I have a package called studentServer which contains two sub packages student and common.
The common folder has references to the student package and i would like to be able to compile this. How could i do this?
javac student\*.java - compiles the student package
but when i try something similar with the common package errors are thrown - I understand it's something to do with the classpath
javac -verbose -classpath "\student" common\*.java
But I couldn't get this working. Any help would be great.
http://pastebin.com/m2a2f5d5d - here's the output from the compiler
This is a bit vague, but I suspect the classpath for the student code is wrong. Try without the leading backslash.
If you have a directory structure
source/
studentServer/
student/
common/
classes/
And you're in the directory above source, then you want to set the source path to 'source' with the -sourcepath option. You probably also want to use the -d option to tell javac where to put the compiled classes, so they aren't all mixed up with the source:
java -d classes -sourcepath source source/studentServer/student/*.java source/studentServer/common/*.java
go like this
c:\>
use change directory command cd until you get the desired directory
(ex: c:\javaEx\proj1\)
now
cd javaEx go like this
c:\javaEx\proj1\javac *.java
now compilation done in all java files in the proj1 directory.
Related
I'm trying to run java from the command line, and haven't had to include extra packages with the javac command before and I can't figure out what I'm doing wrong.
I'm running javac -d bin -cp jar1:jar2:...:jarN:PackageName MyClass.java but I'm still getting an error: package PackageName does not exist
I'm using the absolute paths for everything, and I also tried individually listing the java files inside the package but that didn't work either. I'm using a colon since I'm on a mac.
Anyone know what I am doing wrong? Thanks for any help!
I realized that I needed to compile the java files in PackageName before I could compile MyClass.java, which depended on them. So what I needed to do was: javac -d bin -cp jar1:jar2:...:jarN PackageName/*.java and then I could compile MyClass.java with bin added to the classpath as well as the jars.
Based on this tutorial I tried to create my own basic Lucene search application. You can also use the given example directly, it has no bearing on my question.
So my file B.java begins with:
import org.apache.lucene.analysis.standard.StandardAnalyzer;
And although I have supplied the classpaths in javac,
javac -cp ~/lucene-4.10.2/core/lucene-core-4.10.2.jar
:~/lucene-4.10.2/analysis/common/lucene-analyzers-common-4.10.2.jar
B.java
I get errors like this:
B.java:1: error: package org.apache.lucene.analysis.standard does not exist
I use the plural because this also occurs for other packages where the .class is inside a given JAR (checked using unzip -l). I assume if I can find the solution for this, it should apply for the other cases as well... what am I missing out here?
OK, I seem to have found the answer.
For some reason, when including the ~ which expands to my $HOME directory, this makes javac unable to find the correct path:
javac -cp ~/lucene-4.10.2/core/lucene-core-4.10.2.jar
:~/lucene-4.10.2/analysis/common/lucene-analyzers-common-4.10.2.jar
B.java
I made a soft link to the directory instead:
$ ln -s ~/lucene-4.10.2/ lucenepath
Then using the symlink, it worked:
javac -cp lucenepath/core/lucene-core-4.10.2.jar
:lucenepath/analysis/common/lucene-analyzers-common-4.10.2.jar
B.java
Not sure why this is the case.
I just got a makefile like this
CLASSPATH=.:/usr/share/java/antlr.jar
Mipsim.class: Mipsim.java MipsimLexer.class MipsimLexerTokenTypes.class MipsimParser.class Memory.class Processor.class
javac -classpath .:/usr/share/java/antlr.jar Mipsim.java
Memory.class: Memory.java MemoryAccessible.class
javac Memory.java
Processor.class: Processor.java
javac Processor.java
MemoryAccessible.class: MemoryAccessible.java
javac MemoryAccessible.java
MipsimLexer.java MipsimLexerTokenTypes.java MipsimParser.java: Mipsim.g
antlr Mipsim.g
MipsimLexerTokenTypes.class: MipsimLexerTokenTypes.java
javac MipsimLexerTokenTypes.java
MipsimLexer.class: MipsimLexer.java
javac MipsimLexer.java
MipsimParser.class: MipsimParser.java
javac MipsimParser.java
clean:
rm -f *.class MipsimLexer.* MipsimLexerTokenTypes.* MipsimParser.*
I have to run this make file, and build the object code.
