仿照ibatis的风格实现Log，以及添加ConnectionChecker

git-svn-id: http://code.alibabatech.com/svn/druid/trunk@299 b9813039-fb51-4c41-a8b9-e21c2acb5095

src/main/java/com/alibaba/druid/logging/Jdk14LoggingImpl.java

@@ -0,0 +1,39 @@
+package com.alibaba.druid.logging;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Jdk14LoggingImpl implements Log {
+
+    private Logger log;
+
+    public Jdk14LoggingImpl(Class<?> clazz){
+        log = Logger.getLogger(clazz.toString());
+    }
+
+    public boolean isDebugEnabled() {
+        return log.isLoggable(Level.FINE);
+    }
+
+    public void error(String s, Throwable e) {
+        log.log(Level.SEVERE, s, e);
+    }
+
+    public void error(String s) {
+        log.log(Level.SEVERE, s);
+    }
+
+    public void debug(String s) {
+        log.log(Level.FINE, s);
+    }
+
+    public void warn(String s) {
+        log.log(Level.WARNING, s);
+    }
+
+    @Override
+    public void warn(String s, Throwable e) {
+        log.log(Level.WARNING, s, e);
+    }
+
+}