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Converting String time format of HH:MM:SS (AM/PM) into Seconds

So I have this assignment that is asking us to take in a String format of time in the order of HH:MM:SSAM or HH:SS:MMPM. The constraint is that it cannot run if it is in wrong format, let it be missing any form of the AM or PM, missing a number, or if it is in 24 Hour Format.
I have the whole idea down, however for my statements, it is giving me the error of:
bad operand types for binary operator '>'
incomparable types: String and int
Did I convert them improperly or am I doing something else wrong?
public static void main(String args[]) {
//Test Methods
String fullTime1 = "03:21:36AM";
secondsAfterMidnight(fullTime1);
}
public static int secondsAfterMidnight(String time) {
String[] units = time.split(":");
int hours = Integer.parseInt(units[0]);
int minutes = Integer.parseInt(units[1]);
int seconds = Integer.parseInt(units[2]);
int totalSeconds = 0;
if (units[0] > 12 || units[1] > 59 || units[2] > 59) { //1st Error applies to these three, units[0] > 12 units[1] > 59 units[2] > 59
return -1;
} else if (time.equalsIgnoreCase("AM") || time.equalsIgnoreCase("PM")) {
totalSeconds = (hours * 3600) + (minutes * 60) + (seconds);
} else if (time.equalsIgnoreCase("AM") && units[0] == 12) { //2nd Error applies to this units[0] == 12
totalSeconds = (minutes * 60) + (seconds);
} else {
return -1;
}
return totalSeconds;
}

You have already parsed the String values and saved them in the variables hours , minutes, seconds. Then you can use those for the check in the if.
Also the presence of AM?PM in the Integer.parseInt() will cause NumberFormatException to avoid it remove the String part from the number by using regex.
Also for checking the presence of AM/PM you can use String.contains.
Please check the reformatted code below:
public static int secondsAfterMidnight(String time) {
String[] units = time.split(":");
int hours = Integer.parseInt(units[0]);
int minutes = Integer.parseInt(units[1]);
int seconds = Integer.parseInt(units[2].replaceAll("[^0-9]", ""));
int totalSeconds = 0;
if (hours > 12 || minutes > 59 || seconds > 59) {
return -1;
} else if (time.contains("AM") || time.contains("PM")) {
totalSeconds = (hours * 3600) + (minutes * 60) + (seconds);
} else if (time.contains("AM") && hours == 12) {
totalSeconds = (minutes * 60) + (seconds);
} else {
return -1;
}
return totalSeconds;
}

Please note that even though you have converted the String to int, you are still comparing String with int. There would also be a RuntimeException when you do this:
int seconds = Integer.parseInt(units[2]);
As units[2] will contain 36AM. So you should be using substring() to remove the "AM/PM" part.

units is of type String and you are trying to compare it with an int hence the compile time error.
You need to convert the String to an int and then compare it, as shown below :
Integer.parseInt(units[0]) > 12
so on and so forth.
Also rather than re-inventing the wheel, you can make use of the already existing java-8's LocalTime to find the number of seconds for a particular time:
public static int secondsAfterMidnight(String time) {
LocalTime localTime = LocalTime.parse(time, DateTimeFormatter.ofPattern("hh:mm:ss a"));
return localTime.toSecondOfDay();
}

I haven't verified your logic to calculate the seconds, but this code has corrections:
public static int secondsAfterMidnight(String time) {
String[] units = time.split(":");
int hours = Integer.parseInt(units[0]);
int minutes = Integer.parseInt(units[1]);
int seconds = 0;
String amPm = "";
if ( units[2].contains("AM") || units[2].contains("PM") ||
units[2].contains("am") || units[2].contains("pm") ) {
seconds = Integer.parseInt(units[2].substring(0, 2));
amPm = units[2].substring(2);
}
else {
seconds = Integer.parseInt(units[2]);
}
int totalSeconds = 0;
if (hours > 12 || minutes > 59 || seconds > 59) {
return -1;
} else if (amPm.equalsIgnoreCase("AM") || amPm.equalsIgnoreCase("PM")) {
totalSeconds = (hours * 3600) + (minutes * 60) + (seconds);
} else if (amPm.equalsIgnoreCase("AM") && hours == 12) {
totalSeconds = (minutes * 60) + (seconds);
} else {
return -1;
}
return totalSeconds;
}

java.time
static DateTimeFormatter timeFormatter
= DateTimeFormatter.ofPattern("HH:mm:ssa", Locale.ENGLISH);
public static int secondsAfterMidnight(String time) {
try {
return LocalTime.parse(time, timeFormatter).get(ChronoField.SECOND_OF_DAY);
} catch (DateTimeParseException dtpe) {
return -1;
}
}
Let’s try it out using the test code from your question:
String fullTime1 = "03:21:36AM";
System.out.println(secondsAfterMidnight(fullTime1));
12096
This is the recommended way for production code.
Only if you are doing an exercise training string manipulation, you should use one of the other answers.
Link: Oracle tutorial: Date Time explaining how to use java.time.

