Talend：如何在tFileOutputExcel中使用相对路径或如何获取项目目录？

Question

Working with talend, I want to keep the project portable and therefore I need to avoid hardcoded absolute paths. Now I need to export a file as XLSX.

Assume my project resides here on my local hard drive under Windows "D:/MyLongAndFancyPathToProjects/MyCurrentProject/talend.project"

I the tFileOutputExcel component at "File Name" I started with "D:/MyLongAndFancyPathToProjects/MyCurrentProject/MyOutput/test.xlsx" which works great - but is exactly what I don't want.

Then I tried

• "MyCurrentProject/MyOutput/test.xlsx"
• "/MyCurrentProject/MyOutput/test.xlsx"

Somewhere those files where create, but where? Wasn't able to find them...

They where NOT created in the project directory: "D:/MyLongAndFancyPathToProjects/MyCurrentProject/"

How can I get the current project in Talend? If possible, I want to avoid configuration settings. This should work dynamically somehow.

Answer 1

I found the interested phenomenan that use simple relative directory statement "./" .

First, I used "tCreateTemporaryFile" with setting the directory "./test". When I execute in TOS, "test" directory was created in "C:/TOS_DI-Win32-r****-V5.3.1/test".

Next, I exported this job(name "myjob" ) to my Desktop and execute via batch, "test" directory was created in "Desktop/myjob_0.1/myjob/test".

Third, I resset the directory "../test" and expoted and executed at Desktop. The "test" directory was created in "Desktop/myjob_0.1/test".

We may be able to use simple relative directory "./" as current and "../" as parent.

Answer 2

I know you want it to work dynamically but your first step should be to create a context variable with the path to the folder containing your Excel file.

This can then be provided at run time or given a default value that works for you.

Once you have that working, the next trick is to try and get the path for where your job is executed from and use that if no path has been explicitly provided by context variable.

I've not got access to a Studio client right now to test this but it should be possible to use the tSystem component to get the current working directory. So in a Linux based OS you could run pwd from a tSystem component to get the folder path.

This should then be set as the folder path context variable if the provided one is null or blank.

Answer 3

Your File Structure Will be created in your talend installation directory For me it is C:\\Telend\\TOS_DI-Win32-20141207_1530-V5.6.1 now you have to get this path and store it in variable using globalMap.put("HOME_DIR", System.getProperty("user.dir"));
and now when ever try to give path to any file just add this globalMap before any file name ie : globalMap.get("HOME_DIR").toString()+"/config.csv"

and at last when you export job you have to put the same file near you exiqutable bat file so that will solve your problem :)

by doing this you can give dynamic path to your file

Answer 4

Here is a solution that I found. Note that the project path is only available when running from Talend Open Studio, not when running as a standalone app.

Add this Talend helper class in your routines:

package routines;

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.Optional;
import java.util.stream.Stream;

public class Talend {
    /**
     * @param projectName The project name, available as `projectName` in Talend components
     * @return the project path when run from Talend Open Studio or null when run as a standalone executable
     */
    public static Path projectPath(String projectName) {
        String[] classPathElements = System.getProperty("java.class.path", "").split(";");
        Stream<Path> classPaths = Arrays.stream(classPathElements).map(path -> Paths.get(path));
        Optional<Path> classesPath = classPaths.filter(path -> path.endsWith(Paths.get(".Java", "target", "classes"))).findAny();
        if (classesPath.isPresent()) {
            Path workspacePath = classesPath.get().getParent().getParent().getParent();
            Path projectPath = workspacePath.resolve(projectName);
            if (Files.isDirectory(projectPath)) {
                return projectPath;
            }
        }
        return null;
    }
}

Then in a tJava component at the beginning of your job you can save the project path in the global map for example:

java.nio.file.Path projectPath = Talend.projectPath(projectName);
if (projectPath != null) {
    globalMap.put("projectPath", projectPath.toString());
}