[Java] Generate package-info.java for codecs. Issue #703.

Author: mjpt777

build.gradle

@@ -409,7 +409,6 @@ project(':sbe-samples') {
         classpath = sourceSets.main.runtimeClasspath
         main = 'uk.co.real_logic.sbe.examples.OtfExample'
         workingDir = 'src/main/resources'
-        systemProperties System.getProperties()
     }
 
     task runJavaExamples {

sbe-samples/src/main/resources/example-extension-schema.xml

@@ -5,7 +5,7 @@
                    id="1"
                    version="1"
                    semanticVersion="5.2"
-                   description="Example schema with extension"
+                   description="Example schema which extends baseline schema."
                    byteOrder="littleEndian">
     <xi:include href="common-types.xml"/>
     <types>

sbe-samples/src/main/resources/example-schema.xml

@@ -5,7 +5,7 @@
                    id="1"
                    version="0"
                    semanticVersion="5.2"
-                   description="Example schema"
+                   description="Example base schema which can be extended."
                    byteOrder="littleEndian">
     <xi:include href="common-types.xml"/>
     <types>

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/java/JavaGenerator.java

@@ -46,6 +46,7 @@ enum CodecType
     }
 
     private static final String META_ATTRIBUTE_ENUM = "MetaAttribute";
+    private static final String PACKAGE_INFO = "package-info";
     private static final String BASE_INDENT = "";
     private static final String INDENT = "    ";
     private static final String FLYWEIGHT = "Flyweight";
@@ -165,6 +166,7 @@ public void generateTypeStubs() throws IOException
 
     public void generate() throws IOException
     {
+        generatePackageInfo();
         generateTypeStubs();
         generateMessageHeaderStub();
 
@@ -1652,13 +1654,28 @@ private static CharSequence generateDeclaration(
             implementsString);
     }
 
+    private void generatePackageInfo() throws IOException
+    {
+        try (Writer out = outputManager.createOutput(PACKAGE_INFO))
+        {
+            out.append(
+                "/* Generated SBE (Simple Binary Encoding) message codecs.*/\n" +
+                "/**\n" +
+                " * ").append(ir.description()).append("\n")
+                .append(
+                " */\n" +
+                "package ").append(ir.applicableNamespace()).append(";\n");
+        }
+    }
+
     private void generateMetaAttributeEnum() throws IOException
     {
         try (Writer out = outputManager.createOutput(META_ATTRIBUTE_ENUM))
         {
-            out.append(String.format(
+            out.append(
                 "/* Generated SBE (Simple Binary Encoding) message codec. */\n" +
-                "package %s;\n\n" +
+                "package ").append(ir.applicableNamespace()).append(";\n\n")
+                .append(
                 "/**\n" +
                 " * Meta attribute enum for selecting a particular meta attribute value.\n" +
                 " */\n" +
@@ -1680,8 +1697,7 @@ private void generateMetaAttributeEnum() throws IOException
                 "     * Field presence indication. Can be optional, required, or constant.\n" +
                 "     */\n" +
                 "    PRESENCE\n" +
-                "}\n",
-                ir.applicableNamespace()));
+                "}\n");
         }
     }
 

sbe-tool/src/main/java/uk/co/real_logic/sbe/ir/Ir.java

@@ -33,6 +33,7 @@ public class Ir
     private final String namespaceName;
     private final int id;
     private final int version;
+    private final String description;
     private final String semanticVersion;
     private final ByteOrder byteOrder;
 
@@ -48,7 +49,8 @@ public class Ir
      * @param packageName     that should be applied to generated code.
      * @param namespaceName   that should be applied to generated code.
      * @param id              identifier for the schema.
-     * @param version         of the schema
+     * @param version         of the schema.
+     * @param description     of the schema.
      * @param semanticVersion semantic version for mapping to the application domain.
      * @param byteOrder       byte order for all types in the schema.
      * @param headerTokens    representing the message headerStructure.
@@ -58,6 +60,7 @@ public Ir(
         final String namespaceName,
         final int id,
         final int version,
+        final String description,
         final String semanticVersion,
         final ByteOrder byteOrder,
         final List<Token> headerTokens)
@@ -69,6 +72,7 @@ public Ir(
         this.namespaceName = namespaceName;
         this.id = id;
         this.version = version;
+        this.description = description;
         this.semanticVersion = semanticVersion;
         this.byteOrder = byteOrder;
         this.headerStructure = new HeaderStructure(new ArrayList<>(headerTokens));
@@ -203,6 +207,16 @@ public int version()
         return version;
     }
 
+    /**
+     * Get the description for the schema.
+     *
+     * @return the description for the schema.
+     */
+    public String description()
+    {
+        return description;
+    }
+
     /**
      * Get the semantic version of the schema.
      *

sbe-tool/src/main/java/uk/co/real_logic/sbe/ir/IrDecoder.java

@@ -121,7 +121,8 @@ public Ir decode()
         }
 
         final ByteOrder byteOrder = tokens.size() > 0 ? tokens.get(0).encoding().byteOrder() : null;
-        final Ir ir = new Ir(irPackageName, irNamespaceName, irId, irVersion, semanticVersion, byteOrder, irHeader);
+        final Ir ir = new Ir(
+            irPackageName, irNamespaceName, irId, irVersion, null, semanticVersion, byteOrder, irHeader);
 
         for (int size = tokens.size(); i < size; i++)
         {

sbe-tool/src/main/java/uk/co/real_logic/sbe/ir/generated/package-info.java

@@ -0,0 +1,5 @@
+/* Generated SBE (Simple Binary Encoding) message codecs.*/
+/**
+ * SBE IR Serialization Codecs.
+ */
+package uk.co.real_logic.sbe.ir.generated;

sbe-tool/src/main/java/uk/co/real_logic/sbe/xml/IrGenerator.java

@@ -50,6 +50,7 @@ public Ir generate(final MessageSchema schema, final String namespace)
             namespace,
             schema.id(),
             schema.version(),
+            schema.description(),
             schema.semanticVersion(),
             schema.byteOrder(),
             headerTokens);

sbe-tool/src/main/resources/sbe-ir.xml

@@ -4,7 +4,7 @@
                    id="1"
                    version="0"
                    byteOrder="littleEndian"
-                   description="SBE IR Serialization">
+                   description="SBE IR Serialization Codecs.">
     <types>
         <composite name="messageHeader" description="Message identifiers and length of message root">
             <type name="blockLength" primitiveType="uint16"/>

sbe-tool/src/test/java/uk/co/real_logic/sbe/generation/rust/RustTest.java

@@ -43,7 +43,7 @@ public void happyPathRustGeneratorThatThrowsNoExceptions() throws IOException
 
     static Ir minimalDummyIr()
     {
-        return new Ir("a", "b", 0, 1, "2", ByteOrder.BIG_ENDIAN,
+        return new Ir("a", "b", 0, 1, null, "2", ByteOrder.BIG_ENDIAN,
             Arrays.asList(
                 dummyToken(Signal.ENCODING, HeaderStructure.BLOCK_LENGTH),
                 dummyToken(Signal.ENCODING, HeaderStructure.SCHEMA_ID),