Changes for sorting article

This commit is contained in:
maverick 2016-11-29 19:36:59 +05:30
parent 3af165fb11
commit 751a3ca19f
2 changed files with 274 additions and 0 deletions

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@ -0,0 +1,58 @@
package org.baeldung.java.sorting;
public class Employee implements Comparable {
private String name;
private int age;
private double salary;
public Employee(String name, int age, double salary) {
this.name = name;
this.age = age;
this.salary = salary;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
@Override
public boolean equals(Object obj) {
return ((Employee) obj).getName().equals(getName());
}
@Override
public int compareTo(Object o) {
Employee e = (Employee) o;
return getName().compareTo(e.getName());
}
@Override
public String toString() {
return new StringBuffer()
.append("(").append(getName())
.append(getAge()).append(",")
.append(getSalary()).append(")").toString();
}
}

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@ -1,5 +1,221 @@
package org.baeldung.java.sorting;
import static org.junit.Assert.assertTrue;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.commons.lang3.ArrayUtils;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.manipulation.Sortable;
import com.google.common.primitives.Ints;
public class JavaSorting {
private int [] toSort;
private int [] sortedInts;
private int [] sortedRangeInts;
// private Integer [] integers;
// private Integer [] sortedIntegers;
// private List<Integer> integersList;
// private List<Integer> sortedIntegersList;
private Employee[] employees;
private Employee[] employeesSorted;
private Employee[] employeesSortedByAge;
private HashMap<Integer, String> map;
@Before
public void initVariables () {
toSort = new int[]
{ 5, 1, 89, 255, 7, 88, 200, 123, 66 };
sortedInts = new int[]
{1, 5, 7, 66, 88, 89, 123, 200, 255};
sortedRangeInts = new int[]
{5, 1, 89, 7, 88, 200, 255, 123, 66};
// integers = new Integer[]
// { 5, 1, 89, 255, 7, 88, 200, 123, 66 };
// sortedIntegers = new Integer[]
// {1, 5, 7, 66, 88, 89, 123, 200, 255};
//
// integersList = Arrays.asList(new Integer[] { 5, 1, 89, 255, 7, 88, 200, 123, 66 });
// sortedIntegersList = Arrays.asList(new Integer[] {1, 5, 7, 66, 88, 89, 123, 200, 255});
employees = new Employee[] {
new Employee("John", 23, 5000),
new Employee("Steve", 26, 6000),
new Employee("Frank", 33, 7000),
new Employee("Earl", 43, 10000),
new Employee("Jessica", 23, 4000),
new Employee("Pearl", 33, 6000)};
employeesSorted = new Employee[] {
new Employee("Earl", 43, 10000),
new Employee("Frank", 33, 70000),
new Employee("Jessica", 23, 4000),
new Employee("John", 23, 5000),
new Employee("Pearl", 33, 4000),
new Employee("Steve", 26, 6000)};
employeesSortedByAge = new Employee[] {
new Employee("John", 23, 5000),
new Employee("Jessica", 23, 4000),
new Employee("Steve", 26, 6000),
new Employee("Frank", 33, 70000),
new Employee("Pearl", 33, 4000),
new Employee("Earl", 43, 10000)};
HashMap<Integer, String> map = new HashMap<>();
map.put(55, "John");
map.put(22, "Apple");
map.put(66, "Earl");
map.put(77, "Pearl");
map.put(12, "George");
map.put(6, "Rocky");
}
@Test
public void givenIntArray_whenUsingSort_thenSortedArray() {
Arrays.sort(toSort);
assertTrue(Arrays.equals(toSort, sortedInts));
}
@Test
public void givenIntegerArray_whenUsingSort_thenSortedArray() {
