java either monad

build.sbt

libraryDependencies ++= Seq(
  "org.codehaus.jackson" % "jackson-mapper-asl" % "1.9.7"
 ,"org.functionaljava" % "functionaljava" % "3.1"
)

JavaMain.java

import fj.data.Either;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;
import java.net.URL;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.map.ObjectMapper;

public class MainJava{

  public static void main(String[] args){
    final String url = "http://search.twitter.com/search.json?q=scala";
    final Either<Exception,String> str = get(url);
    if(str.isRight()){
      final Either<Exception,JsonNode> json = parse(str.right().value());
      if(json.isRight()){
        System.out.println(json.right().value());
      }else{
        json.left().value().printStackTrace();
      }
    }else{
       str.left().value().printStackTrace();
    }
  }

  static final Either<Exception,JsonNode> parse(final String jsonString){
    try{
      return Either.right(new ObjectMapper().readValue(jsonString,JsonNode.class));
    }catch(Exception e){
      return Either.left(e);
    }
  }

  static final Either<Exception,String> get(final String urlString){
    try{
      final URL url = new URL(urlString);
      InputStream content = (InputStream)url.getContent();
      final BufferedReader bf = new BufferedReader(new InputStreamReader(content));
      String line;
      final StringBuilder sb = new StringBuilder();
      while ((line = bf.readLine()) != null){
        sb.append(line);
      }
      return Either.right(sb.toString());
    }catch(Exception e){
      return Either.left(e);
    }
  }
}

ScalaMain.scala

import java.io.BufferedReader
import java.io.InputStreamReader
import java.io.InputStream
import java.net.URL
import org.codehaus.jackson.JsonNode
import org.codehaus.jackson.map.ObjectMapper

object MainScala{

  def main(args:Array[String]){
    val url = "http://search.twitter.com/search.json?q=scala"
    get(url).right.flatMap(parse).fold(
      _.printStackTrace
      ,
      println _
    )
  }

  val parse = (jsonString:String) =>
    try{
      Right(new ObjectMapper().readValue(jsonString,classOf[JsonNode]))
    }catch{
      case e => Left(e)
    }

  val get = (urlString:String) =>
    try{
      val url = new URL(urlString)
      val content = url.getContent().asInstanceOf[InputStream]
      val bf = new BufferedReader(new InputStreamReader(content))
      var line:String = null
      val sb = new StringBuilder()
      while ({line = bf.readLine();line} != null){
        sb.append(line)
      }
      Right(sb.toString)
    }catch{
      case e => Left(e)
    }

}