Example usage for java.util Scanner hasNext

Introduction

In this page you can find the example usage for java.util Scanner hasNext.

Prototype

public boolean hasNext() 

Source Link

Document

Returns true if this scanner has another token in its input.

Usage

From source file:ReversePolishNotation.java

/**
 * This method will calculate the answer of the given Reverse Polar Notation
 * equation. All exceptions are thrown to the parent for handling.
 * //  www . j a va2s.c o m
 * @param input
 *            is the equation entered by the user
 * @throws EmptyRPNException
 *             when there is no RPN equation to be evaluated.
 * @throws RPNDivideByZeroException
 *             when the RPN equation attempts to divide by zero.
 * @throws RPNUnderflowException
 *             when the RPN equation has a mathematical operator before
 *             there are enough numerical values for it to evaluate.
 * @throws InvalidRPNException
 *             when the RPN equation is a String which is unable to be
 *             manipulated.
 * @throws RPNOverflowException
 *             when the RPN equation has too many numerical values and not
 *             enough mathematical operators with which to evaluate them.
 * @return the top item of the stack; the calculated answer of the Reverse
 *         Polish Notation equation
 */
public static double calcRPN(String input) {
    // eliminate any leading or trailing whitespace from input
    input = input.trim();
    // scanner to manipulate input and stack to store double values
    String next;
    Stack<Double> stack = new Stack<Double>();
    Scanner scan = new Scanner(input);

    // loop while there are tokens left in scan
    while (scan.hasNext()) {
        // retrieve the next token from the input
        next = scan.next();

        // see if token is mathematical operator
        if (nextIsOperator(next)) {
            // ensure there are enough numbers on stack
            if (stack.size() > 1) {
                if (next.equals("+")) {
                    stack.push((Double) stack.pop() + (Double) stack.pop());
                } else if (next.equals("-")) {
                    stack.push(-(Double) stack.pop() + (Double) stack.pop());
                } else if (next.equals("*")) {
                    stack.push((Double) stack.pop() * (Double) stack.pop());
                } else if (next.equals("/")) {
                    double first = stack.pop();
                    double second = stack.pop();

                    if (first == 0) {
                        System.out.println("The RPN equation attempted to divide by zero.");
                    } else {
                        stack.push(second / first);
                    }
                }
            } else {
                System.out.println(
                        "A mathematical operator occured before there were enough numerical values for it to evaluate.");
            }
        } else {
            try {
                stack.push(Double.parseDouble(next));
            } catch (NumberFormatException c) {
                System.out.println("The string is not a valid RPN equation.");
            }
        }
    }

    if (stack.size() > 1) {
        System.out.println(
                "There too many numbers and not enough mathematical operators with which to evaluate them.");
    }

    return (Double) stack.pop();
}

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From source file:UtilFunctions.java

public static String[] parseFileTypes(String inputString) {

    //ArrayList to store each parsed filetype
    ArrayList<String> fileTypes = new ArrayList<>();

    //Scanner to iterate over the string filetype by filetype
    Scanner in = new Scanner(inputString);
    in.useDelimiter("[,] | [, ]");

    //Iterate over the string
    while (in.hasNext()) {
        fileTypes.add(in.next());/*from   w w  w .j  a  va  2s.c  om*/
    }

    if (fileTypes.size() > 0) {
        //Generate an array from the ArrayList
        String[] returnArray = new String[fileTypes.size()];
        returnArray = fileTypes.toArray(returnArray);

        //Return that magnificent array
        return returnArray;

    } else {
        return null;
    }
}

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From source file:cpd3314.buildit12.CPD3314BuildIt12.java

/**
 * Build a program that asks the user for a filename. It then reads a file
 * line-by-line, and outputs its contents in uppercase.
 *
 * Make sure that the program exits gracefully when the file does not exist.
 *
 *///  w  ww . ja  v a2  s  .co  m
public static void doBuildIt1() {
    // Prompt the User for a Filename
    Scanner kb = new Scanner(System.in);
    System.out.println("Filename: ");
    String filename = kb.next();

    try {
        // Attempt to Access the File, this may cause an Exception
        File file = new File(filename);
        Scanner input = new Scanner(file);

        // Iterate through the File and Output in Upper Case
        while (input.hasNext()) {
            System.out.println(input.nextLine().toUpperCase());
        }
    } catch (IOException ex) {
        // If the File is Not Found, Tell the User and Exit Gracefully
        System.err.println("File not found: " + filename);
    }
}

---

From source file:Main.java

/**
 * @return A map of all storage locations available
 */// w  ww. java 2  s .c  o m
public static Map<String, File> getAllStorageLocations() {
    Map<String, File> map = new HashMap<String, File>(10);

    List<String> mMounts = new ArrayList<String>(10);
    List<String> mVold = new ArrayList<String>(10);
    mMounts.add("/mnt/sdcard");
    mVold.add("/mnt/sdcard");

    try {
        File mountFile = new File("/proc/mounts");
        if (mountFile.exists()) {
            Scanner scanner = new Scanner(mountFile);
            while (scanner.hasNext()) {
                String line = scanner.nextLine();
                if (line.startsWith("/dev/block/vold/")) {
                    String[] lineElements = line.split(" ");
                    String element = lineElements[1];

