String str = "apple,banana,cherry"; List<String> fruits = Splitter.on(",").splitToList(str); List<String> fruits = Lists.newArrayList("apple", "banana", "cherry"); String str = Joiner.on(",").join(fruits); String str = " guava "; String trimmed = Strings.nullToEmpty(str.trim()); <dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> <version>30.1-jre</version> </dependency> import com.google.common.base.Splitter;