[ISSUE-alibaba#4567] Refactor nacos-client Load Logging Configuration…

… code. (alibaba#4572)

* for alibaba#4567, refactor nacos-client logging load Configuration code.

* Modify exception handling.

* When customizing AbstractNacosLogging Load Configuration Fail, use the default Logging Load Configuration.

* NacosLogging has been modified to a single-column mode.

client/src/main/java/com/alibaba/nacos/client/logging/NacosLogging.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * 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.alibaba.nacos.client.logging;
+
+import com.alibaba.nacos.client.logging.log4j2.Log4J2NacosLogging;
+import com.alibaba.nacos.client.logging.logback.LogbackNacosLogging;
+import org.slf4j.LoggerFactory;
+import org.slf4j.Logger;
+
+/**
+ * nacos logging.
+ *
+ * @author mai.jh
+ */
+public class NacosLogging {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(NacosLogging.class);
+
+    private AbstractNacosLogging nacosLogging;
+
+    private boolean isLogback = false;
+
+    private NacosLogging() {
+        try {
+            Class.forName("ch.qos.logback.classic.Logger");
+            nacosLogging = new LogbackNacosLogging();
+            isLogback = true;
+        } catch (ClassNotFoundException e) {
+            nacosLogging = new Log4J2NacosLogging();
+        }
+    }
+
+    private static class NacosLoggingInstance {
+
+        private static final NacosLogging INSTANCE = new NacosLogging();
+    }
+
+    public static NacosLogging getInstance() {
+        return NacosLoggingInstance.INSTANCE;
+    }
+
+    /**
+     * Load logging Configuration.
+     */
+    public void loadConfiguration() {
+        try {
+            nacosLogging.loadConfiguration();
+        } catch (Throwable t) {
+            if (isLogback) {
+                LOGGER.warn("Load Logback Configuration of Nacos fail, message: {}", t.getMessage());
+            } else {
+                LOGGER.warn("Load Log4j Configuration of Nacos fail, message: {}", t.getMessage());
+            }
+        }
+    }
+}

client/src/main/java/com/alibaba/nacos/client/utils/LogUtils.java

@@ -16,9 +16,7 @@
 
 package com.alibaba.nacos.client.utils;
 
-import com.alibaba.nacos.client.logging.AbstractNacosLogging;
-import com.alibaba.nacos.client.logging.log4j2.Log4J2NacosLogging;
-import com.alibaba.nacos.client.logging.logback.LogbackNacosLogging;
+import com.alibaba.nacos.client.logging.NacosLogging;
 import org.slf4j.Logger;
 
 import static org.slf4j.LoggerFactory.getLogger;
@@ -34,33 +32,7 @@ public class LogUtils {
     public static final Logger NAMING_LOGGER;
 
     static {
-        try {
-            boolean isLogback = false;
-            AbstractNacosLogging nacosLogging;
-
-            try {
-                Class.forName("ch.qos.logback.classic.Logger");
-                nacosLogging = new LogbackNacosLogging();
-                isLogback = true;
-            } catch (ClassNotFoundException e) {
-                nacosLogging = new Log4J2NacosLogging();
-            }
-
-            try {
-                nacosLogging.loadConfiguration();
-            } catch (Throwable t) {
-                if (isLogback) {
-                    getLogger(LogUtils.class)
-                            .warn("Load Logback Configuration of Nacos fail, message: {}", t.getMessage());
-                } else {
-                    getLogger(LogUtils.class)
-                            .warn("Load Log4j Configuration of Nacos fail, message: {}", t.getMessage());
-                }
-            }
-        } catch (Throwable ex) {
-            getLogger(LogUtils.class).warn("Init Nacos Logging fail, message: {}", ex.getMessage());
-        }
-
+        NacosLogging.getInstance().loadConfiguration();
         NAMING_LOGGER = getLogger("com.alibaba.nacos.client.naming");
     }