javac

问题 I'm trying to understand the difference between javac's -classpath and -sourcepath options, regarding automatic recompilation of source code files. I read the Java documentation on the subject of javac, and for its -sourcepath option it stated - Note: Classes found through the class path may be subject to automatic recompilation if their sources are also found I also looked at this webpage (idevelopment.info), to learn more about javac's -classpath and -sourcepath options. In their example,

问题 Currently we are in the process of re-scripting all of our build system for a large project (around 2000 source files) and there has been talk of doing a binary comparison on the files to ensure that everything is correct which leads to the following question: Is the output of javac guaranteed to be same across compilations or could it be subject to change? Another question implied that the constant pool could have a different order, but assuming we are able to control for the order of the

问题 After upgrading a Maven project to Java 9 and adding a module descriptor, javac complains about a transitive dependency for an automatic module: [WARNING] /.../src/main/java/module-info.java:[3,35] requires transitive directive for an automatic module An example module-info.java to reproduce the problem: module com.example.mymodule { exports com.example.mymodule.myexportedpackage; requires transitive com.google.common; } The meaning of this warning is completely clear, here are some related

问题 After upgrading a Maven project to Java 9 and adding a module descriptor, javac complains about a transitive dependency for an automatic module: [WARNING] /.../src/main/java/module-info.java:[3,35] requires transitive directive for an automatic module An example module-info.java to reproduce the problem: module com.example.mymodule { exports com.example.mymodule.myexportedpackage; requires transitive com.google.common; } The meaning of this warning is completely clear, here are some related

问题 the following code: @Retention(RetentionPolicy.RUNTIME) @Target( { ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE }) @Constraint(validatedBy = { MinTimeIntCoConstraintValidator.class, MinTimeIntCoListConstraintValidator.class, MinTimeDoubleCoConstraintValidator.class, MinTimeDoubleCoListConstraintValidator.class, }) @Documented public @interface MinTimeValueCo { int value(); String message() default "value does not match minimum requirements"; Class<?>[] groups() default {

问题 I have the following piece of code public class TeeingCollector { public static void main(String[] args) { // var strs = List.of("abc"); var dividedStrings = Stream.of("foo", "hello", "bar", "world") .collect(Collectors.teeing( Collectors.filtering((String s) -> s.length() <= 3, Collectors.toList()), Collectors.filtering((String s) -> s.length() > 3, Collectors.toList()), List::of )); System.out.println(dividedStrings); } private static class Employee { boolean isActive; public Employee

问题 Can anybody tell me the jsr14 target option of javac will be still available with JDK7/8? Say, $ javac -source 1.5 -target jsr14 Hello.java 回答1: We are heavily using -jsr14 in OSGi because it allows us to use generics in our API but still deploy on 1.4 environments, which are still popular in embedded. Unfortunately, they made JDK 7 not backward compatible with Java 6 and 5. Javac 1.7 ignores the generic information that is actually present in the JAR files. There is fortunately no problem at

问题 I have a project where I am responsible for fixing some errors and another developer is responsible for other errors. The number of errors is well over a hundred, and as I'm fixing my errors, her errors are piling up. I'm at the point where I see 99 of her errors and one of mine, and I assume I will soon get to a point where it is 100 of hers. I looked into using this configuration for maven: <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId>

问题 I'm using reflection to load MyClass.class (an external file) at runtime. MyClass.class uses the library Bar , which would mean that I need to place import foo.Bar; at the top of the file. However, the Bar library is already loaded in the main class loading MyClass . Is there a way for me to tell javac to ignore that Bar doesn't exist and just compile without it? 回答1: No this is not possible. When compiling a class, the compiler has no "memory" of which classes were already "loaded" (don't

问题 I'm building the basic Slick game example explained here: http://slick.cokeandcode.com/wiki/doku.php?id=01_-_a_basic_slick_game, and I'm running into some problems. Specifically, the game compiles just fine, but when I try to run it, Java complains: Exception in thread "main" java.lang.UnsatisfiedLinkError: no lwjgl in java.library.path at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1856) at java.lang.Runtime.loadLibrary0(Runtime.java:845) at java.lang.System.loadLibrary(System.java