                    // don't add the default mount path
                    // it's already in the list.
                    if (!element.equals("/mnt/sdcard"))
                        mMounts.add(element);
                }
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }

    try {
        File voldFile = new File("/system/etc/vold.fstab");
        if (voldFile.exists()) {
            Scanner scanner = new Scanner(voldFile);
            while (scanner.hasNext()) {
                String line = scanner.nextLine();
                if (line.startsWith("dev_mount")) {
                    String[] lineElements = line.split(" ");
                    String element = lineElements[2];

                    if (element.contains(":"))
                        element = element.substring(0, element.indexOf(":"));
                    if (!element.equals("/mnt/sdcard"))
                        mVold.add(element);
                }
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }

    for (int i = 0; i < mMounts.size(); i++) {
        String mount = mMounts.get(i);
        if (!mVold.contains(mount))
            mMounts.remove(i--);
    }
    mVold.clear();

    List<String> mountHash = new ArrayList<String>(10);

    for (String mount : mMounts) {
        File root = new File(mount);
        if (root.exists() && root.isDirectory() && root.canWrite()) {
            File[] list = root.listFiles();
            String hash = "[";
            if (list != null) {
                for (File f : list) {
                    hash += f.getName().hashCode() + ":" + f.length() + ", ";
                }
            }
            hash += "]";
            if (!mountHash.contains(hash)) {
                String key = SD_CARD + "_" + map.size();
                if (map.size() == 0) {
                    key = SD_CARD;
                } else if (map.size() == 1) {
                    key = EXTERNAL_SD_CARD;
                }
                mountHash.add(hash);
                map.put(key, root);
            }
        }
    }

    mMounts.clear();

    if (map.isEmpty()) {
        map.put(SD_CARD, Environment.getExternalStorageDirectory());
    }
    return map;
}

---

From source file:adviewer.util.JSONIO.java

/**
 * Take in file and return one string of json data
 * //from w w  w.  jav a2  s  . c  o  m
 * @return
 * @throws IOException
 */
public static String readJSONFile(File inFile) {
    String readFile = "";

    try {
        File fileIn = inFile;

        //if the file is not there then create the file
        if (fileIn.createNewFile()) {
            System.out.println(fileIn + " was created ");
        }

        FileReader fr = new FileReader(fileIn);
        Scanner sc = new Scanner(fr);

        while (sc.hasNext()) {
            readFile += sc.nextLine().trim();
        }

        return readFile;

    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    // System.out.println( readFile  );
    return readFile;
}

---

From source file:org.hancel.http.HttpUtils.java

private static JSONObject execute(String base, List<NameValuePair> params, String method)
        throws IOException, JSONException {

    URL url;// w w  w.j  av a2s  .  c o  m
    HttpURLConnection urlConnection = null;

    if (method.equals("GET")) {
        url = new URL(base + getQuery(params));
        urlConnection = (HttpURLConnection) url.openConnection();
    }
    try {
        InputStream in = new BufferedInputStream(urlConnection.getInputStream());
        Scanner s = new Scanner(in).useDelimiter("\\A");
        String parseString = s.hasNext() ? s.next() : "";
        in.close();
        return new JSONObject(parseString);
    } finally {
        urlConnection.disconnect();

    }
}

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From source file:org.n52.util.CommonUtilities.java

public static String readResource(InputStream res) {
    Scanner sc = new Scanner(res);
    StringBuilder sb = new StringBuilder();
    while (sc.hasNext()) {
        sb.append(sc.nextLine());/*from  w  w w .  j  ava2 s.  c  o  m*/
        sb.append(NEW_LINE_CHAR);
    }
    sc.close();
    return sb.toString();
}

---

From source file:edu.msu.cme.rdp.unifrac.Unifrac.java

private static Map<String, UnifracSample> readSampleMap(String sampleFile) throws IOException {
    Map<String, UnifracSample> ret = new HashMap();
    Map<String, MCSample> sampleMap = new HashMap();

    int lineno = 1;
    Scanner s = new Scanner(new File(sampleFile)).useDelimiter("\n");
    while (s.hasNext()) {
        String line = s.next().trim();
        if (line.equals("")) {
            continue;
        }/*from   w  ww  . ja  v a 2s .  c om*/

        String[] tokens = line.split("\\s+");
        if (tokens.length < 2) {
            throw new IOException("Failed to parse sample mapping file (lineno=" + lineno + ")");
        }

        String sampleName = tokens[1];
        String seqName = tokens[0];
        int sampleCount = 1;

        try {
            sampleCount = Integer.parseInt(tokens[2]);
        } catch (Exception e) {
        }

        if (!sampleMap.containsKey(sampleName))
            sampleMap.put(sampleName, new MCSample(sampleName));

        UnifracSample unifracSample = new UnifracSample();
        unifracSample.sample = sampleMap.get(sampleName);
        unifracSample.count = sampleCount;

        ret.put(seqName, unifracSample);

        lineno++;
    }
    s.close();

    return ret;
}

---

From source file:org.apache.oodt.cas.protocol.http.util.HttpUtils.java

public static String readUrl(HttpURLConnection conn) throws IOException {
    // create URL source reader
    Scanner scanner = new Scanner(conn.getInputStream());

    // Read in link
    StringBuilder sb = new StringBuilder("");
    while (scanner.hasNext()) {
        sb.append(scanner.nextLine());//ww w  .j ava 2  s .  co  m
    }

    return sb.toString();
}

---

From source file:azureml_besapp.AzureML_BESApp.java

/**
 * Read the JSON schema from the file rrsJson.json
 * /*from w  w w .  jav a 2s.c o  m*/
 * @param filename It expects a fully qualified file name that contains input JSON file
 */
public static void readJson(String filename) {
    try {
        File apiFile = new File(filename);
        Scanner sc = new Scanner(apiFile);
        jsonBody = "";
        while (sc.hasNext()) {
            jsonBody += sc.nextLine() + "\n";
        }
    } catch (Exception e) {
        System.out.println(e.toString());
    }
}

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