GWT 2.8 编译器警告

Question

当我从GWT 2.7切换到2.8时，我开始收到以下警告。我正在使用ant和Oracle Java 7从命令行编译。当我切换回GWT 2.7时，我不会收到任何这些警告。

                           [WARN] Ignoring unresolvable annotation type java.lang.FunctionalInterface
 [java]    Resolving java.lang.Runnable
 [java]       Found type 'java.lang.Runnable'
 [java]          [WARN] Ignoring unresolvable annotation type java.lang.FunctionalInterface
 [java]    Resolving java.util.Arrays
 [java]       Found type 'java.util.Arrays'
 [java]          Resolving method parallelPrefix
 [java]             Found type 'java.util.function.BinaryOperator'
 [java]                [WARN] Ignoring unresolvable annotation type java.lang.FunctionalInterface
 [java]                Found type 'java.util.function.BiFunction'
 [java]                   [WARN] Ignoring unresolvable annotation type java.lang.FunctionalInterface
 [java]          Resolving method setAll
 [java]             Found type 'java.util.function.IntFunction'
 [java]                [WARN] Ignoring unresolvable annotation type java.lang.FunctionalInterface
 [java]          Resolving method stream
 [java]             Found type 'java.util.stream.Stream'
 [java]                Resolving method collect
 [java]                   Found type 'java.util.stream.Collector'
 [java]                      Resolving method supplier
 [java]                         Found type 'java.util.function.Supplier'
 [java]                            [WARN] Ignoring unresolvable annotation type java.lang.FunctionalInterface
 [java]                      Resolving method accumulator
 [java]                         Found type 'java.util.function.BiConsumer'
 [java]                            [WARN] Ignoring unresolvable annotation type java.lang.FunctionalInterface
 [java]                Resolving method flatMapToDouble
 [java]                   Found type 'java.util.stream.DoubleStream'
 [java]                      Resolving method collect
 [java]                         Found type 'java.util.function.ObjDoubleConsumer'
 [java]                            [WARN] Ignoring unresolvable annotation type java.lang.FunctionalInterface
 [java]                      Resolving method flatMap
 [java]                         Found type 

- user2411465

Answer 1

java.lang.FunctionalInterface 是在Java 8中添加的，而GWT是从类路径解析注释的，因此，由于Java运行时模拟库已更新到Java 8，当使用Java 7 VM与GWT 2.8一起使用时，会出现这些警告。

由于Java 7已经EOL'd了一段时间，因此在这种情况下有这些警告被认为是可以接受的。与GWT无关，建议您升级到Java 8。

- Thomas Broyer