I have a method getFormattedValue(List<String> dataHeaders, List<String> data) that returns String value based contents of dataHeaders and data list. dataHeaders list can have 10 distinct values and based on value at particular index output string formation changes.
Below code was working fine tiil the time when dataHeaders contents are received in specific order , but lately this order is changing many atimes. As this input is received from other app/ system, i do not have control over order of elements. Hence i want to update my code so that it works correctly even after input order is altered.
If 1'st element of dataHeaders list is "OPERATION_NAME" then i need not take any action, but if "OPERATION_NAME" comes at 2'nd index in dataHeaders list then i need to do special formatting to output value. And so on....
My Pain is that i receive 10 dataHeaders. Please suggest me any good approach to handle this issue. I am posting my code below, suggestions are welcome.
import java.util.ArrayList;
import java.util.List;
public class ValueGenerator {
public String getFormattedValue(List<String> dataHeaders, List<String> data){
String formattedOutValue=null;
if(dataHeaders!=null && data!=null &&
dataHeaders.size() == data.size()){
if(dataHeaders.get(0).equals("OPERATION_NAME")){
formattedOutValue=data.get(0); // Add no spaces
}else if(dataHeaders.get(1).equals("OPERATION_NAME")){
formattedOutValue=data.get(1)+" "; // Add 4 blank spaces
}else if(dataHeaders.get(2).equals("OPERATION_NAME")){
formattedOutValue=data.get(2)+" "; // Add 6 blank spaces
}
}
//likewise i want to avoid redundant if - else if check
return formattedOutValue;
}
}
I assume that you want data.get(2) in the case of dataHeaders.get(2) and not data.get(1)
Basically you just need to find the index of the string OPERATION_NAME in dataHeaders and use it for data. The simplest way is to iterate over the list dataHeaders with an index and stop when you find it.
If you need to handle more strings then you could use a Map to map the strings you want to evaluate to their indices, this could look like this:
final static Map<Integer, String> formatByIndexMap;
static {
formatByIndexMap = new HashMap<>();
formatByIndexMap.put(0, "");
formatByIndexMap.put(1, " ");
formatByIndexMap.put(2, " ");
// and so on
formatByIndexMap.put(9, "----format for 10----");
}
public String getFormattedValue(List<String> dataHeaders, List<String> data){
String formattedOutValue = null;
if (dataHeaders != null && data != null &&
dataHeaders.size() == data.size()) {
Map<String, Integer> dhm = new HashMap<>();
for(int i = 0; i < dataHeaders.size(); i++) {
dhm.put(dataHeaders.get(i), i);
}
Integer operationNameIndex = dhm.get("OPERATION_NAME");
if(operationNameIndex != null) {
formattedOutValue = data.get(operationNameIndex.intValue()) +
formatByIndexMap.get(operationNameIndex);
}
}
return formattedOutValue;
}
The format map formatByIndexMap is defines as final static.
An for some basic testing:
#Test
public void getFormattedValue() {
List<String> data = Arrays.asList("operation", "foo", "bar");
List<String> dataHeaders;
String formated;
dataHeaders = Arrays.asList("OPERATION_NAME", "FOO_NAME", "BAR_NAME");
formated = getFormattedValue(dataHeaders, data);
Assert.assertEquals("operation", formated); // no spaces
dataHeaders = Arrays.asList("FOO_NAME", "OPERATION_NAME", "BAR_NAME");
formated = getFormattedValue(dataHeaders, data);
Assert.assertEquals("foo ", formated); // four spaces
dataHeaders = Arrays.asList("FOO_NAME", "BAR_NAME", "OPERATION_NAME");
formated = getFormattedValue(dataHeaders, data);
Assert.assertEquals("bar ", formated); // six spaces
dataHeaders = Arrays.asList("FOO_NAME", "BAR_NAME", "", "", "", "", "",
"", "", "OPERATION_NAME");
data = Arrays.asList("operation", "foo", "bar", "", "", "", "",
"", "", "tail");
formated = getFormattedValue(dataHeaders, data);
// ----format for 10----
Assert.assertEquals("tail----format for 10----", formated);
}
Related
The task is to read the given file and return list of full names. I've separated the lines successfully and should be able to get both first and last names, but I'm a bit confused about how should I do that.
How am I able to get full names from readData()?
What I'm looking for is this output ["Alice Smith", "Bob Brown", "Carol White", "David Doe"] and not duplicated names.
