Add support for file parser factory

CHANGELOG.md

@@ -4,6 +4,8 @@ on [Keep a CHANGELOG](http://keepachangelog.com/). This project adheres to
 [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
+### Added
+- Support for FileParser Factory
 
 ## [2.3.0]
 ### Changed

generator-plugin-it/pom.xml

@@ -116,7 +116,7 @@
                             <generatorName>
                                 uk.gov.justice.maven.generator.io.files.parser.json.test.JsonTitleAppendingGeneratorFactory
                             </generatorName>
-                            <parserName>uk.gov.justice.maven.generator.io.files.parser.JsonSchemaFileParser</parserName>
+                            <parserName>uk.gov.justice.maven.generator.io.files.parser.JsonSchemaFileParserFactory</parserName>
                             <basePackageName>uk.gov.justice.api</basePackageName>
                             <sourceDirectory>${basedir}/src/json</sourceDirectory>
                             <outputDirectory>${project.build.directory}/generated-sources

generator-plugin/src/main/java/uk/gov/justice/maven/generator/io/files/parser/generator/FileParserInstanceFactory.java

@@ -0,0 +1,32 @@
+package uk.gov.justice.maven.generator.io.files.parser.generator;
+
+import static java.lang.Class.forName;
+import static java.lang.String.format;
+import static java.util.Arrays.asList;
+
+import uk.gov.justice.maven.generator.io.files.parser.FileParser;
+import uk.gov.justice.maven.generator.io.files.parser.FileParserFactory;
+
+public class FileParserInstanceFactory {
+
+    public FileParser newInstanceOf(final String parserName) {
+
+        try {
+            final Object instance = forName(parserName).newInstance();
+
+            if (isFileParserFactory(instance)) {
+                final FileParserFactory fileParserFactory = (FileParserFactory) instance;
+                return fileParserFactory.create();
+            }
+
+            return (FileParser) instance;
+
+        } catch (InstantiationException | IllegalAccessException | ClassNotFoundException ex) {
+            throw new FileParserInstantiationException(format("Failed to instantiate file parser: %s", parserName), ex);
+        }
+    }
+
+    private boolean isFileParserFactory(final Object instance) {
+        return asList(instance.getClass().getInterfaces()).contains(FileParserFactory.class);
+    }
+}

generator-plugin/src/main/java/uk/gov/justice/maven/generator/io/files/parser/generator/FileParserInstantiationException.java

@@ -0,0 +1,8 @@
+package uk.gov.justice.maven.generator.io.files.parser.generator;
+
+public class FileParserInstantiationException extends RuntimeException {
+
+    public FileParserInstantiationException(final String message, final Throwable cause) {
+        super(message, cause);
+    }
+}

generator-plugin/src/main/java/uk/gov/justice/maven/generator/io/files/parser/generator/GenerateMojo.java

@@ -1,9 +1,7 @@
 package uk.gov.justice.maven.generator.io.files.parser.generator;
 
-import static java.lang.Class.forName;
 import static org.apache.maven.plugins.annotations.ResolutionScope.COMPILE_PLUS_RUNTIME;
 
-import uk.gov.justice.maven.generator.io.files.parser.FileParser;
 import uk.gov.justice.maven.generator.io.files.parser.common.BasicMojo;
 import uk.gov.justice.maven.generator.io.files.parser.core.GeneratorProperties;
 import uk.gov.justice.maven.generator.io.files.parser.io.FileTreeScannerFactory;
@@ -71,7 +69,7 @@ public void execute() throws MojoExecutionException {
                 new GenerateGoalProcessor(
                         new MojoGeneratorFactory(),
                         new FileTreeScannerFactory(),
-                        (FileParser) forName(parserName).newInstance())
+                        new FileParserInstanceFactory().newInstanceOf(parserName))
                         .generate(configuration(sourcePaths));
             } catch (Exception e) {
                 throw new MojoExecutionException("Failed to apply generator to source file", e);

generator-plugin/src/test/java/uk/gov/justice/maven/generator/io/files/parser/generator/FileParserInstanceFactoryTest.java

