We Keep Coding

I'm having a logic error on my program, the if statement works, but when a user inputs a bloodType & rhFactor it still shows O+ regardless of uinput

Here's the first part:
package Week5;
class BloodData
{
private String bloodType;
private String rhFactor;
public BloodData()
{
bloodType = "O";
rhFactor = "+";
}
public void setBloodType (String bloodType){
this.bloodType = bloodType;
}
public void setRhFactor (String rhFactor){
this.rhFactor = rhFactor;
}
String getBloodType(){
return this.bloodType;
}
String getRhFactor(){
return this.rhFactor;
}
}
here's the main method:
package Week5;
import java.util.Scanner;
public class RunBloodData
{
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
BloodData bd = new BloodData();
System.out.print("Enter blood type of patient : ");
bd.setBloodType(input.nextLine());
System.out.print("Enter the Rhesus factor (+ or -) : ");
bd.setRhFactor(input.nextLine());
if(bd.getBloodType().equals("") && bd.getRhFactor().equals(""))
{
bd = new BloodData();
System.out.println (bd.getBloodType().toUpperCase() + bd.getRhFactor() + " is added to the bloodbank.");
}
else
{
bd = new BloodData();
System.out.println (bd.getBloodType().toUpperCase() + bd.getRhFactor() + " is added to the bloodbank.");
}
}
}
NOTE: I HIGHLY SUSPECT THAT I HAVE TO PUT SOMETHING INSIDE of new bloodData in:
else
{
bd = new BloodData();
I just don't know what to call considering bloodType and rhFactor are private and non-static.

I fixed it, I just had to remove bd = new BloodData(); in my else statement so any input will be registered.

NullPointerException in put method of hashmap in chat class

I keep getting null pointer exception when I try to put into messages
( I have removed all unnecessary code)
I dont get the error when I initialize messages inside add function
How can I resolve this?
class Chat {
HashMap< Integer, String> messages;
void Chat() {
this.messages = new HashMap<>();
}
public void add(int id, String newMessage) {
if (!newMessage.isEmpty()) {
System.out.println(newMessage + " "
+ Integer.parseInt(String.valueOf(id)));
this.messages.put(Integer.parseInt(String.valueOf(id)),
newMessage);
System.out.println(messages.values() + "Added to hashset");
}
}
}
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
Chat obj = new Chat();
int size = Integer.parseInt(sc.nextLine());
for (int i = 0; i < size; i++) {
String str = sc.nextLine();
if (!str.isEmpty()) {
obj.add(i + 1, str);
}
}
}
}

Handling a .data file with uneven whitespaces delimited and populate to an bean object using java program

