[Java Worker] Support raylet on Java (#2479)

java/common/src/main/java/org/ray/util/MethodId.java

@@ -117,7 +117,7 @@ public final class MethodId {
       cls = Class
           .forName(className, true, loader == null ? this.getClass().getClassLoader() : loader);
     } catch (Throwable e) {
-      RayLog.core.error("Cannot load class " + className, e);
+      RayLog.core.error("Cannot load class {}", className, e);
       return null;
     }
 
@@ -148,7 +148,7 @@ public final class MethodId {
 
     if (methods.size() != 1) {
       RayLog.core.error(
-          "Load method " + toString() + " failed as there are " + methods.size() + " definitions");
+          "Load method {} failed as there are {} definitions.", toString(), methods.size());
       return null;
     }
 

java/common/src/main/java/org/ray/util/NetworkUtil.java

@@ -35,9 +35,9 @@ public class NetworkUtil {
           return addr.getHostAddress();
         }
       }
-      RayLog.core.warn("you may need to correctly specify [ray.java] net_interface in config");
+      RayLog.core.warn("You need to correctly specify [ray.java] net_interface in config.");
     } catch (Exception e) {
-      RayLog.core.error("Can't get our ip address, use 127.0.0.1 as default.", e);
+      RayLog.core.error("Can't get ip address, use 127.0.0.1 as default.", e);
     }
 
     return "127.0.0.1";

java/common/src/main/java/org/ray/util/Sha1Digestor.java

@@ -10,8 +10,8 @@ public class Sha1Digestor {
     try {
       return MessageDigest.getInstance("SHA1");
     } catch (Exception e) {
-      RayLog.core.error("cannot get SHA1 MessageDigest", e);
-      throw new RuntimeException("cannot get SHA1 digest", e);
+      RayLog.core.error("Cannot get SHA1 MessageDigest", e);
+      throw new RuntimeException("Cannot get SHA1 digest", e);
     }
   });