migrate to try-with-resources

src/main/java/net/fabricmc/loom/mixin/MixinMappingWriterTiny.java

@@ -46,13 +46,10 @@ public class MixinMappingWriterTiny extends MappingWriter {
 	@Override
 	public void write(String output, ObfuscationType type, IMappingConsumer.MappingSet<MappingField> fields, IMappingConsumer.MappingSet<MappingMethod> methods) {
 		if (output != null) {
-			PrintWriter writer = null;
+			String from = type.getKey().split(":")[0];
+			String to = type.getKey().split(":")[1];
 
-			try {
+			try (PrintWriter writer = this.openFileWriter(output, type + " output TinyMappings")) {
-				String from = type.getKey().split(":")[0];
-				String to = type.getKey().split(":")[1];
-
-				writer = this.openFileWriter(output, type + " output TinyMappings");
 				writer.println(String.format("v1\t%s\t%s", from, to));
 				for (IMappingConsumer.MappingSet.Pair<MappingField> pair : fields) {
 					writer.println(String.format("FIELD\t%s\t%s\t%s\t%s", pair.from.getOwner(), pair.from.getDesc(), pair.from.getSimpleName(), pair.to.getSimpleName()));
@@ -62,13 +59,6 @@ public class MixinMappingWriterTiny extends MappingWriter {
 				}
 			} catch (IOException e) {
 				e.printStackTrace();
-			} finally {
-				if (writer != null) {
-					try {
-						writer.close();
-					} catch (Exception e) {
-					}
-				}
 			}
 		}
 	}

src/main/java/net/fabricmc/loom/mixin/MixinServiceGradle.java

@@ -149,10 +149,9 @@ public class MixinServiceGradle implements IClassBytecodeProvider, IClassProvide
 	}
 
 	public byte[] getClassBytes(String name, String transformedName) throws IOException {
-		InputStream inputStream = getResourceAsStream(name.replace(".", "/") + ".class");
+		try (InputStream inputStream = getResourceAsStream(name.replace(".", "/") + ".class")) {
-		byte[] classBytes = ByteStreams.toByteArray(inputStream);
+			return ByteStreams.toByteArray(inputStream);
-		inputStream.close();
+		}
-		return classBytes;
 	}
 
 	@Override

src/main/java/net/fabricmc/loom/providers/MinecraftAssetsProvider.java

@@ -66,9 +66,10 @@ public class MinecraftAssetsProvider {
 
 		ProgressLogger progressLogger = ProgressLogger.getProgressFactory(project, MinecraftAssetsProvider.class.getName());
 		progressLogger.start("Downloading assets...", "assets");
-		FileReader fileReader = new FileReader(assetsInfo);
+		AssetIndex index;
-		AssetIndex index = new Gson().fromJson(fileReader, AssetIndex.class);
+		try (FileReader fileReader = new FileReader(assetsInfo)) {
-		fileReader.close();
+			index = new Gson().fromJson(fileReader, AssetIndex.class);
+		}
 		Map<String, AssetObject> parent = index.getFileMap();
 		final int totalSize = parent.size();
 		int position = 0;

src/main/java/net/fabricmc/loom/providers/MinecraftJarProvider.java

@@ -54,11 +54,10 @@ public class MinecraftJarProvider {
 
 	public void mergeJars(Project project) throws IOException {
 		project.getLogger().lifecycle(":merging jars");
-		JarMerger jarMerger = new JarMerger(minecraftProvider.MINECRAFT_CLIENT_JAR, minecraftProvider.MINECRAFT_SERVER_JAR, minecraftProvider.MINECRAFT_MERGED_JAR);
+		try (JarMerger jarMerger = new JarMerger(minecraftProvider.MINECRAFT_CLIENT_JAR, minecraftProvider.MINECRAFT_SERVER_JAR, minecraftProvider.MINECRAFT_MERGED_JAR)) {
-		jarMerger.enableSyntheticParamsOffset();
+			jarMerger.enableSyntheticParamsOffset();
-
+			jarMerger.merge();
-		jarMerger.merge();
+		}
-		jarMerger.close();
 	}
 
 	private void initFiles(Project project, MinecraftProvider minecraftProvider) {

src/main/java/net/fabricmc/loom/providers/MinecraftProvider.java

@@ -63,9 +63,9 @@ public class MinecraftProvider extends DependencyProvider {
 		initFiles(project);
 
 		downloadMcJson(project);
-		FileReader reader = new FileReader(MINECRAFT_JSON);
+		try (FileReader reader = new FileReader(MINECRAFT_JSON)) {
-		versionInfo = gson.fromJson(reader, MinecraftVersionInfo.class);
+			versionInfo = gson.fromJson(reader, MinecraftVersionInfo.class);
-		reader.close();
+		}
 