How to handle file data as shown below, which is delimited by uneven whitespaces, where if tokenizer is used based on space, it'll give tokens which cannot be assigned to java bean fields directly.
Below is the content Data of cheapdata4.data:
(TX 260816.<
0954F2003EGGPLEIBLNX37PU ZC550 Z <CA C A L L8 STAF P18 UL15 KIDL
0001F0148BIKFEDDSGWI2797 ZA319 Z <CATGWI2 C M V104 GMH4 GMH UL60 EDDS
4893F1416EGPGEGHFGJOID ZSR20 Z <AAEGPGD C A LT TLA DCS L612 N859 Q41
7945F1400EGSHEGCCLOG63JF ZD328 Z <(A C A R L OTBE Y70 EGCC
7946F1647EGSHEGGWAZE01F ZE50P Z <(A C A R LT MAM1 LAPR ABBO BKY2
7947F1701EGSHEGCCLOG63JF ZD328 Z <(A C A R L / MAM0 OTBE POL ROSU
4368F1657ESSBEGGWBLJ59BF ZC56X Z <RAUBLJ5 A LT UN86 UP7 UP25 EGGW
4369F1728ESSBEGCCETI226L MLJ45 012<RAUETI2 A L UL97 Y70 EGCC
4370F0551LHBPEGGWWZZ196 ZA321 Z <RAUWZZ1 A MT UL60 UY6 UM20 EGGW
7950END 260816.<
package com.msa.parser;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import com.msa.bean.CheapData;
public class FinalParser {
public static void main(String[] args) {
BufferedReader reader;
try {
StringBuilder sb = new StringBuilder();
reader = new BufferedReader(
new FileReader(
"C:\\Users\\Desktop\\assignment\\cheapdata4.data"));
System.out.println("Reading file...");
String line = reader.readLine();
line = line.replaceAll("\\s{2,}", " ");
String[] toks = line.replace(" ", ",").trim().split(",");
line = line.replaceAll("\\s{2,}", " ");
String[] headerTokens = line.split(" +");
String fileStartDate = headerTokens[1].substring(0, 6);
List<String> cheapDataContent = new ArrayList<>();
String[] lineTokens = { "" };
CheapData cheapFileDets = null;
List<CheapData> cheapDataList = new ArrayList<>();
while (line != null) {
line = reader.readLine();
line = line.replaceAll("\\s{2,4}", " ");
// line = line.replaceAll("\\s{2}", " NA ");
// line = line.replaceAll(" ",", ");
// line = line.replaceAll("\\,{2}", "");
lineTokens = line.split(" +");
int len = lineTokens.length;
// String fileEndDate ="";
if (len == 2) {
String fileEndDate = lineTokens[1].substring(0, 6);
if (fileStartDate.equals(fileEndDate)) {
break;
} else {
System.out.println("Date mismatch...");
}
}
if (len >= 6) {
cheapFileDets = new CheapData();
String lineNum = lineTokens[0].substring(0, 4);
cheapFileDets.setLineNum(lineNum);
String cheapReference = lineTokens[0].substring(4);
cheapFileDets.setCheapReference(cheapReference);
cheapFileDets.setDate(fileStartDate);
cheapFileDets.setAircraftCode(lineTokens[1]);
cheapFileDets.setIdentifierCode(lineTokens[2]);
cheapFileDets.setLicenseCode(lineTokens[3]);
if (lineTokens[4].equals("C"))
cheapFileDets.setCodeOne(lineTokens[4]);
else
cheapFileDets.setCodeOne(null);
if (lineTokens[5].equals("A"))
cheapFileDets.setCodeTwo(lineTokens[5]);
else
cheapFileDets.setCodeTwo(null);
if (lineTokens[6].equals("R"))
cheapFileDets.setCodeThree(lineTokens[6]);
else
cheapFileDets.setCodeThree(null);
} else {
if (len == 7)
cheapFileDets.setIdCode(lineTokens[7]);
else
cheapFileDets.setIdCode(null);
}
List<String> miscList = new ArrayList<>();
for (int i = 7; i < len - 1; i++) {
miscList.add(lineTokens[i]);
}
StringBuilder miscAll = new StringBuilder("");
for (String miscs : miscList) {
miscAll.append(miscs + " ");
}
cheapFileDets.setMiscAll(miscAll.toString());
cheapDataList.add(cheapFileDets);
}
System.out.println("File content" + sb.toString());
System.out.println("file date is: " + fileStartDate);
System.out.println("*************");
/*
* for (String strToks : lineTokens) { System.out.println(strToks);
* }
*/
// System.out.println(cheapDataList);
Iterator<CheapData> itrCheapData = cheapDataList.listIterator();
while (itrCheapData.hasNext()) {
System.out.println(itrCheapData.next());
}
} catch (IOException e) {
System.out.println(e.getMessage());
}
}
}
package com.msa.bean;
public class CheapData {
private String lineNum;
private String date;
private String cheapReference;
private String aircraftCode;
private String identifierCode;
private String licenseCode;
private String codeOne;
private String codeTwo;
private String codeThree;
private String idCode;
private String miscAll;
public String getLineNum() {
return lineNum;
}
public void setLineNum(String lineNum) {
this.lineNum = lineNum;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public String getCheapReference() {
return cheapReference;
}
public void setCheapReference(String cheapReference) {
this.cheapReference = cheapReference;
}
public String getAircraftCode() {
return aircraftCode;
}
public void setAircraftCode(String aircraftCode) {
this.aircraftCode = aircraftCode;
}
public String getIdentifierCode() {
return identifierCode;
}
public void setIdentifierCode(String identifierCode) {
this.identifierCode = identifierCode;
}
public String getLicenseCode() {
return licenseCode;
}
public void setLicenseCode(String licenseCode) {
this.licenseCode = licenseCode;
}
public String getCodeOne() {
return codeOne;
}
public void setCodeOne(String lineTokens) {
this.codeOne = lineTokens;
}
public String getCodeTwo() {
return codeTwo;
}
public void setCodeTwo(String lineTokens) {
this.codeTwo = lineTokens;
}
public String getCodeThree() {
return codeThree;
}
public void setCodeThree(String codeThree) {
this.codeThree = codeThree;
}
public String getIdCode() {
return idCode;
}
public void setIdCode(String idCode) {
this.idCode = idCode;
}
public String getMiscAll() {
return miscAll;
}
public void setMiscAll(String miscAll) {
this.miscAll = miscAll;
}
public CheapData(String lineNum, String date, String cheapReference,
String aircraftCode, String identifierCode, String licenseCode,
String codeOne, String codeTwo, String codeThree, String idCode,
String miscAll) {
super();
this.lineNum = lineNum;
this.date = date;
this.cheapReference = cheapReference;
this.aircraftCode = aircraftCode;
this.identifierCode = identifierCode;
this.licenseCode = licenseCode;
this.codeOne = codeOne;
this.codeTwo = codeTwo;
this.codeThree = codeThree;
this.idCode = idCode;
this.miscAll = miscAll;
}
#Override
public String toString() {
return "CheapData [lineNum=" + lineNum + ", date=" + date
+ ", cheapReference=" + cheapReference + ", aircraftCode="
+ aircraftCode + ", identifierCode=" + identifierCode
+ ", licenseCode=" + licenseCode + ", codeOne=" + codeOne
+ ", codeTwo=" + codeTwo + ", codeThree=" + codeThree
+ ", idCode=" + idCode + ", miscAll=" + miscAll + "]";
}
public CheapData() {
super();
}
}
Please can anyone help me out in this regard. I want to parse above file and populate each columns from that to an object using setters in java.
Please do suggest me how to achieve this and kindly let me know if my query not clear.

