摘要：配合一下方法使用類似的方法，用于提取一個里頭的一個屬性出來。當然，也可以簡寫為主要用來過濾集合。配合使用功能與相同，只是把該篩選條件內置在中然后這里直接使用，傳入參數與功能相反集合分區只取出一個符合條件的計數與條件滿足判斷其他轉參考

配合一下方法使用：

collect

flatCollect

groupBy

minBy

maxBy

toSortedListBy

sortThisBy

toMap

類似guava的transform方法，用于提取一個object里頭的一個屬性出來。

Function nameFunction = Customer::getName;
MutableList customerNames = customers.collect(nameFunction);

當然，也可以簡寫為

MutableList customerNames = customers.collect(Customer::getName);

MutableList allOrderedLineItems = company.getOrders().flatCollect(Order::getLineItems);

MutableSet actualItemNames = allOrderedLineItems.collect(LineItem::getName).toSet();

主要用來過濾集合。配合使用：

select

reject

detect

count

anySatisfy

allSatisfy

MutableList customersFromLondon = customers.select(c -> "London".equals(c.getCity()));

功能與select相同，只是把該篩選條件內置在domain中
Customer:

public boolean livesIn(String city){
        return this.city.equals(city);
}

然后這里直接使用，傳入參數：

MutableList customersFromLondon = customers.selectWith(Customer::livesIn,"London");

與selectWith功能相反

MutableList customersNotFromLondon = company.getCustomers().rejectWith(Customer::livesIn, "London");

PartitionMutableList partitionedList = this.company.getCustomers().partitionWith(Customer::livesIn, "London");
        MutableList customersFromLondon = partitionedList.getSelected();
        MutableList customersNotFromLondon = partitionedList.getRejected();

public Customer getCustomerNamed(String name) {
        return customers.detect(c -> name.equals(c.getName()));
    }

int numberOfCustomerFromLondon = company.getCustomers().countWith(Customer::livesIn,"London");

MutableList sortedTotalValues = company.getCustomers().collect(Customer::getTotalOrderValue).sortThis();
Assert.assertEquals("Highest total order value", Double.valueOf(857.0), sortedTotalValues.getLast());
Assert.assertEquals("Lowest total order value", Double.valueOf(71.0), sortedTotalValues.getFirst());

Double maximumTotalOrderValue = company.getCustomers().collect(Customer::getTotalOrderValue).max();
Customer customerWithMaxTotalOrderValue = company.getCustomers().maxBy(Customer::getTotalOrderValue);

Predicate CUSTOMER_FROM_LONDON = customer -> customer.getCity().equals("London");
boolean anyCustomersFromLondon = company.getCustomers().anySatisfy(CUSTOMER_FROM_LONDON);
boolean allCustomersFromLondon = company.getCustomers().allSatisfy(CUSTOMER_FROM_LONDON);

MutableBag bag    = HashBag.newBagWith("one","two","two","three","three","three");    
Assert.assertEquals(3,bag.occurrencesOf("three"));    
bag.add("one");    
Assert.assertEquals(2,bag.occurrencesOf("one"));

MutableMap petTypeCounts = UnifiedMap.newMap();

MutableList轉MutableSet

MutableList allOrderedLineItems = company.getOrders().flatCollect(Order::getLineItems);
MutableSet actualItemNames = allOrderedLineItems.collect(LineItem::getName).toSet();

UnifiedSet.newSetWith

MutableSet people = UnifiedSet.newSetWith(mrSmith,mrsSmith,mrJones);    
int numAddresses = people.collect(addressFunction).size();    
System.out.println(numAddresses);

MutableListMultimap multimap = company.getCustomers().groupBy(Customer::getCity);
Assert.assertEquals(FastList.newListWith(this.company.getCustomerNamed("Mary")),multimap.get("Liphook"));
MutableList Liphooks = multimap.get("Liphook");

public boolean hasSupply(String itemName){
    return ArrayIterate.contains(itemNames,itemName);
}

List orders = this.company.getMostRecentCustomer().getOrders();
MutableList orderValues = ListIterate.collect(orders, Order::getValue);

String tildeSeparatedNames = company.getSuppliers().collect(Supplier::getName).makeString("~");

eclipse-collections-kata