javac

问题 I receive the following warning: [javac] build.xml:9: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds What does this mean? 回答1: Ant Runtime Simply set includeantruntime="false" : <javac includeantruntime="false" ...>...</javac> If you have to use the javac -task multiple times you might want to consider using PreSetDef to define your own javac -task that always sets includeantruntime="false" . Additional Details From http:/

问题 Working with some basic java apps on CentOS 5 linux and I have my classpath set to point to home/pathToJava/bin which contains javac and java and I have .java files in home/pathToFolderA/src and home/pathToFolderB/gen-java When I run javac and java in home/pathToFolderA/src everything works perfectly But when I run javac from within home/pathToFolderB/gen-java on fileName.java I get a file not found error, specifically javac: file Not found: fileName.java Usage: javac <options> <source files>

问题 Ex. javac -g ButtMonkey.java Where do you configure the -g flag when Eclipse compiles Java source? (Using Ganymede but I doubt that has changed in later versions so any answer probably helps.) What I need is: -g Generate all debugging information, including local variables. By default, only line number and source file information is generated. 回答1: Select the menu: Window > Preferences > Java > Compiler There you will find several check boxes under the heading "Classfile Generation". 回答2: For

问题 Recently I encountered a file character encoding issue that I cannot remember ever having faced. It's quite common to have to be aware of character encoding of text files and write code that handles encoding correctly when run on different platforms. But the problem I found was caused by compilation on a different platform from the execution platform. That was entirely unexpected, because in my experience when javac creates a class file, the important parameters are the java source and target

问题 To tell the truth, I am quite confused on all these terms (JDK/JRE/Java SDK). I am not sure what each one does. When I first started doing simple java examples in eclipse, I am pretty sure I only had the JRE, which I believed was the default java installer regular users use to be able to run java programs/applets on their system. However, now in class we are using Google Appengine, and this requires the JDK which I am guessing is the same as Java SDK. After wasting some time finding out that

问题 I saved my Java source file specifying it's encoding type as UTF-8 (using Notepad, by default Notepad's encoding type is ANSI) and then I tried to compile it using: javac -encoding "UTF-8" One.java but it gave an error message" One.java:1: illegal character: \65279 ?public class One { ^ 1 error Is there any other way, I can compile this? Here is the source: public class One { public static void main( String[] args ){ System.out.println("HI"); } } 回答1: Your file is being read as UTF-8,

问题 The Java static compiler (javac) inlines some static final variables and brings the values directly to the constant pool. Consider the following example. Class A defines some constants (public static final variables): public class A { public static final int INT_VALUE = 1000; public static final String STRING_VALUE = "foo"; } Class B uses these constants: public class B { public static void main(String[] args) { int i = A.INT_VALUE; System.out.println(i); String s = A.STRING_VALUE; System.out

问题 I have read the previously posted questions. Some are vague and none solved my problem so I am forced to ask again. I have two simple classes, package One; import One.Inner.MyFrame; public class test { public static void main(String args[]) { MyFrame f= new MyFrame(); } } And the other class is, package One.Inner; import java.awt.*; import javax.swing.*; public class MyFrame extends JFrame { public MyFrame() { setPreferredSize(new Dimension(400,560)); setVisible(true); } } I am at base folder

问题 I'm trying to use javac with the windows command prompt, but it's not working. After adding the directory "C:\Program Files\Java\jdk1.6.0_16\bin\" to the end of the PATH environment variable, the java command works fine, but using javac gives me the following error: 'javac' is not recognized as an internal or external command, operable program or batch file. 回答1: If you added it in the control panel while your command prompt was open, that won't affect your current command prompt. You'll need

问题 I'm trying to use javac with the windows command prompt, but it's not working. After adding the directory "C:\Program Files\Java\jdk1.6.0_16\bin\" to the end of the PATH environment variable, the java command works fine, but using javac gives me the following error: 'javac' is not recognized as an internal or external command, operable program or batch file. 回答1: If you added it in the control panel while your command prompt was open, that won't affect your current command prompt. You'll need