to the
list defined by {@link #DEFAULT_HIDDEN_ATTRIBUTES} (which
uses the same format). If the value of this attribute begins
with an "=", then the remainder of the string defines the
complete list of attribute patterns. | | public static final String | DEFAULT_HIDDEN_ATTRIBUTESDefault list of attributes not to show. | | private static final SortedSet | defaultHiddenStrings | | private static final SortedSet | defaultHiddenPrefixes | | public static final String | SERVER_CONNECTION_TIMEOUT Name of the attribute that specifies the timeout to keep a
server side connection after answering last client request.
The default value is 120000 milliseconds. | | public static final String | CLIENT_CONNECTION_CHECK_PERIOD Name of the attribute that specifies the period in
millisecond for a client to check its connection. The default
value is 60000 milliseconds. | | private static final ClassLogger | logger |
| Methods Summary |
|---|
| public static void | checkAttributes(java.util.Map attributes)
/* Check that all attributes have a key that is a String.
Could make further checks, e.g. appropriate types for attributes. */
for (Iterator it = attributes.keySet().iterator(); it.hasNext(); ) {
Object key = it.next();
if (!(key instanceof String)) {
final String msg =
"Attributes contain key that is not a string: " + key;
throw new IllegalArgumentException(msg);
}
}
| | public static java.util.Map | filterAttributes(java.util.Map attributes)
if (logger.traceOn()) {
logger.trace("filterAttributes", "starts");
}
SortedMap map = new TreeMap(attributes);
purgeUnserializable(map.values());
hideAttributes(map);
return map;
| | public static java.lang.Throwable | getCause(java.lang.Throwable t)Returns the cause field of a Throwable object.
The cause field can be got only if t has an
{@link Throwable#getCause()} method (JDK Version >= 1.4)
Throwable ret = t;
try {
java.lang.reflect.Method getCause =
t.getClass().getMethod("getCause", (Class[]) null);
ret = (Throwable)getCause.invoke(t, (Object[]) null);
} catch (Exception e) {
// OK.
// it must be older than 1.4.
}
return (ret != null) ? ret: t;
| | public static long | getConnectionCheckPeriod(java.util.Map env)Returns the client connection check oeriod.
return getIntegerAttribute(env, CLIENT_CONNECTION_CHECK_PERIOD, 60000L,
0, Long.MAX_VALUE);
| | public static long | getFetchTimeout(java.util.Map env)Returns the timeout for a client to fetch notifications.
return getIntegerAttribute(env, FETCH_TIMEOUT, 60000L, 0,
Long.MAX_VALUE);
| | public static long | getIntegerAttribute(java.util.Map env, java.lang.String name, long defaultValue, long minValue, long maxValue)Get an integer-valued attribute with name name
from env. If env is null, or does
not contain an entry for name, return
defaultValue. The value may be a Number, or it
may be a String that is parsable as a long. It must be at
least minValue and at mostmaxValue.
final Object o;
if (env == null || (o = env.get(name)) == null)
return defaultValue;
final long result;
if (o instanceof Number)
result = ((Number) o).longValue();
else if (o instanceof String) {
result = Long.parseLong((String) o);
/* May throw a NumberFormatException, which is an
IllegalArgumentException. */
} else {
final String msg =
"Attribute " + name + " value must be Integer or String: " + o;
throw new IllegalArgumentException(msg);
}
if (result < minValue) {
final String msg =
"Attribute " + name + " value must be at least " + minValue +
": " + result;
throw new IllegalArgumentException(msg);
}
if (result > maxValue) {
final String msg =
"Attribute " + name + " value must be at most " + maxValue +
": " + result;
throw new IllegalArgumentException(msg);
}
return result;
| | public static int | getMaxFetchNotifNumber(java.util.Map env)Returns the maximum notification number which a client will
fetch every time.
return (int) getIntegerAttribute(env, MAX_FETCH_NOTIFS, 1000, 1,
Integer.MAX_VALUE);
| | public static long | getServerConnectionTimeout(java.util.Map env)Returns the server side connection timeout.
