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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package sun.jvmstat.monitor;
import java.net.*;
/**
* An abstraction that identifies a target Java Virtual Machine.
* The VmIdentifier, or vmid, provides a convenient string representation
* of the information needed to locate and communicate with a target
* Java Virtual Machine. The string, based on a {@link URI}, may specify
* the communications protocol, host name, local vm identifier, and protocol
* specific information for a target Java Virtual Machine. The format for
* a VmIdentifier string is:
* <pre>
* [<I>protocol</I>:][<I>//</I>]<I><B>lvmid</B></I>[<I>@hostname</I>][<I>:port</I>][<I>/servername</I>]
* </pre>
* The only required component of this string is the Local Virtual Machine
* Identifier, or <tt>lvmid</tt>, which uniquely identifies the target
* Java Virtual Machine on a host. The optional components of the VmIdentifier
* include:
* <ul>
* <li><p><tt>protocol</tt> - The communications protocol. A VmIdentifier
* omitting the protocol must be resolved against a HostIdentifier
* using {@link HostIdentifier#resolve}.
* </p></li>
* <li><p><tt>hostname</tt> - A hostname or IP address indicating the target
* host. A VmIdentifier omitting the protocol must be resolved
* against a HostIdentifier using {@link HostIdentifier#resolve}.
* </p></li>
* <li><p><tt>port</tt> - The port for the communications protocol.
* Treatment of the <tt>port</tt> parameter is implementation
* (protocol) specific. A VmIdentifier omitting the protocol should
* be resolved against a HostIdentifier using
* {@link HostIdentifier#resolve}.
* </p></li>
* <li><p><tt>servername</tt> - The treatment of the Path, Query, and
* Fragment components of the VmIdentifier are implementation
* (protocol) dependent. A VmIdentifier omitting the protocol should
* be resolved against a HostIdentifier using
* {@link HostIdentifier#resolve}.
* </p></li>
* </ul>
* <p>
* All VmIdentifier instances are constructed as absolute, hierarchical URIs.
* The constructors will accept relative (and even some malformed,
* though convenient) URI strings. Such strings are transformed into
* legitimate, absolute URI strings.
* </p>
* <p>
* With the exception of <em>file:</em> based VmIdentifier strings, all
* VmIdentifier strings must include a <tt>lvmid</tt>. Attempting to construct
* a non-file based VmIdentifier that doesn't include a <tt>lvmid</tt>
* component will result in a <tt>MonitorException</tt>.
* </p>
* <p>
* Here are some examples of VmIdentifier strings.
* <ul>
* <li><p>Relative URIs</p></li>
* <ul>
* <li><p><em>1234</em> - Specifies the Java Virtual Machine
* identified by lvmid <em>1234</em> on an unnamed host.
* This string is transformed into the absolute form
* <em>//1234</em>, which must be resolved against a
* HostIdentifier.
* </p></li>
* <li><p><em>1234@hostname</em> - Specifies the Java Virtual
* Machine identified by lvmid <em>1234</em> on host
* <em>hostname</em> with an unnamed protocol.
* This string is transformed into the absolute form
* <em>//1234@hostname</em>, which must be resolved against
* a HostIdentifier.
* </p></li>
* <li><p><em>1234@hostname:2099</em> - Specifies the Java Virtual
* Machine identified by lvmid <em>1234</em> on host
* <em>hostname</em> with an unnamed protocol, but with
* port <em>2099</em>. This string is transformed into
* the absolute form <em>//1234@hostname:2099</em>, which
* must be resolved against a HostIdentifier.
* </p></li>
* </ul>
* <li><p>Absolute URIs</p></li>
* <ul>
* <li><p><em>rmi://1234@hostname:2099/remoteobjectname</em> -
* Specifies the Java Virtual Machine identified by lvmid
* <em>1234</em> on host <em>hostname</em> accessed
* using the <em>rmi:</em> protocol through the rmi remote
* object named <em>remoteobjectname</em> as registered with
* the <em>rmiserver</em> on port <em>2099</em> on host
* <em>hostname</em>.
* </p></li>
* <li><p><em>file:/path/file</em> - Identifies a Java Virtual Machine
* through accessing a special file based protocol to use as
* the communications mechanism.
