执行commands有问题

for (String command : commands) {
                if (command == null) {
                    continue;
                }

```
            // donnot use os.writeBytes(commmand), avoid chinese charset error
            os.write(command.getBytes());
            os.writeBytes(COMMAND_LINE_END);
            os.flush();
        }
```

当传入的commands数组过大，os write将近64M的字节时会出现错误
