8302685: Some javac unit tests aren't reliably closing open files

Reviewed-by: darcy, vromero

Author: archiecobbs

test/langtools/tools/javac/4241573/T4241573.java

@@ -131,16 +131,11 @@ File createDir(File dir, String... entries) throws Exception {
 
     /** Create a jar file containing one or more entries. */
     File createJar(File jar, String... entries) throws IOException {
-        OutputStream out = new FileOutputStream(jar);
-        try {
-            JarOutputStream jos = new JarOutputStream(out);
+        try (JarOutputStream jos = new JarOutputStream(new FileOutputStream(jar))) {
             for (String e: entries) {
                 jos.putNextEntry(new JarEntry(getPathForZipEntry(e)));
                 jos.write(getBodyForEntry(e).getBytes());
             }
-            jos.close();
-        } finally {
-            out.close();
         }
         return jar;
     }

test/langtools/tools/javac/6400872/T6400872.java

@@ -91,10 +91,9 @@ static void jar(File jar, Iterable<File> classPath, File base, File... files)
             mainAttrs.put(Attributes.Name.MANIFEST_VERSION, "1.0");
             mainAttrs.put(Attributes.Name.CLASS_PATH, join(classPath, " "));
         }
-        OutputStream out = new BufferedOutputStream(new FileOutputStream(jar));
-        JarOutputStream j = new JarOutputStream(out, m);
-        add(j, base, files);
-        j.close();
+        try (JarOutputStream j = new JarOutputStream(new BufferedOutputStream(new FileOutputStream(jar)), m)) {
+            add(j, base, files);
+        }
     }
 
     static void add(JarOutputStream j, File base, File... files) throws IOException {
@@ -124,15 +123,16 @@ static void add(JarOutputStream j, File base, File file) throws IOException {
 
     static byte[] read(File f) throws IOException {
         byte[] buf = new byte[(int) f.length()];
-        BufferedInputStream in = new BufferedInputStream(new FileInputStream(f));
-        int offset = 0;
-        while (offset < buf.length) {
-            int n = in.read(buf, offset, buf.length - offset);
-            if (n < 0)
-                throw new EOFException();
-            offset += n;
+        try (BufferedInputStream in = new BufferedInputStream(new FileInputStream(f))) {
+            int offset = 0;
+            while (offset < buf.length) {
+                int n = in.read(buf, offset, buf.length - offset);
+                if (n < 0)
+                    throw new EOFException();
+                offset += n;
+            }
+            return buf;
         }
-        return buf;
     }
 
     static <T> Iterable<T> iterable(T single) {