java-8

问题 Imagine having some sort of incoming data either by callback or an InputStream that you need to continuously convert into a Java 8 Stream . We don't know when the incoming data-stream stops, but we know that it can stop. So far I've seen two ways of getting around this problem and I'm interested in the best practices on how to achieve this. Mainly because I this must be something someone has faced before. There must be a simpler way of doing it than the ideas below. 1) The most simple way is

问题 I am setting the id for each list item where primary address for two list are equal. Server POJO public class Server { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name="id") public Integer id; @OneToMany (mappedBy = "server",cascade = CascadeType.ALL, orphanRemoval = true) private List<IPAddress> ipaddresses; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public void setIpaddresses(List<IPAddress> ipaddresses) { this.ipaddresses =

问题 We update tomcat to 8.5.6 from 8.0.32 recently, and we meet a AccessControlException when try to load /opt/apache-tomcat-8.5.6_1/webapps/example/WEB-INF/classes/com/sun/xml/internal/ws/runtime/config/jaxb.properties , and I debug the source code between tomcat 8.5.6 and 8.0.32, it's different in org.apache.catalina.loader.WebappClassLoaderBase.findResource Tomcat8.0 public URL findResource(final String name) { if (log.isDebugEnabled()) log.debug(" findResource(" + name + ")");

问题 I'm using Android Studio 2.3 within gradle 2.3.3 . I face a weird problem and being stuck for a week. It hangs out very often when I type some lines of code, right before it shows the auto complete box. Or if I didn't type anything but use Command-click to find implementation of a variable or method, it show the dialog says Resolving Reference and hangs there. Sometime, if I switch to another application for awhile and switch back to view Android Studio, it hangs as well. I already tried many

问题 I have two java classes like so: public class FooA { private List<FooB> fooB; } public class FooB { private Integer id; private String name; private double num; } I want to compare the FooA and it tell me what fields inside the list object changed. But when I do this: FooA old = new FooA(Arrays.asList(new FooB(1, "old", 1.0))); FooA new = new FooA(Arrays.asList(new FooB(1, "new", 1.0))); Javers javers = JaversBuilder.javers() .withListCompareAlgorithm(LEVENSHTEIN_DISTANCE) .build(); javers

问题 Not able to compile JSP files in JBoss 5.1 with Java 1.8. Able to compile regular Java files and even complete Spring project which does not have JSPs. It is working properly, if we kept compiled class files for those JSP files. Following is the error I am getting when I am trying to run a JSP file: 2016-07-15 14:56:00,758 ERROR [org.apache.jasper.compiler.Compiler] (http-0.0.0.0-80-31) Compilation error org.eclipse.jdt.internal.compiler.classfmt.ClassFormatException at org.eclipse.jdt

问题 I wanted to play an Ultra HD (4K) Video with JavaFX 2 MediaPlayer but do only get a black screen (run on JRE 8/Windows 7). There are no error messages. Does anyone know if JavaFX can play Ultra HD (4K) videos or where I can find these information? Thank you. 回答1: I can confirm the player doesn't support anything higher than 1920 pixels wide. I created a video this weekend with X pixels of 1980 and it couldn't play. I figured out last night to drop it down to 1920 to make the video play. The Y

问题 I've been using modelmapper and java 8 Optionals all around the application which was working fine because they were primitive types; until I changed one of my model objects' field to Optional type. Then all hell broke loose. Turns out many libraries cannot handle generics very well. Here is the structure public class MyObjectDto { private Optional<MySubObjectDto> mySubObject; } public MyObject { privae Optional<MySubjObject> mySubObject; } When I attempt to map MyObjectDto to MyObject ,

问题 I'm facing the following exception when using Java 8 (1.8.0_60), Spring 4.2.1 and MyBatis 3.3.0 Sep 29, 2015 11:02:58 AM org.springframework.context.annotation.AnnotationConfigApplicationContext prepareRefresh INFO: Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@246b179d: startup date [Tue Sep 29 11:02:58 EDT 2015]; root of context hierarchy Sep 29, 2015 11:02:58 AM org.mybatis.spring.mapper.ClassPathMapperScanner checkCandidate WARNING: Skipping

问题 I'm experimenting with multi-threaded scripts loading and evaluation in Nashorn and get kind of shocking behavior: // having some object o loaded in another thread print(o.constructor === o.constructor); // false print(o.constructor === Object); // false as well print(o.foo === o.foo); // true - OK How can this be possible within single script engine? o above is just an object created using object literal notation (in another thread). Printing o.constructor gives usual function Object() {