buildjar: close streams

Use try-with-resources to close all streams.

I hope this will fix the spurious file deletion
failures on Windows, where the persistent
JavaBuilder worker cannot delete outputs from
previous builds because, supposedly, they are
still open, because a stale object that's ready
to be GC'd hasn't yet been actually GC'd.

Change-Id: Ia57b8bd0ba1b6ee0691d34467c92e86e35d4d71d
PiperOrigin-RevId: 175941520

3 files changed, 11 insertions, 5 deletions

diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass/GenClass.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass/GenClass.java
index 1aed0f9779..4bc1f922fe 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass/GenClass.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass/GenClass.java
@@ -122,6 +122,9 @@ public class GenClass {
         String className = name.substring(0, name.length() - ".class".length());
         if (prefixesContains(generatedPrefixes, className)) {
           Files.createDirectories(tempDir.resolve(name).getParent());
+          // InputStream closing: JarFile extends ZipFile, and ZipFile.close() will close all of the
+          // input streams previously returned by invocations of the getInputStream method.
+          // See https://docs.oracle.com/javase/8/docs/api/java/util/zip/ZipFile.html#close--
           Files.copy(jar.getInputStream(entry), tempDir.resolve(name));
         }
       }
diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/jarhelper/JarCreator.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/jarhelper/JarCreator.java
index 46232bc879..eb25a23e4d 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/jarhelper/JarCreator.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/jarhelper/JarCreator.java
@@ -147,13 +147,16 @@ public class JarCreator extends JarHelper {
   }
 
   private byte[] manifestContent() throws IOException {
-    Manifest manifest;
     if (manifestFile != null) {
-      FileInputStream in = new FileInputStream(manifestFile);
-      manifest = new Manifest(in);
+      try (FileInputStream in = new FileInputStream(manifestFile)) {
+        return manifestContentImpl(new Manifest(in));
+      }
     } else {
-      manifest = new Manifest();
+      return manifestContentImpl(new Manifest());
     }
+  }
+
+  private byte[] manifestContentImpl(Manifest manifest) throws IOException {
     Attributes attributes = manifest.getMainAttributes();
     attributes.put(Attributes.Name.MANIFEST_VERSION, "1.0");
     Attributes.Name createdBy = new Attributes.Name("Created-By");
diff --git a/third_party/ijar/test/ijar_test.sh b/third_party/ijar/test/ijar_test.sh
index 5279f15f84..0b9a92fb2d 100755
--- a/third_party/ijar/test/ijar_test.sh
+++ b/third_party/ijar/test/ijar_test.sh
@@ -41,7 +41,7 @@ shift
 source ${DIR}/testenv.sh || { echo "testenv.sh not found!" >&2; exit 1; }
 
 function cleanup() {
-  rm -fr "${TEST_TMPDIR:-sentinel}"/*
+  rm -fr "$TEST_TMPDIR"/*
 }
 
 trap cleanup EXIT