I want to use the class IpAddress instead of String in my List, like this:
ArrayList<IpAddress> IpAddresses = new ArrayList<>();
But it doesn't work. I cannot add the string line to my list, so the program does not work as I want. What should I do?
public class IpAddress implements Comparable<IpAddress> {
private String ip;
public IpAddress(String ip) {
this.ip = ip;
}
#Override
public int compareTo(IpAddress o) {
return this.ip.compareTo(o.ip);
}
}
public class IPvLIST {
public static void main(String[] args) throws IOException {
FileReader fr = new FileReader(new File("ip.txt"));
BufferedReader br = new BufferedReader(fr);
ArrayList<String> IpAddresses = new ArrayList<>();
String line;
int n = 0;
while ((line = br.readLine()) != null) {
IpAddresses.add(line);
}
}
}
You need to convert the string line to an IpAddress. Based on the code you have, change the while statement to
while ((line = br.readLine()) != null) {
IpAddresses.add(new IpAddress(line));
}
Depending if this is a simple test program or something more, you might also look into the .NET class IPAddress. This has a parse function that will take the string and convert it to an IPAddress which makes it easier to perform actual network functions.
Related
In Apache Flink, I am not able to see the output in std out, but my job is running successfully and data is coming
As you are running your job on a cluster, DataStreams are printed to the stdout of the TaskManager process. This TaskManager stdout is directed to an .out file in the ./log/ directory of the Flink root directory. I believe this is here you have seen your output.
I don't know if it is possible to change the stdout of TaskManagers, however, a quick and dirty solution could be to write the output to a socket :
output.writeToSocket(outputHost, outputPort, new SimpleStringSchema())
public static void main(String[] args) throws Exception {
// the host and the port to connect to
final String hostname = "192.168.1.73";
final int port = 9000;
final StreamExecutionEnvironment env = StreamExecutionEnvironment.createRemoteEnvironment("192.168.1.68", 6123);
// get input data by connecting to the socket
DataStream<String> text = env.socketTextStream(hostname, port, "\n");
// parse the data, group it, window it, and aggregate the counts
DataStream<WordWithCount> windowCounts = text
.flatMap(new FlatMapFunction<String, WordWithCount>() {
public void flatMap(String value, Collector<WordWithCount> out) {
for (String word : value.split("\\s")) {
out.collect(new WordWithCount(word, 1L));
}
}
})
.keyBy("word").timeWindow(Time.seconds(5))
.reduce(new ReduceFunction<WordWithCount>() {
public WordWithCount reduce(WordWithCount a, WordWithCount b) {
return new WordWithCount(a.word, a.count + b.count);
}
});
// print the results with a single thread, rather than in parallel
windowCounts.print().setParallelism(1);
env.execute("Socket Window WordCount");
}
public static class WordWithCount {
public String word;
public long count;
public WordWithCount() {
}
public WordWithCount(String word, long count) {
this.word = word;
this.count = count;
}
#Override
public String toString() {
return word + " : " + count;
}
}
Write a program that shall calculate the vocabulary richness of a text in a file and the frequency of the most common word. The vocabulary richness is the number of words in the text divided by the number of distinct words. The frequency of a word is the number of times the word is mentioned in the text divided by the total number of words in the text.
Define and implement class WordCounter with two private fields String word and int count, constructor WordCounter(String word), and public methods String getName(), int getCount(), and void addToCounter().
Define and implement class Corpus (as in text corpus) with one private field ArrayList<WordCounter> words, constructor Corpus(BufferedReader infile), and public methods double getVocabularyRichness() and String getMostFrequentWord().
Implement a test program (as the public static void main method in Corpus) that reads all files in a specific folder, creates a Corpus object from each (previously opened) file, and saves the requested statistics into another file stats.csv. You can either create a new Corpus object for each file or define an ArrayList<Corpus> of the corpora.
Each line of the CSV file must consist of three fields separated by commas (but no spaces!): the file name, the vocabulary richness, and the most frequently used word. Run your program on all Shakespeare's plays. Submit the CSV file together with the Java file.
