使用 Java 识别 *.properties 文件中的键=值对

Question

We have many *.properties files in my project, and in each, we have lots and lots of key=value pairs.

The task is to find all keys that start with _format_ followed by any word (we can freely assume that that word will not contain any special characters nor whitespace characters) AND the value of that key IS NOT EQUAL to null (case-insensitive).

Using an example:

_format_Date1=null
_format_Date2=null
_format_endTerm=null
_isUpdatable_somethingA=false
_isUpdatable_somethingB=false
_format_begingTerm=null
_format_countOfMoney=\#0.00#\ -- The kind of row that must be identified with the pattern
_javaType_name1=String
_javaType_name2=String

We can also assume all of the key=values pairs will loaded up in a collection and read line by line.

Any help would be appreciated...

Answer 1

Just iterate over the files, read them in and filter line by line.

I suppose something like this could do it:

    Files.walk(Paths.get("path"))
         .filter(Files::isRegularFile)
         .filter(path -> path.endsWith(".properties"))
         .forEach(path -> {
                      try {
                          Files.lines(path)
                               .filter(s -> s.startsWith("_format_"))
                               .filter(s -> !s.split("=")[1].toLowerCase().equals("null"))
                               .forEach(s -> System.out.println("File " + path.toString() + " has amtching line " + s));
                      } catch (final IOException e) {
                          e.printStackTrace();
                      }
                  }
         );