@Exported public abstract class AttachProvider extends Object
An attach provider is a concrete subclass of this class that has a zero-argument constructor and implements the abstract methods specified below.
An attach provider implementation is typically tied to a Java virtual machine implementation, version, or even mode of operation. That is, a specific provider implementation will typically only be capable of attaching to a specific Java virtual machine implementation or version. For example, Sun's JDK implementation ships with provider implementations that can only attach to Sun's HotSpot virtual machine. In general, if an environment consists of Java virtual machines of different versions and from different vendors then there will be an attach provider implementation for each family of implementations or versions.
 An attach provider is identified by its name and
 type. The name is typically, but not required to
 be, a name that corresponds to the VM vendor. The Sun JDK implementation,
 for example, ships with attach providers that use the name "sun". The
 type typically corresponds to the attach mechanism. For example, an
 implementation that uses the Doors inter-process communication mechanism
 might use the type "doors". The purpose of the name and type is to
 identify providers in environments where there are multiple providers
 installed. 
 AttachProvider implementations are loaded and instantiated at the first
 invocation of the providers method. This method
 attempts to load all provider implementations that are installed on the
 platform. 
All of the methods in this class are safe for use by multiple concurrent threads.
| Modifier | Constructor and Description | 
|---|---|
| protected  | AttachProvider()Initializes a new instance of this class. | 
| Modifier and Type | Method and Description | 
|---|---|
| abstract VirtualMachine | attachVirtualMachine(String id)Attaches to a Java virtual machine. | 
| VirtualMachine | attachVirtualMachine(VirtualMachineDescriptor vmd)Attaches to a Java virtual machine. | 
| abstract List<VirtualMachineDescriptor> | listVirtualMachines()Lists the Java virtual machines known to this provider. | 
| abstract String | name()Return this provider's name. | 
| static List<AttachProvider> | providers()Returns a list of the installed attach providers. | 
| abstract String | type()Return this provider's type. | 
protected AttachProvider()
SecurityException - If a security manager has been installed and it denies
          AttachPermission
          ("createAttachProvider")public abstract String name()
public abstract String type()
public abstract VirtualMachine attachVirtualMachine(String id) throws AttachNotSupportedException, IOException
A Java virtual machine is identified by an abstract identifier. The nature of this identifier is platform dependent but in many cases it will be the string representation of the process identifier (or pid).
 This method parses the identifier and maps the identifier to a Java
 virtual machine (in an implementation dependent manner). If the identifier
 cannot be parsed by the provider then an AttachNotSupportedException
 is thrown. Once parsed this method attempts to attach to the Java virtual machine.
 If the provider detects that the identifier corresponds to a Java virtual machine
 that does not exist, or it corresponds to a Java virtual machine that does not support
 the attach mechanism implemented by this provider, or it detects that the
 Java virtual machine is a version to which this provider cannot attach, then
 an AttachNotSupportedException is thrown. 
id - The abstract identifier that identifies the Java virtual machine.SecurityException - If a security manager has been installed and it denies
          AttachPermission
          ("attachVirtualMachine"), or other permission
          required by the implementation.AttachNotSupportedException - If the identifier cannot be parsed, or it corresponds to
          to a Java virtual machine that does not exist, or it
          corresponds to a Java virtual machine which this
          provider cannot attach.IOException - If some other I/O error occursNullPointerException - If id is nullpublic VirtualMachine attachVirtualMachine(VirtualMachineDescriptor vmd) throws AttachNotSupportedException, IOException
 A Java virtual machine can be described using a VirtualMachineDescriptor.
 This method invokes the descriptor's provider() method
 to check that it is equal to this provider. It then attempts to attach to the
 Java virtual machine.
vmd - The virtual machine descriptorSecurityException - If a security manager has been installed and it denies
          AttachPermission
          ("attachVirtualMachine"), or other permission
          required by the implementation.AttachNotSupportedException - If the descriptor's provider() method
          returns a provider that is not this provider, or it does not correspond
          to a Java virtual machine to which this provider can attach.IOException - If some other I/O error occursNullPointerException - If vmd is nullpublic abstract List<VirtualMachineDescriptor> listVirtualMachines()
 This method returns a list of VirtualMachineDescriptor elements. Each
 VirtualMachineDescriptor describes a Java virtual machine
 to which this provider can potentially attach.  There isn't any
 guarantee that invoking attachVirtualMachine on each descriptor in the list will succeed.
public static List<AttachProvider> providers()
An AttachProvider is installed on the platform if:
It is installed in a JAR file that is visible to the defining
   class loader of the AttachProvider type (usually, but not required
   to be, the system
   class loader).
The JAR file contains a provider configuration named com.sun.tools.attach.spi.AttachProvider in the resource directory META-INF/services.
The provider configuration file lists the full-qualified class name of the AttachProvider implementation.
The format of the provider configuration file is one fully-qualified class name per line. Space and tab characters surrounding each class name, as well as blank lines are ignored. The comment character is '#' (0x23), and on each line all characters following the first comment character are ignored. The file must be encoded in UTF-8.
AttachProvider implementations are loaded and instantiated (using the zero-arg constructor) at the first invocation of this method. The list returned by the first invocation of this method is the list of providers. Subsequent invocations of this method return a list of the same providers. The list is unmodifable.
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