Finding exact string using line.contains - java

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.

Related

swap both user input and database to lowercase before comparing

I am trying to find a way to "collect all the classes from a selected date to another, managed by a specific teacher", and so far, its going okay. I have used to uppercase to match with a capital letter as the first one in the name... but since some teachers (McGonnagal) for example is having capital letters in her lastname, is there a way to, say , get the input to lowercase, and also transfer the data in the database (McGonnagal) all to lowercase?
So it would always be a match even if the user inserted McGoNNaGal in the program.... anyone got any ideas?`
try {
String lararesNamn = txtLoCLarare.getText();
String LFN = lararesNamn.toUpperCase().charAt(0)+lararesNamn.substring(1);
String datumFrom = txtLoCfom.getText();
String datumTom = txtLoCtom.getText();
String lararesEN = txtLarareEN.getText();
String LEN = lararesEN.toUpperCase().charAt(0)+lararesEN.substring(1);
ArrayList<HashMap<String,String>> listOfClasses = databas.fetchRows("SELECT KURSNAMN FROM KURS JOIN LARARE ON KURSLARARE = LARAR_ID WHERE KURSSTART >= " + "'" + datumFrom + "'" + " AND KURSSLUT <= " + "'" + datumTom + "'" + " AND(LARARE.FORNAMN = " + "'" + LFN + "'" + " AND LARARE.EFTERNAMN = " + "'" + LEN + "'" + ")");
System.out.println(listOfClasses);
JOptionPane.showMessageDialog(null, listOfClasses);
} catch(InfException ex){
System.out.println(ex.getMessage());
}
Best regards!

You can convert the fetched name from SQL DB to lower or upper case. For LOWER case modify your query to.
SELECT KURSNAMN FROM KURS JOIN LARARE ON KURSLARARE = LARAR_ID WHERE KURSSTART >= " + "'" + datumFrom + "'" + " AND KURSSLUT <= " + "'" + datumTom + "'" + " AND(LOWER(LARARE.FORNAMN) = " + "'" + LFN + "'" + " AND LOWER(LARARE.EFTERNAMN) = " + "'" + LEN + "'" + ")"
You can use UPPER function for upper case

Exception in main thread No such element exception

I'm pretty new to Java and I'm having some trouble figuring out where I'm going wrong with my program. I have it so it's doing a mad libs sort of thing where it reads a document with questions(or categories), then prompts for an answer on loop till it has all the answers. It commits these answers to a text file called "answers" then reads the file and prints a message, along with another file containing the full madlib.
I don't actually get an error upon compiling but after I've input all the answers I get
Exception in thread "main" java.util.NoSuchElementException: no line found
-at java.util.Scanner.nextLine(Scanner.java:1540)
-at reader.main(reader.java:68)
Here's the complete code for reference
import java.util.Scanner; // importing scanner object for usage
import java.io.*;
import java.io.PrintWriter;
public class reader{
public static void main(String[] args) throws IOException
{
Scanner keyboard = new Scanner(System.in);
System.out.println("enter the name of a file");
String filename = keyboard.nextLine();
File file = new File(filename);
Scanner inputFile = new Scanner(file);
int limit = inputFile.nextInt();
int n;
inputFile.nextLine();
PrintWriter answers = new PrintWriter("answers.txt");
for(n = 0; n < limit; n++)
{
String line = inputFile.nextLine();
System.out.println(line);
String answer = keyboard.nextLine();
answers.println(answer);
}
inputFile.close();
answers.close();
File useanswers = new File("answers.txt");
Scanner inputFile2 = new Scanner(useanswers);
String outputline = inputFile2.nextLine();
String outputline2 = inputFile2.nextLine();
String outputline3 = inputFile2.nextLine();
String outputline4 = inputFile2.nextLine();
String outputline5 = inputFile2.nextLine();
String outputline6 = inputFile2.nextLine();
String outputline7 = inputFile2.nextLine();
String outputline8 = inputFile2.nextLine();
String outputline9 = inputFile2.nextLine();
String outputline10 = inputFile2.nextLine();
String outputline11 = inputFile2.nextLine();
String outputline12 = inputFile2.nextLine();
String outputline13 = inputFile2.nextLine();
String outputline14 = inputFile2.nextLine();
String outputline15 = inputFile2.nextLine();
String outputline16 = inputFile2.nextLine();
String outputline17 = inputFile2.nextLine();
String outputline18 = inputFile2.nextLine();
String outputline19 = inputFile2.nextLine();
PrintWriter result = new PrintWriter("Madlibs_result.txt");
System.out.println("Batman is " + outputline + ". Teenager " + outputline2 +
"was traumatized by " + outputline3 + "his parent's murder and vowed to " + outputline4 +
" their deaths by bringing the " + outputline5 + " to justice. " + outputline6 + " used his " +
outputline7 + "fortune to study criminology, to train his body to " + outputline8 + " perfection, " +
"and to acquire hight tech vehicles and " + outputline9 + " to fight crime in his homw town of " + outputline10 + ". One night " +
outputline11 + "was " + outputline + " by a bat outside his window and decided to dress himself as a \"bat man\" to strike " +
outputline12 + " in the \"" + outputline13 + " and " + outputline14 + "\" hearts of " + outputline15 + ". From that moment forward, " +
outputline16 + " became \"Batman\" in his altered " + outputline17);
result.println("Batman is " + outputline + ". Teenager " + outputline2 +
"was traumatized by " + outputline3 + "his parent's murder and vowed to " + outputline4 +
" their deaths by bringing the " + outputline5 + " to justice. " + outputline6 + " used his " +
outputline7 + "fortune to study criminology, to train his body to " + outputline8 + " perfection, " +
"and to acquire hight tech vehicles and " + outputline9 + " to fight crime in his homw town of " + outputline10 + ". One night " +
outputline11 + "was " + outputline + " by a bat outside his window and decided to dress himself as a \"bat man\" to strike " +
outputline12 + " in the \"" + outputline13 + " and " + outputline14 + "\" hearts of " + outputline15 + ". From that moment forward, " +
outputline16 + " became \"Batman\" in his altered " + outputline17);
result.close();
}
}

Resolved, I had too many String outputline... lines, and I assume when it tried to go to the nonexistent 19th and 20th lines of the text file created, it gave me an error.

