Example usage for java.util Collection size

Introduction

In this page you can find the example usage for java.util Collection size.

Prototype

int size();

Source Link

Document

Returns the number of elements in this collection.

Usage

From source file:Main.java

public static int sizeOf(Collection<?> collection) {
    if (isEmpty(collection)) {
        return 0;
    }/*from   w ww  . j  ava2  s. c  o m*/
    return collection.size();
}

From source file:Main.java

@SuppressWarnings("unchecked")
public static <S, D extends S> D[] downcastToArray(Collection<S> source, Class<D> destClass) {
    D[] dest = (D[]) Array.newInstance(destClass, source.size());
    Iterator<S> it = source.iterator();
    for (int i = 0; i < dest.length; i++) {
        S s = it.next();//ww w  .  ja  v  a  2 s.c  om
        if (destClass.isAssignableFrom(s.getClass()))
            dest[i] = (D) s;
        else
            throw new IllegalArgumentException("Could not downcast element from class "
                    + s.getClass().getSimpleName() + " to " + destClass.getSimpleName());
    }
    return dest;
}

From source file:Main.java

public static <T> boolean isOutOfBound(Collection<T> coll, int index) {
    if (isEmpty(coll)) {
        return true;
    }/*from   w  w w  .  j a  va 2 s .  co m*/
    if ((index >= coll.size()) || (index < 0)) {
        return true;
    } else {
        return false;
    }
}

From source file:Main.java

/**
 * Null safe summation of the sizes of all of the given collections
 *//*  w  w w.  j  a va 2 s .  co  m*/
public static int size(Collection... collections) {
    int size = 0;
    if (collections != null) {
        for (Collection collection : collections) {
            if (collection != null)
                size += collection.size();
        }
    }
    return size;
}

From source file:uk.co.blackpepper.support.spring.jdbc.jooq.SpringJdbcJooqUtils.java

@VisibleForTesting
static int[] getSqlTypes(Collection<? extends Param<?>> params) {
    List<Integer> types = new ArrayList<>(params.size());

    for (Param<?> param : params) {
        types.add(javaTypeToSqlParameterType(param.getType()));
    }//  www .j  a va  2  s . c o m

    return Ints.toArray(types);
}

From source file:Main.java

public static <T> String join(Collection<T> col, String separator) {
    String ret = "";
    if (col != null && col.size() > 0) {
        for (Object x : col) {
            if (x instanceof java.lang.String) {
                ret += separator + (String) x;
            } else {
                ret += separator + x.toString();
            }/*www .j  a va2s . c  om*/
        }
    }
    return ret.replaceFirst(separator, "");

}

From source file:Main.java

/**
 * @return The intersection of two sets A and B is the set of elements common to A and B
 *//*from  w w w  .j ava2 s.c  o m*/
public static <T> List<T> setIntersection(Collection<T> listA, Collection<T> listB) {
    ArrayList<T> intersection = new ArrayList<T>(listA.size());

    for (T obj : listA) {
        if (listB.contains(obj)) {
            intersection.add(obj);
        }
    }
    return intersection;
}

From source file:Main.java

public static String collectionToString(Collection c) {
    StringBuffer buff = new StringBuffer();
    int i = 0;//from  w  w  w. j  av  a2 s  .c o  m
    int size = c.size();
    for (Iterator iter = c.iterator(); iter.hasNext();) {
        Object object = iter.next();
        if (size > 1 && i == (size - 1)) {
            buff.append("and ");
        }
        buff.append(object);
        if (i < (size - 1)) {
            if (size > 2) {
                buff.append(", ");
            } else {
                buff.append(" ");
            }
        }
        i++;
    }
    return buff.toString();

}

From source file:Main.java

/**
 * @param <T>//from w ww.  j  a  va 2s . c o  m
 * @param col
 * @return a list without null elements
 */
public static <T> ArrayList<T> clearNulls(Collection<T> col) {
    ArrayList<T> list = new ArrayList<T>(col.size());

    for (T t : col) {
        if (t != null) {
            list.add(t);
        }
    }

    return list;
}

From source file:Main.java

/**
 * Put all of the elements in items into the given array
 * This assumes that the array has been pre-allocated
 * @param <T>/*from   www  .  j a  va 2  s . com*/
 * @param items
 * @param array
 */
public static <T> void toArray(Collection<T> items, Object array[], boolean convert_to_primitive) {
    assert (items.size() == array.length);

    int i = 0;
    for (T t : items) {
        if (convert_to_primitive) {
            if (t instanceof Long) {
                array[i] = ((Long) t).longValue();
            } else if (t instanceof Integer) {
                array[i] = ((Integer) t).intValue();
            } else if (t instanceof Double) {
                array[i] = ((Double) t).doubleValue();
            } else if (t instanceof Boolean) {
                array[i] = ((Boolean) t).booleanValue();
            }
        } else {
            array[i] = t;
        }
    }
    return;
}