Refactor IdlClass.java to not require JarCreator

PiperOrigin-RevId: 722757040
Change-Id: I5227b25d67a14ec1f42b09feb181f047b743d36e

Author: ted-xie

src/tools/java/com/google/devtools/build/android/idlclass/BUILD

@@ -1,5 +1,4 @@
-load("@rules_java//java:defs.bzl", "java_binary", "java_import", "java_library")
-load("//tools/android:defs.bzl", "run_singlejar")
+load("@rules_java//java:defs.bzl", "java_binary", "java_library")
 
 package(
     default_applicable_licenses = ["//:license"],
@@ -13,21 +12,6 @@ java_binary(
     runtime_deps = [":idlclass_lib"],
 )
 
-# NOTE: jarhelper actually exists in @bazel_tools, but its visibility is set too restrictively.
-run_singlejar(
-    name = "jarhelper_jar_gen",
-    srcs = ["@android_tools//:all_android_tools_deploy.jar"],
-    out = "jarhelper.jar",
-    include_prefixes = [
-        "com/google/devtools/build/buildjar/jarhelper/",
-    ],
-)
-
-java_import(
-    name = "jarhelper_jar",
-    jars = [":jarhelper.jar"],
-)
-
 java_library(
     name = "idlclass_lib",
     srcs = glob(["*.java"]),
@@ -37,7 +21,6 @@ java_library(
         "//src/tools/java/com/google/devtools/build/android:__pkg__",
     ],
     deps = [
-        ":jarhelper_jar",
         "//src/tools/java/com/google/devtools/build/android:android_builder_lib",
         "//src/tools/java/com/google/devtools/build/android:android_options_utils",
         "@bazel_tools//src/main/protobuf:java_compilation_java_proto",

src/tools/java/com/google/devtools/build/android/idlclass/IdlClass.java

@@ -14,33 +14,47 @@
 
 package com.google.devtools.build.android.idlclass;
 
+import static java.util.stream.Collectors.toCollection;
+
 import com.beust.jcommander.JCommander;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
+import com.google.common.hash.Hashing;
 import com.google.devtools.build.android.AndroidOptionsUtils;
-import com.google.devtools.build.buildjar.jarhelper.JarCreator;
 import com.google.devtools.build.buildjar.proto.JavaCompilation.CompilationUnit;
 import com.google.devtools.build.buildjar.proto.JavaCompilation.Manifest;
+import java.io.BufferedOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.nio.file.attribute.FileTime;
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.List;
 import java.util.Set;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
+import java.util.stream.Stream;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
 
 /**
  * IdlClass post-processes the output of a Java compilation, and produces
  * a jar containing only the class files for sources that were generated
  * from idl processing.
  */
 public class IdlClass {
+  // Cribbed from AarGeneratorAction.java
+  private static final Instant DEFAULT_TIMESTAMP =
+      LocalDateTime.of(2010, 1, 1, 0, 0, 0).atZone(ZoneId.systemDefault()).toInstant();
 
   public static void main(String[] args) throws IOException {
     IdlClassOptions idlClassOptions = new IdlClassOptions();
@@ -160,10 +174,31 @@ private static void extractIdlClasses(
 
   /** Writes the generated class files to the output jar. */
   private static void writeOutputJar(Path outputJar, Path tempDir) throws IOException {
-    JarCreator output = new JarCreator(outputJar.toString());
-    output.setCompression(true);
-    output.setNormalize(true);
-    output.addDirectory(tempDir.toString());
-    output.execute();
+    // Zip up the contents of tempDir into outputJar.
+
+    try (final ZipOutputStream zip =
+        new ZipOutputStream(new BufferedOutputStream(Files.newOutputStream(outputJar)))) {
+      zip.setMethod(ZipOutputStream.STORED);
+
+      List<Path> files;
+      try (Stream<Path> stream = Files.walk(tempDir).filter(Files::isRegularFile)) {
+        files = stream.collect(toCollection(ArrayList::new));
+      }
+
+      for (Path path : files) {
+        ZipEntry entry = new ZipEntry(tempDir.relativize(path).toString());
+        entry.setTime(DEFAULT_TIMESTAMP.toEpochMilli());
+        entry.setSize(Files.size(path));
+        entry.setCompressedSize(Files.size(path));
+        entry.setCrc(Hashing.crc32().hashBytes(Files.readAllBytes(path)).asInt());
+        zip.putNextEntry(entry);
+        zip.write(Files.readAllBytes(path));
+        zip.closeEntry();
+      }
+      zip.close();
+    } catch (IOException e) {
+      throw new IOException("Failed to write output jar: " + outputJar, e);
+    }
+    Files.setLastModifiedTime(outputJar, FileTime.from(DEFAULT_TIMESTAMP));
   }
 }