How to use JavaCompiler from tools.jar without JDK
I am trying to create an application that can compile a provided .java file during runtime. I understand that there is a programmatical compiler available within the tools.jar of the JDK. However, I cannot guarantee that the user of the application has JDK. I have attempted to package tools.jar within the application and reference it as a library. This seems to work within the Eclipse IDE when I have tools.jar added into the Bootstrap Entries of the classpath. When exporting the application to a runnable jar (with tools.jar packaged with it),
ToolProvider.getSystemJavaCompiler(); returns null. I am not exactly sure what the issue is, but I believe it may have to do with the Bootstrap Entries of the classpath not being properly preserved when the application is exported to a runnable jar. Any ideas? Are there any alternatives to the tools.jar compiler that I could use? Thanks for your patience, as this is my first question posted here!
java eclipse classpath javacompiler tools.jar
asked Nov 14 '18 at 2:22
rgoulazian
82
add a comment |
I am trying to create an application that can compile a provided .java file during runtime. I understand that there is a programmatical compiler available within the tools.jar of the JDK. However, I cannot guarantee that the user of the application has JDK. I have attempted to package tools.jar within the application and reference it as a library. This seems to work within the Eclipse IDE when I have tools.jar added into the Bootstrap Entries of the classpath. When exporting the application to a runnable jar (with tools.jar packaged with it),
ToolProvider.getSystemJavaCompiler(); returns null. I am not exactly sure what the issue is, but I believe it may have to do with the Bootstrap Entries of the classpath not being properly preserved when the application is exported to a runnable jar. Any ideas? Are there any alternatives to the tools.jar compiler that I could use? Thanks for your patience, as this is my first question posted here!
java eclipse classpath javacompiler tools.jar
asked Nov 14 '18 at 2:22
rgoulazian
82
add a comment |
I am trying to create an application that can compile a provided .java file during runtime. I understand that there is a programmatical compiler available within the tools.jar of the JDK. However, I cannot guarantee that the user of the application has JDK. I have attempted to package tools.jar within the application and reference it as a library. This seems to work within the Eclipse IDE when I have tools.jar added into the Bootstrap Entries of the classpath. When exporting the application to a runnable jar (with tools.jar packaged with it),
ToolProvider.getSystemJavaCompiler(); returns null. I am not exactly sure what the issue is, but I believe it may have to do with the Bootstrap Entries of the classpath not being properly preserved when the application is exported to a runnable jar. Any ideas? Are there any alternatives to the tools.jar compiler that I could use? Thanks for your patience, as this is my first question posted here!
java eclipse classpath javacompiler tools.jar
asked Nov 14 '18 at 2:22
rgoulazian
82
I am trying to create an application that can compile a provided .java file during runtime. I understand that there is a programmatical compiler available within the tools.jar of the JDK. However, I cannot guarantee that the user of the application has JDK. I have attempted to package tools.jar within the application and reference it as a library. This seems to work within the Eclipse IDE when I have tools.jar added into the Bootstrap Entries of the classpath. When exporting the application to a runnable jar (with tools.jar packaged with it),
ToolProvider.getSystemJavaCompiler(); returns null. I am not exactly sure what the issue is, but I believe it may have to do with the Bootstrap Entries of the classpath not being properly preserved when the application is exported to a runnable jar. Any ideas? Are there any alternatives to the tools.jar compiler that I could use? Thanks for your patience, as this is my first question posted here!
java eclipse classpath javacompiler tools.jar
java eclipse classpath javacompiler tools.jar
asked Nov 14 '18 at 2:22
rgoulazian
82
asked Nov 14 '18 at 2:22
rgoulazian
82
asked Nov 14 '18 at 2:22
rgoulazian
82
asked Nov 14 '18 at 2:22
rgoulazian
82
asked Nov 14 '18 at 2:22
rgoulazian
82
82
add a comment |
add a comment |
1 Answer
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You need to use the compiler within "tools.jar"
ToolProvider.getSystemJavaCompiler()
will return the compiler from the jdk defined in the path variable,
you can do this instead:
File file = new File(pathToToolsJar);
URL urls = new URL{ file.toURI().toURL() };
ClassLoader loader = new URLClassLoader(urls);
Class compilerClass = loader.loadClass("com.sun.tools.javac.api.JavacTool");
JavaCompiler compiler = (JavaCompiler) compilerClass.getConstructor().newInstance();
Or you can add tools.jar as a library at compile time
import com.sun.tools.javac.api.JavacTool;
...
