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Articles by Nancy Den
Page 14 of 18
How to convert string Stream to join them in Java?
Let us create string Stream:Stream stream = Stream.of("Bing Bang Theory", "Vampire Diaries", "Game of Thrones", "Homecoming");Convert the above string stream and join them with Collectors:final String str = stream.collect(Collectors.joining(" "));The following is an example to convert string Stream to join them:Exampleimport java.util.stream.Collectors; import java.util.stream.Stream; public class Demo { public static void main(String[] args) { Stream stream = Stream.of("Bing Bang Theory", "Vampire Diaries", "Game of Thrones", "Homecoming"); final String str = stream.collect(Collectors.joining(" ")); System.out.println("Join result..."+str); } }OutputJoin result... Bing Bang Theory Vampire Diaries Game of Thrones Homecoming
Read MoreHow to convert Stream to TreeSet in Java?
Let us first create a Stream:Stream stream = Stream.of("UK", "US", "India", "Australia", "Armenia", "Canada", "Poland");Now convert Stream to TreeSet:Set set = stream.collect(Collectors.toCollection(TreeSet::new));The following is an example to convert String to TreeSet in Java:Exampleimport java.util.Set; import java.util.TreeSet; import java.util.stream.Collectors; import java.util.stream.Stream; public class Demo { public static void main(String[] args) { Stream stream = Stream.of("UK", "US", "India", "Australia", "Armenia", "Canada", "Poland"); Set set = stream.collect(Collectors.toCollection(TreeSet::new)); set.forEach(val -> System.out.println(val)); } }OutputArmenia Australia Canada India Poland UK US
Read MoreHow to count element after filtering in Java?
Let’s say the following is the String List:List list = new ArrayList(); list.add("Tom"); list.add("John"); list.add("David"); list.add("Paul"); list.add("Gayle"); list.add("Narine"); list.add("Joseph");Now, let’s say you need to filter elements beginning with a specific letter. For that, use filter() and startsWith():long res = list .stream() .filter((s) -> s.startsWith("J")) .count();We have also counted the elements above after filtering using count().The following is an example to count element after filtering in Java:Exampleimport java.util.ArrayList; import java.util.List; public class Demo { public static void main(final String[] args) { List list = new ArrayList(); list.add("Tom"); list.add("John"); ...
Read MoreHow to filter empty string values from a Java List?
Let’s say we have a String List with an empty value. Here, we have empty array elements before Football and after Squash:List sports = Arrays.asList("", "Football", "Cricket", "Tennis", "Squash", "", "Fencing", "Rugby");Now filter the empty string values. At first, we have used Predicate to negate values:Stream stream = sports.stream(); Predicate empty = String::isEmpty; Predicate emptyRev = empty.negate(); stream.filter(emptyRev).collect(Collectors.toList()));The following is an example to filter empty string values from a List:Exampleimport java.util.Arrays; import java.util.List; import java.util.function.Predicate; import java.util.stream.Collectors; import java.util.stream.Stream; public class Demo { public static void main(String[] args) { List sports = Arrays.asList("", "Football", "Cricket", "Tennis", ...
Read MoreHow to filter non-null value in Java?
Let’s say the following is our List with string elements:List leagues = Arrays.asList("BBL", "IPL", "MLB", "FPL", "NBA", "NFL");Now, create a stream and filter elements that end with a specific letter:Stream stream = leagues.stream().filter(leagueName -> leagueName.endsWith("L"));Now, use Objects::nonnull for non-null values:List list = stream.filter(Objects::nonNull).collect(Collectors.toList());The following is an example to filter non-null value in Java:Exampleimport java.util.Arrays; import java.util.List; import java.util.Objects; import java.util.stream.Collectors; import java.util.stream.Stream; public class Demo { public static void main(String[] args) { List leagues = Arrays.asList("BBL", "IPL", "MLB", "FPL", "NBA", "NFL"); Stream stream = leagues.stream().filter(leagueName -> leagueName.endsWith("L")); List list = ...
Read MoreHow to insert Date value into table in JDBC?
You can insert date values in SQL using the date datatype, The java.sql.Date class maps to the SQL DATE type.The PreparedStatement interface provides a method named setDate(). Using this you can insert date into a table. This method accepts two parameters −An integer representing the parameter index of the place holder (?) to which we need to set date value.a Date object representing the date value to be passed. The constructor of java.sql.Date class accepts a variable of long type representing the number of milliseconds from the epoch (standard base time I.e. January 1, 1970, 00:00:00 GMT).ExampleAssume we have created ...
Read MoreHow to retrieve Date from a table in JDBC?
The ResultSet interface provides a method named getDate() this method accepts an integer parameter representing the index of the column, (or, a String parameter representing the name of the column) from which you need to retrieve the date value. To retrieve date value from a table −Register the driver class using the registerDriver() method of the DriverManager class. Pass the driver class name to it, as parameter.Connect to the database using the getConnection() method of the DriverManager class. Passing URL (String), username (String), password (String) as parameters to it.Create a Statement object using the createStatement() method of the Connection interface.Execute ...
Read MoreHow can we set time in a table in JDBC?
You can insert time values in SQL using the time datatype, The java.sql.Time class maps to the SQL Time type.The PreparedStatement interface provides a method named setTime(). Using this you can insert time into a table. This method accepts two parameters −An integer representing the parameter index of the place holder (?) to which we need to set date value.A Time object representing the time value to be passed. The constructor of java.sql.Time class accepts a variable of long type representing the number of milliseconds from the epoch (standard base time I.e. January 1, 1970, 00:00:00 GMT).ExampleAssume we have created ...
Read MoreHow to fetch the value from a KeyValue Tuple in Java?
To fetch the value from a KeyValue tuple in Java, use the getValue() method. Let us first see what we need to work with JavaTuples. To work with KeyValue class in JavaTuples, you need to import the following package:import org.javatuples.KeyValue;Note: Download JavaTuples Jar library to run JavaTuples program. If you are using Eclipse IDE, then Right Click Project → Properties → Java Build Path → Add External Jars and upload the downloaded JavaTuples jar file. Refer the below guide for all the steps to run JavaTuples:Steps: How to run JavaTuples program in EclipseThe following is an example to fetch the ...
Read MoreFetch the key from a KeyValue Tuple in Java
To fetch the key from a KeyValue tuple in Java, use the getKey() method. Let us first see what we need to work with JavaTuples. To work with KeyValue class in JavaTuples, you need to import the following package:import org.javatuples.KeyValue;Note: Download JavaTuples Jar library to run JavaTuples program. If you are using Eclipse IDE, then Right Click Project → Properties → Java Build Path → Add External Jars and upload the downloaded JavaTuples jar file. Refer the below guide for all the steps to run JavaTuples:Steps: How to run JavaTuples program in EclipseThe following is an example to fetch the ...
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