DPML Notify

[niclas AT netcompartner.com]

Author: niclas
Date: Tue Mar  1 05:31:32 2005
New Revision: 1914

Added:
   
development/laboratory/planet/components/protocol/packetimpl/src/main/net/dpml/protocol/packet/impl/FixedLengthString.java
   (contents, props changed)
Log:
Fixed length field added.

Added: 
development/laboratory/planet/components/protocol/packetimpl/src/main/net/dpml/protocol/packet/impl/FixedLengthString.java
==============================================================================
--- (empty file)
+++ 
development/laboratory/planet/components/protocol/packetimpl/src/main/net/dpml/protocol/packet/impl/FixedLengthString.java
  Tue Mar  1 05:31:32 2005
@@ -0,0 +1,161 @@
+/*
+ * Copyright 2005, Niclas Hedhman
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.protocol.packet.impl;
+
+import java.io.UnsupportedEncodingException;
+import java.nio.charset.Charset;
+
+import java.util.Locale;
+
+import net.dpml.parameters.ParameterException;
+import net.dpml.parameters.Parameters;
+
+import net.dpml.protocol.packet.FieldType;
+import net.dpml.protocol.packet.IllegalPacketFormatException;
+
+/** Handles translation of strings into a fixed length character sequence.
+ *
+ * @metro.component name="fixed-length-string" lifestyle="singleton"
+ * @metro.service type="net.dpml.protocol.packet.FieldType"
+ */
+public class FixedLengthString
+    implements FieldType
+{
+    private int m_fieldLength;
+    private String m_encoding;
+
+    public FixedLengthString( Parameters params )
+        throws IllegalArgumentException, ParameterException
+    {
+        m_fieldLength = params.getParameterAsInteger( "field-length", 1 );
+        m_encoding = params.getParameter( "char-encoding", "ISO8859-1" );
+        if( false == Charset.isSupported( m_encoding ) )
+        {
+            throw new ParameterException( "Encoding '" + m_encoding + "' is 
not supported on this system." );
+        }
+    }
+
+    public int getFieldLength()
+    {
+        return m_fieldLength;
+    }
+
+    /** Returns the FieldType name.
+     * This method should return the name of the implementation that
+     * handles the serialization/deserialization of the byte stream.
+     * @return the name in english of the FieldType.
+     */
+    public String getName()
+    {
+        return "FixedLengthString";
+    }
+
+    /** Returns a human-readable description of the FieldType.
+     * @return a description of the field type in the locale provided.
+     */
+    public String getDescription( Locale locale )
+    {
+        return "TODO: Not implemented yet.";
+    }
+
+    /** Returns the size of the field.
+     * This method returns how many bytes that the field type consists of at 
a
+     * minimum. Zero-length is not possible, as the field type would then not
+     * be able to deserialize properly. Furher constraint is that the minimum
+     * size of the field type can not be larger than the maximum field size, 
and
+     * if the <code>isVariableSize</code> method returns false, then both the
+     * <code>getMinimumSize</code> and <code>getMaximumSize</code> methods
+     * must return the same number.
+     *
+     * @return the minimum number of bytes that the serialized field can
+     *         consist of.
+     */
+    public int getMinimumSize()
+    {
+        return m_fieldLength;
+    }
+
+    /** Returns the size of the field.
+     * This method returns how many bytes that the field type consists of at 
a
+     * maximum. A constraint is that the minimum
+     * size of the field type can not be larger than the maximum field size, 
and
+     * if the <code>isVariableSize</code> method returns false, then both the
+     * <code>getMinimumSize</code> and <code>getMaximumSize</code> methods
+     * must return the same number.
+     * @return the minimum number of bytes that the serialized field can
+     *         consist of.
+     */
+    public int getMaximumSize()
+    {
+        return m_fieldLength;
+    }
+
+    /** Query whether this field can be varied in length.
+     * If this method returns false, then both the
+     * <code>getMinimumSize</code> and <code>getMaximumSize</code> methods
+     * must return the same number.
+     * @return true if the field is not a fixed length field.
+     */
+    public boolean isVariableSize()
+    {
+        return true;
+    }
+
+    /** Serialize the content.
+     * @param content the data to be stored in the field.
+     * @return the resulting byte array of the serialized data. This byte 
array
+     *         must be of the exact size and may not contain any
+     *         non-significant bytes at the beginning or end of the array.
+     */
+    public byte[] serialize( String content )
+        throws IllegalPacketFormatException
+    {
+        try
+        {
+            if( content.length() != m_fieldLength )
+                throw new IllegalPacketFormatException( "The expected field 
length was '" + m_fieldLength + "', but the length of the content was '" + 
content.length() + "'.", this );
+            return content.getBytes( m_encoding );
+        }
+        catch( UnsupportedEncodingException e )
+        {
+            // Can not happen. Encoding name has been verified in the
+            // constructor.
+            return null;
+        }
+    }
+
+    /** Deserializes the content from the input stream.
+     * @param input the byte[] that contains the content.
+     * @return the deserialized content from the input stream.
+     */
+    public String deserialize( byte[] input )
+        throws IllegalPacketFormatException
+    {
+        try
+        {
+            return new String( input, m_encoding );
+        }
+        catch( UnsupportedEncodingException e )
+        {
+            // Can not happen. Encoding name has been verified in the
+            // constructor.
+            return null;
+        }
+    }
+}