Returning New Lines

public String toString()
{
String name = "Customer name: " + this.name;
String address = "Customer address: " + street + " " + city + " " + state + " " + zip;
String bala = "Balance: " + bal;
return name + "\n" + address + "\n" + bala;
}
I want these variables to be returned in three separate lines, but the actual string "\n" is just being added where I want the new line to be. Any help?

Untested, but may work :
return name + System.lineSeparator() + address + System.lineSeparator() + bala;

Do I need to cast to String when adding an Integer or a Double to a String?

If I have
'String t = "";
int i = 1;
double d = 3.3;'
May I do
t = t + " " + i + " " + d
or I need to cast?

Yes you can..No need to cast..
Simply you can do like you said, t = t + " " + i + " " + d;

No. You don't
t = t + " " + i + " " + d --> "New" String = string + " " + String.valueOf(integer) + " " + String.valueOf(double)

Try it :
double total = 10;
String total = String.valueOf(total);

Writing the resultset to csv file

I have a method getstaffinfo, which has 3 parameter (var_1, connection, filewriter fw), the var_1 value is read from a text file. So the method will be called as many times based on all the var_1 value passed from text file . approx ( 15000)
public static String getstaffid(String var_1, Connection connection,
FileWriter fw) throws SQLException, Exception
// Create a statement
{
String record = null;
ResultSet rs = null;
Statement stmt = connection.createStatement();
boolean empty = true;
try {
rs = stmt
.executeQuery("select username, firstname, lastname, middlename, street, city, stateorprovince, ziporpostalcode, countryorregion, fax, phone, extension, mobile, pager, title, primaryemail, secondaryemail, officename, description, comments, suspendeddate, userdata, employeeid, createuser, updateuser, createdate, updatedate, employeetype, servicedeskticketnumber, startdate, enddate, manager, businessapprover, technicalapprover, delegate, location, jobcodes, customproperty1, customproperty2, customproperty3, customproperty4, customproperty5, customproperty6, customproperty7, customproperty8, customproperty9, customproperty10 from globalusers where username = '"+ var_1 + "'");
ResultSetMetaData metaData = rs.getMetaData();
int columns = metaData.getColumnCount();
ArrayList<String> records = new ArrayList<String>();
while (rs.next()) {
empty = false;
//record = rs.getString(1) + " " + rs.getString(2) + " " + rs.getString(3) + " " + rs.getString(4) + " " + rs.getString(5) + " " + rs.getString(6) + " " + rs.getString(7) + " " + rs.getString(8) + " " + rs.getString(9) + " " + rs.getString(10) + " " + rs.getString(11) + " " + rs.getString(12) + " " + rs.getString(13) + " " + rs.getString(14) + " " + rs.getString(15) + " " + rs.getString(16) + " " + rs.getString(17) + " " + rs.getString(18) + " " + rs.getString(19) + " " + rs.getString(20) + " " + rs.getString(21) + " " + rs.getString(22) + " " + rs.getString(23) + " " + rs.getString(24) + " " + rs.getString(25) + " " + rs.getString(26) + " " + rs.getString(27) + " " + rs.getString(28) + " " + rs.getString(29) + " " + rs.getString(30) + " " + rs.getString(31) + " " + rs.getString(32) + " " + rs.getString(33) + " " + rs.getString(34) + " " + rs.getString(35) + " " + rs.getString(36) + " " + rs.getString(37) + " " + rs.getString(38) + " " + rs.getString(39) + " " + rs.getString(40) + " " + rs.getString(41) + " " + rs.getString(42) + " " + rs.getString(43) + " " + rs.getString(44) + " " + rs.getString(45) + " " + rs.getString(46) + " " + rs.getString(47);
for (int i = 1; i <= columns; i++) {
String value = rs.getString(i);
records.add(value);
}
for (int j = 0; j < records.size(); j++) {
record = records.get(j) + ",";
}
fw.append(record);
}
/*fw.append(rs.getString(1));
fw.append(',');
fw.append(rs.getString(2));
fw.append(',');
fw.append(rs.getString(3));
fw.append('\n'); */
} finally {
fw.flush();
rs.close();
stmt.close();
}
return record;
}
As you can see, am executing a query for 47 values, which could be null or it can have some value.
Then i iterate through this 47 column, take the value and store it to an array list. Then i iterate the array list and write all the values to the string record with comma seperated value. Which is written to a csv file.
But it does not work fine. Any inputs would be appreciated...

You may have already solved the problem. Just let you know that I tried to use your code just now and found the issue was here:
record = records.get(j) + ",";
You should use something like this:
record = record + records.get(j) + ",";
Also change String to StringBuffer will improve the performance.

You didn't write the exact problem you face, but there is one for sure: you never write a line break into the file, so all data gets in one line.
while (rs.next()) {
... // your code, with the for loops
fw.append(record); //writing out the line, from your code
fw.append("\r\n"); //line break -- add this line
} //this is the end of the "while(rs.next())" loop
...

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