My code looks like this so far:
public class GradeRepository {
public GradeRepository(){
readData();
}
public void readData() {
for (String line : readLines()) {
String[] parts = line.split("\\|");
String firstName = parts[0];
String lastName = parts[1];
String subject = parts[2];
String grade = parts[3];
System.out.println(firstName);
System.out.println(lastName);
System.out.println(subject);
System.out.println(grade);
System.out.println(Arrays.toString(parts));
}
}
public List<String> getFullNames() {
List<String> fullNames = new ArrayList<>();
return fullNames;
}
private List<String> readLines() {
try {
return Files.readAllLines(Paths.get("src/ex1/grades.txt"));
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
Given text file:
grades.txt
Alice|Smith|math|5
Bob|Brown|english|4
David|Doe|math|3
Bob|Brown|math|4
Bob|Brown|chemistry|5
Alice|Smith|english|4
Carol|White|chemistry|3
David|Doe|chemistry|4
readData needs to be modified either to return a list of String[] where each string array represents a line or a field List<String[]> data needs to be created in GradeRepository and populated in readData.
Next, to get rid of duplicate names a Set<String> should be used as suggested in the comments, and LinkedHashSet implementation allows to keep the insertion order.
Example implementation where readData returns a list:
public List<String[]> readData() {
List<String[]> data = new ArrayList<>();
for (String line : readLines()) {
String[] parts = line.split("\\|");
// ... print parts as above if necessary...
data.add(parts);
}
return data;
}
public Set<String> getFullNames() {
Set<String> fullNames = new LinkedHashSet<>();
for (String[] row : readData()) {
fullNames.add(row[0] + " " + row[1]);
}
return fullNames;
}
It may be more preferable to use Stream API to avoid creation of intermediate collections, so all these methods may be rewritten into one:
public Set<String> getFullNames() throws Exception {
return Files.lines(Path.of("dataset.txt")) // Stream<String>
.map(line -> line.split("\\|")) // Stream<String[]>
.filter(arr -> arr.length > 1) // ensure there are 2 columns at least
.map(arr -> arr[0] + " " + arr[1]) // Stream<String>
.collect(Collectors.toCollection(LinkedHashSet::new)); // get collection of unique names
}
I only want to check for:
if (lore.contains("§eSigned of ")) {
but it doesn't get that it does contain "§eSigned of "
I wrote a Minecraft Command /sign you can add a lore to an item ("Signed of playerrank | playername").
Then i wanted to add an /unsign command to remove this lore.
ItemStack is = p.getItemInHand();
ItemMeta im = is.getItemMeta();
List<String> lore = im.hasLore() ? im.getLore() : new ArrayList<String>();
if (lore.contains("§eSigned of " + getChatName(p))) { // this line is important!
for (int i = 0; i < 3; i++) {
int size = lore.size();
lore.remove(size - 1);
}
im.setLore(lore);
is.setItemMeta(im);
p.setItemInHand(is);
sendMessage(p, "§aThis item is no longer signed");
} else {
sendMessage(p, "§aThis item is not signed!");
}
return CommandResult.None;
Everything works fine until you e.g. change your name. than you can't remove the sign because getChatName(p) has changed.
To fix this i only want to check
if (lore.contains("§eSigned of ")) {
but than it doesn't get it and returns false. (it says lore does not contain "§eSigned of ")
I tried a lot but it only works with the string "§eSigned of " and getChatName(p).
As the documentation "contains" searches for the specific string so it should work as I thought right?
Add:
getChatName(p) returns the rank of the player and the playername like: "Member | domi"
sendMessage(p, "") sends a simple message in the Minecraft chat
The problem you run into is that contains(String) looks for a matching string. What you search for is a check if any string in the list starts with "§eSigned of ".
I would suggest adding a function isSignedItem like this:
private boolean isSignedItem(List<String> lore) {
for (String st : lore)
if (st.startsWith("§eSigned of "))
return true;
return false;
}
and then to use this function to check if the item is signed or not:
[...]
List<String> lore = im.hasLore() ? im.getLore() : new ArrayList<String>();
if (isSignedItem(lore)) { // this line is important!
for (int i = 0; i < 3; i++) {
int size = lore.size();
lore.remove(size - 1);
}
[...]
I am new to Java and practicing parsing csv file into the object. I've tried but cannot figure it out.
