java FileWriter怎样向一个已存在内容的txt中尾部继续添加内容

File file = new File("D:/Test.txt");  
File dest = new File("D:/new.txt");  
try {  
    BufferedReader reader = new BufferedReader(new FileReader(file));  
    BufferedWriter writer  = new BufferedWriter(new FileWriter(dest,true));  
    String line = reader.readLine();  
    while(line!=null){  
        writer.write(line);  
        line = reader.readLine();  
    }  
    writer.flush();  
    reader.close();  
    writer.close();  
} catch (FileNotFoundException e) {  
    e.printStackTrace();  
} catch (IOException e) {  
    e.printStackTrace();  
}