Print all characters from ArrayList after each other - java

I have this ArrayList
ArrayList<Character> wrongLetters;
And this syso
System.out.println("Number of errors: " + wrongLetters.size() + " (" + String.join("", String.valueOf(wrongLetters)) + ")");
It now prints like this
Number of errors: 9 ([X, M, S, K, B, Q, L, I, U])
But how can I make it like this
Number of errors: 9 (XMSKBQLIU)


Java 8 or later:
final String result = wrongLetters.stream().map(String::valueOf).collect(Collectors.joining());
System.out.println("Number of errors: " + wrongLetters.size() + " (" + result + ")");


You can use wrongLetters.forEach(System.out::print); in Java 8


You can do it by this way using Java 8
System.out.println(wrongLetters.stream().map(x -> x.toString()).collect(Collectors.joining()));


Stupid answer (just remove non-alphanumerics):
System.out.println("Number of errors: " + wrongLetters.size() + " (" + String.join("", String.valueOf(wrongLetters).replaceAll("[^A-Za-z0-9]", ""))+ ")");
One more for Java 8+:
StringJoiner joiner = new StringJoiner("");
wrongLetters.stream().forEach(err -> joiner.add(String.valueOf(err)));
System.out.println("Number of errors: " + wrongLetters.size() + " (" + joiner + ")");
No Java 8 (using StringBuilder):
StringBuilder sb = new StringBuilder(" (");
for (Character character : wrongLetters) {
sb.append(character);
}
sb.append(")");
System.out.println("Number of errors: " + wrongLetters.size() + sb.toString());


String.valueOf(wrongLetters) calls toString() on array of characters thats why it look likt this. Join is called only for one String here [X, M, S, K, B, Q, L, I, U].
You have to change ArrayList to String. Check this -> Converting ArrayList of Characters to a String?


make a string from the arraylist of the characters
String str = "";
for (Character c : wrongLetters) {
str += c;
}
then :
System.out.println("Number of errors: " + wrongLetters.size() + " (" + String.join("", str) + ")");
or make a string builder :
StringBuilder stringBuilder= new StringBuilder(wrongLetters.size());
for (Character c : wrongLetters) {
stringBuilder.append(c);
}
then:
System.out.println("Number of errors: " + wrongLetters.size() + " (" + String.join("", stringBuilder.toString()) + ")");