 		// Add Loom as an annotation processor
         addDependency(project.files(this.getClass().getProtectionDomain().getCodeSource().getLocation()), project, "compileOnly");

src/main/java/net/fabricmc/loom/util/MixinRefmapHelper.java

@@ -83,8 +83,7 @@ public final class MixinRefmapHelper {
         ZipUtil.iterate(output, (stream, entry) -> {
             if (!entry.isDirectory() && entry.getName().endsWith(".json") && !entry.getName().contains("/") && !entry.getName().contains("\\")) {
                 // JSON file in root directory
-                InputStreamReader inputStreamReader = new InputStreamReader(stream);
+                try (InputStreamReader inputStreamReader = new InputStreamReader(stream)) {
-                try {
                     JsonObject json = GSON.fromJson(inputStreamReader, JsonObject.class);
 
                     if (json != null) {
@@ -100,9 +99,6 @@ public final class MixinRefmapHelper {
                     }
                 } catch (Exception e) {
                     // ...
-                } finally {
-                    inputStreamReader.close();
-                    stream.close();
                 }
             }
         });
@@ -116,17 +112,13 @@ public final class MixinRefmapHelper {
         ZipUtil.iterate(output, (stream, entry) -> {
             if (!entry.isDirectory() && entry.getName().endsWith(".json") && !entry.getName().contains("/") && !entry.getName().contains("\\")) {
                 // JSON file in root directory
-                InputStreamReader inputStreamReader = new InputStreamReader(stream);
+                try (InputStreamReader inputStreamReader = new InputStreamReader(stream)) {
-                try {
                     JsonObject json = GSON.fromJson(inputStreamReader, JsonObject.class);
                     if (json != null && json.has("refmap")) {
                         mixinRefmapFilenames.add(json.get("refmap").getAsString());
                     }
                 } catch (Exception e) {
                     // ...
-                } finally {
-                    inputStreamReader.close();
-                    stream.close();
                 }
             }
         });

src/main/java/net/fabricmc/loom/util/ModProcessor.java

@@ -190,33 +190,33 @@ public class ModProcessor {
 
 	static void readInstallerJson(File file, Project project){
 		try {
-			JarFile jarFile = new JarFile(file);
-
 			LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
 			String launchMethod = extension.getLoaderLaunchMethod();
 
+			String jsonStr;
 			int priority = 0;
 
-			ZipEntry entry = null;
+			try (JarFile jarFile = new JarFile(file)) {
-			if (!launchMethod.isEmpty()) {
+				ZipEntry entry = null;
-				entry = jarFile.getEntry("fabric-installer." + launchMethod + ".json");
+				if (!launchMethod.isEmpty()) {
-				if (entry == null) {
+					entry = jarFile.getEntry("fabric-installer." + launchMethod + ".json");
-					project.getLogger().warn("Could not find loader launch method '" + launchMethod + "', falling back");
+					if (entry == null) {
+						project.getLogger().warn("Could not find loader launch method '" + launchMethod + "', falling back");
+					}
 				}
-			}
 
-			if(entry == null){
-				entry = jarFile.getEntry("fabric-installer.json");
-				priority = 1;
 				if (entry == null) {
-					jarFile.close();
+					entry = jarFile.getEntry("fabric-installer.json");
-					return;
+					priority = 1;
+					if (entry == null) {
+						return;
+					}
+				}
+
+				try (InputStream inputstream = jarFile.getInputStream(entry)) {
+					jsonStr = IOUtils.toString(inputstream, StandardCharsets.UTF_8);
 				}
 			}
-			InputStream inputstream = jarFile.getInputStream(entry);
-			String jsonStr = IOUtils.toString(inputstream, StandardCharsets.UTF_8);
-			inputstream.close();
-			jarFile.close();
 
 			JsonObject jsonObject = GSON.fromJson(jsonStr, JsonObject.class);
 			extension.setInstallerJson(jsonObject, priority);

src/main/java/net/fabricmc/loom/util/RunConfig.java

@@ -168,9 +168,10 @@ public class RunConfig {
 	}
 
 	public String fromDummy(String dummy) throws IOException {
-		InputStream input = SetupIntelijRunConfigs.class.getClassLoader().getResourceAsStream(dummy);
+		String dummyConfig;
-		String dummyConfig = IOUtils.toString(input, StandardCharsets.UTF_8);
+		try (InputStream input = SetupIntelijRunConfigs.class.getClassLoader().getResourceAsStream(dummy)) {
-		input.close();
+			dummyConfig = IOUtils.toString(input, StandardCharsets.UTF_8);
+		}
 
 		dummyConfig = dummyConfig.replace("%NAME%", configName);
 		dummyConfig = dummyConfig.replace("%MAIN_CLASS%", mainClass);