Issue #37: json file processor

config/import-control.xml

@@ -14,6 +14,12 @@
         <allow pkg="org.immutables.gson"/>
     </subpackage>
 
+    <subpackage name="extract">
+        <allow pkg="com.google.gson"/>
+        <allow class="com.sun.tools.javac.util.ServiceLoader"/>
+        <allow class="java.lang.reflect.Type"/>
+    </subpackage>
+
     <subpackage name="git">
         <allow pkg="org.eclipse.jgit"/>
     </subpackage>

pom.xml

@@ -285,11 +285,6 @@
                                         <branchRate>0</branchRate>
                                         <lineRate>0</lineRate>
                                     </regex>
-                                    <regex>
-                                        <pattern>com.github.checkstyle.regression.data.ModuleExtractInfo</pattern>
-                                        <branchRate>0</branchRate>
-                                        <lineRate>0</lineRate>
-                                    </regex>
                                     <regex>
                                         <pattern>com.github.checkstyle.regression.data.ModuleInfo</pattern>
                                         <branchRate>0</branchRate>

src/main/java/com/github/checkstyle/regression/extract/ExtractInfoProcessor.java

@@ -0,0 +1,86 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2017 the original author or authors.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+////////////////////////////////////////////////////////////////////////////////
+
+package com.github.checkstyle.regression.extract;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.lang.reflect.Type;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import com.github.checkstyle.regression.data.ModuleExtractInfo;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.sun.tools.javac.util.ServiceLoader;
+
+/**
+ * Processes the module extract info grabbed from checkstyle project.
+ * @author LuoLiangchen
+ */
+public final class ExtractInfoProcessor {
+    /** The {@link Gson} instance. */
+    private static final Gson GSON;
+
+    /** The type of {@code List<ModuleExtractInfo>}. */
+    private static final Type TYPE_EXTRACT_INFO_LIST = new TypeToken<List<ModuleExtractInfo>>() {
+    }.getType();
+
+    /** Prevents instantiation. */
+    private ExtractInfoProcessor() {
+    }
+
+    static {
+        final GsonBuilder gsonBuilder = new GsonBuilder();
+        for (TypeAdapterFactory factory : ServiceLoader.load(TypeAdapterFactory.class)) {
+            gsonBuilder.registerTypeAdapterFactory(factory);
+        }
+        GSON = gsonBuilder.create();
+    }
+
+    /**
+     * Gets the module extract info map from the given reader. Map key is the
+     * fully qualified module name.
+     * @param reader the given reader
+     * @return the full qualified name to module extract info map
+     */
+    public static Map<String, ModuleExtractInfo> getModuleExtractInfosFromReader(
+            Reader reader) {
+        final List<ModuleExtractInfo> modules;
+
+        try {
+            try {
+                modules = GSON.fromJson(reader, TYPE_EXTRACT_INFO_LIST);
+            }
+            finally {
+                reader.close();
+            }
+        }
+        catch (IOException ex) {
+            throw new IllegalStateException(
+                    "Failed when loaing hardcoded checkstyle module information", ex);
+        }
+
+        return modules.stream().collect(Collectors.toMap(
+                ModuleExtractInfo::fullName, extractInfo -> extractInfo));
+    }
+}

src/main/java/com/github/checkstyle/regression/extract/package-info.java

@@ -0,0 +1,24 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2017 the original author or authors.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Contains execution of checkstyle maven extract process and extract file processor.
+ * @author LuoLiangchen
+ */
+package com.github.checkstyle.regression.extract;

src/test/java/com/github/checkstyle/regression/extract/ExtractInfoProcessorTest.java

