Velocity: prepare function to avoid expansion of Java comments (due to conflicts with JavaDoc notation)

Author: Olivier Chafik

src/main/java/com/nativelibs4java/velocity/Utils.java

@@ -0,0 +1,63 @@
+package com.nativelibs4java.velocity;
+
+import com.google.common.base.Function;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class Utils {
+    
+
+    protected static String processComments(String source, Function<String, String> processor) {
+        Pattern p = Pattern.compile("(?m)(?s)/\\*\\*?.*?\\*/");
+        Matcher m = p.matcher(source);
+        StringBuffer sb = new StringBuffer();
+        while (m.find()) {
+            String comment = m.group();
+            String replacement = processor.apply(comment);
+            m.appendReplacement(sb, "");
+            sb.append(replacement);
+        }
+        m.appendTail(sb);
+        return sb.toString();
+    }
+    
+    protected static String quoteSharpsInComments(String source) {
+        return processComments(source, new Function<String, String>() {
+            public String apply(String f) {
+                return f.replaceAll("#", "\\\\#");
+            }
+        });
+    }
+    
+    protected static String unquoteSharpsInComments(String source) {
+        return processComments(source, new Function<String, String>() {
+            public String apply(String f) {
+                return f.replaceAll("\\\\#", "#");
+            }
+        });
+    }
+    
+    static String readTextFile(File file) throws IOException {
+        BufferedReader sourceIn = new BufferedReader(new FileReader(file));
+        StringWriter sourceOut = new StringWriter();
+        PrintWriter sourcePOut = new PrintWriter(sourceOut);
+        String line;
+        while ((line = sourceIn.readLine()) != null) {
+            sourcePOut.println(line);
+        }
+        return sourceOut.toString();
+    }
+    
+    static void writeTextFile(File file, String text) throws IOException {
+        FileWriter f = new FileWriter(file);
+        f.write(unquoteSharpsInComments(text));
+        f.close();
+    }
+}

src/main/java/com/nativelibs4java/velocity/VelocityMojo.java

@@ -15,22 +15,30 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+import static com.nativelibs4java.velocity.Utils.*;
+import com.google.common.base.Function;
+import java.io.BufferedReader;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.model.Resource;
 
 import java.io.File;
+import java.io.FileReader;
 import java.io.FileWriter;
 import java.io.IOException;
+import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Map;
 import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import org.apache.velocity.*;
 import org.apache.velocity.app.VelocityEngine;
 import org.apache.velocity.app.Velocity;
+import org.codehaus.plexus.util.IOUtil;
 
 /**
  * Generates source code with velocity templates
@@ -254,8 +262,6 @@ private boolean executeAll(File velocitySources, boolean isTest) throws MojoExec
                 }
 
                 VelocityEngine ve = createEngine(canoPath);
-                org.apache.velocity.Template template = ve.getTemplate(cano);//file.getName());
-
                 VelocityContext context = new VelocityContext();//execution.getParameters());
                 context.put("primitives", Primitive.getPrimitives());
                 context.put("primitivesNoBool", Primitive.getPrimitivesNoBool());
@@ -279,15 +285,21 @@ private boolean executeAll(File velocitySources, boolean isTest) throws MojoExec
                 }
 
                 StringWriter out = new StringWriter();
-                template.merge(context, out);
+                
+                boolean quoteComments = false;
+                if (quoteComments) {
+                    String source = readTextFile(file);
+                    String quoted = quoteSharpsInComments(source);
+                    ve.evaluate(context, out, "velocity", quoted);
+                } else {
+                    org.apache.velocity.Template template = ve.getTemplate(cano);//file.getName());
+                    template.merge(context, out);
+                }
                 out.close();
 
                 outFile.getParentFile().mkdirs();
-
-
-                FileWriter f = new FileWriter(outFile);
-                f.write(out.toString());
-                f.close();
+                String transformed = out.toString();
+                writeTextFile(outFile, transformed);
                 //getLog().info("\tGenerated '" + outFile.getName() + "'");
 
             } catch (Exception ex) {

src/test/java/com/nativelibs4java/velocity/UtilsTest.java

@@ -0,0 +1,27 @@
+/*
+ * To change this template, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package com.nativelibs4java.velocity;
+
+import static com.nativelibs4java.velocity.Utils.*;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ *
+ * @author ochafik
+ */
+public class UtilsTest {
+    @Test
+    public void testQuote() {
+        assertEquals(quoteSharpsInComments("#"), "#");
+        String q = quoteSharpsInComments("a#\n/*\n#c*/");
+        assertEquals("a#\n/*\n\\#c*/", quoteSharpsInComments("a#\n/*\n#c*/"));
+        assertEquals("a#\n/*\n#c*/", unquoteSharpsInComments("a#\n/*\n\\#c*/"));
+    }
+}