Related

Read a Fixed Length position based file and insert into a oracle Table in Java

Currently I am working on a solution to read a 454 character/line based huge file (minimum 50000 rows) via Java.As per the requirement it is a positioned based file, we first need to read the file , then parse the position based values and need to insert into a table. (minimum 96 positions will be inserted into 96 columns of the table).
I took this concept after the parsing.
[ INSERT ALL INTO<TABLE NAME> [COL1,COL2,COL3] Values [VAL1,VAL2,VAL3]
INTO<TABLE NAME> [COL1,COL2,COL3] Values [VAL1,VAL2,VAL3]
SELECT * FROM DUAL;]
Here is my code:
try{
char[] line = new char[456];
while(br.read(line) > 0){
StringBuilder input = new StringBuilder(new String(line));
if(batchCounter>0){
int detailFileId = interfaceFileSequence();
sql.append(initSql+"(" +
detailFileId + "," + interfaceHeaderId + ", SYSDATE," +
interfaceRunId + "," + isSpace(input.substring(0, 2).trim()) + "," + "TO_DATE("+isSpace(input.substring(2, 12).trim())+",'YYYY-MM-DD')" +","+isSpace(input.substring(12, 22).trim()) + "," +
Double.parseDouble(input.substring(22, 35)+ "." + input.substring(35, 37)) + ", " +
Double.parseDouble(input.substring(22, 35)+ "." + input.substring(35, 37)) + ", " +
isSpace(input.substring(38, 44).trim()) + ","+isSpace(input.substring(38, 44).trim())+"," +isSpace(input.substring(38, 44).trim())+"," + isSpace(input.substring(44, 54).trim())+","+
isSpace(input.substring(54, 60).trim()) + "," + isSpace(input.substring(60, 68).trim()) + "," + isSpace(input.substring(68, 83).trim()) + "," +
isSpace(input.substring(83, 89).trim()) + "," + isSpace(input.substring(89, 94).trim()) + "," +
isSpace(input.substring(94, 102).trim()) + "," +
isSpace(input.substring(102, 103).trim()) + ","+"TO_DATE("+isSpace(input.substring(103,113).trim())+",'YYYY-MM-DD')"+"," +isSpace(input.substring(113, 125).trim()) + "," + isSpace(input.substring(125, 128).trim()) + "," +
isSpace(input.substring(131, 133).trim()) + "," + isSpace(input.substring(133, 135).trim()) + "," + isSpace(input.substring(135, 136).trim()) + "," +
isSpace(input.substring(136, 137).trim()) + "," + isSpace(input.substring(137, 142).trim()) + "," + isSpace(input.substring(142, 147).trim()) + "," +
isSpace(input.substring(147, 148).trim()) + "," + isSpace(input.substring(149, 159).trim()) + "," +
isSpace(input.substring(159, 160).trim()) + "," + isSpace(input.substring(160, 175).trim()) + "," + isSpace(input.substring(160, 175).trim()) + "," +
isSpace(input.substring(190, 220).trim()) +"," +"TO_DATE("+isSpace(input.substring(216, 220)+"-"+input.substring(220, 222)+"-"+input.substring(222, 224))+",'YYYY-MM-DD')"+","+
"TO_DATE("+isSpace(input.substring(216, 220)+"-"+input.substring(220, 222)+"-"+input.substring(222, 224))+",'YYYY-MM-DD')"+","+ isSpace(input.substring(226,227).trim()) + "," + isSpace(input.substring(231,236).trim()) + "," +
isSpace(input.substring(242, 245).trim()) + "," + isSpace(input.substring(245,275).trim()) + "," + isSpace(input.substring(275,280).trim()) + "," +
isSpace(input.substring(280, 290).trim()) + "," + isSpace(input.substring(290,293).trim()) + "," + isSpace(input.substring(293,303).trim()) + "," +
isSpace(input.substring(303, 314).trim()) + "," +
isSpace(input.substring(313,316).trim()) + //need check
"," + isSpace(input.substring(317,337).trim()) + "," +
isSpace(input.substring(337, 422).trim()) +
"," + isSpace(input.substring(422,433).trim()) + "," + isSpace(input.substring(433,443).trim())+","+isSpace(input.substring(22, 39).trim())+
")");
sql.append('\n');
}
/*if (batchCounter % 500 == 0) {
System.out.println("sql:::::::::::"+sql);
int executeUpdate = em.createNativeQuery(sql.toString()).executeUpdate();
System.out.println("executeUpdateexecu:::"+executeUpdate);
em.flush();
insertionCounter += executeUpdate;
System.out.println("insertionCounter::::"+insertionCounter);
sql.setLength(0);
System.out.println("SQL");
System.out.println("initSql"+initSql);
sql.append(initSql);
}*/
batchCounter++;
}
sql.append(" SELECT * FROM dual");
int executeUpdate = em.createNativeQuery(sql.toString()).executeUpdate();
em.flush();
insertionCounter += executeUpdate;
System.out.println("Check Rows in file::"+(batchCounter-1)+" Insertion counter::"+insertionCounter);
if((batchCounter-1)==insertionCounter){
detailFileObj = new DetailFileObject(FileName, "DETAIL", (batchCounter-1), "SUCCESS");
}
else {
detailFileObj = new DetailFileObject(FileName, "DETAIL", (batchCounter-1), "FAILED");
}
} catch (IOException e) {
e.printStackTrace();
}
But once I am running the code, if there are 40-50 lines, it is working fine.But it is more than that I am getting exception. Can anyone share me proper approach along with running code, so that I can use it.
Thanks

