Use try-with-resources (#8757)

To ensure the resource is automatically closed

server/src/main/java/com/vaadin/server/themeutils/SASSAddonImportFileCreator.java

@@ -85,9 +85,8 @@ public class SASSAddonImportFileCreator {
         LocationInfo info = ClassPathExplorer
                 .getAvailableWidgetSetsAndStylesheets();
 
-        try {
-            PrintStream printStream = new PrintStream(
-                    new FileOutputStream(addonImports));
+        try (PrintStream printStream = new PrintStream(
+                    new FileOutputStream(addonImports))) {
 
             printStream.println("/* " + ADDON_IMPORTS_FILE_TEXT + " */");
 

server/src/test/java/com/vaadin/tests/server/ClassesSerializableTest.java

@@ -352,15 +352,16 @@ public class ClassesSerializableTest {
     private Collection<String> findClassesInJar(File file) throws IOException {
         Collection<String> classes = new ArrayList<>();
 
-        JarFile jar = new JarFile(file);
-        Enumeration<JarEntry> e = jar.entries();
-        while (e.hasMoreElements()) {
-            JarEntry entry = e.nextElement();
-            if (entry.getName().endsWith(".class")) {
-                String nameWithoutExtension = entry.getName()
-                        .replaceAll("\\.class", "");
-                String className = nameWithoutExtension.replace('/', '.');
-                classes.add(className);
+        try (JarFile jar = new JarFile(file)) {
+            Enumeration<JarEntry> e = jar.entries();
+            while (e.hasMoreElements()) {
+                JarEntry entry = e.nextElement();
+                if (entry.getName().endsWith(".class")) {
+                    String nameWithoutExtension = entry.getName()
+                            .replaceAll("\\.class", "");
+                    String className = nameWithoutExtension.replace('/', '.');
+                    classes.add(className);
+                }
             }
         }
         return classes;

server/src/test/java/com/vaadin/tests/server/SimpleMultiPartInputStreamTest.java

@@ -22,22 +22,23 @@ public class SimpleMultiPartInputStreamTest {
     protected void checkBoundaryDetection(byte[] input, String boundary,
             byte[] expected) throws Exception {
         ByteArrayInputStream bais = new ByteArrayInputStream(input);
-        SimpleMultiPartInputStream smpis = new SimpleMultiPartInputStream(bais,
-                boundary);
-        ByteArrayOutputStream resultStream = new ByteArrayOutputStream();
-        int outbyte;
-        try {
-            while ((outbyte = smpis.read()) != -1) {
-                resultStream.write(outbyte);
+        try (SimpleMultiPartInputStream smpis = new SimpleMultiPartInputStream(bais,
+                boundary)) {
+            ByteArrayOutputStream resultStream = new ByteArrayOutputStream();
+            int outbyte;
+            try {
+                while ((outbyte = smpis.read()) != -1) {
+                    resultStream.write(outbyte);
+                }
+            } catch (IOException e) {
+                throw new IOException(
+                        e.getMessage() + "; expected " + new String(expected)
+                        + " but got " + resultStream.toString());
+            }
+            if (!Arrays.equals(expected, resultStream.toByteArray())) {
+                throw new Exception("Mismatch: expected " + new String(expected)
+                        + " but got " + resultStream.toString());
             }
-        } catch (IOException e) {
-            throw new IOException(
-                    e.getMessage() + "; expected " + new String(expected)
-                            + " but got " + resultStream.toString());
-        }
-        if (!Arrays.equals(expected, resultStream.toByteArray())) {
-            throw new Exception("Mismatch: expected " + new String(expected)
-                    + " but got " + resultStream.toString());
         }
     }
 

uitest/src/main/java/com/vaadin/tests/components/table/EditableTableLeak.java

@@ -45,15 +45,14 @@ public class EditableTableLeak extends TestBase {
         }
 
         public static long getSize(Object object) {
-            ByteCountNullOutputStream os = new ByteCountNullOutputStream();
-            ObjectOutputStream oos;
-            try {
-                oos = new ObjectOutputStream(os);
+            try (ByteCountNullOutputStream os = new ByteCountNullOutputStream()) {
+                ObjectOutputStream oos = new ObjectOutputStream(os);
                 oos.writeObject(object);
+                return os.getBytes();
             } catch (IOException e) {
                 e.printStackTrace();
+                return 0;
             }
-            return os.getBytes();
         }
     }
 

uitest/src/test/java/com/vaadin/tests/tb3/AbstractTB3Test.java

@@ -942,16 +942,17 @@ public abstract class AbstractTB3Test extends ParallelTest {
             String hostName = ce.getAddressOfRemoteServer().getHost();
             int port = ce.getAddressOfRemoteServer().getPort();
             HttpHost host = new HttpHost(hostName, port);
-            DefaultHttpClient client = new DefaultHttpClient();
-            URL sessionURL = new URL("http://" + hostName + ":" + port
-                    + "/grid/api/testsession?session=" + d.getSessionId());
-            BasicHttpEntityEnclosingRequest r = new BasicHttpEntityEnclosingRequest(
-                    "POST", sessionURL.toExternalForm());
-            HttpResponse response = client.execute(host, r);
-            JsonObject object = extractObject(response);
-            URL myURL = new URL(object.getString("proxyId"));
-            if ((myURL.getHost() != null) && (myURL.getPort() != -1)) {
-                return myURL.getHost();
+            try (DefaultHttpClient client = new DefaultHttpClient()) {
+                URL sessionURL = new URL("http://" + hostName + ":" + port
+                        + "/grid/api/testsession?session=" + d.getSessionId());
+                BasicHttpEntityEnclosingRequest r = new BasicHttpEntityEnclosingRequest(
+                        "POST", sessionURL.toExternalForm());
+                HttpResponse response = client.execute(host, r);
+                JsonObject object = extractObject(response);
+                URL myURL = new URL(object.getString("proxyId"));
+                if ((myURL.getHost() != null) && (myURL.getPort() != -1)) {
+                    return myURL.getHost();
+                }
             }
         } catch (Exception e) {
             e.printStackTrace();