collections

问题 I have a class called Employee that implements the Comparable interface. Now I have 5 Employee objects in my list, each of which has its own salary property. I want to find all of the Employee objects that have the max salary. I can get a single object using Employee employee = Collections.max(employeeList); but that only returns a single Employee , while I am trying retrieve an array or list of all of the objects with the same max value. How can I do this? 回答1: To be efficient, you should

问题 I have a class called Employee that implements the Comparable interface. Now I have 5 Employee objects in my list, each of which has its own salary property. I want to find all of the Employee objects that have the max salary. I can get a single object using Employee employee = Collections.max(employeeList); but that only returns a single Employee , while I am trying retrieve an array or list of all of the objects with the same max value. How can I do this? 回答1: To be efficient, you should

问题 I need a HashMap that (1) matches keys by Object reference, and (2) maintains insertion order when iterating These functionalities are implemented in IdentityHashMap and LinkedHashMap separately. Is there any way to get a data structure that suits my need? Either one that is present in Java standard OR 3rd party libraries (like Guava), OR by using some trick on LinkedHashMap maybe, so that it uses object reference for matching keys? 回答1: You can use Guava's Equivalence for this: Equivalence

问题 I need a HashMap that (1) matches keys by Object reference, and (2) maintains insertion order when iterating These functionalities are implemented in IdentityHashMap and LinkedHashMap separately. Is there any way to get a data structure that suits my need? Either one that is present in Java standard OR 3rd party libraries (like Guava), OR by using some trick on LinkedHashMap maybe, so that it uses object reference for matching keys? 回答1: You can use Guava's Equivalence for this: Equivalence

问题 I have a List in which I need to add a prefix in all the elements of my list. Below is the way I am doing it by iterating the list and then adding it. Is there any other better way to do it? Any one-two liner that can do the same stuff? private static final List<DataType> DATA_TYPE = getTypes(); public static LinkedList<String> getData(TypeFlow flow) { LinkedList<String> paths = new LinkedList<String>(); for (DataType current : DATA_TYPE) { paths.add(flow.value() + current.value()); } return

问题 I need a HashMap that (1) matches keys by Object reference, and (2) maintains insertion order when iterating These functionalities are implemented in IdentityHashMap and LinkedHashMap separately. Is there any way to get a data structure that suits my need? Either one that is present in Java standard OR 3rd party libraries (like Guava), OR by using some trick on LinkedHashMap maybe, so that it uses object reference for matching keys? 回答1: You can use Guava's Equivalence for this: Equivalence

问题 I have a List in which I need to add a prefix in all the elements of my list. Below is the way I am doing it by iterating the list and then adding it. Is there any other better way to do it? Any one-two liner that can do the same stuff? private static final List<DataType> DATA_TYPE = getTypes(); public static LinkedList<String> getData(TypeFlow flow) { LinkedList<String> paths = new LinkedList<String>(); for (DataType current : DATA_TYPE) { paths.add(flow.value() + current.value()); } return

问题 I have a List in which I need to add a prefix in all the elements of my list. Below is the way I am doing it by iterating the list and then adding it. Is there any other better way to do it? Any one-two liner that can do the same stuff? private static final List<DataType> DATA_TYPE = getTypes(); public static LinkedList<String> getData(TypeFlow flow) { LinkedList<String> paths = new LinkedList<String>(); for (DataType current : DATA_TYPE) { paths.add(flow.value() + current.value()); } return

问题 I have a List in which I need to add a prefix in all the elements of my list. Below is the way I am doing it by iterating the list and then adding it. Is there any other better way to do it? Any one-two liner that can do the same stuff? private static final List<DataType> DATA_TYPE = getTypes(); public static LinkedList<String> getData(TypeFlow flow) { LinkedList<String> paths = new LinkedList<String>(); for (DataType current : DATA_TYPE) { paths.add(flow.value() + current.value()); } return

问题 I have a List in which I need to add a prefix in all the elements of my list. Below is the way I am doing it by iterating the list and then adding it. Is there any other better way to do it? Any one-two liner that can do the same stuff? private static final List<DataType> DATA_TYPE = getTypes(); public static LinkedList<String> getData(TypeFlow flow) { LinkedList<String> paths = new LinkedList<String>(); for (DataType current : DATA_TYPE) { paths.add(flow.value() + current.value()); } return