使用 slf4j 打印数组只打印第一个元素

Question

I have the following code:

private static final Logger logger = LoggerFactory.getLogger(Some.class);
...
String[] splits=someString.split("..");
logger.info("The string was split into <{}>",splits); // prints first element

What is the right way to print the full content of an array with slf4j?

Answer 1

The issue is that with the following code

logger.info("The string was split into <{}>", splits);

you are invoking the method info(String format, Object... arguments) . Note that the last argument is a varargs. Therefore, the array you pass is interpreted as each argument of the variable argument.

However, in this case, you want to pass an array as first argument. A simple workaround is to cast it to Object .

String[] splits = { "foo", "bar" };
logger.info("The string was split into {}", (Object) splits);

will log The string was split into [foo, bar] , as expected.

Answer 2

I am facing a strange issue where the entire list of arguments is logged for the first place holder eg: log.info("Initializing Service. arg1={}, arg2={}, pid={}", arg1, arg2, arg3);

logs the following: Initializing Service. build=[123456, main, 77378], branch=null, pid={}