Question

我正在尝试为用户登录的每个用户名创建一个文件夹。目前我有

private String destination = "C:/Users/Richard/printing~subversion/fileupload/web/WEB-INF/uploaded/"; // main location for uploads
File theFile = new File(destination + username); // will create a sub folder for each user

但File theFile位不会为用户名创建新文件夹。我该怎么做？

我试过了

private String destination;

public void File() 
{
    destination = "C:/Users/Richard/printing~subversion/fileupload/web/WEB-INF/uploaded/"; // main location for uploads
    File theFile = new File(destination + username); // will create a sub folder for each user (currently does not work, below hopefully is a solution) 
    theFile.mkdirs();
}

但我需要稍后在程序中使用目的地，我该怎么做？

这是我的全部代码：

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package richard.fileupload;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.annotation.PostConstruct;
import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.faces.event.ActionEvent;
import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import javax.faces.context.FacesContext;
import java.io.File;
import org.primefaces.event.FileUploadEvent;

@ViewScoped
@ManagedBean(name = "fileUploadController")
public class FileUploadController {

    /*
     public void handleFileUpload(FileUploadEvent event) {
     System.out.println("called");
     FacesMessage msg = new FacesMessage("Succesful", event.getFile().getFileName() + " is uploaded.");
     FacesContext.getCurrentInstance().addMessage(null, msg);
     }
     }
     */
    private String username;
    private String destination;

    @PostConstruct
    public void init() {
        System.out.println("called get username");
        username = FacesContext.getCurrentInstance().getExternalContext().getRemoteUser();
    }

    public void File() {
    destination = "C:/Users/Richard/printing~subversion/fileupload/web/WEB-INF/uploaded/"; // main location for uploads
    File theFile = new File(destination + username); // will create a sub folder for each user (currently does not work, below hopefully is a solution) 
    theFile.mkdirs();
}

    public File getDirectory(String destination, String username) {
        System.out.println("called get directory");
        // currently not working, is not calling the username or destination 
        //set the user directory from the destinarion and the logged user name
        File directory = new File(destination, username);
        //check if the location exists
        if (!directory.exists()) {
            //let's try to create it
            try {
                directory.mkdir();
            } catch (SecurityException secEx) {
                //handle the exception
                secEx.printStackTrace(System.out);
                directory = null;
            }
        }
        return directory;
    }

    public void handleFileUpload(FileUploadEvent event) {
        System.out.println("called handle file");
        FacesMessage msg = new FacesMessage("Succesful", event.getFile().getFileName() + " is uploaded."); //Displays to user on the webpage
        FacesContext.getCurrentInstance().addMessage(null, msg);
        try {
            copyFile(event.getFile().getFileName(), event.getFile().getInputstream());
        } catch (IOException e) {
            //handle the exception
            e.printStackTrace();
        }
    }

    public void copyFile(String fileName, InputStream in) {
        try {


            // write the inputStream to a FileOutputStream
            OutputStream out = new FileOutputStream(new File(destination + fileName)); // cannot find path when adding username atm
            System.out.println("Called CopyFile"); //testing 
            System.out.println(destination + fileName);

            int read = 0;
            byte[] bytes = new byte[1024];

            while ((read = in.read(bytes)) != -1) {
                out.write(bytes, 0, read);
            }

            in.close();
            out.flush();
            out.close();
//make sure new file is created, (displays in glassfish server console not to end user)
            System.out.println("New file created!");//testing
        } catch (IOException e) {
            e.printStackTrace();

            FacesMessage error = new FacesMessage("The files were not uploaded!");
            FacesContext.getCurrentInstance().addMessage(null, error);
        }
    }
}

最终编辑（希望）

 public void copyFile(String fileName, InputStream in) {
        try {

            destination = "C:/Users/Richard/printing~subversion/fileupload/web/WEB-INF/uploaded/"; // main location for uploads
            File theFile = new File(destination + "/" + username); 
            theFile.mkdirs();// will create a sub folder for each user (currently does not work, below hopefully is a solution) (DOES NOW WORK)

            System.out.println("Completed File");
            // write the inputStream to a FileOutputStream
            OutputStream out = new FileOutputStream(new File(destination + fileName)); // cannot find path when adding username atm
            System.out.println("Called CopyFile"); //testing 
            System.out.println(destination + fileName);

            int read = 0;
            byte[] bytes = new byte[1024];

            while ((read = in.read(bytes)) != -1) {
                out.write(bytes, 0, read);
            }

            in.close();
            out.flush();
            out.close();
//make sure new file is created, (displays in glassfish server console not to end user)
            System.out.println("New file created!");//testing
        } catch (IOException e) {
            e.printStackTrace();

            FacesMessage error = new FacesMessage("The files were not uploaded!");
            FacesContext.getCurrentInstance().addMessage(null, error);
        }
    }
}

我怎样才能打印出新目的地并在以后使用它，因为它目前创建了新文件夹但未选择使用

编辑解决了这个问题：

    NewDestination = "C:/Users/Richard/printing~subversion/fileupload/web/WEB-INF/uploaded/" + username;

添加了上述代码，现在一切正常

Answer 1

你必须实际调用一些方法来创建目录。仅创建file对象不会在文件系统上创建相应的文件或目录。

您可以使用File#mkdirs()方法创建目录： -

theFile.mkdirs();

File#mkdir()和File#mkdirs()之间的区别在于，如果它不存在，后者将创建任何中间目录。

Answer 2

如果在创建/编辑文件时不存在中间文件夹，请使用此代码段创建中间文件夹：

File outFile = new File("/dir1/dir2/dir3/test.file");
outFile.getParentFile().mkdirs();
outFile.createNewFile();

Answer 3

Benoit Blanchon here可以找到一个很好的Java 7+答案：

使用Java 7，您可以使用Files.createDirectories()。

例如：

Files.createDirectories(Paths.get("/path/to/directory"));

如果不存在，则创建中间文件夹

3 个答案: