collection issues #1983

core/src/main/java/com/taobao/arthas/core/command/basic1000/VMOptionCommand.java

@@ -2,7 +2,7 @@ package com.taobao.arthas.core.command.basic1000;
 
 import java.lang.management.ManagementFactory;
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import com.alibaba.arthas.deps.org.slf4j.Logger;
@@ -77,7 +77,7 @@ public class VMOptionCommand extends AnnotatedCommand {
                     process.end(-1, "In order to change the system properties, you must specify the property value.");
                     return;
                 } else {
-                    process.appendResult(new VMOptionModel(Arrays.asList(option)));
+                    process.appendResult(new VMOptionModel(Collections.singletonList(option)));
                 }
             } else {
                 VMOption vmOption = hotSpotDiagnosticMXBean.getVMOption(name);

core/src/main/java/com/taobao/arthas/core/command/monitor200/TimeTunnelAdviceListener.java

@@ -12,7 +12,7 @@ import com.taobao.arthas.core.shell.command.CommandProcess;
 import com.taobao.arthas.core.util.LogUtil;
 import com.taobao.arthas.core.util.ThreadLocalWatch;
 
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.Date;
 
 /**
@@ -90,7 +90,7 @@ public class TimeTunnelAdviceListener extends AdviceListenerAdapter {
 
         TimeFragmentVO timeFragmentVO = TimeTunnelCommand.createTimeFragmentVO(index, timeTunnel);
         TimeTunnelModel timeTunnelModel = new TimeTunnelModel()
-                .setTimeFragmentList(Arrays.asList(timeFragmentVO))
+                .setTimeFragmentList(Collections.singletonList(timeFragmentVO))
                 .setFirst(isFirst);
         process.appendResult(timeTunnelModel);
 

core/src/main/java/com/taobao/arthas/core/env/AbstractPropertyResolver.java

@@ -16,6 +16,7 @@
 
 package com.taobao.arthas.core.env;
 
+import java.util.Arrays;
 import java.util.LinkedHashSet;
 import java.util.Set;
 
@@ -111,9 +112,7 @@ public abstract class AbstractPropertyResolver implements ConfigurablePropertyRe
 
     @Override
     public void setRequiredProperties(String... requiredProperties) {
-        for (String key : requiredProperties) {
-            this.requiredProperties.add(key);
-        }
+        this.requiredProperties.addAll(Arrays.asList(requiredProperties));
     }
 
     @Override

core/src/main/java/com/taobao/arthas/core/server/ArthasBootstrap.java

@@ -8,6 +8,7 @@ import java.lang.instrument.UnmodifiableClassException;
 import java.lang.reflect.Method;
 import java.security.CodeSource;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -400,9 +401,7 @@ public class ArthasBootstrap {
             if (configure.getDisabledCommands() != null) {
                 String[] strings = StringUtils.tokenizeToStringArray(configure.getDisabledCommands(), ",");
                 if (strings != null) {
-                    for (String s : strings) {
-                        disabledCommands.add(s);
-                    }
+                    disabledCommands.addAll(Arrays.asList(strings));
                 }
             }
             BuiltinCommandPack builtinCommands = new BuiltinCommandPack(disabledCommands);

core/src/main/java/com/taobao/arthas/core/util/StringUtils.java

@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.io.StringReader;
 import java.lang.reflect.Modifier;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import java.util.Properties;
@@ -671,17 +672,8 @@ public abstract class StringUtils {
     }
 
     public static Set<String> commaDelimitedListToSet(String str) {
-        TreeSet<String> set = new TreeSet<String>();
         String[] tokens = commaDelimitedListToStringArray(str);
-        String[] var3 = tokens;
-        int var4 = tokens.length;
-
-        for(int var5 = 0; var5 < var4; ++var5) {
-            String token = var3[var5];
-            set.add(token);
-        }
-
-        return set;
+        return new TreeSet<String>(Arrays.asList(tokens));
     }
 
     /**

core/src/main/java/com/taobao/arthas/core/util/reflect/FieldUtils.java

@@ -7,6 +7,7 @@ import java.lang.reflect.Field;
 import java.lang.reflect.Member;
 import java.lang.reflect.Modifier;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -257,9 +258,7 @@ public class FieldUtils {
         Class<?> currentClass = cls;
         while (currentClass != null) {
             final Field[] declaredFields = currentClass.getDeclaredFields();
-            for (final Field field : declaredFields) {
-                allFields.add(field);
-            }
+            allFields.addAll(Arrays.asList(declaredFields));
             currentClass = currentClass.getSuperclass();
         }
         return allFields;

core/src/main/java/com/taobao/arthas/core/view/ObjectView.java

@@ -586,23 +586,19 @@ public class ObjectView implements View {
                     appendStringBuilder(buf, format("@%s[%s]", className, obj));
                 } else {
                     appendStringBuilder(buf, format("@%s[", className));
-                    List<Field> fields = new ArrayList<Field>();
+                    final List<Field> fields;
                     Class<?> objClass = obj.getClass();
                     if (GlobalOptions.printParentFields) {
+                        fields = new ArrayList<Field>();
                         // 当父类为null的时候说明到达了最上层的父类(Object类).
                         while (objClass != null) {
-                            for (Field field : objClass.getDeclaredFields()) {
-                                fields.add(field);
-                            }
+                            fields.addAll(Arrays.asList(objClass.getDeclaredFields()));
                             objClass = objClass.getSuperclass();
                         }
                     } else {
-                        for (Field field : objClass.getDeclaredFields()) {
-                            fields.add(field);
-                        }
+                        fields = new ArrayList<Field>(Arrays.asList(objClass.getDeclaredFields()));
                     }
 
-                    if (null != fields) {
                     for (Field field : fields) {
 
                         field.setAccessible(true);
@@ -628,7 +624,6 @@ public class ObjectView implements View {
                         }
                     }//for
                     appendStringBuilder(buf, "\n");
-                    }//if
                     for (int i = 0; i < deep; i++) {
                         appendStringBuilder(buf, TAB);
                     }

tunnel-server/src/main/java/com/alibaba/arthas/tunnel/server/cluster/RedisTunnelClusterStore.java

@@ -4,7 +4,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;