javanetbeansfile-iorelative-pathd2rq

How I can write a file using relative path in Java


I have a question:

I have this Java Code:

public void generate_mapping() throws FileNotFoundException {

        String fileMapping = "./src/mappingFile.ttl";
        SystemLoader loader = new SystemLoader();

        File f = new File(mappingFile);
        try {
            f.createNewFile();
        } catch (IOException ex) {
            Logger.getLogger(Prova.class.getName()).log(Level.SEVERE, null, ex);
        }
        PrintStream out;
        out = new PrintStream(new FileOutputStream(f));
        MappingGenerator generator = loader.openMappingGenerator();
        try {
            generator.setInstanceNamespaceURI("http://Group");
            generator.setVocabNamespaceURI("http://relation");
            generator.writeMapping(out);
        } finally {
            loader.closeMappingGenerator();
        }

    }

this code generates a mapping and uses D2RQ library. When I execute this code, I get this error given from the relative path:

java.io.IOException: Impossibile trovare il percorso specificato
    at java.io.WinNTFileSystem.createFileExclusively(Native Method)
    at java.io.File.createNewFile(File.java:1006)
    at MyPackage.Prova.generate_mapping(Prova.java:56)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
    at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
    at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4695)
    at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:630)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:582)
    at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:55)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:582)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
    at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4667)
    at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4655)
    at com.sun.ejb.containers.WebServiceInvocationHandler.invoke(WebServiceInvocationHandler.java:193)
    at com.sun.proxy.$Proxy299.publishLinkedOpenData(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.glassfish.webservices.InvokerImpl.invoke(InvokerImpl.java:82)
    at org.glassfish.webservices.EjbInvokerImpl.invoke(EjbInvokerImpl.java:82)
    at com.sun.xml.ws.server.InvokerTube$2.invoke(InvokerTube.java:149)
    at com.sun.xml.ws.server.sei.SEIInvokerTube.processRequest(SEIInvokerTube.java:88)
    at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
    at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
    at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
    at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
    at com.sun.xml.ws.api.pipe.helper.AbstractTubeImpl.process(AbstractTubeImpl.java:136)
    at org.glassfish.webservices.MonitoringPipe.process(MonitoringPipe.java:142)
    at com.sun.xml.ws.api.pipe.helper.PipeAdapter.processRequest(PipeAdapter.java:119)
    at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
    at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
    at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
    at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
    at com.sun.xml.ws.api.pipe.helper.AbstractTubeImpl.process(AbstractTubeImpl.java:136)
    at com.sun.enterprise.security.webservices.CommonServerSecurityPipe.processRequest(CommonServerSecurityPipe.java:210)
    at com.sun.enterprise.security.webservices.CommonServerSecurityPipe.process(CommonServerSecurityPipe.java:142)
    at com.sun.xml.ws.api.pipe.helper.PipeAdapter.processRequest(PipeAdapter.java:119)
    at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
    at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
    at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
    at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
    at com.sun.xml.ws.server.WSEndpointImpl$2.process(WSEndpointImpl.java:420)
    at com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:687)
    at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:266)
    at com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:169)
    at org.glassfish.webservices.Ejb3MessageDispatcher.handlePost(Ejb3MessageDispatcher.java:110)
    at org.glassfish.webservices.Ejb3MessageDispatcher.invoke(Ejb3MessageDispatcher.java:80)
    at org.glassfish.webservices.EjbWebServiceServlet.dispatchToEjbEndpoint(EjbWebServiceServlet.java:203)
    at org.glassfish.webservices.EjbWebServiceServlet.service(EjbWebServiceServlet.java:146)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.glassfish.grizzly.servlet.ServletHandler.doServletService(ServletHandler.java:242)
    at org.glassfish.grizzly.servlet.ServletHandler.service(ServletHandler.java:193)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:246)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
    at java.lang.Thread.run(Thread.java:744)

Grave:   java.io.FileNotFoundException: .\src\mappingFile.ttl (Impossibile trovare il percorso specificato)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:171)
    at MyPackage.Prova.generate_mapping(Prova.java:56)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
    at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
    at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4695)
    at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:630)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:582)
    at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:55)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:582)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
    at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4667)
    at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4655)
    at com.sun.ejb.containers.WebServiceInvocationHandler.invoke(WebServiceInvocationHandler.java:193)
    at com.sun.proxy.$Proxy299.publishLinkedOpenData(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.glassfish.webservices.InvokerImpl.invoke(InvokerImpl.java:82)
    at org.glassfish.webservices.EjbInvokerImpl.invoke(EjbInvokerImpl.java:82)
    at com.sun.xml.ws.server.InvokerTube$2.invoke(InvokerTube.java:149)
    at com.sun.xml.ws.server.sei.SEIInvokerTube.processRequest(SEIInvokerTube.java:88)
    at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
    at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
    at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
    at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
    at com.sun.xml.ws.api.pipe.helper.AbstractTubeImpl.process(AbstractTubeImpl.java:136)
    at org.glassfish.webservices.MonitoringPipe.process(MonitoringPipe.java:142)
    at com.sun.xml.ws.api.pipe.helper.PipeAdapter.processRequest(PipeAdapter.java:119)
    at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
    at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
    at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
    at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
    at com.sun.xml.ws.api.pipe.helper.AbstractTubeImpl.process(AbstractTubeImpl.java:136)
    at com.sun.enterprise.security.webservices.CommonServerSecurityPipe.processRequest(CommonServerSecurityPipe.java:210)
    at com.sun.enterprise.security.webservices.CommonServerSecurityPipe.process(CommonServerSecurityPipe.java:142)
    at com.sun.xml.ws.api.pipe.helper.PipeAdapter.processRequest(PipeAdapter.java:119)
    at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
    at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
    at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
    at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
    at com.sun.xml.ws.server.WSEndpointImpl$2.process(WSEndpointImpl.java:420)
    at com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:687)
    at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:266)
    at com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:169)
    at org.glassfish.webservices.Ejb3MessageDispatcher.handlePost(Ejb3MessageDispatcher.java:110)
    at org.glassfish.webservices.Ejb3MessageDispatcher.invoke(Ejb3MessageDispatcher.java:80)
    at org.glassfish.webservices.EjbWebServiceServlet.dispatchToEjbEndpoint(EjbWebServiceServlet.java:203)
    at org.glassfish.webservices.EjbWebServiceServlet.service(EjbWebServiceServlet.java:146)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.glassfish.grizzly.servlet.ServletHandler.doServletService(ServletHandler.java:242)
    at org.glassfish.grizzly.servlet.ServletHandler.service(ServletHandler.java:193)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:246)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
    at java.lang.Thread.run(Thread.java:744)

My question is: how I can write a file using a relative path? And How I can read this file after I have write it? I'm using Netbeans.


Solution

  • You should do something like this:

    Path relativePath = Paths.get("<put your path here>");
    Path absolutePath = relativePath.toAbsolutePath();
    System.out.println("Current relative path is: " + absolutePath.toString());
    

    Another option could be:

    String workingDir = System.getProperty("user.dir");
    

    This gives you the current working dir, so then work you path from it.

    EDIT

    For what you say in the comment: There is no problem in using relative paths, Your problem then could be one of these alternatives:

    But, even you you want to work with relative paths, at some point (even if you do not do it explicitly), they get converted to absolute paths, so it would do no harm to you to convert them to absolute paths just before using them, at least when debugging or while you get some confidence working with paths.