java 生成一个txt文件 并写入

String filepath = “D:\test”;
File writename = new File(filepath);
if(!writename.exists()){
    writename.mkdirs();
}
String log = "hello word";
String filename = "aaa.txt";
writename = new File(filepath +File.separator+filename );
OutputStreamWriter out = new OutputStreamWriter(new FileOutputStream(filepath +File.separator+filename), "UTF-8");
out.write(log );
out.flush();
out.close();