Java --- I/O(1) 存取file
===

## 幫助做IO的各種class都在 java.io.* 中

---

## (1) 建立新.txt檔並寫入資料

### ==FileWriter== 為提供各種method之class

For instance : 新建一文字檔叫test,並在內容寫入100.

public static void main(String arg[])
{
    FileWriter fw = new FileWriter("test.txt");
    try
    { 
        fw.write("100");
        fw.flush();
    }
    catch(IOException e)
    {
        ;
    }
    finally
    {
        fw.close();
    }
}

## (2) 讀取某file的內容

### ==FileReader== 為提供各種method之class

For instance: 讀取某file的所有內容

public static void main(String arg[])
{
    String content = "";
    FileReader fr = new FileReader("test.txt");
    BufferedReader br = new BufferedReader(fr);
    try
    {
         while(br.ready())
        {
        content += br.readLine();
        content += "\n";
        }
    }
    catch(IOException e)
    {
        ;
    }
    finally
    {
        fr.close();
    }
}

###### tags: `java` `教學`