Using Guava Splitter and Joiner

In my last post: Solr RssResponseWriter by Extending XMLWriter, I need parse the field mapping string like: topic:title,url:link,description:description to a map.

If we have to write our own code, the code would look like below:

public void splitOnOurOwn() {
 String mapStr = "topic: title, url: link, description: description ";
 String[] pairs = mapStr.split(",");
 Map<String,String> map = new HashMap<String,String>();
 for (String pair : pairs) {
  String[] str = pair.split(":");
  map.put(str[0].trim(), str[1].trim());
 }
 System.out.println("toString: " + Objects.toString(map));
}

But if we use Guava it would be just two lines:

private static MapSplitter splitter = Splitter.on(",").trimResults()
  .withKeyValueSeparator(Splitter.on(':').trimResults());
private static MapJoiner joinner = Joiner.on(",").withKeyValueSeparator(":");

public void guavaSplit() {
 String mapStr = "topic: title, url: link, description: description ";
 Map<String,String> map = splitter.split(mapStr.trim());
 System.out.println("toString: " + Objects.toString(map));
 System.out.println("join: " + joinner.join(map));
}

Guava Splitter provides some other useful methods such as fixedLength, omitEmptyStrings, trimResults, limit.


As described in code above, Guava provides a Joiner that can join text with a separator. Joiner also provides useful methods such as skipNulls, useForNull(nullText).
Resources
Strings Explained
Splitter Javadoc
Joiner Javadoc
Guava Splitter vs StringUtils