Java读写文件和Scala读写文件

妖狐艹你老母 2023-02-13 05:49 28阅读 0赞

### **Java实现** ###

package com.xtd.test.java;
    
    import java.io.*;
    
    public class AppentFile {
    
        private static FileWriter fileWriter = null;
        private static FileReader fileReader = null;
        private static BufferedWriter bufferedWriter = null;
        private static BufferedReader bufferedReader = null;
    
        public static void main(String[] args) {
            // 写入文件的路径
            String filePath = "F:/IDEA-WorkSpace/spark";
            // 写入的文件名称
            String fileName = "MMSIFile";
            readAndWrite(filePath,fileName);
        }
        public static void readAndWrite(String filePath,String fileName){
    
            try {
                /************** 写文件 ************/
                // true：追加写入，flase：覆盖写入（默认覆盖写入）
                fileWriter = new FileWriter(filePath+"/"+fileName,true);
                // 对于小量数据少数写入使用 fileWriter 效率更高
                fileWriter.append("Java FileWriter Apend Write File!\n");
                // 对于大量数据对此写入使用 bufferedWriter 效率更高
                bufferedWriter = new BufferedWriter(fileWriter);
                bufferedWriter.write("Java BufferedWriter Apend Write File!\n");
                bufferedWriter.close();
                fileWriter.close();
    
                /************** 读文件 ************/
                fileReader = new FileReader(filePath+"/"+fileName);
                bufferedReader = new BufferedReader(fileReader);
                String str;
                while ( null != (str = bufferedReader.readLine()) ) {
                    System.out.println(str);
                }
                bufferedReader.close();
                fileReader.close();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

### **Scala实现** ###

package com.xtd.test.scala
    
    import java.io.{BufferedReader, BufferedWriter, FileReader, FileWriter, IOException}
    
    object AppentFile {
    
      private var fileWriter:FileWriter = null
      private var fileReader:FileReader = null
      private var bufferedWriter:BufferedWriter = null
      private var bufferedReader:BufferedReader = null
    
      def main(args: Array[String]): Unit = {
        // 写入文件的路径
        val filePath = "F:/IDEA-WorkSpace/spark"
        // 写入的文件名称
        val fileName = "MMSIFile"
        readAndWrite(filePath, fileName)
      }
    
      def readAndWrite(filePath: String, fileName: String): Unit = {
        try {
          /** ************ 写文件 ************/
          // true：追加写入，flase：覆盖写入（默认覆盖写入）
          fileWriter = new FileWriter(filePath + "/" + fileName, true)
          // 对于小量数据少数写入使用 fileWriter 效率更高
          fileWriter.append("Scala FileWriter Apend Write File!\n")
          // 对于大量数据对此写入使用 bufferedWriter 效率更高
          bufferedWriter = new BufferedWriter(fileWriter)
          bufferedWriter.write("Scala BufferedWriter Apend Write File!\n")
          bufferedWriter.close()
          fileWriter.close()
    
          /** ************ 读文件 ************/
          fileReader = new FileReader(filePath + "/" + fileName)
          bufferedReader = new BufferedReader(fileReader)
          var str:String = null
          while ( None!=(str = bufferedReader.readLine) && null!=str ) println(str)
          bufferedReader.close()
          fileReader.close()
        } catch {
          case e: IOException =>
            e.printStackTrace()
        }
      }
    }

### 运行效果 ###

> Java FileWriter Apend Write File!  
> Java BufferedWriter Apend Write File!  
> Scala FileWriter Apend Write File!  
> Scala BufferedWriter Apend Write File!