1 files changed, 53 insertions, 0 deletions
diff --git a/core/src/main/java/com/google/googlejavaformat/java/GoogleJavaFormatTool.java b/core/src/main/java/com/google/googlejavaformat/java/GoogleJavaFormatTool.java
new file mode 100644
index 0000000..3c315aa
--- /dev/null
+++ b/core/src/main/java/com/google/googlejavaformat/java/GoogleJavaFormatTool.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2021 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 com.google.googlejavaformat.java;
+
+import static com.google.common.collect.Sets.toImmutableEnumSet;
+
+import com.google.auto.service.AutoService;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.util.Arrays;
+import java.util.Set;
+import javax.lang.model.SourceVersion;
+import javax.tools.Tool;
+
+/** Provide a way to be invoked without necessarily starting a new VM. */
+@AutoService(Tool.class)
+public class GoogleJavaFormatTool implements Tool {
+  @Override
+  public String name() {
+    return "google-java-format";
+  }
+
+  @Override
+  public Set<SourceVersion> getSourceVersions() {
+    return Arrays.stream(SourceVersion.values()).collect(toImmutableEnumSet());
+  }
+
+  @Override
+  public int run(InputStream in, OutputStream out, OutputStream err, String... args) {
+    PrintStream outStream = new PrintStream(out);
+    PrintStream errStream = new PrintStream(err);
+    try {
+      return Main.main(in, outStream, errStream, args);
+    } catch (RuntimeException e) {
+      errStream.print(e.getMessage());
+      errStream.flush();
+      return 1; // pass non-zero value back indicating an error has happened
+    }
+  }
+}