Java – String to Reader

In this quick tutorial we’ll take a look at how to convert a String to a Reader ,first using plain Java then Guava and finally the Commons IO library.

This article is part of the “Java – Back to Basic” series here on VietMX’s Blog.

1. With Plain Java

Let’s start with the Java solution:

@Test
public void givenUsingPlainJava_whenConvertingStringIntoReader_thenCorrect() throws IOException {
    String initialString = "With Plain Java";
    Reader targetReader = new StringReader(initialString);
    targetReader.close();
}

As you can see, the StringReader is available out of the box for this simple conversion.

2. With Guava

Next – the Guava solution:

@Test
public void givenUsingGuava_whenConvertingStringIntoReader_thenCorrect() throws IOException {
    String initialString = "With Google Guava";
    Reader targetReader = CharSource.wrap(initialString).openStream();
    targetReader.close();
}

We’re making use here of the versatile CharSource abstraction that allows us to open up a Reader from it.

3. With Apache Commons IO

And finally – here’s the Commons IO solution, also using a ready to go Reader implementation:

@Test
public void givenUsingCommonsIO_whenConvertingStringIntoReader_thenCorrect() throws IOException {
    String initialString = "With Apache Commons IO";
    Reader targetReader = new CharSequenceReader(initialString);
    targetReader.close();
}

So there we have it – 3 dead simple ways to convert a String to a Reader in Java. Make sure to check out the sample over on GitHub.