io.robe.common.utils.FileOperations Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of robe-common Show documentation

There is a newer version: 0.5.0.0-1039

package io.robe.common.utils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.UUID;

/**
 * Util Class for all file operations.
 */
public class FileOperations {

    public static final String JAVA_IO_TMP_DIR = "java.io.tmpdir";
    public static final String TEMP_DIR = System.getProperty(JAVA_IO_TMP_DIR);

    private FileOperations() {

    }


    /**
     * Writes inputstream to a temporary file under OS's native temp folder with a unique name.
     *
     * @param in InputStream from any source.
     * @return File instance of temporary file.
     * @throws java.io.IOException
     */
    public static File writeToTemp(InputStream in) throws IOException {

        //Create an unique name and replace all unwanted chars.
        String tempName = UUID.randomUUID().toString().replaceAll("-", "");

        //Create new temp file under OS's temp folder with a random name
        File tempFile = new File(TEMP_DIR, tempName + ".tmp");
        if (!tempFile.createNewFile()) {
            throw new IOException("Can not create temp file :" + tempFile.getParent());
        } else if (in == null) {
            return tempFile;
        }
        //Write file with a 1024 byte buffer.
        try (FileOutputStream tempOS = new FileOutputStream(tempFile)) {
            byte[] buf = new byte[1024];
            int i = in.read(buf);
            while (i != -1) {
                tempOS.write(buf, 0, i);
                i = in.read(buf);
            }
        } finally {
            in.close();
        }
        return tempFile;
    }

}