java-8

问题 Trying to get drools to run java8 jvm (upgraded from Java6). However, compilation has failed and the goal pushed further. Did a couple of things that helped: Ecj compiler: updated to 'org.eclipse.jdt.core.compiler:ecj:4.5.1' Mvel: Using updated mvel2-2.1.3.Final.jar Additionally, added org.codehaus.janino:janino:jar:2.5.16 to compile dependency to use janino compiler as per this https://copyrightdev.tumblr.com/post/146315831773/getting-drools-5x-to-operate-smoothly-with-java-8 blog. However,

问题 I have an application that tries to connect to Impala and Oracle. Below are the 2 beans defined. Impala Driver - ImpalaJDBC41-2.5.41.jar Oracle Driver - ojdbc6.jar <bean id="ID1" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="com.cloudera.impala.jdbc41.Driver"/> <property name="url" value="jdbc:impala://impalahost:21050/;AuthMech=1;KrbRealm=myrealm;KrbServicName=impala;KrbHostFQDN=xxx" /> </bean> <bean id="ID2" class="org

问题 I wrote a java code to execute Vowpal Wabbit in the following way: System.out.println("Executing command " + command); final Runtime r = Runtime.getRuntime(); final Process p = r.exec(command); System.out.println("waiting for the process"); try (final BufferedReader b = new BufferedReader(new InputStreamReader(p.getInputStream()))) { String line; while ((line = b.readLine()) != null) { final T lineResult = textParser.parseLine(line); parserResultCombiner.addToCombiner(lineResult); } } p

问题 I installed grakn 1.0.0 on debian/wheezy with jdk8 while starting grakn server it says STORAGE .... STARTED QUEUE ..... FAILED I found nothing useful in the log directory. any clues where I could look or where I could ask will be appreciated thanks, Gerald 回答1: I had the same problem. After failing to start, it created a file (like hs_err_pid20005.log) that said: # There is insufficient memory for the Java Runtime Environment to continue. # Native memory allocation (mmap) failed to map

问题 I have a map which looks like this: Map<String,String[]> urlFormEncoded = new HashMap<String,String[]>(); and I would like to sum all values stored in String[] arrays as a double value I tried something like this: double requestAmount = urlFormEncoded.entrySet().stream().mapToDouble(k -> Arrays.stream(k.getValue()).).sum(); but unfortunately I don't know how to convert this String[] to value :( I would like to do this using streams and lambda expressions 回答1: The first step would be to

问题 I'm having a validate method that return a boolean . I'm using invoking this method (Java 7) as follow: boolean isValid = true; for (String key: aMap.keySet()) { isValid &= validate(key, aMap.get(key)); } I would like to rewrite this code in Java 8. Java 8 allows iterating across a Map using: aMap.forEach((k,v) -> validate(k, v)); But this won't work: aMap.forEach((k,v) -> isValid &= validate(k, v)); Question How can I rewrite the the Java 7 code into Java 8 to achieve the same result? Note:

问题 Code: Map<Integer, HashSet<String>> test = new TreeMap<>(); test.put(1, new HashSet<>()); test.put(2, new HashSet<>()); test.put(3, new HashSet<>()); test.put(4, new HashSet<>()); test.get(1).add("1"); test.get(2).add("2"); test.get(3).add("2"); test.get(4).add("3, 33"); //get value of treemap and get rid of the duplicate by using distinct and printout //at the end test.values().stream().distinct().forEach(i -> System.out.println(i)); output: [1] [2] [3, 33] My question is how I can printout

问题 I am trying to compile a project containing some Java 8 source files using lambdas using SBT 0.13.7. Now, I set -java-home /Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk/Home in /usr/local/etc/sbtopts And apparently SBT does take this into consideration, because if I supply the wrong path it complains about no java being present. However, when I try compiling, I get the following [error] /Users/edafinov/GitRepos/Java8SBTTest/src/main/java/Main.java:10: error: illegal start of expression

问题 Let me say that I have a single string concatenated uris. http://...[sp]http://...[sp]http://... I'm trying to convert each split string to URIs. Stream.of(string.split("\\s")).map(uri -> URI::new); Compiler complains. Cannot infer type-variable(s) R What did I do wrong? 回答1: Stream.of(s.split("//s")).map(URI::new); click here for an example 来源： https://stackoverflow.com/questions/27613957/how-to-map-strings-to-uris

问题 After Java 7 to 8 migration, your project may exhibit an increased 500 error rate and you may see this error: Uncaught exception from servlet java.lang.OutOfMemoryError: Java heap space 回答1: Each application running in the standard environment on Google App Engine has an instance class, which determines its compute resources. A B2 instance class (or below) may no longer big enough and we recommend upgrading to a B4 instance. For more information on instance classes, see https://cloud.google