Improve 'CompilerUtil'

Author: emmanue1

src/test/java/org/jd/core/v1/compiler/CompilerUtil.java

@@ -11,34 +11,82 @@
 import java.io.File;
 import java.io.StringWriter;
 import java.util.Arrays;
+import java.util.List;
 
 public class CompilerUtil {
     protected static final File DESTINATION_DIRECTORY = new File("build/test-recompiled");
     protected static final String DESTINATION_DIRECTORY_PATH = DESTINATION_DIRECTORY.getAbsolutePath();
 
-    public static boolean compile(String javaVersion, JavaFileObject... JavaFileObjects) throws Exception {
+    public static boolean compile(String preferredJavaVersion, JavaFileObject... javaFileObjects) throws Exception {
         boolean compilationSuccess = false;
+        String javaVersion = getJavaVersion(preferredJavaVersion);
 
         DESTINATION_DIRECTORY.mkdirs();
 
         JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
         StringWriter writer = new StringWriter();
         DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<>();
+        List<String> options = Arrays.asList("-source", javaVersion, "-target", javaVersion, "-d", DESTINATION_DIRECTORY_PATH, "-cp", System.getProperty("java.class.path"));
+        List<JavaFileObject> compilationUnits = Arrays.asList(javaFileObjects);
 
         try (StandardJavaFileManager fileManager = compiler.getStandardFileManager(diagnostics, null, null)) {
-            Iterable<String> options = Arrays.asList("-source", javaVersion, "-target", javaVersion, "-d", DESTINATION_DIRECTORY_PATH);
-            Iterable<? extends JavaFileObject> compilationUnits = Arrays.asList(JavaFileObjects);
             compilationSuccess = compiler.getTask(writer, fileManager, diagnostics, options, null, compilationUnits).call();
 
-            for (Diagnostic d : diagnostics.getDiagnostics()) {
-                if (d.getLineNumber() > 0) {
-                    System.err.print(String.format("%-7s - line %-4d- %s%n", d.getKind(), d.getLineNumber(), d.getMessage(null)));
-                } else {
-                    System.err.print(String.format("%-7s -          - %s%n", d.getKind(), d.getMessage(null)));
+            if (!diagnostics.getDiagnostics().isEmpty()) {
+                StringBuilder sb = new StringBuilder();
+
+                for (Diagnostic d : diagnostics.getDiagnostics()) {
+                    switch (d.getKind()) {
+                        case NOTE:
+                        case WARNING:
+                            break;
+                        default:
+                            if (d.getLineNumber() > 0) {
+                                sb.append(String.format("%-7s - line %-4d- %s%n", d.getKind(), d.getLineNumber(), d.getMessage(null)));
+                            } else {
+                                sb.append(String.format("%-7s -          - %s%n", d.getKind(), d.getMessage(null)));
+                            }
+                            break;
+                    }
+                }
+
+                if (sb.length() > 0) {
+                    System.err.println(compilationUnits.get(0).getName());
+                    System.err.print(sb.toString());
                 }
             }
         }
 
         return compilationSuccess;
     }
+
+    private static String getJavaVersion(String preferredJavaVersion) {
+        int numericSystemJavaVersion = parseJavaVersion(System.getProperty("java.version"));
+
+        if (numericSystemJavaVersion <= 8) {
+            return preferredJavaVersion;
+        } else {
+            int numericPreferredJavaVersion = parseJavaVersion(preferredJavaVersion);
+
+            if (numericPreferredJavaVersion < 6) {
+                return "1.6";
+            } else {
+                return preferredJavaVersion;
+            }
+        }
+    }
+
+    private static int parseJavaVersion(String javaVersion) {
+        if(javaVersion.startsWith("1.")) {
+            javaVersion = javaVersion.substring(2, 3);
+        } else {
+            int index = javaVersion.indexOf(".");
+
+            if(index != -1) {
+                javaVersion = javaVersion.substring(0, index);
+            }
+        }
+
+        return Integer.parseInt(javaVersion);
+    }
 }