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dongjoon pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/orc.git
The following commit(s) were added to refs/heads/main by this push:
new 46fb72aed ORC-2053: Use Java `Set.of` instead of `Collections.emptySet`
46fb72aed is described below
commit 46fb72aed67e8868a167c3fe6f7129cd851c9629
Author: Dongjoon Hyun <[email protected]>
AuthorDate: Sun Jan 4 11:16:20 2026 +0900
ORC-2053: Use Java `Set.of` instead of `Collections.emptySet`
### What changes were proposed in this pull request?
This PR aims to use Java 9+ `Set.of()` API instead of
`Collections.emptySet()` and add a new checkstyle rule to ban
`Collections.emptySet`.
### Why are the changes needed?
We had better use `Set` simply and uniformly.
```java
- import java.util.Collections;
...
- private Set<Integer> filterColumnIds = Collections.emptySet();
+ private Set<Integer> filterColumnIds = Set.of();
```
### Does this PR introduce _any_ user-facing change?
No behavior change.
### How was this patch tested?
Pass the CIs.
### Was this patch authored or co-authored using generative AI tooling?
No.
Closes #2476 from dongjoon-hyun/ORC-2053.
Authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>
---
java/checkstyle.xml | 4 ++++
java/core/src/java/org/apache/orc/impl/TreeReaderFactory.java | 3 +--
java/core/src/java/org/apache/orc/impl/reader/StripePlanner.java | 3 +--
3 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/java/checkstyle.xml b/java/checkstyle.xml
index 26a3918be..3e184c27d 100644
--- a/java/checkstyle.xml
+++ b/java/checkstyle.xml
@@ -52,6 +52,10 @@
<property name="ignoreComments" value="true"/>
<property name="message" value="No starting LAND and LOR allowed."/>
</module>
+ <module name="RegexpSinglelineJava">
+ <property name="format" value="Collections\.emptySet"/>
+ <property name="message" value="Use Set.of() instead." />
+ </module>
<module name="Indentation">
<property name="severity" value="error"/>
<property name="basicOffset" value="2"/>
diff --git a/java/core/src/java/org/apache/orc/impl/TreeReaderFactory.java
b/java/core/src/java/org/apache/orc/impl/TreeReaderFactory.java
index e9122a1c6..43d3a33b2 100644
--- a/java/core/src/java/org/apache/orc/impl/TreeReaderFactory.java
+++ b/java/core/src/java/org/apache/orc/impl/TreeReaderFactory.java
@@ -53,7 +53,6 @@ import java.io.IOException;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
-import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@@ -143,7 +142,7 @@ public class TreeReaderFactory {
private ReaderEncryption encryption;
private boolean useProlepticGregorian;
private boolean fileUsedProlepticGregorian;
- private Set<Integer> filterColumnIds = Collections.emptySet();
+ private Set<Integer> filterColumnIds = Set.of();
Consumer<OrcFilterContext> filterCallback;
public ReaderContext setSchemaEvolution(SchemaEvolution evolution) {
diff --git a/java/core/src/java/org/apache/orc/impl/reader/StripePlanner.java
b/java/core/src/java/org/apache/orc/impl/reader/StripePlanner.java
index d796bcb0a..2501e7e72 100644
--- a/java/core/src/java/org/apache/orc/impl/reader/StripePlanner.java
+++ b/java/core/src/java/org/apache/orc/impl/reader/StripePlanner.java
@@ -44,7 +44,6 @@ import java.nio.ByteBuffer;
import java.security.Key;
import java.util.ArrayList;
import java.util.Arrays;
-import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@@ -123,7 +122,7 @@ public class StripePlanner {
boolean ignoreNonUtf8BloomFilter,
long maxBufferSize) {
this(schema, encryption, dataReader, version, ignoreNonUtf8BloomFilter,
maxBufferSize,
- Collections.emptySet());
+ Set.of());
}
public StripePlanner(StripePlanner old) {
