BAEL-1584 : Finding an element in list (#4067)

* BAEL-1584 : Find an Element in Given List
2018-05-01 02:23:17 +05:30
parent 47a7aaae5d
commit b559157482
5 changed files with 272 additions and 187 deletions
@@ -0,0 +1,37 @@
+package com.baeldung.findanelement;
+
+public class Customer {
+
+    private int id;
+    private String name;
+
+    public Customer(int id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public int hashCode() {
+        return id * 20;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof Customer) {
+            Customer otherCustomer = (Customer) obj;
+            if (id == otherCustomer.id)
+                return true;
+        }
+        return false;
+    }
+
+
+}
@@ -0,0 +1,77 @@
+package com.baeldung.findanelement;
+
+import java.util.Iterator;
+import java.util.List;
+
+import org.apache.commons.collections4.IterableUtils;
+
+import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
+
+public class FindACustomerInGivenList {
+
+    public Customer findUsingGivenIndex(int indexOfCustomer, List<Customer> customers) {
+        if (indexOfCustomer >= 0 && indexOfCustomer < customers.size())
+            return customers.get(indexOfCustomer);
+        return null;
+    }
+
+    public int findUsingIndexOf(Customer customer, List<Customer> customers) {
+        return customers.indexOf(customer);
+    }
+
+    public boolean findUsingContains(Customer customer, List<Customer> customers) {
+        return customers.contains(customer);
+    }
+
+    public Customer findUsingIterator(String name, List<Customer> customers) {
+        Iterator<Customer> iterator = customers.iterator();
+        while (iterator.hasNext()) {
+            Customer customer = iterator.next();
+            if (customer.getName().equals(name)) {
+                return customer;
+            }
+        }
+        return null;
+    }
+
+    public Customer findUsingEnhancedForLoop(String name, List<Customer> customers) {
+        for (Customer customer : customers) {
+            if (customer.getName().equals(name)) {
+                return customer;
+            }
+        }
+        return null;
+    }
+
+    public Customer findUsingStream(String name, List<Customer> customers) {
+        return customers.stream()
+            .filter(customer -> customer.getName().equals(name))
+            .findFirst()
+            .orElse(null);
+    }
+
+    public Customer findUsingParallelStream(String name, List<Customer> customers) {
+        return customers.parallelStream()
+            .filter(customer -> customer.getName().equals(name))
+            .findAny()
+            .orElse(null);
+    }
+
+    public Customer findUsingGuava(String name, List<Customer> customers) {
+        return Iterables.tryFind(customers, new Predicate<Customer>() {
+            public boolean apply(Customer customer) {
+                return customer.getName().equals(name);
+            }
+        }).orNull();
+    }
+
+    public Customer findUsingApacheCommon(String name, List<Customer> customers) {
+        return IterableUtils.find(customers, new org.apache.commons.collections4.Predicate<Customer>() {
+            public boolean evaluate(Customer customer) {
+                return customer.getName().equals(name);
+            }
+        });
+    }
+
+}
@@ -1,71 +0,0 @@
-package com.baeldung.findanelement;
-
-import java.util.List;
-import java.util.ListIterator;
-import org.apache.commons.collections4.IterableUtils;
-import com.google.common.base.Predicate;
-import com.google.common.collect.Iterables;
-
-public class FindElementInAList<T> {
-
-    public T findUsingIndexOf(T element, List<T> list) {
-        int index = list.indexOf(element);
-        if (index >= 0) {
-            return element;
-        }
-        return null;
-    }
-
-    public boolean findUsingListIterator(T element, List<T> list) {
-        ListIterator<T> listIterator = list.listIterator();
-        while (listIterator.hasNext()) {
-            T elementFromList = listIterator.next();
-            if (elementFromList.equals(element)) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    public boolean findUsingEnhancedForLoop(T element, List<T> list) {
-        for (T elementFromList : list) {
-            if (element.equals(elementFromList)) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    public T findUsingStream(T element, List<T> list) {
-        return list.stream()
-            .filter(integer -> integer.equals(element))
-            .findFirst()
-            .orElse(null);
-    }
-
-    public T findUsingParallelStream(T element, List<T> list) {
-        return list.parallelStream()
-            .filter(integer -> integer.equals(element))
-            .findAny()
-            .orElse(null);
-    }
-
-    public T findUsingGuava(T element, List<T> list) {
-        T foundElement = Iterables.tryFind(list, new Predicate<T>() {
-            public boolean apply(T input) {
-                return element.equals(input);
-            }
-        }).orNull();
-        return foundElement;
-    }
-
-    public T findUsingApacheCommon(T element, List<T> list) {
-        T foundElement = IterableUtils.find(list, new org.apache.commons.collections4.Predicate<T>() {
-            public boolean evaluate(T input) {
-                return element.equals(input);
-            }
-        });
-        return foundElement;
-    }
-
-}