javax.jms: public interface: MapMessage

javax.jms
public interface: MapMessage [javadoc | source]

All Implemented Interfaces:
Message

A MapMessage object is used to send a set of name-value pairs. The names are String objects, and the values are primitive data types in the Java programming language. The names must have a value that is not null, and not an empty string. The entries can be accessed sequentially or randomly by name. The order of the entries is undefined. MapMessage inherits from the Message interface and adds a message body that contains a Map.

The primitive types can be read or written explicitly using methods for each type. They may also be read or written generically as objects. For instance, a call to MapMessage.setInt("foo", 6) is equivalent to MapMessage.setObject("foo", new Integer(6)). Both forms are provided, because the explicit form is convenient for static programming, and the object form is needed when types are not known at compile time.

When a client receives a MapMessage, it is in read-only mode. If a client attempts to write to the message at this point, a MessageNotWriteableException is thrown. If clearBody is called, the message can now be both read from and written to.

MapMessage objects support the following conversion table. The marked cases must be supported. The unmarked cases must throw a JMSException. The String-to-primitive conversions may throw a runtime exception if the primitive's valueOf() method does not accept it as a valid String representation of the primitive.

A value written as the row type can be read as the column type.

|        | boolean byte short char int long float double String byte[]
|----------------------------------------------------------------------
|boolean |    X                                            X
|byte    |          X     X         X   X                  X
|short   |                X         X   X                  X
|char    |                     X                           X
|int     |                          X   X                  X
|long    |                              X                  X
|float   |                                    X     X      X
|double  |                                          X      X
|String  |    X     X     X         X   X     X     X      X
|byte[]  |                                                        X
|----------------------------------------------------------------------

Attempting to read a null value as a primitive type must be treated as calling the primitive's corresponding valueOf(String) conversion method with a null value. Since char does not support a String conversion, attempting to read a null value as a char must throw a NullPointerException.

Also see:

javax.jms.Session#createMapMessage()

javax.jms.BytesMessage

javax.jms.Message

javax.jms.ObjectMessage

javax.jms.StreamMessage

javax.jms.TextMessage

Method from javax.jms.MapMessage Summary:
getBoolean, getByte, getBytes, getChar, getDouble, getFloat, getInt, getLong, getMapNames, getObject, getShort, getString, itemExists, setBoolean, setByte, setBytes, setBytes, setChar, setDouble, setFloat, setInt, setLong, setObject, setShort, setString

Method from javax.jms.MapMessage Detail:
public boolean getBoolean(String name) throws JMSException Returns the `boolean` value with the specified name.
public byte getByte(String name) throws JMSException Returns the `byte` value with the specified name.
public byte[] getBytes(String name) throws JMSException Returns the byte array value with the specified name.
public char getChar(String name) throws JMSException Returns the Unicode character value with the specified name.
public double getDouble(String name) throws JMSException Returns the `double` value with the specified name.
public float getFloat(String name) throws JMSException Returns the `float` value with the specified name.
public int getInt(String name) throws JMSException Returns the `int` value with the specified name.
public long getLong(String name) throws JMSException Returns the `long` value with the specified name.
public Enumeration getMapNames() throws JMSException Returns an `Enumeration` of all the names in the `MapMessage` object.
public Object getObject(String name) throws JMSException Returns the value of the object with the specified name. This method can be used to return, in objectified format, an object in the Java programming language ("Java object") that had been stored in the Map with the equivalent `setObject` method call, or its equivalent primitive `settype` method. Note that byte values are returned as `byte[]`, not `Byte[]`.
public short getShort(String name) throws JMSException Returns the `short` value with the specified name.
public String getString(String name) throws JMSException Returns the `String` value with the specified name.
public boolean itemExists(String name) throws JMSException Indicates whether an item exists in this `MapMessage` object.
public void setBoolean(String name, boolean value) throws JMSException Sets a `boolean` value with the specified name into the Map.
public void setByte(String name, byte value) throws JMSException Sets a `byte` value with the specified name into the Map.
public void setBytes(String name, byte[] value) throws JMSException Sets a byte array value with the specified name into the Map.
public void setBytes(String name, byte[] value, int offset, int length) throws JMSException Sets a portion of the byte array value with the specified name into the Map.
public void setChar(String name, char value) throws JMSException Sets a Unicode character value with the specified name into the Map.
public void setDouble(String name, double value) throws JMSException Sets a `double` value with the specified name into the Map.
public void setFloat(String name, float value) throws JMSException Sets a `float` value with the specified name into the Map.
public void setInt(String name, int value) throws JMSException Sets an `int` value with the specified name into the Map.
public void setLong(String name, long value) throws JMSException Sets a `long` value with the specified name into the Map.
public void setObject(String name, Object value) throws JMSException Sets an object value with the specified name into the Map. This method works only for the objectified primitive object types (`Integer`, `Double`, `Long` ...), `String` objects, and byte arrays.
public void setShort(String name, short value) throws JMSException Sets a `short` value with the specified name into the Map.
public void setString(String name, String value) throws JMSException Sets a `String` value with the specified name into the Map.