1. 读取操作

String path = "/sdcard/foo.txt"; 	String content = ""; //文件内容字符串 //打开文件 File file = new File(path); //如果path是传递过来的参数，可以做一个非目录的判断 if (file.isDirectory()){
         		Toast.makeText(EasyNote.this, "没有指定文本文件！", 1000).show(); } else{
         		try {
         			InputStream instream = new FileInputStream(file); if (instream != null) {
         				InputStreamReader inputreader = new InputStreamReader(instream);     				BufferedReader buffreader = new BufferedReader(inputreader);     				String line; //分行读取 while (( line = buffreader.readLine()) != null) {
         					content += line + "\n"; }				     			instream.close(); } catch (java.io.FileNotFoundException e) {
         			Toast.makeText(EasyNote.this, "文件不存在", Toast.LENGTH_SHORT).show(); } catch (IOException e) {
         			e.printStackTrace(); } }

2. 写入操作

String filePath = "/sdcard/foo2.txt"; 		String content = "这是将要写入到文本文件的内容"; //如果filePath是传递过来的参数，可以做一个后缀名称判断； 没有指定的文件名没有后缀，则自动保存为.txt格式 if(!filePath.endsWith(".txt") && !filePath.endsWith(".log"))             		filePath += ".txt"; //保存文件 File file = new File(filePath);             	try {
                 		OutputStream outstream = new FileOutputStream(file);             		OutputStreamWriter out = new OutputStreamWriter(outstream);             		out.write(content);             		out.close(); } catch (java.io.IOException e) {
                 		e.printStackTrace(); }