Bazel server, tools: ensure Readers are closed

Follow-up to commit 59f17d6e0550bf63a0b6ef182e2d63474e058ede.

Use try-with-resources to ensure Reader objects
are closed eagerly.

Eagerly closing Readers avoids hanging on to
file handles until the garbage collector finalizes
the object, meaning Bazel on Windows (and
other processes) can delete or mutate these files.

Hopefully this avoids intermittent file deletion
errors that sometimes occur on Windows.

See https://github.com/bazelbuild/bazel/issues/5512

RELNOTES: none
PiperOrigin-RevId: 203771262

2 files changed, 7 insertions, 15 deletions

diff --git a/src/tools/android/java/com/google/devtools/build/android/incrementaldeployment/StubApplication.java b/src/tools/android/java/com/google/devtools/build/android/incrementaldeployment/StubApplication.java
index 0b91d03207..5cf15fad73 100644
--- a/src/tools/android/java/com/google/devtools/build/android/incrementaldeployment/StubApplication.java
+++ b/src/tools/android/java/com/google/devtools/build/android/incrementaldeployment/StubApplication.java
@@ -434,8 +434,7 @@ public class StubApplication extends Application {
 
   private static Map<String, String> parseManifest(File file) throws IOException {
     Map<String, String> result = new HashMap<>();
-    BufferedReader reader = new BufferedReader(new FileReader(file));
-    try {
+    try (BufferedReader reader = new BufferedReader(new FileReader(file))) {
       while (true) {
         String line = reader.readLine();
         if (line == null) {
@@ -445,8 +444,6 @@ public class StubApplication extends Application {
         String[] items = line.split(" ");
         result.put(items[0], items[1]);
       }
-    } finally {
-      reader.close();
     }
 
     return result;
diff --git a/src/tools/android/java/com/google/devtools/build/android/ziputils/SplitZip.java b/src/tools/android/java/com/google/devtools/build/android/ziputils/SplitZip.java
index 7a1f81a7e9..25a32a05cc 100644
--- a/src/tools/android/java/com/google/devtools/build/android/ziputils/SplitZip.java
+++ b/src/tools/android/java/com/google/devtools/build/android/ziputils/SplitZip.java
@@ -118,7 +118,7 @@ public class SplitZip implements EntryHandler {
   }
 
   // Package private for testing with mock file
-  SplitZip setMainClassListFile(InputStream clInputStream) {
+  SplitZip setMainClassListStreamForTesting(InputStream clInputStream) {
     filterInputStream = clInputStream;
     return this;
   }
@@ -446,21 +446,16 @@ public class SplitZip implements EntryHandler {
    */
   private Set<String> readPaths(String fileName) throws IOException {
     Set<String> paths = new HashSet<>();
-    BufferedReader reader = null;
-    try {
-      if (filterInputStream == null) {
-        filterInputStream = new FileInputStream(fileName);
-      }
-      reader = new BufferedReader(new InputStreamReader(filterInputStream, UTF_8));
+    if (filterInputStream == null) {
+      filterInputStream = new FileInputStream(fileName);
+    }
+    try (BufferedReader reader =
+        new BufferedReader(new InputStreamReader(filterInputStream, UTF_8))) {
       String line;
       while (null != (line = reader.readLine())) {
         paths.add(fixPath(line));
       }
       return paths;
-    } finally {
-      if (reader != null) {
-        reader.close();
-      }
     }
   }