java - java中属性的使用

Question

我是新来的，我想问一下properties如何与java代码一起工作，我的意思是properties内部的values code> 将用作变量。例如，我在 config.properties 中有 file1.txt 和 file2.txt 并将其存储在 Arraylist 中，然后扫描文件夹，如果找到文件，则将其复制。我的工作仅显示存储在数组列表中的属性中的数据名称，但我的另一个问题是如何将这些数据复制到另一个文件夹。

到目前为止，这是我的代码

     public class MainClass {

          static Properties prop = new Properties();
    static InputStream input = null;
    static String filename = "";

    public static void main(String[] args) throws IOException {

        File source = new File("D:/ojt");
        File dest = new File("D:/ojt/New folder");


        Properties prop = new Properties();
        InputStream input = null;


        try {

    //    getFiles(filename);


        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            if (input != null) {
                try {
                    input.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
       private static void copyFileUsingStream(File source, File dest) throws IOException {
            InputStream is = null;
            OutputStream os = null;

            try {
                is = new FileInputStream(source);
                os = new FileOutputStream(dest);
                byte[] buffer = new byte[1024];
                int length;
                while ((length = is.read(buffer)) > 0) {
                    os.write(buffer, 0, length);
                }
            } finally {
                is.close();
                os.close();
            }
        }
       private static void copy(String fromPath, String outputPath)
       {
    //       filter = new FileTypeOrFolderFilter(fileType);
           File currentFolder = new File(fromPath);
           File outputFolder = new File(outputPath);
           scanFolder(currentFolder, outputFolder);


       }

      private static void getFiles(String path) throws IOException{
        //Put filenames in arraylist<string>
        String filename = "bydatefilesdir.props";
        input = MainClass.class.getClassLoader().getResourceAsStream(filename);
        Scanner s = new Scanner(input);
        File dir = new File(path);
        final ArrayList<String> list = new ArrayList<String>();
        while (s.hasNextLine()){
            list.add(s.nextLine());
        }
//      ArrayList<String> filenames = new ArrayList<String>();
//      for(File file : dir.listFiles()){
//          filenames.add(file.getName());
//      }

        prop.load(input);
        //Check if the files are in the arraylist
        for (int i = 0; i < list.size(); i++){
            String s1 = list.get(i);
            System.out.println("File "+i+" : "+s1);
        }
        System.out.println("\n");
    }

    private static void copyFileUsingStream(File source, File dest) throws IOException {
        InputStream is = null;
        OutputStream os = null;

        try {
            is = new FileInputStream(source);
            os = new FileOutputStream(dest);
            byte[] buffer = new byte[1024];
            int length;
            while ((length = is.read(buffer)) > 0) {
                os.write(buffer, 0, length);
            }
        } finally {
            is.close();
            os.close();
        }
    }
    private static void copy(String source, String dest)
    {
        //       filter = new FileTypeOrFolderFilter(fileType);
        File currentFolder = new File(source);
        File outputFolder = new File(dest);
        scanFolder(currentFolder, outputFolder);


    }

    private static void scanFolder(File source, File dest)
    {
        System.out.println("Scanning folder [" + source.toString() + "]...\n");
        File[] files = source.listFiles();
        for (File file : files) {
            if (file.isDirectory()) {
                scanFolder(source, dest);
            } else {
                try {
                    copyFileUsingStream(source, dest);
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

PS:对于刚刚接触 java 的糟糕编程感到抱歉......仍在学习
编辑:我已经包含了上面更新的代码..

Answer 1

我想 java.util.Properties 具有内置方法来实现您正在尝试的目标。请引用这个example你会找到更好的解决方案。

public class App {

  public static void main( String[] args ){

    Properties prop = new Properties();
    InputStream input = null;

    try {

        String filename = "config.properties";
        input = App.class.getClassLoader().getResourceAsStream(filename);
        if(input==null){
                System.out.println("Sorry, unable to find " + filename);
            return;
        }

        //load a properties file from class path, inside static method
        prop.load(input);

            //get the property value and print it out
            System.out.println(prop.getProperty("file1.txt"));
            System.out.println(prop.getProperty("file2.txt"));


    } catch (IOException ex) {
        ex.printStackTrace();
    } finally{
        if(input!=null){
            try {
            input.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        }
    }

}
}