RATIS-2269. Remove all import java.util.* statements. (#1243)

Author: hfutatzhanghb

ratis-common/src/main/java/org/apache/ratis/protocol/RaftGroup.java

@@ -19,7 +19,13 @@
 
 import org.apache.ratis.util.Preconditions;
 
-import java.util.*;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+
 
 /**
  * Description of a raft group, which has a unique {@link RaftGroupId} and a collection of {@link RaftPeer}.

ratis-common/src/main/java/org/apache/ratis/util/CollectionUtils.java

@@ -17,7 +17,14 @@
  */
 package org.apache.ratis.util;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.function.BiFunction;

ratis-common/src/main/java/org/apache/ratis/util/FileUtils.java

@@ -27,7 +27,18 @@
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
-import java.nio.file.*;
+import java.nio.file.AtomicMoveNotSupportedException;
+import java.nio.file.CopyOption;
+import java.nio.file.FileAlreadyExistsException;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.LinkOption;
+import java.nio.file.OpenOption;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.StandardCopyOption;
+import java.nio.file.StandardOpenOption;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.Arrays;
 import java.util.List;

ratis-common/src/main/java/org/apache/ratis/util/NetUtils.java

@@ -23,7 +23,13 @@
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
-import java.net.*;
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;

ratis-common/src/main/java/org/apache/ratis/util/ReflectionUtils.java

@@ -20,11 +20,17 @@
 
 package org.apache.ratis.util;
 
-
 import java.lang.ref.WeakReference;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.WeakHashMap;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**

ratis-examples/src/test/java/org/apache/ratis/examples/ParameterizedBaseTest.java

@@ -35,7 +35,12 @@
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 

ratis-examples/src/test/java/org/apache/ratis/examples/filestore/FileStoreAsyncBaseTest.java

@@ -32,7 +32,11 @@
 import java.io.File;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.*;
+import java.util.concurrent.Callable;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 public abstract class FileStoreAsyncBaseTest<CLUSTER extends MiniRaftCluster>
     extends BaseTest

ratis-grpc/src/main/java/org/apache/ratis/grpc/server/GrpcLogAppender.java

@@ -51,7 +51,13 @@
 
 import java.io.IOException;
 import java.io.InterruptedIOException;
-import java.util.*;
+import java.util.Comparator;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Queue;
+import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutionException;

ratis-server/src/main/java/org/apache/ratis/server/impl/ConfigurationManager.java

@@ -25,7 +25,10 @@
 import org.apache.ratis.util.Preconditions;
 import org.apache.ratis.util.StringUtils;
 
-import java.util.*;
+import java.util.NavigableMap;
+import java.util.SortedMap;
+import java.util.TreeMap;
+
 
 /**
  * Maintain the mappings between log index and corresponding raft configuration.

ratis-server/src/main/java/org/apache/ratis/server/impl/RaftServerProxy.java

@@ -67,7 +67,12 @@
 import java.util.Objects;
 import java.util.Optional;
 import java.util.UUID;
-import java.util.concurrent.*;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.TimeUnit;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;