String给出的类编译

Question

我有以下代码：

public static void compileClass() {
    JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
    DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<>();

    StringWriter writer = new StringWriter();
    PrintWriter out = new PrintWriter(writer);
    out.println("package ccc;");
    out.println("public class HelloWorld {");
    out.println("  public static void main(String args[]) {");
    out.println("    System.out.println(\"This is in another java file\");");
    out.println("  }");
    out.println("}");
    out.close();
    JavaFileObject file = new JavaSourceFromString("HelloWorld", writer.toString());

    Iterable<? extends JavaFileObject> compilationUnits = Arrays.asList(file);
    CompilationTask task = compiler.getTask(null, null, diagnostics, null, null, compilationUnits);

    boolean success = task.call();
    for (Diagnostic diagnostic : diagnostics.getDiagnostics()) {
        System.out.println(diagnostic.getCode());
        System.out.println(diagnostic.getKind());
        System.out.println(diagnostic.getPosition());
        System.out.println(diagnostic.getStartPosition());
        System.out.println(diagnostic.getEndPosition());
        System.out.println(diagnostic.getSource());
        System.out.println(diagnostic.getMessage(null));

    }
    System.out.println("Success: " + success);

    if (success) {
        try {
            Class.forName("ccc.HelloWorld").getDeclaredMethod("main", new Class[]{String[].class})
                    .invoke(null, new Object[]{null});
        } catch (ClassNotFoundException e) {
            System.err.println("Class not found: " + e);
        } catch (NoSuchMethodException e) {
            System.err.println("No such method: " + e);
        } catch (IllegalAccessException e) {
            System.err.println("Illegal access: " + e);
        } catch (InvocationTargetException e) {
            System.err.println("Invocation target: " + e);
        }
    }
}

}

附加课程：

class JavaSourceFromString extends SimpleJavaFileObject {
    final String code;
    JavaSourceFromString(String name, String code) {
        super(URI.create("string:///" + name.replace('.', '/') + Kind.SOURCE.extension), Kind.SOURCE);
        this.code = code;
    }

    @Override
    public CharSequence getCharContent(boolean ignoreEncodingErrors) {
        return code;
    }
}

问题：运行方法 compileClass 时，一切都清晰但排成一行：

Class.forName("ccc.HelloWorld").getDeclaredMethod("main", new Class[]{String[].class})
                    .invoke(null, new Object[]{null});

抛出异常：

  

未找到类：java.lang.ClassNotFoundException：ccc.HelloWorld