Replace try/finally with try-with-resources, add a PMD rule to enforc…

…e it
GeoWebCache · Dec 29, 2020 · 3637dc5 · 3637dc5
1 parent c02517b
commit 3637dc5
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Showing 8 changed files with 11 additions and 37 deletions.
diff --git a/geowebcache/core/src/main/java/org/geowebcache/config/XMLFileResourceProvider.java b/geowebcache/core/src/main/java/org/geowebcache/config/XMLFileResourceProvider.java
@@ -223,17 +223,15 @@ private File findOrCreateConfFile() throws IOException {
                             + getClass().getResource(templateLocation).toExternalForm());
             // grab template from classpath
             try {
-                InputStream templateStream = getClass().getResourceAsStream(templateLocation);
-                try {
+                try (InputStream templateStream =
+                        getClass().getResourceAsStream(templateLocation)) {
                     OutputStream output = new FileOutputStream(xmlFile);
                     try {
                         IOUtils.copy(templateStream, output);
                     } finally {
                         output.flush();
                         output.close();
                     }
-                } finally {
-                    templateStream.close();
                 }
             } catch (IOException e) {
                 throw new IOException(

diff --git a/geowebcache/core/src/main/java/org/geowebcache/filter/request/BlankTileException.java b/geowebcache/core/src/main/java/org/geowebcache/filter/request/BlankTileException.java
@@ -42,22 +42,14 @@ public BlankTileException(RequestFilter reqFilter) {
 
     private Resource getBlankTile() {
         // Use the built-in one:
-        InputStream is = null;
-        try {
-            is = GeoWebCacheDispatcher.class.getResourceAsStream("blank.png");
+        try (InputStream is = GeoWebCacheDispatcher.class.getResourceAsStream("blank.png")) {
             byte[] blankTile = new byte[425];
             int ret = is.read(blankTile);
             log.info("Read " + ret + " from blank PNG file (expected 425).");
 
             return new ByteArrayResource(blankTile);
         } catch (IOException ioe) {
             log.error(ioe);
-        } finally {
-            try {
-                if (is != null) is.close();
-            } catch (IOException e) {
-                // close quietly
-            }
         }
 
         return null;

diff --git a/geowebcache/core/src/main/java/org/geowebcache/locks/NIOLockProvider.java b/geowebcache/core/src/main/java/org/geowebcache/locks/NIOLockProvider.java
@@ -64,7 +64,8 @@ public NIOLockProvider(String root) throws ConfigurationException {
         this.maxLockAttempts = 120 * 1000 / waitBeforeRetry;
     }
 
-    @SuppressWarnings("PMD.CloseResource") // complex but seemingly correct resource handling
+    @SuppressWarnings({"PMD.CloseResource", "PMD.UseTryWithResources"})
+    // complex but seemingly correct resource handling
     public LockProvider.Lock getLock(final String lockKey) throws GeoWebCacheException {
         File file = null;
         // first off, synchronize among threads in the same jvm (the nio locks won't lock

diff --git a/geowebcache/core/src/main/java/org/geowebcache/storage/MetastoreRemover.java b/geowebcache/core/src/main/java/org/geowebcache/storage/MetastoreRemover.java
@@ -54,9 +54,7 @@ public class MetastoreRemover {
     public MetastoreRemover(DefaultStorageFinder finder) throws Exception {
         this.storageFinder = finder;
         File root = new File(storageFinder.getDefaultPath());
-        Connection conn = null;
-        try {
-            conn = getMetaStoreConnection(root);
+        try (Connection conn = getMetaStoreConnection(root)) {
             if (conn != null) {
                 log.info("Migrating the old metastore to filesystem storage");
                 SingleConnectionDataSource ds = new SingleConnectionDataSource(conn, false);
@@ -74,10 +72,6 @@ public MetastoreRemover(DefaultStorageFinder finder) throws Exception {
                     removeTiles(template);
                 }
             }
-        } finally {
-            if (conn != null) {
-                conn.close();
-            }
         }
 
         // wipe out the entire database if the db location is the default one

diff --git a/...che/diskquota/core/src/test/java/org/geowebcache/diskquota/LayerCacheInfoBuilderTest.java b/...che/diskquota/core/src/test/java/org/geowebcache/diskquota/LayerCacheInfoBuilderTest.java
@@ -158,11 +158,8 @@ private void mockSeed(TileLayer layer, int numFiles, int fileSize)
 
             File tileDir = tilePath.getParentFile();
             tileDir.mkdirs();
-            FileOutputStream fout = new FileOutputStream(tilePath);
-            try {
+            try (FileOutputStream fout = new FileOutputStream(tilePath)) {
                 fout.write(mockTileContents);
-            } finally {
-                fout.close();
             }
         }
     }

diff --git a/...ebcache/diskquota/jdbc/src/test/java/org/geowebcache/diskquota/jdbc/FixtureUtilities.java b/...ebcache/diskquota/jdbc/src/test/java/org/geowebcache/diskquota/jdbc/FixtureUtilities.java
@@ -42,16 +42,10 @@ public class FixtureUtilities {
     /** Load {@link Properties} from a {@link File}. */
     public static Properties loadProperties(File file) {
         try {
-            InputStream input = null;
-            try {
-                input = new BufferedInputStream(new FileInputStream(file));
+            try (InputStream input = new BufferedInputStream(new FileInputStream(file))) {
                 Properties properties = new Properties();
                 properties.load(input);
                 return properties;
-            } finally {
-                if (input != null) {
-                    input.close();
-                }
             }
         } catch (Exception e) {
             throw new RuntimeException(e);

diff --git a/geowebcache/pmd-ruleset.xml b/geowebcache/pmd-ruleset.xml
@@ -44,6 +44,7 @@ under the License.
     <rule ref="category/java/bestpractices.xml/UseAssertEqualsInsteadOfAssertTrue" />
     <rule ref="category/java/bestpractices.xml/UseAssertNullInsteadOfAssertTrue" />
     <rule ref="category/java/bestpractices.xml/UseAssertSameInsteadOfAssertTrue" />
+    <rule ref="category/java/bestpractices.xml/UseTryWithResources" />
 
     <rule ref="category/java/codestyle.xml/DontImportJavaLang" />
     <rule ref="category/java/codestyle.xml/DuplicateImports" />

diff --git a/geowebcache/sqlite/src/main/java/org/geowebcache/sqlite/MbtilesBlobStore.java b/geowebcache/sqlite/src/main/java/org/geowebcache/sqlite/MbtilesBlobStore.java
@@ -235,9 +235,8 @@ public boolean get(final TileObject tile) throws StorageException {
                         true,
                         connection -> {
                             // instantiating geotools mbtiles reader
-                            MBTilesFile mbtiles =
-                                    GeoToolsMbtilesUtils.getMBTilesFile(connection, file);
-                            try {
+                            try (MBTilesFile mbtiles =
+                                    GeoToolsMbtilesUtils.getMBTilesFile(connection, file)) {
 
                                 final boolean gzipped = tileIsGzipped(tile);
 
@@ -279,8 +278,6 @@ public boolean get(final TileObject tile) throws StorageException {
                                         "Error loading tile '%s' from MBTiles file '%s'.",
                                         tile,
                                         file);
-                            } finally {
-                                mbtiles.close();
                             }
                             if (LOGGER.isDebugEnabled()) {
                                 LOGGER.debug(