* </p></li>
* </ul>
* </ul>
* </p>
*
* @see URI
* @see HostIdentifier
* @author Brian Doherty
* @since 1.5
*/
public class VmIdentifier {
private URI uri;
/**
* creates a canonical representation of the uriString. This method
* performs certain translations depending on the type of URI generated
* by the string.
*/
private URI canonicalize(String uriString) throws URISyntaxException {
if (uriString == null) {
uriString = "local://0@localhost";
return new URI(uriString);
}
URI u = new URI(uriString);
if (u.isAbsolute()) {
if (u.isOpaque()) {
/*
* rmi:1234@hostname/path#fragment converted to
* rmi://1234@hostname/path#fragment
*/
u = new URI(u.getScheme(), "//" + u.getSchemeSpecificPart(),
u.getFragment());
}
} else {
/*
* make the uri absolute, if possible. A relative URI doesn't
* specify the scheme part, so it's safe to prepend a "//" and
* try again.
*/
if (!uriString.startsWith("//")) {
if (u.getFragment() == null) {
u = new URI("//" + u.getSchemeSpecificPart());
} else {
u = new URI("//" + u.getSchemeSpecificPart() + "#"
+ u.getFragment());
}
}
}
return u;
}
/**
* check that the VmIdentifier includes a unique numerical identifier
* for the target JVM.
*/
private void validate() throws URISyntaxException {
// file:// uri, which is a special case where the lvmid is not required.
String s = getScheme();
if ((s != null) && (s.compareTo("file") == 0)) {
return;
}
if (getLocalVmId() == -1) {
throw new URISyntaxException(uri.toString(), "Local vmid required");
}
}
/**
* Create a VmIdentifier instance from a string value.
*
* @param uriString a string representing a target Java Virtual Machine.
* The syntax of the string must conforms to the rules
* specified in the class documentation.
* @throws URISyntaxException Thrown when the uriString or its canonical
* form is poorly formed.
*/
public VmIdentifier(String uriString) throws URISyntaxException {
URI u;
try {
u = canonicalize(uriString);
} catch (URISyntaxException e) {
/*
* a vmid of the form 1234@hostname:1098 causes an exception,
* so try again with a leading "//"
*/
if (uriString.startsWith("//")) {
throw e;
}
u = canonicalize("//"+uriString);
}
uri = u;
// verify that we have a valid lvmid
validate();
}
/**
* Create a VmIdentifier instance from a URI object.
*
* @param uri a well formed, absolute URI indicating the
* target Java Virtual Machine.
* @throws URISyntaxException Thrown if the URI is missing some
* required component.
*/
public VmIdentifier(URI uri) throws URISyntaxException {
this.uri = uri;
validate();
}
/**
* Return the corresponding HostIdentifier for this VmIdentifier.
* <p>
* This method constructs a HostIdentifier object from the VmIdentifier.
* If the VmIdentifier is not specific about the protocol or other
* components of the URI, then the resulting HostIdentifier will
* be constructed based on this missing information. Typically, the
* missing components will have result in the HostIdentifier assigning
* assumed defaults that allow the VmIdentifier to be resolved according
* to those defaults.
* </p>
* <p>
* For example, a VmIdentifier that specifies only a <tt>lvmid</tt>
* will result in a HostIdentifier for <em>localhost</em> utilizing
* the default local protocol, <em>local:</em>. A VmIdentifier that
* specifies both a <tt>vmid</tt> and a <tt>hostname</tt> will result
* in a HostIdentifier for the specified host with the default remote
* protocol, <em>rmi:</em>, using the protocol defaults for the
* <tt>port</tt> and <tt>servername</tt> components.
* </p>
*
* @return HostIdentifier - the host identifier for the host containing
* the Java Virtual Machine represented by this
* VmIdentifier.
* @throws URISyntaxException Thrown if a bad host URI is constructed.
* This exception may get encapsulated into
* a MonitorException in a future version.
*/
public HostIdentifier getHostIdentifier() throws URISyntaxException {
StringBuffer sb = new StringBuffer();
if (getScheme() != null) {
sb.append(getScheme()).append(":");
}
sb.append("//").append(getHost());
if (getPort() != -1) {
sb.append(":").append(getPort());
}
if (getPath() != null) {
sb.append(getPath());
}
return new HostIdentifier(sb.toString());
}
/**
* Return the Scheme, or protocol, portion of this VmIdentifier.
