On Tue, 9 Mar 2021 21:37:16 GMT, Roger Riggs <[email protected]> wrote:
> ObjectStreamPrinter is a Formatter plugin to the test library HexPrinter.
>
> A binary stream of serialized java objects is converted into a textual form
> by parsing the header, typecodes, and interpreting the stream contents. The
> formatter can be used standalone or with the HexPrinter to align the
> formatted stream with the corresponding hexadecimal bytes.
>
> StreamDump is a test utility to pass the contents of a file to the HexPrinter
> utility. The format of the file is guessed from the encoding and initial
> bytes. ASN.1 and serialized object streams are supported.
The idea is to provide a fairly literal interpretation of the stream contents
with annotations to make it easy to read and understand the nesting, object
handle assignments, internal references, class descriptors, and block data
usage.
A Hashmap with three key/value pairs is formatted:
Map<String, String> map = new HashMap<>();
map.put("1", "One");
map.put("2", "Two");
map.put("2.2", "Two");
0000: ac ed 00 05 // ObjectStream Version:
5
0004: 73 72 00 11 6a 61 76 61 2e 75 74 69 // READ CLASSDESC #0
java.util.HashMap
0010: 6c 2e 48 61 73 68 4d 61 70 //
0019: 05 07 da c1 c3 16 60 // svid:
362498820763181265L
0020: d1 //
0021: 03 // flags:
WRITE_OBJECT, SERIALIZABLE
0022: 00 02 // 2 field(s) {
0024: 46 00 0a 6c 6f 61 64 46 61 63 74 6f // F loadFactor
float;
0030: 72 //
0031: 49 00 09 74 68 72 65 73 68 6f 6c 64 // I threshold int;
003d: 78 // } ENDBLOCK;
003e: 70 // Super: NULL;
003f: // OBJ #1
java.util.HashMap
003f: 3f // loadFactor:0.75
0040: 40 00 00 //
0043: 00 00 00 0c // threshold:12
0047: // CustomData:
0047: 77 08 00 00 00 10 00 00 00 // BLOCKDATA 8[
........];
0050: 03 //
0051: 74 00 01 31 // STRING #2 "1"
0055: 74 00 03 4f 6e 65 // STRING #3 "One"
005b: 74 00 01 32 // STRING #4 "2"
005f: 74 // STRING #5 "Two"
0060: 00 03 54 77 6f //
0065: 74 00 03 32 2e 32 // STRING #6 "2.2"
006b: 71 00 7e 00 05 // REF #5 Two
0070: 78 // ENDBLOCK;
The tests include a number of other examples.
-------------
PR: https://git.openjdk.java.net/jdk/pull/2900
