java-8

问题 I have two entities with one to many relationship which are joined together by composite primary keys. Since Spring Data generates wrong count distinct query for oracle database , I have SQL output with cartesian join which leads to repeating row for parent object for every row of child object. I need to find out distinct parent objects based on composite keys and then add each child object for parent in a list and set it as property of parent object I am able to find out distinct parent

问题 How to filter dynamically nested list object java 8 Example: class Items { List<Mobile> mobiles; } class Mobile{ String mName; List<Plans> plans; } class Plans{ String planId; String planName; } So, I have 3 mobiles (mobiles will be dynamic 3 or 4..etc) with multiple plans on each mobile device. How to dynamically filter common plan for each mobile device ? Example(P1-planId) : Items: M1 - P1,P2,P3,P4 M2 - P4,P5,P6,P1,P8,P2 M3 - P7,P2,P4,P1,P8,P9,P10 Result: Items: M1 - P1,P2,P4 M2 - P1,P2,P4

问题 How to filter dynamically nested list object java 8 Example: class Items { List<Mobile> mobiles; } class Mobile{ String mName; List<Plans> plans; } class Plans{ String planId; String planName; } So, I have 3 mobiles (mobiles will be dynamic 3 or 4..etc) with multiple plans on each mobile device. How to dynamically filter common plan for each mobile device ? Example(P1-planId) : Items: M1 - P1,P2,P3,P4 M2 - P4,P5,P6,P1,P8,P2 M3 - P7,P2,P4,P1,P8,P9,P10 Result: Items: M1 - P1,P2,P4 M2 - P1,P2,P4

问题 How to filter dynamically nested list object java 8 Example: class Items { List<Mobile> mobiles; } class Mobile{ String mName; List<Plans> plans; } class Plans{ String planId; String planName; } So, I have 3 mobiles (mobiles will be dynamic 3 or 4..etc) with multiple plans on each mobile device. How to dynamically filter common plan for each mobile device ? Example(P1-planId) : Items: M1 - P1,P2,P3,P4 M2 - P4,P5,P6,P1,P8,P2 M3 - P7,P2,P4,P1,P8,P9,P10 Result: Items: M1 - P1,P2,P4 M2 - P1,P2,P4

问题 How to filter dynamically nested list object java 8 Example: class Items { List<Mobile> mobiles; } class Mobile{ String mName; List<Plans> plans; } class Plans{ String planId; String planName; } So, I have 3 mobiles (mobiles will be dynamic 3 or 4..etc) with multiple plans on each mobile device. How to dynamically filter common plan for each mobile device ? Example(P1-planId) : Items: M1 - P1,P2,P3,P4 M2 - P4,P5,P6,P1,P8,P2 M3 - P7,P2,P4,P1,P8,P9,P10 Result: Items: M1 - P1,P2,P4 M2 - P1,P2,P4

问题 I would like use some features from Java 9 and 10 in my PC java application which has common code with android app. When I use jdk 10 or jdk 9 android application is building, but it doesn't launch(it is throwing a lots of errors). When I use jdk 8 for whole project everything is working correctly without any error. When I manually build project using 2 different jdk everything is working fine. I tried set targetCompability and sourceCompability for android application for JavaVersion.Version

问题 I would like use some features from Java 9 and 10 in my PC java application which has common code with android app. When I use jdk 10 or jdk 9 android application is building, but it doesn't launch(it is throwing a lots of errors). When I use jdk 8 for whole project everything is working correctly without any error. When I manually build project using 2 different jdk everything is working fine. I tried set targetCompability and sourceCompability for android application for JavaVersion.Version

问题 I have a working AOP (when using inside the project it is written in) but when I build this project (maven install), and use that JAR in another project, and try to use the @TimedLog annotation, nothing happens. I try to breakpoint into it, but it doesn't reach there. It looks like this: @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.METHOD) public @interface TimedLog { boolean shouldAttachMethodArgs() default false; boolean shouldAttachReturnValue() default false; String message()

问题 In the code below, when the endpoint getPerson gets hit, the response will be a JSON of type Person. How does Spring convert CompletableFuture<Person> to Person ? @RestController public class PersonController { @Autowired private PersonService personService; @GetMapping("/persons/{personId}" ) public CompletableFuture<Person> getPerson(@PathVariable("personId") Integer personId) { return CompletableFuture.supplyAsync(() -> personService.getPerson(personId)); } } 回答1: When the

问题 I was trying to write a solution for the problem stated here as Stuart Marks pointed out to use a helper class. I got stuck on the code due to this error: Test.java:27: error: incompatible types: inference variable K has incompatible bounds .collect(Collectors.groupingBy(p -> p.getT2())); ^ equality constraints: Tuple lower bounds: Integer where K,T are type-variables: K extends Object declared in method <T,K>groupingBy(Function<? super T,? extends K>) T extends Object declared in method <T,K