A couple of months ago I was looking at creating QR codes in java, and found ZXING, which is pretty awesome, you should check it out.
For convenience I made a simple wrapper API on top of zxing.
To put it to use just add the dependency to your project, and you will be able to get it from maven central:
example maven pom.xml
<dependencies>
  <dependency>
    <groupId>net.glxn</groupId>
    <artifactId>qrgen</artifactId>
    <version>1.4</version>
  </dependency>
</dependencies>
example build.gradle:
dependencies {
  compile ("net.glxn:qrgen:1.4")
}
After that you can put it to use in your project:
// get QR file from text using defaults
File file = QRCode.from("Hello World").file();
// get QR stream from text using defaults
ByteArrayOutputStream stream = QRCode.from("Hello World").stream();
// override the image type to be JPG
QRCode.from("Hello World").to(ImageType.JPG).file();
QRCode.from("Hello World").to(ImageType.JPG).stream();
// override image size to be 250x250
QRCode.from("Hello World").withSize(250, 250).file();
QRCode.from("Hello World").withSize(250, 250).stream();
// override size and image type
QRCode.from("Hello World").to(ImageType.GIF).withSize(250, 250).file();
QRCode.from("Hello World").to(ImageType.GIF).withSize(250, 250).stream();
// supply own outputstream
QRCode.from("Hello World").to(ImageType.PNG).writeTo(outputStream);
See the github page for more info: http://kenglxn.github.io/QRGen/
If you’d rather use ZXING directly, you will be able to since it is a transitive dependency of QRGen, but you could also just add the ZXING repository definition and dependency to your project:
    <dependencies>
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>core</artifactId>
            <version>2.0</version>
        </dependency>
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>javase</artifactId>
            <version>2.0</version>
        </dependency>
    </dependencies>
    <repositories>
        <repository>
            <id>google-releases</id>
            <url>https://oss.sonatype.org/content/repositories/releases</url>
        </repository>
    </repositories>