dispatchptr.java

java 调用windows的api

	 * 
	 * @see #put(String, Object)
	 */
	public void put(String prop, double val) throws COMException {
		put(prop, new Double(val));
	}

	/**
	 * For setting a new value for a property identified by name and
	 * a single index. Does not necessarely have to be a an integer - 
	 * it depends on how the native put-method interprets the
	 * index.
	 * <br><br>
	 * The {@link Variant#writeObject(Object, LittleEndianOutputStream)} should be
	 * consulted for further information about what type of object should
	 * be passed as value. One of the shortcut methods for simple types could also
	 * be used.
	 * 
	 * @param prop the name of the property.
	 * @param index the index to pass to the the native property
	 * 			put method.
	 * @param val the new value of the property.
	 * 
	 * @throws COMException if no such property, or if the native
	 * 			code failed in any other way.
	 * @throws NullPointerException if prop is null.
	 */
	public void put(String prop, Object index, Object val) throws COMException {
		putN(prop, new Object[] { index }, 1, val);
	}

	/**
	 * Shortcut method for setting a boolean <code>VT_BOOL</code> property
	 * identified by a single index.
	 * 
	 * @see #put(String, Object, Object)
	 */
	public void put(String prop, Object index, boolean val) throws COMException {
		put(prop, index, (val ? Boolean.TRUE : Boolean.FALSE));
	}

	/**
	 * Shortcut method for setting a byte <code>VT_UI1</code> property
	 * identified by a single index.
	 * 
	 * @see #put(String, Object, Object)
	 */
	public void put(String prop, Object index, byte val) throws COMException {
		put(prop, index, new Byte(val));
	}
	
	/**
	 * Shortcut method for setting a short <code>VT_I2</code> property
	 * identified by a single index.
	 * 
	 * @see #put(String, Object, Object)
	 */
	public void put(String prop, Object index, short val) throws COMException {
		put(prop, index, new Short(val));
	}
	
	/**
	 * Shortcut method for setting an integer <code>VT_I4</code> property
	 * identified by a single index.
	 * 
	 * @see #put(String, Object, Object)
	 */
	public void put(String prop, Object index, int val) throws COMException {
		put(prop, index, new Integer(val));
	}

	/**
	 * Shortcut method for setting a long <code>VT_I8</code> property
	 * identified by a single index.
	 * 
	 * @see #put(String, Object, Object)
	 */
	public void put(String prop, Object index, long val) throws COMException {
		put(prop, index, new Long(val));
	}
	
	/**
	 * Shortcut method for setting a float <code>VT_R4</code> property
	 * identified by a single index.
	 * 
	 * @see #put(String, Object, Object)
	 */
	public void put(String prop, Object index, float val) throws COMException {
		put(prop, index, new Float(val));
	}

	/**
	 * Shortcut method for setting a double <code>VT_R8</code> property
	 * identified by a single index.
	 * 
	 * @see #put(String, Object, Object)
	 */
	public void put(String prop, Object index, double val) throws COMException {
		put(prop, index, new Double(val));
	}

	/**
	 * For setting a new value for a property identified by the property name and
	 * multiple index'es. Does not necessarely have to be integers - 
	 * it depends on how the native put-method interprets the
	 * indexes.
	 * <br><br>
	 * One scenario where this can be used, is eg. for setting the
	 * value of a single cell in a spreadsheet, where two "indexes"
	 * (row and column) are needed for identifying the cell.
	 * <br><br>
	 * The {@link Variant#writeObject(Object, LittleEndianOutputStream)} should be
	 * consulted for further information about what type of object should
	 * be passed as value.
	 * 
	 * @param prop the name of the property.
	 * @param indexes the indexes to pass to the the native property
	 * 			put method.
	 * @param val the new value of the property.
	 * @throws COMException if no such property, or if the native
	 * 			code failed in any other way.
	 * @throws NullPointerException if prop is null.
	 */
	public void putN(String prop, Object[] indexes, Object val) throws COMException {
		putN(prop, indexes, (indexes != null ? indexes.length : 0), val);
	}

	/**
	 * @see #putN(String, Object[], Object)
	 */
	public void putN(String prop, Object[] indexes, int indexesExpected, Object val) throws COMException {
		if (prop == null) {
			throw new NullPointerException("Property <null> not allowed.");
		}
		NakedByteStream nbs = new NakedByteStream();
		LittleEndianOutputStream leos = new LittleEndianOutputStream(nbs);
		int len = (indexes != null) ? indexes.length : 0;

		// Marshal property value first
		Variant.writeObject(val, leos);

		// Marshal missing args
		try {
			for (int n = 0, extra = (indexesExpected - len); n < extra; n++) {
				leos.writeShort(VarTypes.VT_ERROR);
			}
		} catch (IOException e) {
			throw new COMException(e);
		}

		// Marshal specified args right to left
		for (int n = (len - 1); n >= 0; n--) {
			Variant.writeObject(indexes[n], leos);
		}

		GenericStub.dispatchInvoke(INVOKE_INST[indexesExpected + 1] + ":", indexesExpected + 1,
				nbs.size(), nbs.getInternalBuffer(), prop, DispatchConstants.DISPATCH_PROPERTYPUT,
				getPeer(), getUnknown());
	}