How to sort from text file and write into another text file Java

I have this textfile which I like to sort based on HC from the pair HC and P3
This is my file to be sorted (avgGen.txt):
7686.88,HC
20169.22,P3
7820.86,HC
19686.34,P3
6805.62,HC
17933.10,P3
Then my desired output into a new textfile (output.txt) is:
6805.62,HC
17933.10,P3
7686.88,HC
20169.22,P3
7820.86,HC
19686.34,P3
How can I sort the pairs HC and P3 from textfile where HC always appear for odd numbered index and P3 appear for even numbered index but I want the sorting to be ascending based on the HC value?
This is my code:
public class SortTest {
public static void main (String[] args) throws IOException{
ArrayList<Double> rows = new ArrayList<Double>();
ArrayList<String> convertString = new ArrayList<String>();
BufferedReader reader = new BufferedReader(new FileReader("avgGen.txt"));
String s;
while((s = reader.readLine())!=null){
String[] data = s.split(",");
double avg = Double.parseDouble(data[0]);
rows.add(avg);
}
Collections.sort(rows);
for (Double toStr : rows){
convertString.add(String.valueOf(toStr));
}
FileWriter writer = new FileWriter("output.txt");
for(String cur: convertString)
writer.write(cur +"\n");
reader.close();
writer.close();
}
}
Please help.

When you read from the input file, you essentially discarded the string values. You need to retain those string values and associate them with their corresponding double values for your purpose.
You can
wrap the double value and the string value into a class,
create the list using that class instead of the double value alone
Then sort the list based on the double value of the class using either a Comparator or make the class implement Comparable interface.
Print out both the double value and its associated string value, which are encapsulated within a class
Below is an example:
static class Item {
String str;
Double value;
public Item(String str, Double value) {
this.str = str;
this.value = value;
}
}
public static void main (String[] args) throws IOException {
ArrayList<Item> rows = new ArrayList<Item>();
BufferedReader reader = new BufferedReader(new FileReader("avgGen.txt"));
String s;
while((s = reader.readLine())!=null){
String[] data = s.split(",");
double avg = Double.parseDouble(data[0]);
rows.add(new Item(data[1], avg));
}
Collections.sort(rows, new Comparator<Item>() {
public int compare(Item o1, Item o2) {
if (o1.value < o2.value) {
return -1;
} else if (o1.value > o2.value) {
return 1;
}
return 0;
}
});
FileWriter writer = new FileWriter("output.txt");
for(Item cur: rows)
writer.write(cur.value + "," + cur.str + "\n");
reader.close();
writer.close();
}

When your program reads lines from the input file, it splits each line, stores the double portion, and discards the rest. This is because only data[0] is used, while data[1] is not part of any expression.
There are several ways of fixing this. One is to create an array of objects that have the double value and the whole string:
class StringWithSortKey {
public final double key;
public final String str;
public StringWithSortKey(String s) {
String[] data = s.split(",");
key = Double.parseDouble(data[0]);
str = s;
}
}
Create a list of objects of this class, sort them using a custom comparator or by implementing Comparable<StringWithSortKey> interface, and write out str members of sorted objects into the output file.

