From e38344cd37402ea594157a119e985dbfbd99bbfb Mon Sep 17 00:00:00 2001
From: 1fanwang <1fannnw@gmail.com>
Date: Tue, 12 May 2026 01:24:58 -0700
Subject: [PATCH] GH-3354: Make LocalInputFile.toString() return the file path

ParquetFileReader uses InputFile.toString() to build the "is not a Parquet
file" error message. HadoopInputFile overrides toString() to return its
Path, so the error message is actionable for Hadoop-backed reads. For
LocalInputFile and any third-party InputFile that does not override
toString(), the message degrades to "ClassName@hashcode is not a Parquet
file (length is too low: 10)", which gives no clue which file was bad.

Override toString() on LocalInputFile so the same code path produces a
path-bearing message for local reads, matching HadoopInputFile.
---
 .../java/org/apache/parquet/io/LocalInputFile.java    |  5 +++++
 .../org/apache/parquet/io/TestLocalInputOutput.java   | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/parquet-common/src/main/java/org/apache/parquet/io/LocalInputFile.java b/parquet-common/src/main/java/org/apache/parquet/io/LocalInputFile.java
index 7174b42d5d..f4f2a996a3 100644
--- a/parquet-common/src/main/java/org/apache/parquet/io/LocalInputFile.java
+++ b/parquet-common/src/main/java/org/apache/parquet/io/LocalInputFile.java
@@ -99,4 +99,9 @@ public void close() throws IOException {
       }
     };
   }
+
+  @Override
+  public String toString() {
+    return path.toString();
+  }
 }
diff --git a/parquet-common/src/test/java/org/apache/parquet/io/TestLocalInputOutput.java b/parquet-common/src/test/java/org/apache/parquet/io/TestLocalInputOutput.java
index 84d728f14e..42d5b7ca6f 100644
--- a/parquet-common/src/test/java/org/apache/parquet/io/TestLocalInputOutput.java
+++ b/parquet-common/src/test/java/org/apache/parquet/io/TestLocalInputOutput.java
@@ -47,6 +47,17 @@ public void outputFileOverwritesFile() throws IOException {
     }
   }
 
+  @Test
+  public void inputFileToStringReturnsPath() throws IOException {
+    Path path = Paths.get(createTempFile().getPath());
+    InputFile read = new LocalInputFile(path);
+    // toString() is used by ParquetFileReader when constructing error messages
+    // such as "<path> is not a Parquet file (length is too low: ...)". A
+    // path-bearing toString() keeps those error messages actionable for
+    // implementations that don't expose a more specific accessor.
+    assertEquals(path.toString(), read.toString());
+  }
+
   @Test
   public void outputFileCreateFailsAsFileAlreadyExists() throws IOException {
     Path path = Paths.get(createTempFile().getPath());