Released version 0.9.30; Custom decoding/encoding implementations can be attached to the Aserix decoder object for any given category;

Author: Dan Geabunea

README.md

@@ -59,7 +59,10 @@ for (AsterixDataBlock asterixDataBlock : dataBlocks) {
 }
 ```
 
-## How to implement a custom Reserved Field
+## How to implement a custom Reserved Field (SP,RE) for an Asterix Category
+
+In order to keep this library flexible, custom implementations for RE and SP fields can be
+attached to the Asterix Decoder object in your own code.
 
 In order to implement a custom reserved AsterixField, you first need to create
 a new class and inherit ReservedAsterixField. Then, you have to add implementations
@@ -98,9 +101,14 @@ public class SomeCustomAsterixFieldFactory implements ReservedFieldFactory {
 }
 ```
 
-Finally, we have to attach the custom factory to our Cat062Record.
+Finally, we have to attach the custom factory to the Asterix Decoder using the attachCustomReservedFieldFactory method.
+The custom factory shall be attached to a given category. This way, different factories can be assigned
+to various categories.
 
 ```java
-ReservedFieldFactory customFieldFactory = new SomeCustomAsterixFieldFactory();
-Cat062Record cat062Record = new Cat062Record(customFieldFactory);
+AsterixDecoder decoder = new AsterixDecoder(62);
+decoder.attachCustomReservedFieldFactory(62, new SomeCustomAsterixFieldFactory());
+...
+List<AsterixDataBlock> dataBlocks = asterixDecoder.decode(...);
+
 ```

pom.xml

@@ -5,7 +5,7 @@
 
     <groupId>jlg-consulting</groupId>
     <artifactId>jade</artifactId>
-    <version>0.9.26</version>
+    <version>0.9.30</version>
     <packaging>jar</packaging>
 
     <name>jade</name>

src/main/java/jlg/jade/asterix/AsterixDataBlock.java

@@ -8,6 +8,7 @@
 
 import jlg.jade.common.DebugMessageSource;
 import jlg.jade.common.Decodable;
+import org.springframework.util.Assert;
 import sun.reflect.generics.reflectiveObjects.NotImplementedException;
 
 import java.util.ArrayList;
@@ -22,10 +23,30 @@
 public class AsterixDataBlock extends DebugMessageSource implements Decodable {
     private final int category;
     private final List<AsterixRecord> records;
+    private ReservedFieldFactory customReservedFieldFactory;
 
+    /**
+     * Create an Asterix data block for the specified category
+     * @param category
+     */
     public AsterixDataBlock(int category) {
         this.category = category;
         this.records = new ArrayList<>();
+        this.customReservedFieldFactory = null;
+    }
+
+    /**
+     * Create an Asterix data block for the specified category with a custom factory
+     * implementation for SP,RE fields.
+     * @param category
+     * @param reservedFieldFactory The custom reserved field factory
+     */
+    public AsterixDataBlock(int category, ReservedFieldFactory reservedFieldFactory) {
+        Assert.notNull(reservedFieldFactory);
+
+        this.category = category;
+        this.records = new ArrayList<>();
+        this.customReservedFieldFactory = reservedFieldFactory;
     }
 
     /**
@@ -39,7 +60,7 @@ public AsterixDataBlock(int category) {
      */
     public int decode(byte[] input, int offset, int length) {
         while (offset < length) {
-            AsterixRecord record = new StandardAsterixRecord(category);
+            AsterixRecord record = buildAsterixRecord(category, customReservedFieldFactory);
 
             offset = record.decode(input, offset, length);
 
@@ -85,6 +106,7 @@ public int decode(byte[] input, int offset, int length) {
         return offset;
     }
 
+
     /**
      * Encodes the current Asterix data block into a byte array, that can be then sent over the
      * network
@@ -108,4 +130,21 @@ public int getCategory() {
     public List<AsterixRecord> getRecords() {
         return records;
     }
+
+    /**
+     * Build an Asterix record, by calling the appropriate constructor.
+     *
+     * @param category
+     * @param customReservedFieldFactory
+     * @return
+     */
+    private AsterixRecord buildAsterixRecord(int category, ReservedFieldFactory customReservedFieldFactory) {
+        AsterixRecord record;
+        if (customReservedFieldFactory == null) {
+            record = new StandardAsterixRecord(category);
+        } else {
+            record = new StandardAsterixRecord(category, customReservedFieldFactory);
+        }
+        return record;
+    }
 }

src/main/java/jlg/jade/asterix/AsterixDecoder.java

@@ -6,6 +6,8 @@
 */
 package jlg.jade.asterix;
 
