java 按行读写文件简单示例

java 按行读写文件简单示例

1、按行写

public class CreatFile {
    public static void main(String[] args) throws Exception {
        //创建一个文件
        String path= "F://Forward.txt";
        File file = new File(path);
        if(file.createNewFile()){
            FileWriter fileWriter = new FileWriter(file);
            BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
            //生成40M  文件
            while (file.length() < 1024*1024*40 ){
                bufferedWriter.write("ForwardData [terminalType=nari_digital, messageType=1, " +
                        "saveDB=false, stationID()=95, terminalID()=1001, time()=1598234388904, " +
                        "cmdID()=12, cmdSerialNo()=11]");
                bufferedWriter.newLine();
            }
            bufferedWriter.close();
            fileWriter.close();
        }

    }
}

2、按行读

public class ReadFile {
    public static void main(String[] args ) throws Exception{
        String path= "F://Forward.txt";
        File file = new File(path);
        FileReader fileReader = null;
            fileReader = new FileReader(file);
            BufferedReader in = new BufferedReader(fileReader);
            String line = null;
            while ((line = in.readLine()) != null) {
                System.out.println("this line：" + line);
                line = null;
            }
            in.close();
            fileReader.close();

    }
}