修改 java 代码从 Linux 命令行读取输入文件

Question

I am new to Java. This is a code for OCR from image/pdf to text using tess4j. I just want to modify it so that it takes OCR_file.png/OCR_file.pdf from input in the command line and not by specifying path as below-

package tess4j;

import java.io.File;
import java.io.*;
import net.sourceforge.tess4j.*;

public class Test{

public static void main(String[] args) {
    // ImageIO.scanForPlugins(); // for server environment
    File imageFile = new File("//home//desktop//OCR_file.png");
    ITesseract instance = new Tesseract(); // JNA Interface Mapping
    // ITesseract instance = new Tesseract1(); // JNA Direct Mapping
    instance.setDatapath("//home//desktop//tessdata"); // replace <parentPath> with path to parent directory of tessdata
    // instance.setLanguage("eng");

    try {
        String result = instance.doOCR(imageFile);
        System.out.println(result);
    } catch (TesseractException e) {
        System.err.println(e.getMessage());
    }
 }
}

Answer 1

that's what the (String[] args) is for, if I'm reading your question correctly.

if you run test.java -"//home//desktop//OCR_file.pdf" in command line/terminal it should be saved to args[0].

so if you rewrite the imageFile initialization to:

File imageFile = new File(args[0]);

that should work since args[0] will be "//home//desktop//OCR_file.pdf"

I also noticed that your imageFile initialization has a typo. the extension at the end is png, but you mentioned that it's supposed to be pdf.

Answer 2

Command - java tess4j.Test "/home/desktop/OCR_file.png"

public static void main(String[] args) {
// ImageIO.scanForPlugins(); // for server environment
String path = args[0]; 
File imageFile = new File(path);
ITesseract instance = new Tesseract(); // JNA Interface Mapping
// ITesseract instance = new Tesseract1(); // JNA Direct Mapping
instance.setDatapath("//home//desktop//tessdata"); // replace <parentPath> with path to parent directory of tessdata
// instance.setLanguage("eng");

try {
    String result = instance.doOCR(imageFile);
    System.out.println(result);
} catch (TesseractException e) {
    System.err.println(e.getMessage());
}
}