运用BufferedWriter把数据写入文件

Posted 2020-11-03 薛文博

public class WriteReadFiles {
    private static Logger log = LoggerFactory.getLogger(WriteReadFiles.class);
    public boolean writeFile(String content) {
        String filename = "E:/java_src/MVCDemo3/MVCDemo3/accounts.txt";
        try {
            File f = new File(filename);
            if (!f.exists()) {
                f.createNewFile();
            }
            OutputStreamWriter write = new OutputStreamWriter(new FileOutputStream(f));
            BufferedWriter writer = new BufferedWriter(write);
            writer.write(content);
            writer.flush(); 
            write.close();
            writer.close();
            log.debug("Write File complete!");
            return true;
        }catch (Exception e){
            e.printStackTrace();
        }
        return false;
    }

使用BufferedWriter 将内容写入文件，先开始少了wriite.flush()这句，发现无法写入内容。查资料后发现，原来BufferedWriter是缓冲输入流，意思是当你调用BufferedWriter的write方法时候。数据是先写入到缓冲区里，并没有直接写入到目的文件里。你必须调用BufferedWriter的flush()方法。这个方法会刷新一下该缓冲流，也就是会把数据写入到目的文件里。必须有这句的样子，实践中如果没有writer.flush(); 仅有writer.close();，会报异常。