Attempting to add an increment method to a time class

I am attempting to add an increment method for a time class I have. I have modified the original code to only have one private integer "totalseconds" that reads the amount of seconds since midnight. That part of the code works fine but now I am trying to create a method that increments the setSecond, setMinute, and setHour. The problem (I believe) I am having is that these set methods all receive their values from totalseconds not int hour, int minute, int second as before. When I run the test for it the way I have it now I get errors at lines 36, 75 (when attempted to increment seconds via Tick method) and 101 (again only when incrementing seconds via Tick method). I have attached both the Time2 class and Time2Test app for reference.
public class Time2 {
private int totalseconds;
//no argument constructor
public Time2()
{
this(0,0,0); //invoke constructor with three arguments default to 0
}
//constructor with hour supplied minute and second default to 0
public Time2(int hour)
{
this(hour, 0, 0); //invoke constructor with 3 args
}
//constructor with hour and minute supplied seconds default to 0
public Time2(int hour, int minute)
{
this(hour, minute, 0); //invoke constructor with 3 args
}
//Time2 constructor with hour minute and second supplied also tests
public Time2(int hour, int minute, int second)
{
this.totalseconds = (hour * 3600);
this.totalseconds += (minute * 60);
this.totalseconds += (second);
}
public Time2(Time2 time)
{
//invoke constructor with 2 args
this(time.getHour(), time.getMinute(), time.getSecond());
}
// SET and GET methods start here, also Universal time conversion and check
public void setTime(int hour, int minute, int second)
{
if (hour < 0 || hour >= 24)
throw new IllegalArgumentException("Hour must be 0-23");
if (minute < 0 || minute >= 59)
throw new IllegalArgumentException("Minute must be 0-59");
if (second < 0 || second >= 59)
throw new IllegalArgumentException("Hour must be 0-59");
this.totalseconds = (hour * 3600);
this.totalseconds += (minute * 60);
this.totalseconds += second;
}
//validate and set hour
public void setHour(int hour)
{
if (hour < 0 || hour >= 23)
throw new IllegalArgumentException("Hour must be 0-23");
this.totalseconds = (hour * 3600);
}
//validate and set minute
public void setMinute(int minute)
{
if (minute < 0 || minute >= 59)
throw new IllegalArgumentException("Minute must be 0-59");
this.totalseconds += (minute * 60);
}
//validate and set second
public void setSecond(int second)
{
if (second < 0 || second >= 59)
throw new IllegalArgumentException("Second must be 0-59");
this.totalseconds += second;
}
//Get Methods start here
//Get hour
public int getHour()
{
return totalseconds / 3600;
}
//get minute
public int getMinute()
{
return (totalseconds - (3600 * getHour())) / 60;
}
//get second
public int getSecond()
{
return totalseconds - (3600 * getHour())- (60 * getMinute());
}
//Assignment 1-2 tick methods start here.
public void Tick()
{
setSecond(totalseconds ++);
if (totalseconds >= 59) incrementMinute();
}
public void incrementMinute()
{
setMinute( totalseconds ++);
if ( totalseconds >= 59) incrementHour();
}
public void incrementHour()
{
setHour ( this.totalseconds ++);
}
//convert our string to universal format (HH:MM:SS)
public String ToUniversalString()
{
return String.format(
"%02d:%02d:%02d", getHour(), getMinute(), getSecond());
}
//conver to standard format (H:MM:SS AM or PM)
public String toString()
{
return String.format("%d:%02d:%02d %s",((getHour() == 0 || getHour() ==
12) ? 12 : getHour() % 12), getMinute(), getSecond(), (getHour()
< 12 ? "AM" : "PM"));
}
}//end class Time2
public class Time2Test
{
public static void main(String[] args)
{
Time2 t1 = new Time2(); //00:00:00
Time2 t2 = new Time2(2); //02:00:00
Time2 t3 = new Time2(21, 34); //21:34:00
Time2 t4 = new Time2(12, 25, 42); //12:25:42
Time2 t5 = new Time2(t4); //12:25:42
System.out.println("Constructed with:");
displayTime("t1: all default arguments", t1);
displayTime("t2: hour specified; defaults for minute and second", t2);
displayTime("t3: hour and minute supplied second defaulted", t3);
displayTime("t4: hour minute and second supplied", t4);
displayTime("t5: Time2 object t4 specified", t5);
//attempt to initialize t6 with invalid args
try
{
Time2 t6 = new Time2(27,74,99); //all invalid values
}
catch (IllegalArgumentException e)
{
System.out.printf("%nException while initializing t6: %s%n",
e.getMessage());
}
System.out.println("Time before increment minute method");
System.out.printf("%s\n", t4.toString());
t4.Tick();
t4.incrementMinute();
t4.incrementHour();
System.out.println("Time after increment minute method");
System.out.printf("%s\n", t4.toString());
}
//display Time2 object in 24 hour and 12 hour formats
private static void displayTime(String header, Time2 t)
{
System.out.printf("%s%n %s%n %s%n", header, t.ToUniversalString(),
t.toString());
}
}