The file looks like this:
[0], [1], [2], [3] , [4] , [5] , [6] , [7] , [8] , [9]
class, gender, age, bodyType, profession, pregnant, isYou ,species, isPet, role
scenario:green, , , , , , , ,
person, female, 24, average , , FALSE , , , , passenger
animal, male , 4, , , FALSE , , dog , TRUE , pedestrian
scenario:red
person, male , 16, athletic, boxer , FALSE , TRUE , , , passenger
person, female, 25, athletic, doctor , TRUE , FALSE , , , pedestrian
I need to parse it by any number of passengers and pedestrians with any scenarios. Finally, add these scenarios into an ArrayList for analyzing.
What I think is to:
loop through each line, stops when reaches to the next scenario:red, adds the passengers and the pedestrians to the Character ArrayList. (I've done adding, but don't how to stop).
Create a scenario using constructor scenario(ArrayList<Character> passenger, ArrayList<Character> pedestrians, boolean redOrGreen);
The ArrayList scenarios add the created scenarios.
What I've done is put everything together instead of separate them. Any help or hint is highly appreciated.
Thanks for this community who helped me, here is what I've got so far.
public void loadCsv() throws IOException {
String csvFile = "config.csv";
String line = "";
String csvSplit = "\\s*,\\s*";
Scenario scenario = new Scenario();
Person person = new Person();
Animal animal = new Animal();
ArrayList<Scenario> scenaios = new ArrayList<Scenario>();
ArrayList<String> csvContents = new ArrayList<String>();
ArrayList<Character> passengers = new ArrayList<Character>();
ArrayList<Character> pedestrians = new ArrayList<Character>();
try (BufferedReader csvReader = new BufferedReader(new FileReader(csvFile));) {
String headerLine = csvReader.readLine(); //get rid of the header
//add each line to the arrayList
while ((line = csvReader.readLine()) != null) {
csvContents.add(line);
}
for(String csvLine : csvContents) {
String[] data = csvLine.split(csvSplit); // split by comma and remove redundant spaces
if (data.length == NO_OF_FIELD) { //check and avoid indexOutOfBoundException
String clazz = data[0].toLowerCase();// cannot use word "class" as a variable
if (clazz.startsWith("scenario") && data.length == 1) {
scenario = new Scenario();
scenario.setLegalCrossing(clazz.endsWith("green"));
continue;
}
else if ("person".equals(clazz) && data.length ==10) {
person = loadCsvPerson(data);
addCharacter(person, data);
}
else if ("animal".equals(clazz) && data.length ==10) {
animal = loadCsvAnimal(data);
addCharacter(animal, data);
}
}
}
}
//passenger and pedestrians are in position
System.out.println("passengers: " + passengers);
System.out.println("pedestrians: " + pedestrians);
if (null != scenario) {
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
If it is possible to change the csv file format, I would add scenario type column (and scenario id or name if required), so you can work with csv file as a result set from database when you join tables (scenario + passenger + pedestrian) and return plain rows.
With this approach you will be able to delegate parsing to any csv library and do your logic (group by scenario id/name/type) separately. With surrogate rows you have (scenario:green...) you have to write your custom parser.
For example, you can use univocity to simply parse file into your model (even using annotations) and iteratively group it and handle.
Or if you need to work with existing file format do something like that:
if (clazz.startsWith("scenario") && data.length == 1) {
// collect existing scenario before starting processing new one
if (scenario != null) {
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
passengers = new ArrayList();
pedestrians = new ArrayList();
scenarios.add(scenario);
}
// now start new group (scenario)
scenario = new Scenario();
scenario.setLegalCrossing(clazz.endsWith("green"));
continue;
}
Following things need to be addressed in your code:
Strive to avoid using the name of a class which is already used by the standard library (and especially when it is in the default package, java.lang) e.g. there is already a class Character in Java library and therefore you should use a different name for your custom class.
Use continue to skip the line, scenario:red
for(String csvLine : csvContents) {
if(csvLine.equals("scenario:red")){
continue;
}
String[] data = csvLine.split(csvSplit); // split by comma and remove redundant spaces
if (data.length == NO_OF_FIELD) {
//..
}
//..
}
If you have already defined final int NO_OF_FIELD = 10, you can use the same instead of using the value 10 directly i.e. you should use NO_OF_FIELD instead of 10 in the following code:
if (data.length == NO_OF_FIELD) { //check and avoid indexOutOfBoundException
String clazz = data[0].toLowerCase();// cannot use word "class" as a variable
//...
else if ("person".equals(clazz) && data.length ==10) {
However, you also need to understand that && data.length ==10 is unnecessary here as you have already checked data.length == NO_OF_FIELD in the enclosing if condition.
