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• org.apache.derby.iapi.services.io: Javadoc index of package org.apache.derby.iapi.services.io.


Package Samples:

• org.apache.derby.iapi.services.io

Classes:

• StoredFormatIds: A format id identifies a stored form of an object for the purposes of locating a class which can read the stored form and reconstruct the object using the java.io.Externalizable interface. An important aspect of the format id concept is that it does not impose an implementation on the stored object. Rather, multiple implementations of an object (or interface) may share a format id. One implementation may store (write) an object and another may restore (read) the object. The implication of this is that a format id specifies the following properties of a stored object. The interface(s) the stored ...
• FormatIdOutputStream: A stream for serializing objects with format id tags. An ObjectOutput (henceforth 'out') preceeds objects it writes with a format id. The companion FormatIdInputStream (henceforth 'in') uses these format ids in parsing the stored data. The stream can be thought of as containing a sequence of (formatId,object) pairs interspersed with other data. The assumption is that out.writeObject() produces these pairs and in.readObject() uses the format ids to construct objects from the pairs that out.writeObject produced. The description below describes each supported pair and how in.readObject() processes ...
• FormatIdUtil: Utility class with static methods for constructing and reading the byte array representation of format id's. This utility supports a number of families of format ids. The byte array form of each family is a different length. In all cases the first two bits of the first byte indicate the family for an id. The list below describes each family and gives its two bit identifier in parens. (0) - The format id is a one byte number between 0 and 63 inclusive. The byte[] encoding fits in one byte. (1) - The format id is a two byte number between 16384 to 32767 inclusive. The byte[] encoding stores the high ...
• RegisteredFormatIds: Registration of TypedFormat classes. A TypedFormat is registered by placing a class name at the correct place in the correct array, driven by the base format number: 2 byte - MIN_TWO_BYTE_FORMAT_ID - TwoByte The offset from the base format number (0 based) gives the offset in the array. The class name is either: The actual class name of the TypeFormat. The name of a class that extends org.apache.derby.iapi.services.io.FormatableInstanceGetter. In this case the monitor will register an instance of the class after calling its setFormatId() method with format id it is registered as.
• CompressedNumber: Static methods to write and read compressed forms of numbers to DataOut and DataIn interfaces. Format written is platform independent like the Data* interfaces and must remain fixed once a product is shipped. If a different format is required then write a new set of methods, e.g. writeInt2. The formats defined by stored format identifiers are implicitly dependent on these formats not changing.
• AccessibleByteArrayOutputStream: This allows us to get to the byte array to go back and edit contents or get the array without having a copy made. Since a copy is not made, users must be careful that no more writes are made to the stream if the array reference is handed off. Users of this must make the modifications *before* the next write is done, and then release their hold on the array.
• TypedFormat: Cloudscape interface for identifying the format id for the stored form of an object. Objects of different classes may have the same format id if: The objects read and write the same stored forms. The object's getTypeId() method returns the same identifier. The objects support all the interfaces the type implies.
• DynamicByteArrayOutputStream: A DynamicByteArrayOutputStream allows writing to a dynamically resizable array of bytes. In addition to dynamic resizing, this extension allows the user of this class to have more control over the position of the stream and can get a direct reference of the array.
• Formatable: Cloudscape interface for creating a stored form for an object and re-constructing an equivalent object from this stored form. The object which creates the stored form and the re-constructed object need not be the same or related classes. They must share the same TypedFormat.
• NewByteArrayInputStream: An InputStream that is like java.io.ByteArrayInputStream but supports a close() call that causes all methods to throw an IOException. Java's ByteInputStream has a close() method that does not do anything.
• FormatIdInputStream: A stream for reading objects with format id tags which was produced by a FormatIdOutputStream. Please see the documentation for FormatIdOutputStream for information about the streams format and capabilites.
• ArrayInputStream: An InputStream that allows reading from an array of bytes. The array of bytes that is read from can be changed without having to create a new instance of this class.
• InputStreamUtil: Utility methods for InputStream that are stand-ins for a small subset of DataInput methods. This avoids pushing a DataInputStream just to get this functionality.
• ApplicationObjectInputStream: An object input stream that implements resolve class in order to load the class through the ClassFactory.loadApplicationClass method.
• Limit: Methods that allow limits to be placed on an input or output stream to avoid clients reading or writing too much information.
• LimitInputStream: An abstract InputStream that provides abstract methods to limit the range that can be read from the stream.
• CounterOutputStream: An OutputStream that simply provides methods to count the number of bytes written to an underlying stream.
• LimitReader: A Reader that provides methods to limit the range that can be read from the reader.
• ArrayUtil: Utility class for constructing and reading and writing arrays from/to formatId streams.
• FormatableProperties: A formatable holder for a java.util.Properties. Used to avoid serializing Properties.
• FormatableHashtable: A formatable holder for a java.util.Hashtable. Used to avoid serializing Properties.
• StreamStorable: Formatable for holding SQL data (which may be null). It supports streaming columns.
• FormatableArrayHolder: A formatable holder for an array of formatables. Used to avoid serializing arrays.
• ErrorInfo: Getting error information for SQLData/serializable data streams.
• FileUtil: A set of public static methods for dealing with File objects.

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