	/**
	 * For invoking a method taking no parameters.
	 * 
	 * @param meth the name of the method to invoke.
	 * @return the return value of the method if any.
	 * @throws COMException if no such method, or if the native
	 * 			code failed in any other way.
	 * @throws NullPointerException if meth is null.
	 */
	public Object invoke(String meth) throws COMException {
		return invokeN(meth, null);
	}
	
	/**
	 * Shortcut method for invoking a method taking one parameter.
	 * 
	 * @see #invokeN(String, Object[])
	 */
	public Object invoke(String meth, Object arg1) throws COMException {
		return invokeN(meth, new Object[] { arg1 });
	}

	/**
	 * Shortcut method for invoking a method taking two parameters.
	 * 
	 * @see #invokeN(String, Object[])
	 */
	public Object invoke(String meth, Object arg1, Object arg2) throws COMException {
		return invokeN(meth, new Object[] { arg1, arg2 });
	}

	/**
	 * Shortcut method for invoking a method taking three parameters.
	 * 
	 * @see #invokeN(String, Object[])
	 */
	public Object invoke(String meth, Object arg1, Object arg2, Object arg3) throws COMException {
		return invokeN(meth, new Object[] { arg1, arg2, arg3 });
	}
	
	/**
	 * Shortcut method for invoking a method taking four parameters.
	 * 
	 * @see #invokeN(String, Object[])
	 */
	public Object invoke(String meth, Object arg1, Object arg2, Object arg3, Object arg4) throws COMException {
		return invokeN(meth, new Object[] { arg1, arg2, arg3, arg4 });
	}

	/**
	 * For invoking a method on dispatch interface.
	 * <br><br>
	 * The {@link Variant#writeObject(Object, LittleEndianOutputStream)} should be
	 * consulted for further information about what type of objects should
	 * be passed as arguments to the method.
	 * 
	 * @param meth the name of the method to invoke.
	 * @param args array of the arguments to pass to the method.
	 * @return the return value of the method if any.
	 * @throws COMException if no such method, or if the native
	 * 			code failed in any other way.
	 * @throws NullPointerException if meth is null.
	 */
	public Object invokeN(String meth, Object[] args) throws COMException {
		return invokeN(meth, args, (args != null ? args.length : 0));
	}

	/**
	 * @see #invokeN(String, Object[])
	 */
	public Object invokeN(String meth, Object[] args, int argsExpected) throws COMException {
		if (meth == null) {
			throw new NullPointerException("<null>-methodname not allowed.");
		}
		try {
			NakedByteStream nbs = new NakedByteStream();
			LittleEndianOutputStream leos = new LittleEndianOutputStream(nbs);
			StringBuffer outInst = new StringBuffer();

			int len = (args != null) ? args.length : 0;
			//arguments marshal from right to left. First, missing args:
			for (int n = 0, extra = (argsExpected - len); n < extra; n++) {
				leos.writeShort(VarTypes.VT_ERROR);
				outInst.append(INVOKE_INST_OUT_SKIP); // skip the size of a variant.
			}

			//Second: specified args
			for (int n = (len - 1); n >= 0; n--) {
				Variant.writeObject(args[n], leos);
				if (args[n] instanceof Variant.ByrefHolder) {
					outInst.append(INVOKE_INST_OUT);
				} else {
					outInst.append(INVOKE_INST_OUT_SKIP); // skip the size of a variant.
				}
			}

			byte[] result = GenericStub.dispatchInvoke(INVOKE_INST[argsExpected] + "V:" + outInst.toString(),
					argsExpected, nbs.size(), nbs.getInternalBuffer(), meth, DispatchConstants.DISPATCH_METHOD,
					getPeer(), getUnknown());

			LittleEndianInputStream leis = new LittleEndianInputStream(new ByteArrayInputStream(result));
			Object resultObj = Variant.readObject(leis);

			// handle any byref/[out] values
			for (int n = (len - 1); n >= 0; n--) {
				if (args[n] instanceof Variant.ByrefHolder) {
					((Variant.ByrefHolder)args[n]).setRef(Variant.readObject(leis));
				}
			}
			return resultObj;
		} catch (IOException ioe) {
			throw new COMException(ioe);
		}
	}

	/**
	 * used too lookup the input part of the marshalling instructions.
	 */
	private static final String INVOKE_INST[] = {
		":",
		"v:",
		"vv:",
		"vvv:",
		"vvvv:",
		"vvvvv:",
		"vvvvvv:",
		"vvvvvvv:",
		"vvvvvvvv:",
		"vvvvvvvvv:",
		"vvvvvvvvvv:",
		"vvvvvvvvvvv:",
		"vvvvvvvvvvvv:",
		"vvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv:",
		"vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv:",
	};
	
	/**
	 * for specifying any [out] variants in the return part of the 
	 * marshalling instructions.
	 */
	private static final char INVOKE_INST_OUT = 'V';
	
	/**
	 * for specifying any variants that should be skipped in the return part
	 * of the marshalling instructions. Skip 16 bytes.
	 */
	private static final String INVOKE_INST_OUT_SKIP = "L" + Variant.SIZEOF;
}