@@ -0,0 +1,49 @@
+package uk.gov.justice.maven.generator.io.files.parser.generator;
+
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.fail;
+
+import uk.gov.justice.maven.generator.io.files.parser.FileParser;
+import uk.gov.justice.maven.generator.io.files.parser.generator.parser.TestFileParser;
+import uk.gov.justice.maven.generator.io.files.parser.generator.parser.TestFileParserFactory;
+
+import org.junit.Test;
+
+public class FileParserInstanceFactoryTest {
+
+    @Test
+    public void shouldCreateInstanceOfFileParserFromGivenFileParserName() throws Exception {
+
+        final String parserName = TestFileParser.class.getName();
+
+        final FileParser fileParser = new FileParserInstanceFactory().newInstanceOf(parserName);
+
+        assertThat(fileParser, is(instanceOf(TestFileParser.class)));
+    }
+
+    @Test
+    public void shouldCreateInstanceOfFileParserFromGivenParserFactoryName() throws Exception {
+
+        final String parserFactoryName = TestFileParserFactory.class.getName();
+
+        final FileParser fileParser = new FileParserInstanceFactory().newInstanceOf(parserFactoryName);
+
+        assertThat(fileParser, is(instanceOf(TestFileParser.class)));
+    }
+
+    @Test
+    public void shouldThrowExceptionIfUnableToInstantiateFileParser() throws Exception {
+
+        final String parserName = "unknown";
+
+        try {
+            new FileParserInstanceFactory().newInstanceOf(parserName);
+            fail();
+        } catch (final FileParserInstantiationException ex) {
+            assertThat(ex.getMessage(), is("Failed to instantiate file parser: unknown"));
+            assertThat(ex.getCause(), is(instanceOf(ClassNotFoundException.class)));
+        }
+    }
+}

generator-plugin/src/test/java/uk/gov/justice/maven/generator/io/files/parser/generator/GenerateMojoTest.java

@@ -120,6 +120,7 @@ public void testShouldGenerateFromOnlyIncludedRaml() throws Exception {
 
     }
 
+    //WARNING: This test will fail in Intellij, as everything is on the one classpath in Intellij
     @SuppressWarnings("unchecked")
     public void testShouldIncludeRamlFilesFromTheClasspath() throws Exception {
         File pom = getTestFile("src/test/resources/includes-excludes-external/pom.xml");

generator-plugin/src/test/java/uk/gov/justice/maven/generator/io/files/parser/generator/parser/TestFileParser.java

@@ -0,0 +1,14 @@
+package uk.gov.justice.maven.generator.io.files.parser.generator.parser;
+
+import uk.gov.justice.maven.generator.io.files.parser.FileParser;
+
+import java.nio.file.Path;
+import java.util.Collection;
+
+public class TestFileParser implements FileParser<String> {
+
+    @Override
+    public Collection<String> parse(final Path baseDir, final Collection<Path> paths) {
+        return null;
+    }
+}

generator-plugin/src/test/java/uk/gov/justice/maven/generator/io/files/parser/generator/parser/TestFileParserFactory.java

@@ -0,0 +1,11 @@
+package uk.gov.justice.maven.generator.io.files.parser.generator.parser;
+
+import uk.gov.justice.maven.generator.io.files.parser.FileParser;
+import uk.gov.justice.maven.generator.io.files.parser.FileParserFactory;
+
+public class TestFileParserFactory implements FileParserFactory<String> {
+
+    public FileParser<String> create() {
+        return new TestFileParser();
+    }
+}

parser-common/src/main/java/uk/gov/justice/maven/generator/io/files/parser/FileParserFactory.java

@@ -0,0 +1,6 @@
+package uk.gov.justice.maven.generator.io.files.parser;
+
+public interface FileParserFactory<T> {
+
+    FileParser<T> create();
+}

schema-parser/src/main/java/uk/gov/justice/maven/generator/io/files/parser/JsonSchemaFileParserFactory.java

@@ -0,0 +1,11 @@
+package uk.gov.justice.maven.generator.io.files.parser;
+
+import javax.json.JsonObject;
+
+public class JsonSchemaFileParserFactory implements FileParserFactory<JsonObject> {
+
+    @Override
+    public FileParser<JsonObject> create() {
+        return new JsonSchemaFileParser();
+    }
+}