空值的传递后判断为空的问题.

Posted 2020-10-07

当前台将一个null空值传输到后台,将会变成一个String的”null”,而后台通过接口传入到另一个系统后台后将会在进行一次封装(传输的值都未经处理),另一个系统要判断传过来是否为空:StringUtils.isEmpty(值)和StringUtils.isNotEmpty(值)进行比较返回都为false,然后通过测试发现必须要用equals比较才能正确的返回true.

本人进过的测试:

System.err.println("customerIdStr:" + customerIdStr);

        System.out.println(customerIdStr == null);

        System.out.println(customerIdStr == "");

        System.out.println(customerIdStr == "null");

        System.out.println(customerIdStr == " ");

        System.out.println(customerIdStr == "null ");

 

        System.out.println(customerIdStr.equals(null));

        System.out.println(customerIdStr.equals(""));

        System.out.println(customerIdStr.equals("null"));只有本结果返回true

        System.out.println(customerIdStr.equals(" "));

        System.out.println(customerIdStr.equals("null "));