However, the terminal told this
antlr Mipsim.g
make: antlr: No such file or directory
make: *** [MipsimLexer.java] Error 1
I guess probably anrlr.jar couldn't be found in this case. So I just changed the CLASSPATH into
CLASSPATH=.:/antlr.jar
and put antlr.jar in the same folder, then tried it again. The same error just happened again.....
Could somebody please help me out?
Thanks
CLASSPATH=.:/antlr.jar
That's not going to work. It says to use the current directory and the antlr.jar file in the root file system (which probably won't exist).
You may want to try:
CLASSPATH=.:./antlr.jar
And make sure that it exists for the duration of the antlr executable. Some make programs will execute each command in a separate shell so changing the CLASSPATH may not carry forward. I tend to use the bash "set variable for one process" method:
CLASSPATH=.:./antlr.jar antlr Mipsim.g
On top of that, the way you generally run antlr is by running java, giving the class you want to run, with something like:
java -cp ./antlr.jar org.antlr.Tool Mipsim.g
If you have an executable file (or script) antlr which will do that for you, it appears not to be in your path.
I know this question has been asked and answered a number of times. But I somehow am not able to get this right. I have a package having the following structure
model/
InputDetails.java
RelationDetails.java
Now the file RelationDetails has the following structure:
package model;
public class RelationDetails {
....
}
And the file InputDetails has the following structure
package model;
public class InputDetails {
.....
}
Now I have compiled the RelationDetails.java file that creates a RelationDetails.class file in the same directory.
But when I try to compile the InputDetails.java file, It shows the error
Symbol not found
wherever RelationDetails has been used. Where am I going wrong??
I'd recommend using an IDE like Eclipse or IntelliJ IDEA. They will do the compiling for you. Or use Ant, Gradle or Maven to compile. I am a professional Java developer and I cannot remember the last time I used javac from the command line. There's no need for it.
If you insist on using javac directly, either compile both files together from the appropriate source folder (the directory above "model").:
javac "model/InputDetails.java" "model/RelationDetails.java"
Or, if you want to compile them separately:
javac -classpath . "model/InputDetails.java"
javac -classpath . "model/RelationDetails.java"
The -classpath . bit adds the current folder to the classpath for the javac executable, so it can find the previously compiled class and you won't get the 'Symbol not found' errors.
$ pwd
/tmp/model
$ ls
InputDetails.java RelationDetails.java
$ javac InputDetails.java RelationDetails.java
$ ls *.class
InputDetails.class RelationDetails.class
I am just tried in my eclipse nothing will be showing errors, better to user Eclipse or STS they will help you like this problems easily I think so..
compile with fully qualifier name.
javac model\YourClass.java
How to compile all files in directory to *.class files?
Well, this seems pretty obvious, so I may be missing something
javac *.java
(With appropriate library references etc.)
Or perhaps:
javac -d bin *.java
to javac create the right directory structure for the output.
Were you looking for something more sophisticated? If so, could you give more details (and also which platform you're on)?
Yet another way using "find" on UNIX is described here:
http://stas-blogspot.blogspot.com/2010/01/compile-recursively-with-javac.html
The following two commands will compile all .java files contained within the directory ./src and its subdirectories:
find ./src -name *.java > sources_list.txt
javac -classpath "${CLASSPATH}" #sources_list.txt
First, find generates sources_list.txt, a file that contains the paths to the Java source files. Next, javac compiles all these sources using the syntax #sources_list.txt.
Here's a code fragment that I use to build an entire project where, as usual, source files are in a deeply nested hierarchy and there are many .jar files that must go into the classpath (requires UNIX utilities):
CLASSPATH=
for x in $(find | grep jar$); do CLASSPATH="$CLASSPATH:$x"; done
SRC=$(find | grep java$)
javac -cp "$CLASSPATH" $SRC