Define a Pojo or bean representing an well defined/organized/structured data type in the file:
class Pojo implements Comparable<Pojo> {
private double value;
private String name;
#Override
public String toString() {
return "Pojo [value=" + value + ", name=" + name + "]";
}
public double getValue() {
return value;
}
public void setValue(double value) {
this.value = value;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
/**
* #param value
* #param name
*/
public Pojo(double value, String name) {
this.value = value;
this.name = name;
}
#Override
public int compareTo(Pojo o) {
return ((Double) this.value).compareTo(o.value);
}
}
then after that: read->sort->store:
public static void main(String[] args) throws IOException {
List<Pojo> pojoList = new ArrayList<>();
BufferedReader reader = new BufferedReader(new FileReader("chat.txt"));
String s;
String[] data;
while ((s = reader.readLine()) != null) {
data = s.split(",");
pojoList.add(new Pojo(Double.parseDouble(data[0]), data[1]));
}
Collections.sort(pojoList);
FileWriter writer = new FileWriter("output.txt");
for (Pojo cur : pojoList)
writer.write(cur.toString() + "\n");
reader.close();
writer.close();
}

Using java-8, there is an easy way of performing this.
public static void main(String[] args) throws IOException {
List<String> lines =
Files.lines(Paths.get("D:\\avgGen.txt"))
.sorted((a, b) -> Integer.compare(Integer.parseInt(a.substring(0,a.indexOf('.'))), Integer.parseInt(b.substring(0,b.indexOf('.')))))
.collect(Collectors.toList());
Files.write(Paths.get("D:\\newFile.txt"), lines);
}
Even better, using a Method reference
public static void main(String[] args) throws IOException {
Files.write(Paths.get("D:\\newFile.txt"),
Files.lines(Paths.get("D:\\avgGen.txt"))
.sorted(Test::compareTheStrings)
.collect(Collectors.toList()));
}
public static int compareTheStrings(String a, String b) {
return Integer.compare(Integer.parseInt(a.substring(0,a.indexOf('.'))), Integer.parseInt(b.substring(0,b.indexOf('.'))));
}

By using double loop sort the items
then just comapre it using the loop and right in the sorted order
public static void main(String[] args) throws IOException {
ArrayList<Double> rows = new ArrayList<Double>();
ArrayList<String> convertString = new ArrayList<String>();
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader("C:/Temp/AvgGen.txt"));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String s;
try {
while((s = reader.readLine())!=null){
String[] data = s.split(",");
convertString.add(s);
double avg = Double.parseDouble(data[0]);
rows.add(avg);
}
} catch (NumberFormatException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
FileWriter writer = new FileWriter("C:/Temp/output.txt");;
Collections.sort(rows);
for (double sorted : rows) {
for (String value : convertString) {
if(Double.parseDouble(value.split(",")[0])==sorted)
{
writer.write(value +"\n");
}
}
}

Output issues: Passing from BufferedReader to array method

I've compiled and debugged my program, but there is no output. I suspect an issue passing from BufferedReader to the array method, but I'm not good enough with java to know what it is or how to fix it... Please help! :)
public class Viennaproj {
private String[] names;
private int longth;
//private String [] output;
public Viennaproj(int length, String line) throws IOException
{
this.longth = length;
this.names = new String[length];
String file = "names.txt";
processFile("names.txt",5);
sortNames();
}
public void processFile (String file, int x) throws IOException, FileNotFoundException{
BufferedReader reader = null;
try {
//File file = new File("names.txt");
reader = new BufferedReader(new FileReader(file));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void sortNames()
{
int counter = 0;
int[] lengths = new int[longth];
for( String name : names)
{
lengths[counter] = name.length();
counter++;
}
for (int k = 0; k<longth; k++)
{
int counter2 = k+1;
while (lengths[counter2]<lengths[k]){
String temp2;
int temp;
temp = lengths[counter2];
temp2 = names[counter2];
lengths[counter2] = lengths[k];
names[counter2] = names[k];
lengths[k] = temp;
names[k] = temp2;
counter2++;
}
}
}
public String toString()
{
String output = new String();
for(String name: names)
{
output = name + "/n" + output;
}
return output;
}
public static void main(String[] args)
{
String output = new String ();
output= output.toString();
System.out.println(output+"");
}
}

In Java, the public static void main(String[] args) method is the starting point of the application.
You should create an object of Viennaproj in your main method. Looking at your implementation, just creating an object of Viennaproj will fix your code.
Your main method should look like below
public static void main(String[] args) throws IOException
{
Viennaproj viennaproj = new Viennaproj(5, "Sample Line");
String output= viennaproj.toString();
System.out.println(output);
}
And, if you are getting a FileNotFound exception when you execute this, it means that java is not able to find the file.
You must provide complete file path of your file to avoid that issue. (eg: "C:/test/input.txt")