摘要：配合一下方法使用類似的方法，用于提取一個(gè)里頭的一個(gè)屬性出來。當(dāng)然，也可以簡(jiǎn)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(nèi)置在中然后這里直接使用，傳入?yún)?shù)與功能相反集合分區(qū)只取出一個(gè)符合條件的計(jì)數(shù)與條件滿足判斷其他轉(zhuǎn)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(gè)object里頭的一個(gè)屬性出來。

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

當(dāng)然，也可以簡(jiǎn)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(nèi)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?yún)?shù)：

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(zhuǎn)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