*
* @return String - the scheme for this VmIdentifier.
* @see URI#getScheme()
*/
public String getScheme() {
return uri.getScheme();
}
/**
* Return the Scheme Specific Part of this VmIdentifier.
*
* @return String - the Scheme Specific Part for this VmIdentifier.
* @see URI#getSchemeSpecificPart()
*/
public String getSchemeSpecificPart() {
return uri.getSchemeSpecificPart();
}
/**
* Return the UserInfo part of this VmIdentifier.
*
* @return String - the UserInfo part for this VmIdentifier.
* @see URI#getUserInfo()
*/
public String getUserInfo() {
return uri.getUserInfo();
}
/**
* Return the Host part of this VmIdentifier.
*
* @return String - the Host part for this VmIdentifier.
* @see URI#getHost()
*/
public String getHost() {
return uri.getHost();
}
/**
* Return the Port part of this VmIdentifier.
*
* @return int - the Port part for this VmIdentifier.
* @see URI#getPort()
*/
public int getPort() {
return uri.getPort();
}
/**
* Return the Authority part of this VmIdentifier.
*
* @return String - the Authority part for this VmIdentifier.
* @see URI#getAuthority()
*/
public String getAuthority() {
return uri.getAuthority();
}
/**
* Return the Path part of this VmIdentifier.
*
* @return String - the Path part for this VmIdentifier.
* @see URI#getPath()
*/
public String getPath() {
return uri.getPath();
}
/**
* Return the Query part of this VmIdentifier.
*
* @return String - the Query part for this VmIdentifier.
* @see URI#getQuery()
*/
public String getQuery() {
return uri.getQuery();
}
/**
* Return the Fragment part of this VmIdentifier.
*
* @return String - the Fragment part for this VmIdentifier.
* @see URI#getFragment()
*/
public String getFragment() {
return uri.getFragment();
}
/**
* Return the Local Virtual Machine Identifier for this VmIdentifier.
* The Local Virtual Machine Identifier is also known as the
* <em>lvmid</em>.
*
* @return int - the lvmid for this VmIdentifier.
*/
public int getLocalVmId() {
int result = -1;
try {
if (uri.getUserInfo() == null) {
result = Integer.parseInt(uri.getAuthority());
} else {
result = Integer.parseInt(uri.getUserInfo());
}
} catch (NumberFormatException e) { }
return result;
}
/**
* Return the mode indicated in this VmIdentifier.
*
* @return String - the mode string. If no mode is specified, then "r"
* is returned. otherwise, the specified mode is returned.
*/
public String getMode() {
String query = getQuery();
if (query != null) {
String[] queryArgs = query.split("\\+");
for (int i = 0; i < queryArgs.length; i++) {
if (queryArgs[i].startsWith("mode=")) {
int index = queryArgs[i].indexOf('=');
return queryArgs[i].substring(index+1);
}
}
}
return "r";
}
/**
* Return the URI associated with the VmIdentifier.
*
* @return URI - the URI.
* @see URI
*/
public URI getURI() {
return uri;
}
/**
* Return the hash code for this VmIdentifier. The hash code is
* identical to the hash code for the contained URI.
*
* @return int - the hashcode.
* @see URI#hashCode()
*/
public int hashCode() {
return uri.hashCode();
}
/**
* Test for quality with other objects.
*
* @param object the object to be test for equality.
* @return boolean - returns true if the given object is of type
* VmIdentifier and its URI field is equal to
* this object's URI field. Otherwise, return false.
*
* @see URI#equals(Object)
*/
public boolean equals(Object object) {
if (object == this) {
return true;
}
if (!(object instanceof VmIdentifier)) {
return false;
}
return uri.equals(((VmIdentifier)object).uri);
}
/**
* Convert to a string representation. Conversion is identical to
* calling getURI().toString(). This may change in a future release.
*
* @return String - a String representation of the VmIdentifier.
*
* @see URI#toString()
*/
public String toString() {
return uri.toString();
}
}