diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/java.compiler/share/classes/javax/tools/DiagnosticCollector.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.compiler/share/classes/javax/tools/DiagnosticCollector.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2006, 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package javax.tools;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * Provides an easy way to collect diagnostics in a list.
+ *
+ * @param <S> the type of source objects used by diagnostics received
+ * by this object
+ *
+ * @author Peter von der Ah&eacute;
+ * @since 1.6
+ */
+public final class DiagnosticCollector<S> implements DiagnosticListener<S> {
+    private List<Diagnostic<? extends S>> diagnostics =
+            Collections.synchronizedList(new ArrayList<Diagnostic<? extends S>>());
+
+    public void report(Diagnostic<? extends S> diagnostic) {
+        Objects.requireNonNull(diagnostic);
+        diagnostics.add(diagnostic);
+    }
+
+    /**
+     * Returns a list view of diagnostics collected by this object.
+     *
+     * @return a list view of diagnostics
+     */
+    public List<Diagnostic<? extends S>> getDiagnostics() {
+        return Collections.unmodifiableList(diagnostics);
+    }
+}