+import org.springframework.util.Assert;
+
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -19,6 +21,7 @@
 public class AsterixDecoder {
     private final HashMap<Integer, Boolean> allowedCategories;
     private final HashMap<Integer, Integer> nbOfDataBlocks;
+    private final HashMap<Integer, ReservedFieldFactory> customReservedFieldFactories;
 
     private AsterixDecoder() {
         allowedCategories = new HashMap<>();
@@ -36,6 +39,8 @@ private AsterixDecoder() {
         nbOfDataBlocks.put(62, 0);
         nbOfDataBlocks.put(65, 0);
         nbOfDataBlocks.put(150, 0);
+
+        customReservedFieldFactories = new HashMap<>();
     }
 
     public AsterixDecoder(int... categoriesToDecode) {
@@ -70,8 +75,9 @@ public AsterixDecoder(String categoriesToDecode) {
     }
 
     public AsterixDecoder(List<Integer> categoriesToDecode) {
-        allowedCategories = new HashMap<>();
-        nbOfDataBlocks = new HashMap<>();
+        this();
+        allowedCategories.clear();
+        nbOfDataBlocks.clear();
         for (int category : categoriesToDecode) {
             allowedCategories.put(category, true);
             nbOfDataBlocks.put(category, 0);
@@ -97,7 +103,11 @@ public List<AsterixDataBlock> decode(byte[] input, int offset, int length) {
 
             Boolean shouldDecodeCategory = allowedCategories.get(dataBlockCategory);
             if (shouldDecodeCategory != null && shouldDecodeCategory) {
-                AsterixDataBlock dataBlock = new AsterixDataBlock(dataBlockCategory);
+
+                AsterixDataBlock dataBlock = buildAsterixDataBlock(
+                        dataBlockCategory,
+                        getCustomReservedFieldFactory(dataBlockCategory)
+                );
 
                 inputIndex += 3;
 
@@ -136,4 +146,43 @@ public HashMap<Integer, Boolean> getAllowedCategories() {
     public HashMap<Integer, Integer> getNbOfDataBlocks() {
         return nbOfDataBlocks;
     }
+
+    /**
+     * Attach a custom reserved field implementation (decoding,encoding of SP,RE) for a given
+     * Asterix category. If there is a factory associated with the category, the old
+     * entry shall be replaced with the new one.
+     *
+     * @param category
+     * @param reservedFieldFactory
+     */
+    public void attachCustomReservedFieldFactory(int category,
+                                                 ReservedFieldFactory reservedFieldFactory) {
+        Assert.notNull(reservedFieldFactory);
+        this.customReservedFieldFactories.put(category, reservedFieldFactory);
+    }
+
+    /**
+     * Get the custom reserved field implementation factory for a given Asterix category,
+     * if it has been attached. Will return NULL if no factory is associated with the category
+     *
+     * @param category
+     * @return
+     */
+    public ReservedFieldFactory getCustomReservedFieldFactory(int category) {
+        return this.customReservedFieldFactories.get(category);
+    }
+
+    private AsterixDataBlock buildAsterixDataBlock(int category, ReservedFieldFactory customReservedFieldFactory) {
+        AsterixDataBlock dataBlock;
+        if (customReservedFieldFactory == null) {
+            dataBlock = new AsterixDataBlock(category);
+        } else {
+            dataBlock = new AsterixDataBlock(
+                    category,
+                    customReservedFieldFactory
+            );
+        }
+
+        return dataBlock;
+    }
 }

src/main/java/jlg/jade/asterix/StandardAsterixRecord.java

@@ -13,6 +13,7 @@
 import jlg.jade.asterix.cat065.Cat065Record;
 import jlg.jade.asterix.cat150.Cat150Record;
 import jlg.jade.common.DebugMessageSource;
+import org.springframework.util.Assert;
 import sun.reflect.generics.reflectiveObjects.NotImplementedException;
 
 import java.util.AbstractMap;
@@ -32,14 +33,18 @@ public class StandardAsterixRecord extends DebugMessageSource implements Asterix
     private Cat150Record cat150Record;
     /**
      * This field is used by 3rd party applications using this library. It helps to
-     * add more informaiton on the ASTERIX record, that can simplify the logic in
+     * add more information on the ASTERIX record, that can simplify the logic in
      * their own apps.
      *
      * @implNote No ASTERIX decoded field shall be inserted here. This will be empty. Only users can
      * add info on this list after the decoding has been done.
      */
     private AbstractMap<String, Object> additionalInfo;
 
+    /**
+     * Create an Asterix Record without any SP,RE fields
+     * @param category
+     */
     public StandardAsterixRecord(int category) {
         this.category = category;
         this.additionalInfo = new HashMap<>();
@@ -73,13 +78,54 @@ public StandardAsterixRecord(int category) {
         }
     }
 
