我最近安装了jdk10.我正在做正常的代码,但它无法正常工作.
我在这里做错了吗?
请参阅代码和异常堆栈跟踪.
据我所知,这种行为应该没有理由.
import com.bean.College;
public class Student {
interface Club {
<T> T get(College<T> key);
}
private Club club;
Student() {
Object obj = club.get(new College<>() {});
}
}
进口的大学课程是:
public class College<T> {
int id;
protected College() {
}
College(int id){
this.id=id;
}
}
在编译时,javac编译器与以下堆栈跟踪崩溃:
java.lang.NullPointerException
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitApply(Flow.java:1233)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1634)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitVarDef(Flow.java:987)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCVariableDecl.accept(JCTree.java:956)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:57)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitBlock(Flow.java:995)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1020)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitMethodDef(Flow.java:962)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:866)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitClassDef(Flow.java:925)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:774)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.analyzeTree(Flow.java:1325)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.analyzeTree(Flow.java:1315)
at jdk.compiler/com.sun.tools.javac.comp.Flow.analyzeTree(Flow.java:216)
at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1393)
at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1367)
at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:965)
at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:306)
at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:165)
at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:57)
at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:43)
解决方法:
这是一个尚未解决的漏洞.计划在jdk 11中解决该错误.
JDK-8203195-匿名类类型推断导致NPE
Type: Bug
Status: In Progress
Priority: P2
Resolution: Unresolved
Affects Version/s: 9, 10, 10.0.1, 11
Fix Version/s: 11
Component/s: tools
Labels: dcsfai reproducer-yes webbug
Subcomponent: javac
CPU: generic
OS: generic
https://bugs.openjdk.java.net/projects/JDK/issues/JDK-8203195?filter=allopenissues
但是,在bug描述中提到了一个工作原理:
Interestingly, changing A.java to do the following:
Object baz => foo.foo(new B<Object>() {});
or changing foo/B.java to the
following:06001
results in a successful compilation.