Total seconds since midnight, Java

I am really new to programming. I am doing an assignment for my intro to Java. In my assignment, we need to find the total number of seconds since midnight and changed this number to hours, minutes and seconds to show the current time. I have small problem. when I test my code, the totalseconds show 0! any help would be appreciated. Sorry the code is a chaos
package clock;
import java.text.DecimalFormat;
import java.util.Calendar; // to get current time
public class Clock {
public static int totalseconds;
public static int seconds;
public static int minutes;
public static int hours;
public static int test;
public Clock(int hours, int minutes, int seconds ) {
setHours(hours);
setMinutes(minutes);
setSeconds(seconds);
}
// use current time
public Clock() {
Calendar c = Calendar.getInstance();
long now = c.getTimeInMillis();
c.set(Calendar.HOUR_OF_DAY, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
long passed = now - c.getTimeInMillis();
long secondsPassed = passed / 1000;
totalseconds = (int) secondsPassed;
}
public void tick() {
addSecond();
}
private void addSecond() {
seconds = totalseconds%60;
}
private void addMinute() {
minutes = totalseconds/60 % 60;
}
private void addHour() {
hours = totalseconds / 3600;
}
public String toString() {
DecimalFormat f = new DecimalFormat("00");
return f.format(hours) + ":" + f.format(minutes) + ":" + f.format(seconds);
}
public int getHours() {
return hours;
}
public int getMinutes() {
return minutes;
}
public int getSeconds() {
return seconds;
}
// the total number of minutes sinces midnight
public int getTotalMinutes() {
return totalseconds / 60 % 60;
}
// the total number of seconds since midnight
public int getTotalSeconds() {
return totalseconds;
}
public void setHours(int hours) {
if (hours > 23 || hours < 0) {
this.hours = 0;
}
else
this.hours = hours;
}
public void setMinutes(int minutes) {
if (minutes > 59 || minutes < 0)
this.minutes = 0;
else
this.minutes = minutes;
}
public void setSeconds(int seconds) {
if (seconds > 59 || seconds < 0)
this.seconds = 0;
else
this.seconds = seconds;
}
// reset hours, minutes and seconds to zero
public void reset() {
hours = minutes = seconds = 0;
}
public static void main(String [] args){
System.out.println("this is total seconds " + test + totalseconds );
}
}

Change main to this.
public static void main(String [] args){
Clock clock = new Clock();
System.out.println("this is total seconds " + test + totalseconds );
}
New you make an instance of Clock and the constructor is called, where all your magic happens.

I agree with what #shmosel suggested. There seems to be confusion in how to use instance variable. Further, I think you should take advantages of Java 8 methods for your time part.
class Clock {
private int totalseconds;
private int seconds;
private int minutes;
private int hours;
int test;
public Clock(int hours, int minutes, int seconds) {
setHours(hours);
setMinutes(minutes);
setSeconds(seconds);
}
// use current time
public Clock() {
LocalTime now = LocalTime.now(ZoneId.systemDefault());
totalseconds = now.toSecondOfDay();
}
public void tick() {
addSecond();
}
private void addSecond() {
seconds = totalseconds % 60;
}
private void addMinute() {
minutes = totalseconds / 60 % 60;
}
private void addHour() {
hours = totalseconds / 3600;
}
public String toString() {
DecimalFormat f = new DecimalFormat("00");
return f.format(hours) + ":" + f.format(minutes) + ":" + f.format(seconds);
}
public int getHours() {
return hours;
}
public int getMinutes() {
return minutes;
}
public int getSeconds() {
return seconds;
}
// the total number of minutes since midnight
public int getTotalMinutes() {
return totalseconds / 60 % 60;
}
// the total number of seconds since midnight
public int getTotalSeconds() {
return totalseconds;
}
public void setHours(int hours) {
if (hours > 23 || hours < 0) {
this.hours = 0;
} else
this.hours = hours;
}
public void setMinutes(int minutes) {
if (minutes > 59 || minutes < 0)
this.minutes = 0;
else
this.minutes = minutes;
}
public void setSeconds(int seconds) {
if (seconds > 59 || seconds < 0)
this.seconds = 0;
else
this.seconds = seconds;
}
// reset hours, minutes and seconds to zero
public void reset() {
hours = minutes = seconds = 0;
}
}
public class SecondsSinceMidnight {
public static void main(String[] args) {
Clock myClock = new Clock();
System.out.println("Total seconds that elapsed since midnight:" + myClock.getTotalSeconds());
System.out.println("Converted to Minutes: " + myClock.getTotalMinutes());
}
}