I couldn't understand the rest of your points. If you clarify them, I'll be able to help you further.
I need to add the previous scenario in the second round.
Since the last set of data won't be captured, I need to set another new scenario to add it in. Thanks for the art sir.
Character character = null;
try (BufferedReader csvReader = new BufferedReader(new FileReader(csvFile));) {
String headerLine = csvReader.readLine(); //get rid of the header
//add each line to the arrayList
while ((line = csvReader.readLine()) != null) {
csvContents.add(line);
}
final int NO_OF_FIELDS = 10;
for(String csvLine : csvContents) {
String[] data = csvLine.split(csvSplit); // split by comma and remove redundant spaces
String clazz = data[0].toLowerCase();// cannot use word "class" as a variable
if (clazz.startsWith("scenario") && data.length == 1) {
// adding scenario after one set of data
// i.e second round adding the first round data
if (passengers.size() != 0 && pedestrians.size() != 0) {
Scenario scenario = new Scenario();
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
scenarios.add(scenario);
}
passengers = new ArrayList<Character>();
pedestrians = new ArrayList<Character>();
if (clazz.endsWith("green")) {
scenario.setLegalCrossing(true);
System.out.println("green light");
}
else if (clazz.endsWith("red")){
scenario.setLegalCrossing(false);
System.out.println("red light");
}
continue;
}
//...
Scenario scenario = new Scenario();
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
scenarios.add(scenario);
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
Audit audit = new Audit();
audit.setScenario(scenarios);
I've this kind of String:
{aa=bbbb, cc=blabla1, ee=ffff, cc=blabla2, gg=hhhh, cc=blabla3,.......}
and i want to get a list of all words after cc=.
How can i do it? I'm not very confident with regex stuff.
public static void main(String[] args) {
String input = "aa=bbbb, cc=blabla1, ee=ffff, cc=blabla2, gg=hhhh, cc=blabla3";
String[] splitValues = input.split(", ");
Map<String,List<String>> results = new Hashtable<>();
List<String> valueList = null;
// iterate through each key=value adding to the results
for (String a : splitValues) {
// a = "aa=bbbb" etc
String[] keyValues = a.split("=");
// you can check if values exist. This assumes they do.
String key = keyValues[0];
String value = keyValues[1];
// if it is already in map, add to its value list
if (results.containsKey(key)) {
valueList = results.get(key);
valueList.add(value);
} else {
valueList = new ArrayList<>();
valueList.add(value);
results.put(key, valueList);
}
}
System.out.println("cc= values");
valueList = results.get("cc");
// assumes value is in results
for (String a : valueList)
System.out.println(a);
}
Your question is very vague but I am guessing the String is provided as is, like:
String toSearch = "{aa=bbbb, cc=blabla1, ee=ffff, cc=blabla2, gg=hhhh, cc=blabla3,.......}";
By list I am guessing you are referring to the abstract List object and not to an array. Here is a solution:
String toSearch = "{aa=bbbb, cc=blabla1, ee=ffff, cc=blabla2, gg=hhhh, cc=blabla3,.......}";
List<String> result = new ArrayList<String>();
int prevMatch = 0;
while (toSearch.indexOf("cc=", prevMatch+1) != -1) {
result.add(toSearch.substring( // Substring method.
toSearch.indexOf("cc=",prevMatch+1)+3,toSearch.indexOf(",") //Getting correct indexes.
));
prevMatch = toSearch.indexOf("cc=",prevMatch+1);
}
The prevMatch variable ensures that the indexOf("cc=") that will be returned will be the next one occurring in the String. For the above String the returning ArrayList will contain the words "blabla1","blabla2", "blabla3" and whatever else is encountered.
Is it possible to parse a delimited file and find column datatypes? e.g
Delimited file:
Email,FirstName,DOB,Age,CreateDate
test#test1.com,Test User1,20/01/2001,24,23/02/2015 14:06:45
test#test2.com,Test User2,14/02/2001,24,23/02/2015 14:06:45
test#test3.com,Test User3,15/01/2001,24,23/02/2015 14:06:45
test#test4.com,Test User4,23/05/2001,24,23/02/2015 14:06:45
Output:
Email datatype: email
FirstName datatype: Text
DOB datatype: date
Age datatype: int
CreateDate datatype: Timestamp
The purpose of this is to read a delimited file and construct a table creation query on the fly and insert data into that table.
