java 写入、读取txt

<span style="font-size:18px;">FileWriter fw = new FileWriter("d://test.txt", true);
fw.write("aaaaaa");
fw.close();</span>

<span style="font-size:18px;">
String encoding = "GBK";
File file = new File(filePath);
if (file.isFile() && file.exists()) {
InputStreamReader read = new InputStreamReader(new FileInputStream(file), encoding);
BufferedReader bufferedReader = new BufferedReader(read);
String lineTxt = null;
while ((lineTxt = bufferedReader.readLine()) != null) {
System.out.println(lineTxt);
}
read.close();
} else {
System.out.println("找不到指定的文件");
}</span>