chore: intrdouce spotbugs for s3stream, and reslove all the P1 issues

s3stream/build.gradle

@@ -1,10 +1,28 @@
 /*
  * This file was generated by the Gradle 'init' task.
  */
+import com.github.spotbugs.snom.Confidence
+import com.github.spotbugs.snom.Effort
 
 plugins {
     id 'java-library'
     id 'maven-publish'
+    id("com.github.spotbugs") version "6.0.7"
+}
+
+spotbugsMain {
+    reports {
+        html {
+            required = true
+            outputLocation = file("$buildDir/reports/spotbugs.html")
+            setStylesheet("fancy-hist.xsl")
+        }
+    }
+}
+
+spotbugs {
+    effort = Effort.valueOf('DEFAULT')
+    reportLevel = Confidence.valueOf('HIGH')
 }
 
 repositories {

s3stream/src/main/java/com/automq/stream/s3/wal/benchmark/WriteBench.java

@@ -55,6 +55,9 @@ public class WriteBench implements AutoCloseable {
     private final WriteAheadLog log;
     private final TrimOffset trimOffset = new TrimOffset();
 
+    // Generate random payloads for this benchmark tool
+    private Random random = new Random();
+
     public WriteBench(Config config) throws IOException {
         BlockWALService.BlockWALServiceBuilder builder = BlockWALService.builder(config.path, config.capacity);
         if (config.depth != null) {
@@ -177,7 +180,7 @@ private void runAppendTask(int index, AppendTaskConfig config, Stat stat) throws
         System.out.printf("Append task %d started\n", index);
 
         byte[] bytes = new byte[config.recordSizeBytes];
-        new Random().nextBytes(bytes);
+        random.nextBytes(bytes);
         ByteBuf payload = Unpooled.wrappedBuffer(bytes).retain();
         int intervalNanos = (int) TimeUnit.SECONDS.toNanos(1) / Math.max(1, config.throughputBytes / config.recordSizeBytes);
         long lastAppendTimeNanos = System.nanoTime();

s3stream/src/main/java/com/automq/stream/utils/S3Utils.java

@@ -69,7 +69,7 @@ public static void checkS3Access(S3Context context) {
             System.exit(1);
         }
 
-        try (MultipartObjectOperationTask task = new MultipartObjectOperationTask(context)) {
+        try (S3MultipartUploadTestTask task = new S3MultipartUploadTestTask(context)) {
             task.run();
         } catch (Throwable e) {
             System.out.println("ERROR: " + ExceptionUtils.getRootCause(e));
@@ -135,9 +135,11 @@ public void close() {
         }
     }
 
-    private static class MultipartObjectOperationTask extends ObjectOperationTask {
-        public MultipartObjectOperationTask(S3Context context) {
-            super(context, MultipartObjectOperationTask.class.getSimpleName());
+    // This task is used to test s3 multipart upload
+    private static class S3MultipartUploadTestTask extends ObjectOperationTask {
+        private Random random = new Random();
+        public S3MultipartUploadTestTask(S3Context context) {
+            super(context, S3MultipartUploadTestTask.class.getSimpleName());
         }
 
         @Override
@@ -152,12 +154,12 @@ public void run() {
                 int totalSize = data1Size + data2Size;
 
                 byte[] randomBytes = new byte[data1Size];
-                new Random().nextBytes(randomBytes);
+                random.nextBytes(randomBytes);
                 ByteBuf data1 = Unpooled.wrappedBuffer(randomBytes);
                 writePart(uploadId, path, bucketName, data1, 1).thenAccept(parts::add).get();
 
                 byte[] randomBytes2 = new byte[data2Size];
-                new Random().nextBytes(randomBytes2);
+                random.nextBytes(randomBytes2);
                 ByteBuf data2 = Unpooled.wrappedBuffer(randomBytes2);
                 writePart(uploadId, path, bucketName, data2, 2).thenAccept(parts::add).get();