return getIntegerAttribute(env, SERVER_CONNECTION_TIMEOUT, 120000L,
0, Long.MAX_VALUE);
| | private static void | hideAttributes(java.util.SortedMap map)
if (map.isEmpty())
return;
final SortedSet hiddenStrings;
final SortedSet hiddenPrefixes;
String hide = (String) map.get(HIDDEN_ATTRIBUTES);
if (hide != null) {
if (hide.startsWith("="))
hide = hide.substring(1);
else
hide += " " + DEFAULT_HIDDEN_ATTRIBUTES;
hiddenStrings = new TreeSet();
hiddenPrefixes = new TreeSet();
parseHiddenAttributes(hide, hiddenStrings, hiddenPrefixes);
} else {
hide = DEFAULT_HIDDEN_ATTRIBUTES;
synchronized (defaultHiddenStrings) {
if (defaultHiddenStrings.isEmpty()) {
parseHiddenAttributes(hide,
defaultHiddenStrings,
defaultHiddenPrefixes);
}
hiddenStrings = defaultHiddenStrings;
hiddenPrefixes = defaultHiddenPrefixes;
}
}
/* Construct a string that is greater than any key in the map.
Setting a string-to-match or a prefix-to-match to this string
guarantees that we will never call next() on the corresponding
iterator. */
String sentinelKey = map.lastKey() + "X";
Iterator keyIterator = map.keySet().iterator();
Iterator stringIterator = hiddenStrings.iterator();
Iterator prefixIterator = hiddenPrefixes.iterator();
String nextString;
if (stringIterator.hasNext())
nextString = (String) stringIterator.next();
else
nextString = sentinelKey;
String nextPrefix;
if (prefixIterator.hasNext())
nextPrefix = (String) prefixIterator.next();
else
nextPrefix = sentinelKey;
/* Read each key in sorted order and, if it matches a string
or prefix, remove it. */
keys:
while (keyIterator.hasNext()) {
String key = (String) keyIterator.next();
/* Continue through string-match values until we find one
that is either greater than the current key, or equal
to it. In the latter case, remove the key. */
int cmp = +1;
while ((cmp = nextString.compareTo(key)) < 0) {
if (stringIterator.hasNext())
nextString = (String) stringIterator.next();
else
nextString = sentinelKey;
}
if (cmp == 0) {
keyIterator.remove();
continue keys;
}
/* Continue through the prefix values until we find one
that is either greater than the current key, or a
prefix of it. In the latter case, remove the key. */
while (nextPrefix.compareTo(key) <= 0) {
if (key.startsWith(nextPrefix)) {
keyIterator.remove();
continue keys;
}
if (prefixIterator.hasNext())
nextPrefix = (String) prefixIterator.next();
else
nextPrefix = sentinelKey;
}
}
| | public static java.lang.Throwable | initCause(java.lang.Throwable t, java.lang.Throwable cause)Init the cause field of a Throwable object.
The cause field is set only if t has an
{@link Throwable#initCause(Throwable)} method (JDK Version >= 1.4)
/* Make a best effort to set the cause, but if we don't
succeed, too bad, you don't get that useful debugging
information. We jump through hoops here so that we can
work on platforms prior to J2SE 1.4 where the
Throwable.initCause method was introduced. If we change
the public interface of JMRuntimeException in a future
version we can add getCause() so we don't need to do this. */
try {
java.lang.reflect.Method initCause =
t.getClass().getMethod("initCause",
new Class[] {Throwable.class});
initCause.invoke(t, new Object[] {cause});
} catch (Exception e) {
// OK.
// too bad, no debugging info
}
return t;
| | public static java.util.Hashtable | mapToHashtable(java.util.Map map)Converts a map into a valid hash table, i.e.
it removes all the 'null' values from the map.
