Java IO

package com.test;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class TestFile {

// private static final String targetPath = "D:\\file\\psu.jpg";

private static final String targetPath = "D:\\file\\psu.jpg";

private static final String targetPath_bak = "D:\\file\\psu_bak.jpg";

public static void main(String[] args) {

System.out.println("TestFile.main start...");

try {
System.out.println(getFileStream(targetPath));
// saveFile(targetPath_bak, readFile(targetPath));
} catch (Exception e) {
e.printStackTrace();
}

System.out.println("TestFile.main end...");
}

private static InputStream getFileStream(String targetPath) throws Exception{

File file = new File(targetPath);

InputStream is = null;

try {
if(!file.isFile() || !file.exists()){
throw new FileNotFoundException("file not exists");
}
is = new FileInputStream(file);
} catch (FileNotFoundException e) {
throw new FileNotFoundException("readFile error: file not exists");
} catch (Exception e) {
throw new Exception("readFile error: Other Exception");
}finally{
if(is != null){
is.close();
}
}
return is;
}

    public static byte[] readFile(String targetPath) throws IOException {

        File file = new File(targetPath);

        if (!file.exists()) {
            throw new FileNotFoundException("readFile error: file" + targetPath + " not exist!");
        }

        FileInputStream inStream = new FileInputStream(file);
        BufferedInputStream bis = new BufferedInputStream(inStream);

        byte[] fileDate = new byte[(int) file.length()];

        try {
            bis.read(fileDate);
            return fileDate;
        } finally {
            bis.close();
            inStream.close();
        }
    }
   
    public static void saveFile(String pathname, byte[] fileData) throws IOException {

        File file = new File(pathname);

        if (file.exists()) {
        throw new FileNotFoundException("saveFile error: file" + pathname + " is exist!");
        }

        FileOutputStream fileOut = new FileOutputStream(file);
        BufferedOutputStream bos = new BufferedOutputStream(fileOut);

        try {
            bos.write(fileData);
        } finally {
            bos.close();
            fileOut.close();
        }
    }

}