I wrote what I think is the correct implementation of the HW problem because it works properly for some of the text files, however only the words.get(i).getName() (I tested with words.get(i).getCount()) method will print a blank space for some of the files. I have tried everything, and can't seem to figure it out. Can you please give me a hint or some guidance as to how to fix this issue?
public class Corpus {
private ArrayList<WordCounter> words = new ArrayList <WordCounter>() ;
Corpus(BufferedReader infile){
String ln;
try {
while((ln = infile.readLine()) != null) {
for (String word : ln.toLowerCase().split("([,.\\s]+)")) {
int reference = 0;
for(int i = 0; i < words.size(); i++) {
if (word.equals(words.get(i).getName())) {
reference++;
words.get(i).addToCounter();
} }
if (reference==0) { words.add(new WordCounter(word)); }
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
public double getVocabularyRichness() {
int word_count=0;
for(int i = 0; i < words.size(); i++) {
word_count=word_count+words.get(i).getCount();
}
return (double)word_count/(double)words.size();
}
public String getMostFrequentWord() {
String winner = "*AN ERROR OCCURRED*";
int max_count = 0;
for(int i = 0; i < words.size(); i++) {
if(words.get(i).getCount() > max_count){
max_count = words.get(i).getCount();
}
}
for(int i = 0; i < words.size(); i++) {
if(words.get(i).getCount() == max_count){
winner = words.get(i).getName();
}
}
//winner="Test " + String.valueOf(words.get(i).getName());;
//return String.valueOf(max_count);
return winner;
}
public static void main(String [] args) throws Exception{
BufferedWriter writer = null;
File folder_location = new File("/Users/joaquindelaguardia/Desktop/Shakespeare");
File[] file_array = folder_location.listFiles();
for(File iteration_file: file_array) {
FileReader current_file = new FileReader(iteration_file);
BufferedReader infile = new BufferedReader(current_file);
Corpus obj1 = new Corpus(infile);
String file_name = iteration_file.getName();
String frequent_word = obj1.getMostFrequentWord();
String vocabulary_richness = String.valueOf(obj1.getVocabularyRichness());
System.out.println(file_name);
System.out.println(frequent_word);
System.out.println(vocabulary_richness);
System.out.println("-----------------------------");
//FileWriter file_writer = new FileWriter("/Users/joaquindelaguardia/Desktop/stats.csv");
//writer = new BufferedWriter(file_writer);
//String output = file_name+", "+frequent_word+", "+vocabulary_richness + "\n";
//writer.append(output);
}
//writer.close();
}
}
public class WordCounter {
private String word;
private int count=1;
WordCounter(String word){
this.word=word;
}
public String getName() {
return word;
}
public int getCount() {
return count;
}
public void addToCounter() {
count++;
}
}
Im testing the information by printing before appending to file, and as you can see with the small fragment of the output included below, for some cases it prints the most common word (and) while in the second case it doesn't print anything.
shakespeare-lovers-62.txt
and
2.2409948542024014
shakespeare-julius-26.txt
6.413205537806177
I'm writing a program but I'm unable to call a few of the methods I made. The errors are as follows:
-method reportMenu(String) in the type CommissionReportSystem is not applicable for the arguments ()
-Cannot make a static reference to the non-static method getSalesData() from the type CommissionReportSystem
-The method computeTotalSales() is undefined for the type CommissionReportSystem
-The method computeSalesCommission(double) in the type CommissionReportSystem is not applicable for the arguments ()
-The method showAgentCommission(double) in the type CommissionReportSystem is not applicable for the arguments ()
I've tried a lot of fixes but nothing seems to be sticking and I'm unsure of how to proceed. I've included the relevant parts of the code below. I would appreciate any tips on how to fix any of these. Thank you!
import java.io.*;
import java.text.*;
import java.util.*;
public class CommissionReportSystem {
private static final String String = null;
public static void main(String[] args) {
getSalesData ();
computeTotalSales ();
computeSalesCommission ();
showAgentCommission ();
shutdown ();
}
String [] getSalesData (){
String [] data = new String [2];
String ticketsSold = "";
String ticketPrice = "";
String buffer = new String ();
data[0] = buffer;
data[1] = buffer;
BufferedReader br = null;
try {
br = new BufferedReader (new InputStreamReader(System.in));
System.out.print ("Enter tickets sold:");
buffer = br.readLine ();
ticketsSold = buffer;
System.out.print ("Enter ticket price:");
buffer = br.readLine ();
ticketPrice = buffer;
} catch (Exception e) {
System.out.println ("Invalid entry");
}
data [0] = ticketsSold;
data [1] = ticketPrice;
return data;
}
public static double totalSales (String ticketsSold, String ticketPrice){
int ticketsSoldNum = Integer.parseInt(ticketsSold);
double ticketPriceNum = Double.parseDouble(ticketPrice);
double totalSalesNum = ticketsSoldNum * ticketPriceNum;
return totalSalesNum;}
public static final double computeSalesCommission (double totalSalesNum){
final double rate1 = 0.025;
final double rate2 = 0.0375;
final double rate3 = 0.0425;
final double salesLimit1 = 2000;
final double salesLimit2 = 4000;
final double agentCommission= 0;
if (totalSalesNum <= 2000) {
agentCommission = rate1 * totalSalesNum;
}
else if (totalSalesNum <= 4000){
agentCommission = rate2 * totalSalesNum;
}
else (totalSalesNum > 4000){
agentCommission = rate3 * totalSalesNum;
}
return agentCommission;
}
public static void showAgentCommission (double agentCommission){
System.out.format ("Congratulation agent Cindy Smith, your current daily commission:" + agentCommission);
}
public static void shutdown (){
System.out.format ("Thank you for your time! Have a great day!");
}
public static void handleInvalidData (){
}
}
1) getSalesData() is an instance method. If you want to call an instance method, create an object of the class and call method using that. Else you have to make the method static. Remember one the thing you cannot access the instance variables inside static method.
