> The commit in this PR implements the proposal for enhancement that was > discussed in the core-libs-dev mailing list recently[1], for > https://bugs.openjdk.java.net/browse/JDK-8231640 > > At a high level - the `store()` APIs in `Properties` have been modified to > now look for the `SOURCE_DATE_EPOCH` environment variable[2]. If that env > variable is set, then instead of writing out the current date time as a date > comment, the `store()` APIs instead will use the value set for this env > variable to parse it to a `Date` and write out the string form of such a > date. The implementation here uses the `d MMM yyyy HH:mm:ss 'GMT'` date > format and `Locale.ROOT` to format and write out such a date. This should > provide reproducibility whenever the `SOURCE_DATE_EPOCH` is set. Furthermore, > intentionally, no changes in the date format of the "current date" have been > done. > > These modified `store()` APIs work in the presence of the `SecurityManager` > too. The caller is expected to have a read permission on the > `SOURCE_DATE_EPOCH` environment variable. If the caller doesn't have that > permission, then the implementation of these `store()` APIs will write out > the "current date" and will ignore any value that has been set for the > `SOURCE_DATE_EPOCH` env variable. This should allow for backward > compatibility of existing applications, where, when they run under a > `SecurityManager` and perhaps with an existing restrictive policy file, the > presence of `SOURCE_DATE_EPOCH` shouldn't impact their calls to the `store()` > APIs. > > The modified `store()` APIs will also ignore any value for > `SOURCE_DATE_EPOCH` that cannot be parsed to an `long` value. In such cases, > the `store()` APIs will write out the "current date" and ignore the value set > for this environment variable. No exceptions will be thrown for such invalid > values. This is an additional backward compatibility precaution to prevent > any rogue value for `SOURCE_DATE_EPOCH` from breaking applications. > > An additional change in the implementation of these `store()` APIs and > unrelated to the date comment, is that these APIs will now write out the > property keys in a deterministic order. The keys will be written out in the > natural ordering as specified by `java.lang.String#compareTo()` API. > > The combination of the ordering of the property keys when written out and the > usage of `SOURCE_DATE_EPOCH` environment value to determine the date comment > should together allow for reproducibility of the output generated by these > `store()` APIs. > > New jtreg test classes have been introduced to verify these changes. The > primary focus of `PropertiesStoreTest` is the ordering aspects of the > property keys that are written out. On the other hand > `StoreReproducibilityTest` focuses on the reproducibility of the output > generated by these APIs. The `StoreReproducibilityTest` runs these tests > both in the presence and absence of `SecurityManager`. Plus, in the presence > of SecurityManager, it tests both the scenarios where the caller is granted > the requisite permission and in other case not granted that permission. > > These new tests and existing tests under `test/jdk/java/util/Properties/` > pass with these changes. > > [1] > https://mail.openjdk.java.net/pipermail/core-libs-dev/2021-August/080758.html > [2] https://reproducible-builds.org/specs/source-date-epoch/
Jaikiran Pai has updated the pull request incrementally with one additional commit since the last revision: Implement Mark's suggestion in CSR to include the java.properties.date in the list of system properties listed in System::getProperties() ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/5372/files - new: https://git.openjdk.java.net/jdk/pull/5372/files/eb31d287..458c1fd3 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5372&range=19 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5372&range=18-19 Stats: 3 lines in 1 file changed: 3 ins; 0 del; 0 mod Patch: https://git.openjdk.java.net/jdk/pull/5372.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/5372/head:pull/5372 PR: https://git.openjdk.java.net/jdk/pull/5372