I tried using apache validator, I believe we need to parse the complete file in order to determine each column data type.
EDIT: The code that I've tried:
CSVReader csvReader = new CSVReader(new FileReader(fileName),',');
String[] row = null;
int[] colLength=(int[]) null;
int colCount = 0;
String[] colDataType = null;
String[] colHeaders = null;
String[] header = csvReader.readNext();
if (header != null) {
colCount = header.length;
}
colLength = new int[colCount];
colDataType = new String[colCount];
colHeaders = new String[colCount];
for (int i=0;i<colCount;i++){
colHeaders[i]=header[i];
}
int templength=0;
String tempType = null;
IntegerValidator intValidator = new IntegerValidator();
DateValidator dateValidator = new DateValidator();
TimeValidator timeValidator = new TimeValidator();
while((row = csvReader.readNext()) != null) {
for(int i=0;i<colCount;i++) {
templength = row[i].length();
colLength[i] = templength > colLength[i] ? templength : colLength[i];
if(colHeaders[i].equalsIgnoreCase("email")){
logger.info("Col "+i+" is Email");
} else if(intValidator.isValid(row[i])){
tempType="Integer";
logger.info("Col "+i+" is Integer");
} else if(timeValidator.isValid(row[i])){
tempType="Time";
logger.info("Col "+i+" is Time");
} else if(dateValidator.isValid(row[i])){
tempType="Date";
logger.info("Col "+i+" is Date");
} else {
tempType="Text";
logger.info("Col "+i+" is Text");
}
logger.info(row[i].length()+"");
}
Not sure if this is the best way of doing this, any pointers in the right direction would be of help
If you wish to write this yourself rather than use a third party library then probably the easiest mechanism is to define a regular expression for each data type and then check if all fields satisfy it. Here's some sample code to get you started (using Java 8).
public enum DataType {
DATETIME("dd/dd/dddd dd:dd:dd"),
DATE("dd/dd/dddd",
EMAIL("\\w+#\\w+"),
TEXT(".*");
private final Predicate<String> tester;
DateType(String regexp) {
tester = Pattern.compile(regexp).asPredicate();
}
public static Optional<DataType> getTypeOfField(String[] fieldValues) {
return Arrays.stream(values())
.filter(dt -> Arrays.stream(fieldValues).allMatch(dt.tester)
.findFirst();
}
}
Note that this relies on the order of the enum values (e.g. testing for datetime before date).
Yes it is possible and you do have to parse the entire file first. Have a set of rules for each data type. Iterate over every row in the column. Start of with every column having every data type and cancel of data types if a row in that column violates a rule of that data type. After iterating the column check what data type is left for the column. Eg. Lets say we have two data types integer and text... rules for integer... well it must only contain numbers 0-9 and may begin with '-'. Text can be anything.
Our column:
345
-1ab
123
The integer data type would be removed by the second row so it would be text. If row two was just -1 then you would be left with integer and text so it would be integer because text would never be removed as our rule says text can be anything... you dont have to check for text basically if you left with no other data type the answer is text. Hope this answers your question
I have slight similar kind of logic needed for my project. Searched lot but did not get right solution. For me i need to pass string object to the method that should return datatype of the obj. finally i found post from #sprinter, it looks similar to my logic but i need to pass string instead of string array.
Modified the code for my need and posted below.
public enum DataType {
DATE("dd/dd/dddd"),
EMAIL("#gmail"),
NUMBER("[0-9]+"),
STRING("^[A-Za-z0-9? ,_-]+$");
private final String regEx;
public String getRegEx() {
return regEx;
}
DataType(String regEx) {
this.regEx = regEx;
}
public static Optional<DataType> getTypeOfField(String str) {
return Arrays.stream(DataType.values())
.filter(dt -> {
return Pattern.compile(dt.getRegEx()).matcher(str).matches();
})
.findFirst();
}
}
For example:
Optional<DataType> dataType = getTypeOfField("Bharathiraja");
System.out.println(dataType);
System.out.println(dataType .get());
Output:
Optional[STRING]
STRING
Please note, regular exp pattern is vary based on requirements, so modify the pattern as per your need don't take as it is.
Happy Coding !