Example usage for java.util Collections unmodifiableMap

Introduction

In this page you can find the example usage for java.util Collections unmodifiableMap.

Prototype

public static <K, V> Map<K, V> unmodifiableMap(Map<? extends K, ? extends V> m)

Source Link

Document

Returns an unmodifiable view of the specified map.

Usage

From source file:MainClass.java

public static void main(String[] s) {
    Hashtable table = new Hashtable();
    table.put("key1", "value1");
    table.put("key2", "value2");
    table.put("key3", "value3");

    Map m = Collections.unmodifiableMap(table);

    m.put("key3", "value3");

    System.out.println(m);/*from w  ww.j  a  v a  2  s  .c  o  m*/

}

From source file:Main.java

public static void main(String[] argv) throws Exception {

    Map map = new HashMap();
    map = Collections.unmodifiableMap(map);

    try {/* ww w  .j a va2s. c o m*/
        map.put("key", "new value");
    } catch (UnsupportedOperationException e) {
        System.out.println(e.getMessage());
    }

}

From source file:Main.java

public static void main(String[] s) {
    Hashtable<String, String> table = new Hashtable<String, String>();
    table.put("key1", "value1");
    table.put("key2", "value2");
    table.put("key3", "value3");

    Map m = Collections.unmodifiableMap(table);

    m.put("key3", "value3");

    System.out.println(m);//from   w  w w.  j a  va 2s .  co m

}

From source file:Main.java

public static void main(String[] s) {
    //object hash table 
    Hashtable<String, String> table = new Hashtable<String, String>();

    // populate the table
    table.put("key1", "value1");
    table.put("key2", "value2");
    table.put("key3", "from java2s.com");

    System.out.println("Initial collection: " + table);

    // create unmodifiable map
    Map<String, String> m = Collections.unmodifiableMap(table);

    // try to modify the collection
    m.put("key3", "value3");
}

From source file:Main.java

public static void main(String[] s) {
    Hashtable<String, String> table = new Hashtable<String, String>();

    table.put("1", "Sunday");
    table.put("2", "Monday");
    table.put("3", "Tuesday");
    table.put("4", "Wednesday");
    table.put("5", "Thursday");
    table.put("6", "Friday");
    table.put("7", "Saturday");

    System.out.println("Initial collection: " + table);

    Map m = Collections.unmodifiableMap(table);

    // m.put("key3", "value3");
}

From source file:Main.java

public static void main(String[] argv) throws Exception {

    List stuff = Arrays.asList(new String[] { "a", "b" });

    List list = new ArrayList(stuff);
    list = Collections.unmodifiableList(list);

    try {/*w  w w  .  j  a v  a  2 s . c o m*/
        list.set(0, "new value");
    } catch (UnsupportedOperationException e) {

    }

    Set set = new HashSet(stuff);
    set = Collections.unmodifiableSet(set);

    Map map = new HashMap();
    map = Collections.unmodifiableMap(map);
}

From source file:Main.java

public static void main(String[] args) {
    Map<Month, String> dobCalendar = Employee.persons().stream()
            .collect(Collectors.collectingAndThen(Collectors.groupingBy(p -> p.getDob().getMonth(),
                    Collectors.mapping(Employee::getName, Collectors.joining(" "))), result -> {
                        for (Month m : Month.values()) {
                            result.putIfAbsent(m, "None");
                        }//from   w  w w.j av  a2s .  c o m
                        return Collections.unmodifiableMap(new TreeMap<>(result));
                    }));

    dobCalendar.entrySet().forEach(System.out::println);
}

From source file:Main.java

public static <K, V> Map<K, V> immutableMap(Map<K, V> map) {
    return Collections.unmodifiableMap(map);
}

From source file:Main.java

public static <K, V> Map<K, V> copyNullSafeHashMap(Map<? extends K, ? extends V> map) {
    if (map.isEmpty()) {
        return Collections.emptyMap();
    }//from ww w  . j av  a  2  s . co m
    return Collections.unmodifiableMap(copyNullSafeMutableHashMap(map));
}

From source file:Main.java

public static final Map<String, String> getMap() {
    Map<String, String> map = new HashMap<String, String>();
    map.put("x", "y");
    return Collections.unmodifiableMap(map);
}