JavaCompiler compiler = new JavacTool();
Or you can change System properties, but that leads to unexpected behaviors
answered Nov 14 '18 at 2:41
Juan
525
Thanks for the fast response. This seems to work perfectly. Any chance I could get a brief explanation as to what the alternative is doing?
– rgoulazian
Nov 14 '18 at 3:00
Uhm, I'm not really sure why I suggested to use reflection, you could just add tools.jar as a library and instance it the old wayimport com.sun.tools.javac.api.JavacTool;JavaCompiler compiler = new JavacTool();
– Juan
Nov 14 '18 at 3:06
What I suggested originaly was to load tools.jar at runtime using reflection; Using URLClassLoader is an easy way to load dependencies at runtime, you just ask the loader for the class you want, and it looks in the urls you specified for the class
– Juan
Nov 14 '18 at 3:11
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You need to use the compiler within "tools.jar"
ToolProvider.getSystemJavaCompiler()
will return the compiler from the jdk defined in the path variable,
you can do this instead:
File file = new File(pathToToolsJar);
URL urls = new URL{ file.toURI().toURL() };
ClassLoader loader = new URLClassLoader(urls);
Class compilerClass = loader.loadClass("com.sun.tools.javac.api.JavacTool");
JavaCompiler compiler = (JavaCompiler) compilerClass.getConstructor().newInstance();
Or you can add tools.jar as a library at compile time
import com.sun.tools.javac.api.JavacTool;
...
JavaCompiler compiler = new JavacTool();
Or you can change System properties, but that leads to unexpected behaviors
answered Nov 14 '18 at 2:41
Juan
525
Thanks for the fast response. This seems to work perfectly. Any chance I could get a brief explanation as to what the alternative is doing?
– rgoulazian
Nov 14 '18 at 3:00
Uhm, I'm not really sure why I suggested to use reflection, you could just add tools.jar as a library and instance it the old wayimport com.sun.tools.javac.api.JavacTool;JavaCompiler compiler = new JavacTool();
– Juan
Nov 14 '18 at 3:06
What I suggested originaly was to load tools.jar at runtime using reflection; Using URLClassLoader is an easy way to load dependencies at runtime, you just ask the loader for the class you want, and it looks in the urls you specified for the class
– Juan
Nov 14 '18 at 3:11
add a comment |
You need to use the compiler within "tools.jar"
ToolProvider.getSystemJavaCompiler()
will return the compiler from the jdk defined in the path variable,
you can do this instead:
File file = new File(pathToToolsJar);
URL urls = new URL{ file.toURI().toURL() };
ClassLoader loader = new URLClassLoader(urls);
Class compilerClass = loader.loadClass("com.sun.tools.javac.api.JavacTool");
JavaCompiler compiler = (JavaCompiler) compilerClass.getConstructor().newInstance();
Or you can add tools.jar as a library at compile time
import com.sun.tools.javac.api.JavacTool;
...
JavaCompiler compiler = new JavacTool();
Or you can change System properties, but that leads to unexpected behaviors
answered Nov 14 '18 at 2:41
Juan
525
Thanks for the fast response. This seems to work perfectly. Any chance I could get a brief explanation as to what the alternative is doing?
– rgoulazian
Nov 14 '18 at 3:00
Uhm, I'm not really sure why I suggested to use reflection, you could just add tools.jar as a library and instance it the old wayimport com.sun.tools.javac.api.JavacTool;JavaCompiler compiler = new JavacTool();
– Juan
Nov 14 '18 at 3:06
What I suggested originaly was to load tools.jar at runtime using reflection; Using URLClassLoader is an easy way to load dependencies at runtime, you just ask the loader for the class you want, and it looks in the urls you specified for the class
– Juan
Nov 14 '18 at 3:11
add a comment |
You need to use the compiler within "tools.jar"
ToolProvider.getSystemJavaCompiler()
will return the compiler from the jdk defined in the path variable,
you can do this instead:
File file = new File(pathToToolsJar);
URL urls = new URL{ file.toURI().toURL() };
ClassLoader loader = new URLClassLoader(urls);
Class compilerClass = loader.loadClass("com.sun.tools.javac.api.JavacTool");
JavaCompiler compiler = (JavaCompiler) compilerClass.getConstructor().newInstance();
Or you can add tools.jar as a library at compile time
import com.sun.tools.javac.api.JavacTool;
...
