+ * Licensed under the Moderne Source Available License (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + *
+ * https://docs.moderne.io/licensing/moderne-source-available-license + *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite.staticanalysis;
+
+import lombok.Getter;
+import org.jspecify.annotations.Nullable;
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Preconditions;
+import org.openrewrite.Recipe;
+import org.openrewrite.Tree;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.java.JavaIsoVisitor;
+import org.openrewrite.java.MethodMatcher;
+import org.openrewrite.java.search.SemanticallyEqual;
+import org.openrewrite.java.search.UsesJavaVersion;
+import org.openrewrite.internal.ListUtils;
+import org.openrewrite.java.tree.*;
+import org.openrewrite.marker.Markers;
+import org.openrewrite.staticanalysis.java.JavaFileChecker;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singleton;
+import static java.util.Collections.singletonList;
+
+public class UseTryWithResources extends Recipe {
+
+ private static final MethodMatcher CLOSE = new MethodMatcher("java.lang.AutoCloseable close()", true);
+ private static final JavaType.ShallowClass AUTO_CLOSEABLE = JavaType.ShallowClass.build("java.lang.AutoCloseable");
+
+ @Getter
+ final String displayName = "Use try-with-resources";
+
+ @Getter
+ final String description = "Refactor try/finally blocks to use try-with-resources when the finally block only closes an `AutoCloseable` resource.";
+
+ @Getter
+ final Duration estimatedEffortPerOccurrence = Duration.ofMinutes(5);
+
+ @Getter
+ final Set
+ * Licensed under the Moderne Source Available License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://docs.moderne.io/licensing/moderne-source-available-license
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite.staticanalysis;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.DocumentExample;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+
+import static org.openrewrite.java.Assertions.java;
+import static org.openrewrite.java.Assertions.javaVersion;
+
+@SuppressWarnings({"ConstantConditions", "TryFinallyCanBeTryWithResources", "unused"})
+class UseTryWithResourcesTest implements RewriteTest {
+
+ @Override
+ public void defaults(RecipeSpec spec) {
+ spec.recipe(new UseTryWithResources())
+ .allSources(s -> s.markers(javaVersion(9)));
+ }
+
+ @DocumentExample
+ @Test
+ void simpleResourceWithDirectClose() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } finally {
+ in.close();
+ }
+ }
+ }
+ """,
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ try (InputStream in = new FileInputStream("file.txt")) {
+ int data = in.read();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void nullGuardedClose() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } finally {
+ if (in != null) {
+ in.close();
+ }
+ }
+ }
+ }
+ """,
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ try (InputStream in = new FileInputStream("file.txt")) {
+ int data = in.read();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void nullGuardedCloseWithoutBraces() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } finally {
+ if (in != null)
+ in.close();
+ }
+ }
+ }
+ """,
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ try (InputStream in = new FileInputStream("file.txt")) {
+ int data = in.read();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void tryCatchWrappedClose() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } finally {
+ try {
+ in.close();
+ } catch (IOException ignored) {
+ }
+ }
+ }
+ }
+ """,
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ try (InputStream in = new FileInputStream("file.txt")) {
+ int data = in.read();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void nullGuardedWithTryCatchClose() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } finally {
+ if (in != null) {
+ try {
+ in.close();
+ } catch (IOException ignored) {
+ }
+ }
+ }
+ }
+ }
+ """,
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ try (InputStream in = new FileInputStream("file.txt")) {
+ int data = in.read();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void preservesCatchBlocks() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } catch (IOException e) {
+ e.printStackTrace();
+ } finally {
+ in.close();
+ }
+ }
+ }
+ """,
+ """
+ import java.io.*;
+
+ class Test {
+ void method() {
+ try (InputStream in = new FileInputStream("file.txt")) {
+ int data = in.read();
+ } catch (IOException e) {
+ e.printStackTrace();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void resourceUsedAfterTryUsesJava9Syntax() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } finally {
+ in.close();
+ }
+ System.out.println(in);
+ }
+ }
+ """,
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try (in) {
+ int data = in.read();
+ }
+ System.out.println(in);
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void doNotChangeResourceReassignedInTry() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file1.txt");
+ try {
+ in = new FileInputStream("file2.txt");
+ int data = in.read();
+ } finally {
+ in.close();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void doNotChangeNonAutoCloseable() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ class Test {
+ static class CustomResource {
+ public void close() {}
+ public void doSomething() {}
+ }
+
+ void method() {
+ CustomResource resource = new CustomResource();
+ try {
+ resource.doSomething();
+ } finally {
+ resource.close();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void doNotChangeAlreadyTryWithResources() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ try (InputStream in = new FileInputStream("file.txt")) {
+ int data = in.read();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void doNotChangeCloseViaHelperMethod() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ static void closeQuietly(InputStream stream) {
+ try {
+ if (stream != null) {
+ stream.close();
+ }
+ } catch (IOException ignored) {}
+ }
+
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } finally {
+ closeQuietly(in);
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void doNotChangeResourceClosedInCatch() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } catch (IOException e) {
+ in.close();
+ throw e;
+ } finally {
+ in.close();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void finallyWithExtraLogicKeepsRemainingStatements() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ InputStream in = new FileInputStream("file.txt");
+ try {
+ int data = in.read();
+ } finally {
+ System.out.println("closing");
+ in.close();
+ }
+ }
+ }
+ """,
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ try (InputStream in = new FileInputStream("file.txt")) {
+ int data = in.read();
+ } finally {
+ System.out.println("closing");
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void doNotChangeQualifiedCloseMethodCall() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ static class Wrapper {
+ InputStream stream;
+ Wrapper(InputStream s) { this.stream = s; }
+ InputStream getStream() { return stream; }
+ }
+
+ void method() throws IOException {
+ Wrapper wrapper = new Wrapper(new FileInputStream("file.txt"));
+ try {
+ int data = wrapper.getStream().read();
+ } finally {
+ wrapper.getStream().close();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void doNotChangeResourceAssignedToField() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ private InputStream fieldStream;
+
+ void method() throws IOException {
+ fieldStream = new FileInputStream("file.txt");
+ try {
+ int data = fieldStream.read();
+ } finally {
+ fieldStream.close();
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void addResourceToExistingTryWithResources() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ OutputStream out = new FileOutputStream("out.txt");
+ try (InputStream in = new FileInputStream("in.txt")) {
+ out.write(in.read());
+ } finally {
+ out.close();
+ }
+ }
+ }
+ """,
+ """
+ import java.io.*;
+
+ class Test {
+ void method() throws IOException {
+ try (InputStream in = new FileInputStream("in.txt"); OutputStream out = new FileOutputStream("out.txt")) {
+ out.write(in.read());
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+
+ @Test
+ void doNotChangeNullInitializedResourceClosedInCatch() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.io.*;
+
+ class Test {
+ void method() {
+ InputStream in = null;
+ try {
+ in = new FileInputStream("file.txt");
+ int data = in.read();
+ } catch (IOException e) {
+ if (in != null) {
+ try {
+ in.close();
+ } catch (IOException ignored) {
+ }
+ }
+ throw new RuntimeException(e);
+ } finally {
+ if (in != null) {
+ try {
+ in.close();
+ } catch (IOException ignored) {
+ }
+ }
+ }
+ }
+ }
+ """
+ )
+ );
+ }
+}