properties是HashTable的子類,具有Map集合的特點,其鍵和值都是字符串;同時也是集合中與IO技術(shù)相結(jié)合的容器

Properties p=new Properties();
p.setProperty("ziti", "songti");
p.setProperty("yanse", "hongse");
System.out.println(p);//{ziti=songti, yanse=hongse}
System.out.println(p.getProperty("yanse"));//hongse

基本方法

• setProperty(String key, String value)
  調(diào)用 Hashtable 的方法 put
  getProperty(String key)
  用指定的鍵在此屬性列表中搜索屬
  list(PrintStream out)
  將屬性列表輸出到指定的輸出流(如果輸出流是System.out的話與System.out.println(p)的效果類似)

BufferedReader br=new BufferedReader(new FileReader("F:\\properties.txt"));
            Properties p=new Properties();
            p.load(br);
            p.setProperty("font", "songti");
            BufferedWriter bw=new BufferedWriter(new FileWriter("F:\\properties.txt"));
            p.store(bw, "huohuo");
            br.close();
            bw.close();

與io技術(shù)結(jié)合的部分

• load(InputStream inStream)
  從輸入流中讀取屬性列表(鍵和元素對)
• store(OutputStream out, String comments)
  以適合使用 load(InputStream) 方法加載到 Properties 表中的格式，將此 Properties 表中的屬性列表（鍵和元素對）寫入輸出流

提取Windows壁紙(舊)

public class 從電腦中提取Windows壁紙 {

    public static void main(String[] args) throws IOException{
        File source = new File("C:\\Users\\DELL\\AppData\\Local\\Packages\\Microsoft.Windows.ContentDeliveryManager_cw5n1h2txyewy\\LocalState\\Assets");
        File mudi = new File("F:\\鎖屏圖片");
        File[] files = source.listFiles();
            int index = Integer.parseInt(new BufferedReader(new FileReader("F:\\鎖屏圖片\\圖片信息.txt")).readLine());
            for (File f : files) {
                if (f.isDirectory()) {
                    continue;
                }
                String newfName = "F:\\鎖屏圖片\\圖片__" + index + ".jpg";
                copy(f.getPath(), newfName);
                index++;
            }
            FileWriter filein = new FileWriter("F:\\鎖屏圖片\\圖片信息.txt");
            filein.write(Integer.toString(index));
            filein.close();
    }

    public static void copy(String oldFilePath, String newFilePath) throws IOException {
        BufferedInputStream oldf = new BufferedInputStream(new FileInputStream(oldFilePath));
        BufferedOutputStream newf = new BufferedOutputStream(new FileOutputStream(newFilePath));
        int ch;
        while ((ch = oldf.read()) != -1) {
            newf.write(ch);
        }
        oldf.close();
        newf.close();
    }
}

缺點:可讀性差,不夠方便

提取Windows壁紙(新)

public class 提取壁紙plus {

    public static void main(String[] args) throws IOException{
        File source = new File("C:\\Users\\DELL\\AppData\\Local\\Packages\\Microsoft."
                + "Windows.ContentDeliveryManager_cw5n1h2txyewy\\LocalState\\Assets");
        File mudi = new File("F:\\鎖屏圖片");
        File[] files = source.listFiles();
        Properties info=new Properties();
        BufferedReader br=new BufferedReader(new FileReader("F:\\鎖屏圖片\\圖片信息.txt"));
        info.load(br);
            int index = Integer.parseInt(info.getProperty("index"));
            for (File f : files) {
                if (f.isDirectory()) {
                    continue;
                }
                String newfName = "F:\\鎖屏圖片\\圖片__" + index + ".jpg";
                copy(f.getPath(), newfName);
                index++;
            }
            FileWriter filein = new FileWriter("F:\\鎖屏圖片\\圖片信息.txt");
            info.setProperty("index", index+"");
            info.store(filein, "Picture Index");
            br.close();
            filein.close();
    }

    public static void copy(String oldFilePath, String newFilePath) throws IOException {
        BufferedInputStream oldf = new BufferedInputStream(new FileInputStream(oldFilePath));
        BufferedOutputStream newf = new BufferedOutputStream(new FileOutputStream(newFilePath));
        int ch;
        while ((ch = oldf.read()) != -1) {
            newf.write(ch);
        }
        oldf.close();
        newf.close();
    }
}

雖然看起來并沒有簡化代碼...但是提高了代碼的閱讀性,特別是當(dāng)屬性比較多的時候使用Properties對象就既簡潔又方便