2) There is no method computeTotalSales() in your class.
3) computeSalesCommission() requires an argument of type double. You have called it without any argument.
4) The last comment is also valid for showAgentCommission().
If I use the File.getText() method in groovy
newFile().text or newFile().getText()
do I have to execute some closure statements to close the used file reader or will the method do it by itself?
It will do it by itself.
Calling new File( 'a.txt' ).text will call ResourceGroovyMethods.getText( File )
public static String getText(File file, String charset) throws IOException {
return IOGroovyMethods.getText(newReader(file, charset));
}
Which as you can see calls IOGroovyMethods.getText( BufferedReader ):
public static String getText(BufferedReader reader) throws IOException {
StringBuilder answer = new StringBuilder();
// reading the content of the file within a char buffer
// allow to keep the correct line endings
char[] charBuffer = new char[8192];
int nbCharRead /* = 0*/;
try {
while ((nbCharRead = reader.read(charBuffer)) != -1) {
// appends buffer
answer.append(charBuffer, 0, nbCharRead);
}
Reader temp = reader;
reader = null;
temp.close();
} finally {
closeWithWarning(reader);
}
return answer.toString();
}
Which as you can see, closes the Reader when done
I am trying to input a file that contains the first and last names of several individuals from a file into a java program. I have a People class that has two Strings for the first and last names, as well as, accessors and mutators to access the information. Inside my main method, I have a while loop that brings in each person line by line until the end of the file. It is suppose to create a new instance of Person through the constructor for each line and make a copy to the array. When I print out the contents of the array once the while loop is over with, it seems that the array is filled with the information of the last person in the file. However, if I comment out the String[] values = line.split("\t"); and Person child = new Person(values[0], values[1]); lines and use a double dimensional array to hold a copy of all the information in the file, then it works fine. Is there something that I am doing wrong that is preventing me from retaining a copy of all the individual’s names contained in the file in the People array?
public class Person
{
protected static String first;
protected static String last;
private static int id;
public Person(String l, String f)
{
last = l;
first = f;
} // end of constructor
public String getFirst()
{
return first;
} // end of getFirst method
public static String getLast()
{
return last;
} // end of getLast method
public static int getID()
{
return id;
} // end of getLast method
public static void setFirst(String name)
{
first = name;
} // end of setFirst method
public static void setLast(String name)
{
last = name;
} // end of setLast method
public static void setID(int num)
{
id = num;
} // end of setLast method
} // end of Person class
public class Driver
{
public static void main(String arg[])
{
Person[] temp = new Person[10];
try
{
BufferedReader br = new BufferedReader(new FileReader(arg[1]));
String line = null;
int counter = 0;
while ((line = br.readLine()) != null)
{
String[] values = line.split("\t");
Person child = new Person(values[0], values[1]);
temp[counter] = child;
System.out.println("Index " + counter + ": Last: " + child.getLast() + " First: " + child.getFirst());
System.out.println("Index " + counter + ": Last: " + temp[counter].getLast() + " First: " + temp[counter].getFirst() + "\n");
counter++;
}
br.close();
}
catch(Exception e)
{
System.out.println("Could not find file");
}
for(int row = 0; row < 7; row++)
{
System.out.print("Row: " + row + " Last: " + temp[row].getLast() + " First: " + temp[row].getFirst() + "\n");
}
}
} // end of Driver class
The fields in class Person should not be static, a static field means shares the value for all instances of the class, that means all the 10 instances Person have the same "first", "last" and "id" values. And you need to change the methods of Person to non-static too, since static method cannot access static fields.