sun.corba

Class Bridge

java.lang.Object

sun.corba.Bridge

public final class Bridge
extends Object

This class provides the methods for fundamental JVM operations needed in the ORB that are not part of the public Java API. This includes:

• throwException, which can throw undeclared checked exceptions. This is needed to handle throwing arbitrary exceptions across a standardized OMG interface that (incorrectly) does not specify appropriate exceptions.
• putXXX/getXXX methods that allow unchecked access to fields of objects. This is used for setting uninitialzed non-static final fields (which is impossible with reflection) and for speed.
• objectFieldOffset to obtain the field offsets for use in the putXXX/getXXX methods
• newConstructorForSerialization to get the special constructor required for a Serializable class
• latestUserDefinedLoader to get the latest user defined class loader from the call stack as required by the RMI-IIOP specification (really from the JDK 1.1 days)

The code that calls Bridge.get() must have the following Permissions:

• RuntimePermission "reflectionFactoryAccess"
• BridgePermission "getBridge"
• ReflectPermission "suppressAccessChecks"

All of these permissions are required to obtain and correctly initialize the instance of Bridge. No security checks are performed on calls made to Bridge instance methods, so access to the Bridge instance must be protected.

This class is a singleton (per ClassLoader of course). Access to the instance is obtained through the Bridge.get() method.

Field Summary

Fields

Modifier and Type	Field and Description
static long	INVALID_FIELD_OFFSET This constant differs from all results that will ever be returned from objectFieldOffset(java.lang.reflect.Field).

Method Summary

Modifier and Type	Method and Description
static Bridge	get() Fetch the Bridge singleton.
boolean	getBoolean(Object o, long offset)
byte	getByte(Object o, long offset)
char	getChar(Object o, long offset)
double	getDouble(Object o, long offset)
float	getFloat(Object o, long offset)
int	getInt(Object o, long offset) Fetches a field element within the given object o at the given offset.
ClassLoader	getLatestUserDefinedLoader() Obtain the latest user defined ClassLoader from the call stack.
long	getLong(Object o, long offset)
Object	getObject(Object o, long offset)
short	getShort(Object o, long offset)
Constructor	newConstructorForSerialization(Class cl, Constructor cons) Obtain a constructor for Class cl using constructor cons which may be the constructor defined in a superclass of cl.
long	objectFieldOffset(Field f) Returns the offset of a non-static field.
void	putBoolean(Object o, long offset, boolean x)
void	putByte(Object o, long offset, byte x)
void	putChar(Object o, long offset, char x)
void	putDouble(Object o, long offset, double x)
void	putFloat(Object o, long offset, float x)
void	putInt(Object o, long offset, int x) Stores a value into a given Java field.
void	putLong(Object o, long offset, long x)
void	putObject(Object o, long offset, Object x)
void	putShort(Object o, long offset, short x)
void	throwException(Throwable ee) Throw the exception.

Methods inherited from class java.lang.Object

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

Field Detail

INVALID_FIELD_OFFSET

public static final long INVALID_FIELD_OFFSET

This constant differs from all results that will ever be returned from objectFieldOffset(java.lang.reflect.Field).

See Also:

Constant Field Values

Method Detail

get

public static final Bridge get()

Fetch the Bridge singleton. This requires the following permissions:

• RuntimePermission "reflectionFactoryAccess"
• BridgePermission "getBridge"
• ReflectPermission "suppressAccessChecks"

Returns:

The singleton instance of the Bridge class

Throws:

SecurityException - if the caller does not have the required permissions and the caller has a non-null security manager.

getLatestUserDefinedLoader

public final ClassLoader getLatestUserDefinedLoader()

Obtain the latest user defined ClassLoader from the call stack. This is required by the RMI-IIOP specification.

getInt

public final int getInt(Object o,
                        long offset)

Fetches a field element within the given object o at the given offset. The result is undefined unless the offset was obtained from objectFieldOffset(java.lang.reflect.Field) on the Field of some Java field and the object referred to by o is of a class compatible with that field's class.

Parameters:

o - Java heap object in which the field from which the offset was obtained resides

offset - indication of where the field resides in a Java heap object

Returns:

the value fetched from the indicated Java field

Throws:

RuntimeException - No defined exceptions are thrown, not even NullPointerException

putInt

public final void putInt(Object o,
                         long offset,
                         int x)

Stores a value into a given Java field.

The first two parameters are interpreted exactly as with getInt(Object, long) to refer to a specific Java field. The given value is stored into that field.

The field must be of the same type as the method parameter x.

Parameters:

o - Java heap object in which the field resides, if any, else null

offset - indication of where the field resides in a Java heap object.

x - the value to store into the indicated Java field

Throws:

RuntimeException - No defined exceptions are thrown, not even NullPointerException

getObject

public final Object getObject(Object o,
                              long offset)

See Also:

getInt(Object, long)

putObject

public final void putObject(Object o,
                            long offset,
                            Object x)

See Also:

putInt(Object, long, int)

getBoolean

public final boolean getBoolean(Object o,
                                long offset)

See Also:

getInt(Object, long)

putBoolean

public final void putBoolean(Object o,
                             long offset,
                             boolean x)

See Also:

putInt(Object, long, int)

getByte

public final byte getByte(Object o,
                          long offset)

See Also:

getInt(Object, long)

putByte

public final void putByte(Object o,
                          long offset,
                          byte x)

See Also:

putInt(Object, long, int)

getShort

public final short getShort(Object o,
                            long offset)

See Also:

getInt(Object, long)

putShort

public final void putShort(Object o,
                           long offset,
                           short x)

See Also:

putInt(Object, long, int)

getChar

public final char getChar(Object o,
                          long offset)

See Also:

getInt(Object, long)

putChar

public final void putChar(Object o,
                          long offset,
                          char x)

See Also:

putInt(Object, long, int)

getLong

public final long getLong(Object o,
                          long offset)

See Also:

getInt(Object, long)

putLong

public final void putLong(Object o,
                          long offset,
                          long x)

See Also:

putInt(Object, long, int)

getFloat

public final float getFloat(Object o,
                            long offset)

See Also:

getInt(Object, long)

putFloat

public final void putFloat(Object o,
                           long offset,
                           float x)

See Also:

putInt(Object, long, int)

getDouble

public final double getDouble(Object o,
                              long offset)

See Also:

getInt(Object, long)

putDouble

public final void putDouble(Object o,
                            long offset,
                            double x)

See Also:

putInt(Object, long, int)

objectFieldOffset

public final long objectFieldOffset(Field f)

Returns the offset of a non-static field.

throwException

public final void throwException(Throwable ee)

Throw the exception. The exception may be an undeclared checked exception.

newConstructorForSerialization

public final Constructor newConstructorForSerialization(Class cl,
                                                        Constructor cons)

Obtain a constructor for Class cl using constructor cons which may be the constructor defined in a superclass of cl. This is used to create a constructor for Serializable classes that constructs an instance of the Serializable class using the no args constructor of the first non-Serializable superclass of the Serializable class.