Tag: SSI Cal iterator returns Force price ArrayList. com greater than
list<map<string, object>> querydata = configdao.queryconfig (expressions, conditions, expressions); Collections.sort (Querydata, New comparator<map<string, object>> () {public int compare (map<string, Object> O1, map<string, object> O2) {//Integer name1 = integer.valueof (o1.get ("category"). toString ());// NAME1 is a//Integer name2 = integer.valueof (o2.get ("category") from your list. ToString ()); Name1 is the second name//return Name1.compareto (name2) from your list, return O1.get ("category"). toString (). CompareTo (O2.get ("category"). toString ());}); Comparator built-in functions, querydate are list arrays that need to be arranged, followed by collations,
Compare (A, B) method: Returns a negative integer, 0, or a positive integer, respectively, based on the first parameter less than, equal to, or greater than the second parameter.
Equals (obj) method: Returns True only if the specified object is also a Comparator and enforces the same sort as this Comparator.
Collections.sort (list, new Pricecomparator ()); The second parameter returns a value of type int, which is equivalent to a flag that tells the sort method what order to sort the list.
Example:
Package com.tjcyjd.comparator; Import java.util.ArrayList; Import java.util.Collections; Import Java.util.Comparator; Import Java.util.GregorianCalendar; Import Java.util.Iterator; Import java.util.list; public class Usecomparator {public static void main (String args[]) {list<book& Gt List = new arraylist<book> (); Array sequence Book B1 = new book (10000, "Red Mansions", 150.86, New GregorianCalendar (2009, 01, 25), "Cao Xueqin, Gao E"); Book b2 = new book (10001, "kingdoms", 99.68, New GregorianCalendar (2008, 7, 8), "Luo Guan Zhong"); Book B3 = new book (10002, "Outlaws of the Marsh", 100.8, New GregorianCalendar (2009, 6, 28), "Shi Naian"); Book B4 = new book (10003, "Journey to the Monkey", 120.8, New GregorianCalendar (2011, 6, 8), "Wu Chengen"); B5 = new book (10004, "Tianlong Eight", 10.4, New GregorianCalendar (2011, 9, 23), "Sohu"); List.add (B1); List.add (B2); List.add (B3); List.add (B4); List.add (B5); Collections.sort (list); Without a default comparer, you cannot sort System.out.println ("elements in the array sequence:"); Myprint (list); Collections.sort (list, new PrIcecomparator ()); Sort by price System.out.println ("Sort by book Price:"); Myprint (list); Collections.sort (list, new Calendarcomparator ()); Sort by Time System.out.println ("Sort by book's publication Time:"); Myprint (list); } //Custom comparators: Sort by price of book static class Pricecomparator implements Comparator {public int compare (obje CT object1, Object object2) {//Implements the method in the interface book P1 = (book) Object1;//cast book P2 = (book) Object2; return new double (p1.price). CompareTo (new double (P2.price)); }} //Custom Comparator: Sort static class Calendarcomparator by book publication Time implements Comparator {public int compare (Object Object1, Object object2) {//implement method in interface book P1 = (book) Object1;//cast book P2 = (book) Object2; return P2.calen Dar.compareto (P1.calendar); }} //Custom method: Branch Print output list element public static void Myprint (List<book> list) {Iterator it = List.iterator (); Gets an iterator that iterates through all the elements in the list while (It.hasnext ()) {//returns True if there are elements in the iterator System.out.prinTLN ("\ T" + it.next ());//Display the element
}
} } override
The Compare method can also add a number of columns
Comparing strings, sorting