Java representing time class

I want to represent time with my time class. I can't use get and set methods.Only I can use listed methods on the code.But it doesn't work.
It returns 0:0:0.
public int addHours(int hours)
{
if(hours>=0&&hours<=23)
{
return hours;
}
return 0;
}
public int addMinutes(int minutes)
{
if(minutes>=0&&minutes<=59)
{
return minutes;
}
return 0;
}
public int addSeconds(int seconds)
{
if(seconds>=0&&seconds<=59)
{
return seconds;
}
return 0;
}
public String showTime()
{
return hours+":"+minutes+":"+seconds;
}
}

your code does nothing.
you need to do something like this:
public void addHours( int hours ){
this.hours += hours; // add hours
this.hours %= 24; // roll over at 24 hours
}
public void addMinutes( int minutes ){
this.minutes += minutes; // add minutes
addHours(this.minutes/60); // carry over to hours
this.minutes %= 60; // roll over at 60 minutes
}
public void addSeconds( int seconds ){
this.seconds += seconds; // add seconds
addMinutes(seconds/60); // carry over to minutes
this.seconds %= 60; // roll over at 60 seconds
}
(it probably won't matter, but this is not thread safe at all)
but this is generally a bad idea. Java 8 has a beautiful time api, pre Java-8 there is the JodaTime library (which is actually the basis of the Java 8 time api). It seems what you want to do could benefit from LocalTime:
LocalTime t = LocalTime.of(13,50,27).addHours(1).addMinutes(1).addSeconds(1);
System.out.println(t.toString());
// prints 14:51:28

Use java.util.Calendar and java.text.SimpleDateFormat:
Calendar cal = Calendar.getInstance();
cal.set(Calendar.HOUR, 0);
cal.add(Calendar.HOUR, 5);
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
System.out.println(sdf.format(cal.getTime()));

How to sum minutes in array if their format is string?

I have an string array that includes some minutes like "00:05", "00:30", "00:25" etc. I want to sum the values as time format? Can anyone help me how do I do this?

Total time in minutes:
int sum = 0;
final String[] mins = new String[] { "00:05", "00:30", "00:25" };
for (String str : mins) {
String[] parts = str.split(":");
sum += Integer.parseInt(parts[1]);
}
System.out.println(sum);
You don't specify exactly how you want this output formatted.
If there may be hour elements as well, then replace the second line of the loop with this:
sum += (Integer.parseInt(parts[0]) * 60) + Integer.parseInt(parts[1]);

I'll go for quick and dirty
Split each String on the ":"
Convert both parts to integer
Multiply the first time by 60 to convert hours to minutes, and add the second part
Do this for each value in your array, and count them together
This results in the total time in minutes, which you can convert to whatever format you like

You could substring it, and then call Integer.parseInt on the result. For the hours part, do the same and multiply it by 60.

Split the strings on ':', pars the values as ints and add 'em up.

this is my suggestion. Neither compiled, ran, tested, nor guaranteed.
long seconds = 0;
for ( String min : minutes )
{
seconds += Integer.parseInt(min.substring(0,1))*60 + Integer.parseInt(min.substring(3,4));
}
return new Date ( seconds / 1000 ) ;

An object oriented approach:
public static TimeAcumm sum(final String[] times) {
final TimeAcumm c = new TimeAcumm();
for (final String time : times) {
c.incrementFromFormattedString(time);
}
return c;
}
public class TimeAcumm {
private int hours = 0;
private int minutes = 0;
private int seconds = 0;
public int getHours() {
return hours;
}
public int getMinutes() {
return minutes;
}
public int getSeconds() {
return seconds;
}
public void incrementFromFormattedString(final String time) {
final String[] parts = time.split(":");
this.minutes += Integer.parseInt(parts[0]);
this.seconds += Integer.parseInt(parts[1]);
validate();
}
private void validate() {
if (this.minutes > 59) {
this.hours++;
this.minutes -= 60;
}
if (this.seconds > 59) {
this.minutes++;
this.seconds -= 60;
}
}
#Override
public String toString() {
final String s = hours + "H:" + minutes + "M:" + seconds + "S";
return s;
}
}