First, DO NOT use string concatenation to build a SQL statement with text values from outside. It leaves you susceptible to SQL Injection attacks, and may cause SQL syntax errors. Use a PreparedStatement with ? parameter markers instead.
Second, if you're inserting a lot of records, use JDBC batching.
Here is an example of how you would use it:
String sql = "INSERT INTO MyTable" +
" ( Col1, Col2, Col3, Col4, Col5, Col6, Col7 )" +
" VALUES (?,?,SYSDATE,?,?,?,?)";
try (PreparedStatement stmt = conn.prepareStatement(sql)) {
char[] line = new char[456];
int batchSize = 0;
while (br.read(line) > 0) {
String input = new String(line);
int detailFileId = interfaceFileSequence();
stmt.setInt (1, detailFileId);
stmt.setInt (2, interfaceHeaderId);
stmt.setInt (3, interfaceRunId);
stmt.setString(4, toString(input.substring(0, 2)));
stmt.setDate (5, toDate(input.substring(2, 12)));
stmt.setString(6, toString(input.substring(12, 22)));
// ...
stmt.addBatch();
if (++batchSize == 1000) {
stmt.executeBatch();
batchSize = 0;
}
}
if (batchSize != 0) {
stmt.executeBatch();
}
} catch (IOException e) {
e.printStackTrace();
}
The above code uses the following helper methods to keep code DRY:
private static String toString(String text) {
String trimmed = text.trim();
return (trimmed.isEmpty() ? null : trimmed);
}
private static java.sql.Date toDate(String text) {
String trimmed = text.trim();
return (trimmed.isEmpty() ? null : java.sql.Date.valueOf(LocalDate.parse(trimmed)));
}

Finding exact string using line.contains

Apologies if some of this information comes across as lacking knowledge, just started learning Java.
In this working the user searches for both road and town. The problem being that when searching for something like 'Cabramatta' the result 'Cabramatta West' will also appear in the results.
The format of the information being read is as follows:
William Street^3^3503^Collins Street^Cabramatta West
William Street^3^3503^Collins Street^Cabramatta
while(fileName.hasNext())
{
String line =fileName.nextLine();
{
if(line.contains(suburbInput) && line.contains(roadInput))
{
String tramDetails[] = line.split("\\^");
String crossStreet = tramDetails[0];
String stopNumber = tramDetails[1];
int stopNumberInt = Integer.parseInt(stopNumber);
String trackerID = tramDetails[2];
int trackerIDInt = Integer.parseInt(trackerID);
String roadName = tramDetails[3];
String suburbName = tramDetails[4];
System.out.print("'Suburb': " + suburbName + " 'Road': " + roadName + " 'Cross Street': " + crossStreet + " 'Stop': " + stopNumberInt + " 'Tracker ID': " + trackerIDInt + "\n");
How do I go about getting it to just find results for 'Cabramatta' when it's searched but also find results for 'Cabramatta West' when that's searched?

You're going to have to split up your inputs before your check so you can use .equals instead of .contains.
while(fileName.hasNext())
{
String line =fileName.nextLine();
String tramDetails[] = line.split("\\^");
String suburbName = tramDetails[4];
String roadName = tramDetails[3];
if(suburbName.equals(suburbInput) && roadName.equals(roadInput))
{
String crossStreet = tramDetails[0];
String stopNumber = tramDetails[1];
int stopNumberInt = Integer.parseInt(stopNumber);
String trackerID = tramDetails[2];
int trackerIDInt = Integer.parseInt(trackerID);
System.out.print("'Suburb': " + suburbName
+ " 'Road': " + roadName
+ " 'Cross Street': " + crossStreet
+ " 'Stop': " + stopNumberInt
+ " 'Tracker ID': " + trackerIDInt + "\n");
}

