merged with rfrowe/master and Pkeidel/master and minor refactoring

Author: trung

src/main/java/org/mdkt/compiler/CompilationException.java

@@ -1,9 +1,25 @@
 package org.mdkt.compiler;
 
+import java.util.List;
+import java.util.Locale;
+import javax.tools.Diagnostic;
+import javax.tools.JavaFileObject;
+
 public class CompilationException extends RuntimeException {
 	private static final long serialVersionUID = 5272588827551900536L;
 
-	public CompilationException(String msg) {
-		super(msg);
+	public CompilationException(List<Diagnostic<? extends JavaFileObject>> diags) {
+		super(buildMessage(diags));
+	}
+
+	private static String buildMessage(List<Diagnostic<? extends JavaFileObject>> diags) {
+		StringBuffer msg = new StringBuffer();
+		msg.append("Unable to compile the source.");
+		for (Diagnostic<?> diag : diags) {
+			msg.append("\n").append("[kind=").append(diag.getKind());
+			msg.append(", ").append("line=").append(diag.getLineNumber());
+			msg.append(", ").append("message=").append(diag.getMessage(Locale.US)).append("]");
+		}
+		return msg.toString();
 	}
 }

src/main/java/org/mdkt/compiler/InMemoryJavaCompiler.java

@@ -5,7 +5,9 @@
 import java.util.Iterator;
 import java.util.Map;
 
+import javax.tools.DiagnosticCollector;
 import javax.tools.JavaCompiler;
+import javax.tools.JavaFileObject;
 import javax.tools.ToolProvider;
 
 /**
@@ -49,12 +51,12 @@ public Map<String, Class<?>> compileAll() throws Exception {
 		for (int i = 0; i < code.length; i++) {
 			code[i] = new CompiledCode(iter.next().getClassName());
 		}
-
+		DiagnosticCollector<JavaFileObject> collector = new DiagnosticCollector<>();
 		ExtendedStandardJavaFileManager fileManager = new ExtendedStandardJavaFileManager(javac.getStandardFileManager(null, null, null), classLoader);
-		JavaCompiler.CompilationTask task = javac.getTask(null, fileManager, null, null, null, compilationUnits);
+		JavaCompiler.CompilationTask task = javac.getTask(null, fileManager, collector, null, null, compilationUnits);
 		boolean result = task.call();
-		if (!result) {
-			throw new RuntimeException("Unknown error during compilation.");
+		if (!result || collector.getDiagnostics().size() > 0) {
+			throw new CompilationException(collector.getDiagnostics());
 		}
 
 		Map<String, Class<?>> classes = new HashMap<String, Class<?>>();

src/test/java/org/mdkt/compiler/InMemoryJavaCompilerTest.java

@@ -3,9 +3,13 @@
 import java.util.Map;
 
 import org.junit.Assert;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 
 public class InMemoryJavaCompilerTest {
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
 
 	@Test
 	public void compile_WhenTypical() throws Exception {
@@ -22,7 +26,7 @@ public void compile_WhenTypical() throws Exception {
 	}
 
 	@Test
-	public void compile_WhenMultipleSources() throws Exception {
+	public void compileAll_WhenTypical() throws Exception {
 		String cls1 = "public class A{ public B b() { return new B(); }}";
 		String cls2 = "public class B{ public String toString() { return \"B!\"; }}";
 
@@ -50,4 +54,17 @@ public void compile_WhenSourceContainsInnerClasses() throws Exception {
 		Assert.assertNotNull(helloClass);
 		Assert.assertEquals(1, helloClass.getDeclaredMethods().length);
 	}
+
+	@Test
+	public void compile_whenError() throws Exception {
+		thrown.expect(CompilationException.class);
+		thrown.expectMessage("Unable to compile the source");
+		StringBuffer sourceCode = new StringBuffer();
+
+		sourceCode.append("package org.mdkt;\n");
+		sourceCode.append("public classHelloClass {\n");
+		sourceCode.append("   public String hello() { return \"hello\"; }");
+		sourceCode.append("}");
+		InMemoryJavaCompiler.newInstance().compile("org.mdkt.HelloClass", sourceCode.toString());
+	}
 }