+    /**
+     * Create an Asterix Record where the SP or RE fields need to have a custom decoding/encoding
+     * implementation
+     * @param category
+     */
+    public StandardAsterixRecord(int category, ReservedFieldFactory customReservedFieldFactory) {
+        Assert.notNull(customReservedFieldFactory); //Use other constructor if no custom factory is needed
+
+        this.category = category;
+        this.additionalInfo = new HashMap<>();
+        switch (category) {
+            case 4: {
+                this.cat004Record = new Cat004Record(customReservedFieldFactory);
+                break;
+            }
+            case 34: {
+                this.cat034Record = new Cat034Record(customReservedFieldFactory);
+                break;
+            }
+            case 48: {
+                this.cat048Record = new Cat048Record(customReservedFieldFactory);
+                break;
+            }
+            case 62: {
+                this.cat062Record = new Cat062Record(customReservedFieldFactory);
+                break;
+            }
+            case 65: {
+                this.cat065Record = new Cat065Record(customReservedFieldFactory);
+                break;
+            }
+            case 150: {
+                //Cat150 does not have SP and RE fields, so we do not need to pass in additional arguments
+                this.cat150Record = new Cat150Record();
+                break;
+            }
+            default:
+                throw new NotImplementedException();
+        }
+    }
+
     /**
      * Decodes the raw data to Asterix data block, containing zero or more Asterix
      * records
      *
      * @param input       The raw data
      * @param offset      The start offset in the raw data, at which reading should begin
-     * @param inputLength The ammount of data that nees to be read from the input
+     * @param inputLength The amount of data that needs to be read from the input
      * @return The new offset in the raw data
      */
     @Override

src/main/java/jlg/jade/asterix/cat034/Cat034Record.java

@@ -32,6 +32,10 @@ public Cat034Record() {
         this.reservedFieldFactory = new DefaultReservedFieldFactory();
     }
 
+    public Cat034Record(ReservedFieldFactory customReservedFieldFactory) {
+        this.reservedFieldFactory = customReservedFieldFactory;
+    }
+
     @Override
     protected int setMaxFspecSizeInBytes() {
         return AsterixItemLength.TWO_BYTES.getValue();

src/main/java/jlg/jade/asterix/cat048/Cat048Record.java

@@ -45,6 +45,10 @@ public Cat048Record() {
         this.reservedFieldFactory = new DefaultReservedFieldFactory();
     }
 
+    public Cat048Record(ReservedFieldFactory customReservedFieldFactory) {
+        this.reservedFieldFactory = customReservedFieldFactory;
+    }
+
     @Override
     protected String setDisplayName() {
         return "*** Category 048 Record ***";

src/test/java/jlg/jade/test/asterix/AsterixDataBlockTest.java

@@ -0,0 +1,15 @@
+package jlg.jade.test.asterix;
+
+import jlg.jade.asterix.AsterixDataBlock;
+import org.junit.Test;
+
+/**
+ * Created by Dan Geabunea on 1/6/2017.
+ */
+public class AsterixDataBlockTest {
+
+    @Test(expected = IllegalArgumentException.class)
+    public void should_throw_if_we_pass_null_custom_reserved_field_factory_in_ctor(){
+        AsterixDataBlock dataBlock = new AsterixDataBlock(62, null);
+    }
+}

src/test/java/jlg/jade/test/asterix/AsterixDecoderTest.java

@@ -7,6 +7,7 @@
 import jlg.jade.asterix.AsterixDataBlock;
 import jlg.jade.asterix.AsterixDecoder;
 import jlg.jade.asterix.AsterixRecord;
+import jlg.jade.asterix.DefaultReservedFieldFactory;
 import jlg.jade.test.utils.TestHelper;
 import org.junit.Test;
 
@@ -54,4 +55,11 @@ public void the_decode_method_should_decode_only_specified_categories_from_the_l
         // assert
         assertEquals("Number of decoded Cat062 items is not correct", 22396, asterixRecords.size());
     }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void attachCustomReservedFieldFactory_should_throw_if_custom_reserved_field_factory_argument_is_null(){
+        AsterixDecoder decoder = new AsterixDecoder(62);
+        decoder.attachCustomReservedFieldFactory(62, new DefaultReservedFieldFactory());
+
+    }
 }

src/test/java/jlg/jade/test/asterix/AsterixRecordTest.java

@@ -0,0 +1,16 @@
+package jlg.jade.test.asterix;
+
+import jlg.jade.asterix.AsterixRecord;
+import jlg.jade.asterix.StandardAsterixRecord;
+import org.junit.Test;
+
+/**
+ * Created by Dan Geabunea on 1/6/2017.
+ */
+public class AsterixRecordTest {
+
+    @Test(expected = IllegalArgumentException.class)
+    public void should_throw_if_we_pass_null_custom_reserved_filed_factory_in_ctor(){
+        AsterixRecord asterixRecord = new StandardAsterixRecord(62, null);
+    }
+}