Split before and then just use equals method of the String. Here is a test code:
String line = "William Street^3^3503^Collins Street^Cabramatta West";
String suburbInput = "Cabramatta";
String roadInput = "Collins Street";
String tramDetails[] = line.split("\\^");
String crossStreet = tramDetails[0];
String stopNumber = tramDetails[1];
int stopNumberInt = Integer.parseInt(stopNumber);
String trackerID = tramDetails[2];
int trackerIDInt = Integer.parseInt(trackerID);
String roadName = tramDetails[3];
String suburbName = tramDetails[4];
if (suburbInput.equals(suburbName) && roadInput.equals(roadName))
System.out.print("'Suburb': " + suburbName + " 'Road': " + roadName + " 'Cross Street': " + crossStreet
+ " 'Stop': " + stopNumberInt + " 'Tracker ID': " + trackerIDInt + "\n");
suburbInput = "Cabramatta West";
if (suburbInput.equals(suburbName) && roadInput.equals(roadName))
System.out.print("'Suburb': " + suburbName + " 'Road': " + roadName + " 'Cross Street': " + crossStreet
+ " 'Stop': " + stopNumberInt + " 'Tracker ID': " + trackerIDInt + "\n");
And output:
'Suburb': Cabramatta West 'Road': Collins Street 'Cross Street': William Street 'Stop': 3 'Tracker ID': 3503
Hope this helps!

You could uses String#endsWith() instead of String#contains() for the suburb:
if (line.endsWith(suburbInput) && line.contains(roadInput))
Of course, this is only a band-aid. 'Cabramatta' would still match 'West Cabramatta' The problem is the if (...) statement, as implemented, is only able to find probable matches. You need to parse the line into the exact fields you want to match against, and then test those fields explicitly.
Alternately (sledge hammer approach), you could implement a regular expression matcher that will match everything exactly in one go.

how to find a letter in a string and how to return two strings in alphabetical order? java [duplicate]

This question already has answers here:
Comparing strings by their alphabetical order
(10 answers)
Closed 8 years ago.
How can I print which word comes first (alphabetically) when I prompts the user to write two words? and how to check if a certain character exist in that scanned words?
For ex: if the user wrote "Word" and "Apple" how can I print these two words in alphabetical order. Also, I wrote a program to check if char 'z' appears on either words or not, but I don't know what's wrong about it? Here is my program:
import java.util.*;
public class Pr7{
public static void main(String[] args){
//print two words and read them..
Scanner scan = new Scanner (System.in);
String Word1;
String Word2;
System.out.println();
System.out.print("* Please write one word: ");
Word1 = scan.nextLine();
System.out.print("* Please write one word: ");
Word2 = scan.nextLine();
//Prints which word has more characters in it..
if (Word1.length() > Word2.length())
System.out.println("- " + "(" + Word1 + ")" + " has more characters.");
else if (Word2.length() > Word1.length())
System.out.println("- " + "(" + Word2 + ")" + " has more characters.");
else
System.out.println("- " + "(" + Word1 + ")" + " has equal characters with " + "(" + Word2 + ")");
//Prints which word comes first (alphabetically)..
/*
char ch;
int compare = Word1.compareTO(Word2);
*/
//Prints whether the letter 'z' appears in either word..
if (Word1.indexOf('z') == true)
System.out.print("- Letter 'z' appears in the first word.");
else if (Word2.indexOf('z') == )
System.out.print("- Letter 'z' appears in the second word.");
else
System.out.print("- Letter 'z' doesn't appears in either word.");
System.out.println();
//Prompts the user for a sentence and reads it..
String Str1;
String Str2;
System.out.println();
System.out.print("* Please write a string: ");
Str1 = scan.nextLine();
System.out.print("* Please write a string: ");
Str2 = scan.nextLine();
//Prints how many characters are in the first sentence and the second sentence..
if (Str1.length() > Str2.length()){
System.out.println("- " + "(" + Str1 + ")" + " has more characters.");
System.out.print("- " + "(" + Str1 + ")" + " = " + Str2.length() + " Character(s)" + " && " + "(" + Word2 + ")" + " = " + Word2.length() + " Character(s)");
}
else if (Str2.length() > Str1.length()){
System.out.println("- " + "(" + Str2 + ")" + " has more characters.");
System.out.print("- " + "(" + Str2 + ")" + " = " + Str2.length() + " Character(s)" + " && " + "(" + Word1 + ")" + " = " + Word1.length() + " Character(s)");
}
else{
System.out.println("- " + "(" + Str1 + ")" + " has equal characters with " + "(" + Str2 + ")");
System.out.print("- " + "(" + Str1 + ")" + " = " + Str1.length() + " Character(s)" + " && " + "(" + Word2 + ")" + " = " + Word2.length() + " Character(s)");
}
System.out.println();
}//main
}//Pr7
I know the methods I need to call, but I don't know how to use it.

