如何将属性文件中的空值添加到 Map

Question

I have a properties file, the content of which are as follows

test=uri=someURI,uname=username,pwd=

The parameters are separated by a comma, and the key and values are separated by = I'm using ResourceBundle.getBundle("fileName") to read the file and getString("test") method to read the entry for test .

What I'm trying to to here is get the strings separated by = inside a Map, using the following method.

public static Map<String, String> configMap(String entry) {
    return Arrays.stream(rb.getString(entry).split(",")).map(e -> e.split("="))
            .collect(Collectors
                    .toMap(keyValue -> keyValue[0].trim(), keyValue -> keyValue[1].trim(), (a, b) -> b));
}

The methods works in a weird manner though. In the properties file, if I assign a space as a value for pwd , it works fine, but if I assign nothing to pwd , not even a space, it gives me the following error

java.lang.ArrayIndexOutOfBoundsException: 1

The Map needs to accept null values too, how can I implement that?

Answer 1

Your can check the length of the keyValue array, and if it doesn't have a second element - put an empty String in the Map .

Unfortunately you can't put a null value in the Map when using Collectors.toMap() .

return Arrays.stream(rb.getString(entry).split(",")).map(e -> e.split("="))
        .collect(Collectors
                .toMap(keyValue -> keyValue[0].trim(), 
                       keyValue -> keyValue.length > 1 ? keyValue[1].trim() : "", 
                       (a, b) -> b));