JavaCompiler compiler = new JavacTool();
Or you can change System properties, but that leads to unexpected behaviors
answered Nov 14 '18 at 2:41
Juan
525
You need to use the compiler within "tools.jar"
ToolProvider.getSystemJavaCompiler()
will return the compiler from the jdk defined in the path variable,
you can do this instead:
File file = new File(pathToToolsJar);
URL urls = new URL{ file.toURI().toURL() };
ClassLoader loader = new URLClassLoader(urls);
Class compilerClass = loader.loadClass("com.sun.tools.javac.api.JavacTool");
JavaCompiler compiler = (JavaCompiler) compilerClass.getConstructor().newInstance();
Or you can add tools.jar as a library at compile time
import com.sun.tools.javac.api.JavacTool;
...
JavaCompiler compiler = new JavacTool();
Or you can change System properties, but that leads to unexpected behaviors
answered Nov 14 '18 at 2:41
Juan
525
edited Nov 14 '18 at 3:10
answered Nov 14 '18 at 2:41
Juan
525
answered Nov 14 '18 at 2:41
Juan
525
answered Nov 14 '18 at 2:41
Juan
525
525
Thanks for the fast response. This seems to work perfectly. Any chance I could get a brief explanation as to what the alternative is doing?
– rgoulazian
Nov 14 '18 at 3:00
Uhm, I'm not really sure why I suggested to use reflection, you could just add tools.jar as a library and instance it the old wayimport com.sun.tools.javac.api.JavacTool;JavaCompiler compiler = new JavacTool();
– Juan
Nov 14 '18 at 3:06
What I suggested originaly was to load tools.jar at runtime using reflection; Using URLClassLoader is an easy way to load dependencies at runtime, you just ask the loader for the class you want, and it looks in the urls you specified for the class
– Juan
Nov 14 '18 at 3:11
add a comment |
Thanks for the fast response. This seems to work perfectly. Any chance I could get a brief explanation as to what the alternative is doing?
– rgoulazian
Nov 14 '18 at 3:00
Uhm, I'm not really sure why I suggested to use reflection, you could just add tools.jar as a library and instance it the old wayimport com.sun.tools.javac.api.JavacTool;JavaCompiler compiler = new JavacTool();
– Juan
Nov 14 '18 at 3:06
What I suggested originaly was to load tools.jar at runtime using reflection; Using URLClassLoader is an easy way to load dependencies at runtime, you just ask the loader for the class you want, and it looks in the urls you specified for the class
– Juan
Nov 14 '18 at 3:11
Thanks for the fast response. This seems to work perfectly. Any chance I could get a brief explanation as to what the alternative is doing?
– rgoulazian
Nov 14 '18 at 3:00
Thanks for the fast response. This seems to work perfectly. Any chance I could get a brief explanation as to what the alternative is doing?
– rgoulazian
Nov 14 '18 at 3:00
Uhm, I'm not really sure why I suggested to use reflection, you could just add tools.jar as a library and instance it the old way
import com.sun.tools.javac.api.JavacTool; JavaCompiler compiler = new JavacTool();– Juan
Nov 14 '18 at 3:06
Uhm, I'm not really sure why I suggested to use reflection, you could just add tools.jar as a library and instance it the old way
import com.sun.tools.javac.api.JavacTool; JavaCompiler compiler = new JavacTool();– Juan
Nov 14 '18 at 3:06
What I suggested originaly was to load tools.jar at runtime using reflection; Using URLClassLoader is an easy way to load dependencies at runtime, you just ask the loader for the class you want, and it looks in the urls you specified for the class
– Juan
Nov 14 '18 at 3:11
What I suggested originaly was to load tools.jar at runtime using reflection; Using URLClassLoader is an easy way to load dependencies at runtime, you just ask the loader for the class you want, and it looks in the urls you specified for the class
– Juan
Nov 14 '18 at 3:11
add a comment |
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