HashMap m = new HashMap(map);
if (m.containsKey(null)) m.remove(null);
for (Iterator i = m.values().iterator(); i.hasNext(); )
if (i.next() == null) i.remove();
return new Hashtable(m);
| | private static void | parseHiddenAttributes(java.lang.String hide, java.util.SortedSet hiddenStrings, java.util.SortedSet hiddenPrefixes)
final StringTokenizer tok = new StringTokenizer(hide);
while (tok.hasMoreTokens()) {
String s = tok.nextToken();
if (s.endsWith("*"))
hiddenPrefixes.add(s.substring(0, s.length() - 1));
else
hiddenStrings.add(s);
}
| | private static void | purgeUnserializable(java.util.Collection objects)Remove from the given Collection any element that is not a
serializable object.
logger.trace("purgeUnserializable", "starts");
ObjectOutputStream oos = null;
int i = 0;
for (Iterator it = objects.iterator(); it.hasNext(); i++) {
Object v = it.next();
if (v == null || v instanceof String) {
if (logger.traceOn()) {
logger.trace("purgeUnserializable",
"Value trivially serializable: " + v);
}
continue;
}
try {
if (oos == null)
oos = new ObjectOutputStream(new SinkOutputStream());
oos.writeObject(v);
if (logger.traceOn()) {
logger.trace("purgeUnserializable",
"Value serializable: " + v);
}
} catch (IOException e) {
if (logger.traceOn()) {
logger.trace("purgeUnserializable",
"Value not serializable: " + v + ": " +
e);
}
it.remove();
oos = null; // ObjectOutputStream invalid after exception
}
}
| | public static java.lang.ClassLoader | resolveClientClassLoader(java.util.Map env)Get the Connector Client default class loader.
Returns:
-
The ClassLoader object found in env for
jmx.remote.default.class.loader, if any.
- The Thread.currentThread().getContextClassLoader()
otherwise.
Usually a Connector Client will call
ClassLoader dcl = EnvHelp.resolveClientClassLoader(env);
in its connect(Map env) method.
if (env == null)
return Thread.currentThread().getContextClassLoader();
Object loader = env.get(DEFAULT_CLASS_LOADER);
if (loader == null)
return Thread.currentThread().getContextClassLoader();
if (loader instanceof ClassLoader) {
return (ClassLoader) loader;
} else {
final String msg =
"ClassLoader object is not an instance of " +
ClassLoader.class.getName() + " : " +
loader.getClass().getName();
throw new IllegalArgumentException(msg);
}
| | public static java.lang.ClassLoader | resolveServerClassLoader(java.util.Map env, javax.management.MBeanServer mbs)Get the Connector Server default class loader.
Returns:
-
The ClassLoader object found in env for
jmx.remote.default.class.loader, if any.
-
The ClassLoader pointed to by the ObjectName found in
env for jmx.remote.default.class.loader.name,
and registered in mbs if any.
-
The current thread's context classloader otherwise.
if (env == null)
return Thread.currentThread().getContextClassLoader();
Object loader = env.get(DEFAULT_CLASS_LOADER);
Object name = env.get(DEFAULT_CLASS_LOADER_NAME);
if (loader != null && name != null) {
final String msg = "Only one of " +
DEFAULT_CLASS_LOADER + " or " +
DEFAULT_CLASS_LOADER_NAME +
" should be specified.";
throw new IllegalArgumentException(msg);
}
if (loader == null && name == null)
return Thread.currentThread().getContextClassLoader();
if (loader != null) {
if (loader instanceof ClassLoader) {
return (ClassLoader) loader;
} else {
final String msg =
"ClassLoader object is not an instance of " +
ClassLoader.class.getName() + " : " +
loader.getClass().getName();
throw new IllegalArgumentException(msg);
}
}
ObjectName on;
if (name instanceof ObjectName) {
on = (ObjectName) name;
} else {
final String msg =
"ClassLoader name is not an instance of " +
ObjectName.class.getName() + " : " +
name.getClass().getName();
throw new IllegalArgumentException(msg);
}
if (mbs == null)
throw new IllegalArgumentException("Null MBeanServer object");
return mbs.getClassLoader(on);
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