src/java.base/share/classes/jdk/internal/vm/VMSupport.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2020, 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

@@ -22,17 +22,18 @@
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package jdk.internal.vm;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.util.Properties;
-import java.util.Set;
 import java.util.jar.JarFile;
 import java.util.jar.Manifest;
 import java.util.jar.Attributes;
+import java.util.*;
+import java.nio.*;
+import java.nio.charset.*;
 
 /*
  * Support class used by JVMTI and VM attach mechanism.
  */
 public class VMSupport {

@@ -48,29 +49,47 @@
         }
         return agentProps;
     }
     private static native Properties initAgentProperties(Properties props);
 
+    private static String convertToBytesStr(String str, boolean escapeSpace) throws Exception {
+        if (escapeSpace) {
+            str = str.replace(" ", "\\ ");
+        }
+
+        var charBuf = CharBuffer.wrap(str);
+        var byteBuf = ByteBuffer.allocate(charBuf.length() * 5); // 1 unicode char might have 4 digits + 2 ('\u')
+        var encoder = StandardCharsets.ISO_8859_1
+                                      .newEncoder()
+                                      .onUnmappableCharacter(CodingErrorAction.REPORT);
+        CoderResult result;
+        do {
+            result = encoder.encode(charBuf, byteBuf, false);
+            if (result.isUnmappable()) {
+                byteBuf.put(String.format("\\u%04X", (int)charBuf.get()).getBytes());
+            } else if (result.isError()) {
+                result.throwException();
+            }
+        } while (result.isError());
+
+        return new String(byteBuf.array());
+    }
+
     /**
      * Write the given properties list to a byte array and return it. Properties with
      * a key or value that is not a String is filtered out. The stream written to the byte
      * array is ISO 8859-1 encoded.
      */
     private static byte[] serializePropertiesToByteArray(Properties p) throws IOException {
-        ByteArrayOutputStream out = new ByteArrayOutputStream(4096);
-
-        Properties props = new Properties();
-
-        // stringPropertyNames() returns a snapshot of the property keys
-        Set<String> keyset = p.stringPropertyNames();
-        for (String key : keyset) {
-            String value = p.getProperty(key);
-            props.put(key, value);
+        var joiner = new StringJoiner("\n");
+        joiner.add((new Date()).toString());
+        for (var entry : p.entrySet()) {
+            var key = convertToBytes(entry.getKey().toString(), true);
+            var value = convertToBytes(entry.getValue().toString(), false);
+            joiner.add(key + "=" + value);
         }
-
-        props.store(out, null);
-        return out.toByteArray();
+        return joiner.toString().getBytes();
     }
 
     public static byte[] serializePropertiesToByteArray() throws IOException {
         return serializePropertiesToByteArray(System.getProperties());
     }