To sort a list of strings in alphabetical order, you can do the following:
List<String> lst = new ArrayList<>();
lst.add("asd");
lst.add("ffsd");
Collections.sort(lst, new Comparator<String>() {
#Override
public int compare(String foo, String bar) {
return String.CASE_INSENSITIVE_ORDER.compare(foo, bar);
}
});
// will print the first of the sorted strings
System.out.println(lst.get(0));

difficulty in List iteration and comparison in java

I have 2 list List<String> existingGuesses which contains characters and List<String> word = new ArrayList<String>(words) which contains words which is a copy of list words as shown in my code below. What I am trying to do is to iterate through all the words of List word and iterate through the characters of list existingGuesses. Then I want to compare the first character of List existingGuesses with all the words of List word one by one and if a match is found then I want to remove the word from the list. Then the same for next character and continue until there are no more words left to compare. Until now, I could only declare a iterator, it's not necessary to use iterator but I don't know any other ways. My code is as follows:
public List<String> getWordOptions(List<String> existingGuesses, String newGuess)
{
List<String> word = new ArrayList<String>(words);
String c = existingGuesses.get(0); //trying to get the first character
ListIterator<String> iterator = word.listIterator(); //iterator to iterate thorugh word list
while(iterator.hasNext())
{
if(word.contains(c)) //trying to compare
{
word.remove(c);
}
}
return null;
}
Can anybody help me out? The original List words is:
private List<String> words = new ArrayList<String>() {
{
// DO NOT CHANGE THESE WORDS!
String w =
"sentence\n"
+ "together\n"
+ "children\n"
+ "mountain\n"
+ "chipmunk\n"
+ "crashing\n"
+ "drinking\n"
+ "insisted\n"
+ "insulted\n"
+ "invented\n"
+ "squinted\n"
+ "standing\n"
+ "swishing\n"
+ "talented\n"
+ "whiplash\n"
+ "complain\n"
+ "granddad\n"
+ "sprinkle\n"
+ "surprise\n"
+ "umbrella\n"
+ "anything\n"
+ "anywhere\n"
+ "baseball\n"
+ "birthday\n"
+ "bluebird\n"
+ "cheerful\n"
+ "colorful\n"
+ "daylight\n"
+ "doghouse\n"
+ "driveway\n"
+ "everyone\n"
+ "faithful\n"
+ "flagpole\n"
+ "graceful\n"
+ "grateful\n"
+ "homemade\n"
+ "homework\n"
+ "housefly\n"
+ "kickball\n"
+ "kingfish\n"
+ "knockout\n"
+ "knothole\n"
+ "lipstick\n"
+ "lunchbox\n"
+ "newscast\n"
+ "nickname\n"
+ "peaceful\n"
+ "sailboat\n"
+ "saturday\n"
+ "shameful\n"
+ "sidewalk\n"
+ "snowball\n"
+ "splendid\n"
+ "suitcase\n"
+ "sunblock\n"
+ "sunshine\n"
+ "swimming\n"
+ "thankful\n"
+ "thinnest\n"
+ "thursday\n"
+ "whatever\n"
+ "whenever\n"
+ "windmill\n"
+ "american\n"
+ "possible\n"
+ "suddenly\n"
+ "airplane\n"
+ "alphabet\n"
+ "bathroom\n"
+ "favorite\n"
+ "medicine\n"
+ "december\n"
+ "dinosaur\n"
+ "elephant\n"
+ "February\n"
+ "football\n"
+ "forehead\n"
+ "headache\n"
+ "hospital\n"
+ "lollipop\n"
+ "november\n"
+ "outdoors\n"
+ "question\n"
+ "railroad\n"
+ "remember\n"
+ "sandwich\n"
+ "scissors\n"
+ "shoulder\n"
+ "softball\n"
+ "tomorrow\n"
+ "upstairs\n"
+ "vacation\n"
+ "restroom";
addAll(Arrays.asList(w.split("\\s+")));
}
};