Integer [] integers = ArrayUtils.toObject(toSort);
Arrays.sort(integers, new Comparator<Integer>() {
@Override
public int compare(Integer a, Integer b) {
return a - b;
}
});
assertTrue(Arrays.equals(integers, ArrayUtils.toObject(sortedInts)));
}
@Test
public void givenArray_whenUsingSortWithLambdas_thenSortedArray() {
Integer [] integersToSort = ArrayUtils.toObject(toSort);
Arrays.sort(integersToSort, (a, b) -> {
return a - b;
});
assertTrue(Arrays.equals(integersToSort, ArrayUtils.toObject(sortedInts)));
}
@Test
public void givenEmpArray_SortEmpArray_thenSortedArrayinNaturalOrder() {
Arrays.sort(employees);
assertTrue(Arrays.equals(employees, employeesSorted));
}
@Test
public void givenIntArray_whenUsingRangeSort_thenRangeSortedArray() {
Arrays.sort(toSort, 3, 7);
assertTrue(Arrays.equals(toSort, sortedRangeInts));
}
@Test
public void givenIntArray_whenUsingParallelSort_thenParallelSortedArray() {
Arrays.parallelSort(toSort);
assertTrue(Arrays.equals(toSort, sortedInts));
}
@Test
public void givenArrayObjects_whenUsingComparing_thenSortedArrayObjects() {
List<Employee> employeesList = Arrays.asList(employees);
employeesList.sort(Comparator.comparing(Employee::getAge));//.thenComparing(Employee::getName));
assertTrue(Arrays.equals(employeesList.toArray(), employeesSortedByAge));
}
@Test
public void givenList_whenUsingSort_thenSortedList() {
List<Integer> toSortList = Ints.asList(toSort);
Collections.sort(toSortList);
assertTrue(Arrays.equals(toSortList.toArray(),
ArrayUtils.toObject(sortedInts)));
}
@Test
public void givenMap_whenSortingByKeys_thenSortedMap() {
Integer[] sortedKeys = new Integer[] { 6, 12, 22, 55, 66, 77 };
List<Map.Entry<Integer, String>> entries = new ArrayList<>(map.entrySet());
Collections.sort(entries, new Comparator<Entry<Integer, String>>() {
@Override
public int compare(Entry<Integer, String> o1, Entry<Integer, String> o2) {
return o1.getKey().compareTo(o2.getKey());
}
});
HashMap<Integer, String> sortedMap = new LinkedHashMap<>();
for (Map.Entry<Integer, String> entry : entries) {
sortedMap.put(entry.getKey(), entry.getValue());
}
assertTrue(Arrays.equals(sortedMap.keySet().toArray(), sortedKeys));
}
@Test
public void givenMap_whenSortingByValues_thenSortedMap() {
String[] sortedValues = new String[]
{ "Apple", "Earl", "George", "John", "Pearl", "Rocky" };
List<Map.Entry<Integer, String>> entries = new ArrayList<>(map.entrySet());
Collections.sort(entries, new Comparator<Entry<Integer, String>>() {
@Override
public int compare(Entry<Integer, String> o1, Entry<Integer, String> o2) {
return o1.getValue().compareTo(o2.getValue());
}
});
HashMap<Integer, String> sortedMap = new LinkedHashMap<>();
for (Map.Entry<Integer, String> entry : entries) {
sortedMap.put(entry.getKey(), entry.getValue());
}
assertTrue(Arrays.equals(sortedMap.values().toArray(), sortedValues));
}
@Test
public void givenSet_whenUsingSort_thenSortedSet() {
HashSet<Integer> integersSet = new LinkedHashSet<>(Ints.asList(toSort));
HashSet<Integer> descSortedIntegersSet = new LinkedHashSet<>(Arrays.asList(new Integer[]
{255, 200, 123, 89, 88, 66, 7, 5, 1}));
ArrayList<Integer> list = new ArrayList<Integer>(integersSet);
Collections.sort(list, (i1, i2) -> {
return i2 - i1;
});
integersSet = new LinkedHashSet<>(list);
assertTrue(Arrays.equals(integersSet.toArray(), descSortedIntegersSet.toArray()));
}
}