@@ -0,0 +1,92 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2017 the original author or authors.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+////////////////////////////////////////////////////////////////////////////////
+
+package com.github.checkstyle.regression.extract;
+
+import static com.github.checkstyle.regression.internal.TestUtils.assertUtilsClassHasPrivateConstructor;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.spy;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.Charset;
+import java.util.Map;
+
+import org.junit.Test;
+
+import com.github.checkstyle.regression.data.ImmutableModuleExtractInfo;
+import com.github.checkstyle.regression.data.ModuleExtractInfo;
+
+public class ExtractInfoProcessorTest {
+    private static final String BASE_PACKAGE = "com.puppycrawl.tools.checkstyle";
+
+    @Test
+    public void testIsProperUtilsClass() throws Exception {
+        assertUtilsClassHasPrivateConstructor(ExtractInfoProcessor.class);
+    }
+
+    @Test
+    public void testGetModuleExtractInfosFromReader() {
+        final InputStream is = ExtractInfoProcessor.class.getClassLoader()
+                .getResourceAsStream("checkstyle_modules.json");
+        final InputStreamReader reader = new InputStreamReader(is, Charset.forName("UTF-8"));
+        final Map<String, ModuleExtractInfo> map =
+                ExtractInfoProcessor.getModuleExtractInfosFromReader(reader);
+
+        final String module1 = "NewlineAtEndOfFileCheck";
+        final ModuleExtractInfo extractInfo1 = ImmutableModuleExtractInfo.builder()
+                .name(module1)
+                .packageName(BASE_PACKAGE + ".checks")
+                .parent("Checker")
+                .build();
+        final String module2 = "EmptyStatementCheck";
+        final ModuleExtractInfo extractInfo2 = ImmutableModuleExtractInfo.builder()
+                .name(module2)
+                .packageName(BASE_PACKAGE + ".checks.coding")
+                .parent("TreeWalker")
+                .build();
+        assertEquals("There should be 2 entries in the extract info map.", 2, map.size());
+        assertEquals("The extract info of NewlineAtEndOfFileCheck is wrong.",
+                extractInfo1, map.get(BASE_PACKAGE + ".checks." + module1));
+        assertEquals("The extract info of EmptyStatementCheck is wrong.",
+                extractInfo2, map.get(BASE_PACKAGE + ".checks.coding." + module2));
+    }
+
+    @Test
+    public void testGetNameToModuleInfoFromInputStreamWithException() throws Exception {
+        final InputStream is = spy(ExtractInfoProcessor.class.getClassLoader()
+                .getResourceAsStream("checkstyle_modules.json"));
+        final InputStreamReader reader = new InputStreamReader(is, Charset.forName("UTF-8"));
+        doThrow(IOException.class).when(is).close();
+
+        try {
+            ExtractInfoProcessor.getModuleExtractInfosFromReader(reader);
+            fail("Exception is expected");
+        }
+        catch (IllegalStateException ex) {
+            assertEquals(
+                    "Exception message is wrong",
+                    "Failed when loaing hardcoded checkstyle module information",
+                    ex.getMessage());
+        }
+    }
+}

src/test/resources/checkstyle_modules.json

@@ -0,0 +1,31 @@
+[
+  {
+    "name": "NewlineAtEndOfFileCheck",
+    "packageName": "com.puppycrawl.tools.checkstyle.checks",
+    "parent": "Checker",
+    "hierarchies": [
+      "com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck",
+      "com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter",
+      "com.puppycrawl.tools.checkstyle.api.AutomaticBean"
+    ],
+    "interfaces": [
+      "com.puppycrawl.tools.checkstyle.api.FileSetCheck",
+      "com.puppycrawl.tools.checkstyle.api.Configurable",
+      "com.puppycrawl.tools.checkstyle.api.Contextualizable"
+    ]
+  },
+  {
+    "name": "EmptyStatementCheck",
+    "packageName": "com.puppycrawl.tools.checkstyle.checks.coding",
+    "parent": "TreeWalker",
+    "hierarchies": [
+      "com.puppycrawl.tools.checkstyle.api.AbstractCheck",
+      "com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter",
+      "com.puppycrawl.tools.checkstyle.api.AutomaticBean"
+    ],
+    "interfaces": [
+      "com.puppycrawl.tools.checkstyle.api.Configurable",
+      "com.puppycrawl.tools.checkstyle.api.Contextualizable"
+    ]
+  }
+]