Some points to consider:
String c = existingGuesses.get(0); //trying to get the first character
gets the first word in a list of words, not the first character.
To get the first character in a String you can do this:
char c = newguess.getCharAt(0);
Then you can search through the list for words starting with that character. Next you do not want to remove words that contain the character, you want to remove words that start with the character.
Also, you want to get each item from the iterator one at a time:
while(iterator.hasNext()){
String w = iterator.next(); //get the next word in the iterator here
//process w here
}
You seem to want to find if the characters correspond. That is, if the guess is "foo" then you want to remove all words that start with f, and all words that has the second character o and all words that have the third character o. That seem a little strange so you may want to check your logic.
Your method seem to be referring to some global variables and that could be causing you some confusion.

Putting user created variables inside of an array

I want to put what the use puts in for x to be stored in the yourNumbers array, how would I do that? Edit: How would I clean up the println parts at the bottom, using loops.
import java.util.Scanner;
public class array {
public class SS_Un8As1 {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int[] yourNumbers = new int[10];
for (int counter=0; counter < yourNumbers.length; counter++){
System.out.print("Enter your number: ");
yourNumbers[counter] = scan.nextInt();
}
System.out.println("Original numbers: " + yourNumbers[0] + "," + yourNumbers[1] + "," + yourNumbers[2] + "," + yourNumbers[3] + "," + yourNumbers[4] + "," + yourNumbers[5] + "," + yourNumbers[6] + "," + yourNumbers[7] + "," + yourNumbers[8] + "," + yourNumbers[9]);
System.out.println("Original numbers multiplied by five: " + yourNumbers[0]*5 + "," + yourNumbers[1]*5 + "," + yourNumbers[2]*5 + "," + yourNumbers[3]*5 + "," + yourNumbers[4]*5 + "," + yourNumbers[5]*5 + "," + yourNumbers[6]*5 + "," + yourNumbers[7]*5 + "," + yourNumbers[8]*5 + "," + yourNumbers[9]*5);
System.out.println("Original numbers minus the next number: " + (yourNumbers[0]-yourNumbers[1]) + "," + (yourNumbers[1]-yourNumbers[2]) + "," + (yourNumbers[2]-yourNumbers[3]) + "," + (yourNumbers[3]-yourNumbers[4]) + "," + (yourNumbers[4]-yourNumbers[5]) + "," + (yourNumbers[5]-yourNumbers[6]) + "," + (yourNumbers[6]-yourNumbers[7]) + "," + (yourNumbers[7]-yourNumbers[8]) + "," + (yourNumbers[8]-yourNumbers[9]) + "," + (yourNumbers[9]-yourNumbers[0]));
}
}

Like this:
yourNumbers[counter] = x;
The above code is stating: store the value of x in the array yourNumbers in the index (position) counter. Because counter is the iteration variable of a for loop, each time the loop advances the counter the next value of x will be stored in the next available position in the array.
You must make sure that the length of the array is the same as the value of counter. In your code, do this:
int[] yourNumbers = new int[10];
Why? because counter goes from 0 to 9, so the array must be of length 10.

replace this
int x = scan.nextInt();
with
yourNumbers[counter] = scan.nextInt();
also, the condition should be counter<9, or better counter<yourNumbers.length

Simply pass the input into the next element of the array, while inside the for loop:
yourNumbers[counter] = x;
I should also point out, however, that you should validate that your input is actually an integer before assigning x the value. If the value isn't an integer, your program will crash.

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