com.ibm.portal.streaming.json
Class JsonParserReader.Entry

java.lang.Object
  java.io.Reader
      com.ibm.portal.streaming.json.JsonParserReader.Entry

All Implemented Interfaces:

Streamable, Writable, java.io.Closeable, java.io.DataInput, java.lang.Readable, java.nio.channels.Channel

Enclosing class:

JsonParserReader

public abstract static class JsonParserReader.Entry
extends java.io.Reader
implements Writable, Streamable, java.io.DataInput, java.nio.channels.Channel

Represents an entry in this input stream. The stream representation of the entry will close the entry but not the complete stream. Depending on the type of the entry, the read method represent the content:

• START_MEMBER: the name of the member
• START_STRING: the value of the string
• START_NUMBER: the value of the number
• START_BOOLEAN: the value of the boolean

In all other cases the entry stream represents the empty stream.

Field Summary

Fields inherited from class java.io.Reader

lock

Constructor Summary

JsonParserReader.Entry()

Method Summary

abstract void	close() Closes this entry, subsequent attempts to read from this reader will fail.
abstract java.io.InputStream	getInputStream() Returns an InputStream that reads the entry as bytes.
abstract JsonParserReader.TYPE	getType() Returns the type of this entry
abstract int	read(java.io.Writer dst) Reads the value of the entry and copies it into the target writer.
abstract void	readFully(byte[] b, int off, int len) Reads the number of bytes from a base64 encoded entry
abstract java.lang.Number	readNumber() Reads a number or null if the entry does not contain data.
abstract java.lang.String	readString() Reads a string or null if the entry does not contain data.

Methods inherited from class java.io.Reader

mark, markSupported, read, read, read, read, ready, reset, skip

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.ibm.utilities.streams.Writable

write

Methods inherited from interface com.ibm.utilities.streams.Streamable

write

Methods inherited from interface java.io.DataInput

readBoolean, readByte, readChar, readDouble, readFloat, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedShort, readUTF, skipBytes

Methods inherited from interface java.nio.channels.Channel

isOpen

Constructor Detail

JsonParserReader.Entry

public JsonParserReader.Entry()

Method Detail

close

public abstract void close()
                    throws java.io.IOException

Closes this entry, subsequent attempts to read from this reader will fail.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.nio.channels.Channel

Specified by:

close in class java.io.Reader

Throws:

java.io.IOException - if an I/O error has occurred

getInputStream

public abstract java.io.InputStream getInputStream()
                                            throws java.io.IOException

Returns an InputStream that reads the entry as bytes. The bytes depend on the content type:

• START_MEMBER: the name of the member as a UTF8 byte sequence
• START_STRING: the value of the string as a UTF8 byte sequence
• START_NUMBER: the value of the number, either as a long number or a IEEE 754 floating-point in big endian format.
• START_BOOLEAN: the value of the boolean, either 0 or 1
• START_NULL: the empty stream

This is compatible to how a DataOutputStream would generate a byte sequence.

Returns:

the stream, null if the entry is closed

Throws:

java.io.IOException - if an I/O error has occurred

getType

public abstract JsonParserReader.TYPE getType()

Returns the type of this entry

Returns:

the type, not null

read

public abstract int read(java.io.Writer dst)
                  throws java.io.IOException

Reads the value of the entry and copies it into the target writer.

Parameters:

dst - target writer, not null

Returns:

the number of characters actually copied

Throws:

java.io.IOException - - if the data could not be read or copied

readFully

public abstract void readFully(byte[] b,
                               int off,
                               int len)
                        throws java.io.IOException

Reads the number of bytes from a base64 encoded entry

Specified by:

readFully in interface java.io.DataInput

Parameters:

b - target byte buffer, not null

off - index into the buffer

len - length of the target buffer, must be >0

Throws:

java.io.IOException - if an I/O error has occurred

readNumber

public abstract java.lang.Number readNumber()
                                     throws java.io.IOException,
                                            java.lang.NumberFormatException

Reads a number or null if the entry does not contain data. The number type is detected automatically. Reading a number on an entry of type START_STRING tries to parse the string to a number.

Returns:

the number or null if no number exists

Throws:

java.io.IOException - if an I/O error has occurred

java.lang.NumberFormatException - if the number cannot be decoded from the string

readString

public abstract java.lang.String readString()
                                     throws java.io.IOException

Reads a string or null if the entry does not contain data. Reading a string for a number entry converts the number into a string.

Returns:

the string or null if no string exists

Throws:

java.io.IOException - if an I/O error has occurred