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author | Yang Song <songy23@users.noreply.github.com> | 2018-09-18 16:25:14 -0700 |
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committer | GitHub <noreply@github.com> | 2018-09-18 16:25:14 -0700 |
commit | 7da904c4e75d68eaf77ecaca59e82fa932251e0c (patch) | |
tree | facb0f32924df0ad6d60a0d1cc54dc101c22efd7 /api/src/main/java | |
parent | 0a3fb9761fbc0d31e06a60dcb650c9e9a8d5f5f3 (diff) | |
download | opencensus-java-7da904c4e75d68eaf77ecaca59e82fa932251e0c.tar.gz |
Common: Add an API Functions.returnToString(). (#1443)
* Common: Add an API Functions.returnToString().
* Fix comments and add tests.
Diffstat (limited to 'api/src/main/java')
-rw-r--r-- | api/src/main/java/io/opencensus/common/Functions.java | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/api/src/main/java/io/opencensus/common/Functions.java b/api/src/main/java/io/opencensus/common/Functions.java index eb5984af..ea3457ca 100644 --- a/api/src/main/java/io/opencensus/common/Functions.java +++ b/api/src/main/java/io/opencensus/common/Functions.java @@ -53,6 +53,14 @@ public final class Functions { } }; + private static final Function<Object, /*@Nullable*/ String> RETURN_TO_STRING = + new Function<Object, /*@Nullable*/ String>() { + @Override + public /*@Nullable*/ String apply(Object input) { + return input == null ? null : input.toString(); + } + }; + /** * A {@code Function} that always ignores its argument and returns {@code null}. * @@ -82,6 +90,16 @@ public final class Functions { } /** + * A {@code Function} that always returns the {@link #toString()} value of the input. + * + * @return a {@code Function} that always returns the {@link #toString()} value of the input. + * @since 0.17 + */ + public static Function<Object, /*@Nullable*/ String> returnToString() { + return RETURN_TO_STRING; + } + + /** * A {@code Function} that always ignores its argument and throws an {@link * IllegalArgumentException}. * |