Java基础知识-IO流相关知识

参考链接：
java IO体系的学习总结
https://blog.csdn.net/nightcurtis/article/details/51324105
Java 常用IO流操作详解
https://blog.csdn.net/MAGIC_JSS/article/details/51475923
Java中常见的IO流及其使用
https://blog.csdn.net/iispring/article/details/46821033
JavaＩＯ流分类详解与常用流用法实例
https://blog.csdn.net/zhangliangzi/article/details/51226652

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   /**
    * 方式一：一次读取一个字节（慢）
    * FileInputStream
    * FileOutputStream
    * @param File or FileName
    *
    * 字节流，文件拷贝处理
    */
   try {
       String filePath1 = "1.txt";
       String filePath2 = "2.txt";
       File file1 = new File(filePath1);
       File file2 = new File(filePath2);
       //FileInputStream fin = new FileInputStream(filePath1);
       //FileOutputStream fout = new FileOutputStream(filePath1);
       FileInputStream fin = new FileInputStream(file1);
       FileOutputStream fout = new FileOutputStream(file2);
       int length = 0;
       while ((length=fin.read())!=-1){
           fout.write(length);
       }
       fin.close();
       fout.close();
   } catch (FileNotFoundException e) {
       e.printStackTrace();
   } catch (IOException e) {
       e.printStackTrace();
   }

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/**
* 方式二：一次读取一个字节数组（中）
* FileInputStream
* FileOutputStream
* @param File or FileName
*
* 字节流，文件拷贝处理
*/
try {
  String filePath1 = "1.txt";
  String filePath2 = "2.txt";
  File file1 = new File(filePath1);
  File file2 = new File(filePath2);
  //FileInputStream fin = new FileInputStream(filePath1);
  //FileOutputStream fout = new FileOutputStream(filePath1);
  FileInputStream fin = new FileInputStream(file1);
  FileOutputStream fout = new FileOutputStream(file2);
  byte[] buf = new byte[1024];
  int length = 0;
  while ((length=fin.read(buf))>0){
      fout.write(buf,0, length);
      System.out.println(new String(buf,0,length));
      fout.flush();//大文件可能持续阻塞
  }
  fin.close();
  fout.close();
} catch (FileNotFoundException e) {
  e.printStackTrace();
} catch (IOException e) {
  e.printStackTrace();
}

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/**
  * 方式三：利用缓冲流读取字节（快）
  * FileInputStream
  * FileOutputStream
  * BufferedInputStream 
  * BufferedOutputStream 
  * @param File or FileName
  *
  * 字节流，文件拷贝处理
  */
 try {
     String filePath1 = "1.txt";
     String filePath2 = "2.txt";
     File file1 = new File(filePath1);
     File file2 = new File(filePath2);
     //FileInputStream fin = new FileInputStream(filePath1);
     //FileOutputStream fout = new FileOutputStream(filePath1);
     FileInputStream fin = new FileInputStream(file1);
     BufferedInputStream bufFin = new BufferedInputStream(fin);
     FileOutputStream fout = new FileOutputStream(file2);
     BufferedOutputStream bufOut = new BufferedOutputStream(fout);
     int length = 0;
     while ((length=bufFin.read())!=-1){
         bufOut.write(length);
     }
     bufFin.close();
     bufOut.close();
     fin.close();
     fout.close();
 } catch (FileNotFoundException e) {
     e.printStackTrace();
 } catch (IOException e) {
     e.printStackTrace();
 }

---

/**
  *
  * ByteArrayInputStream
  * ByteArrayOutputStream
  * @param bytes 数组
  *
  * 字节流，转文件流
  */
 try {
     byte[] bytes = "I am iSpring".getBytes();
     ByteArrayInputStream in = new ByteArrayInputStream(bytes);
     ByteArrayOutputStream out = new ByteArrayOutputStream(bytes.length);
     OutputStream outputStream = new FileOutputStream("3.txt");

     byte[] b=new byte[1024];
     int len = 0;
     while ((len=in.read(b))!=-1){
         out.write(b,0,len);
         out.writeTo(outputStream);
         System.out.println(new String(b,0,len));
         out.flush();
     }
     in.close();
     out.close();
     outputStream.close();
 } catch (FileNotFoundException e) {
     e.printStackTrace();
 } catch (IOException e) {
     e.printStackTrace();
 }

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/**
  * 传入字符串以读取字节
  * StringBufferInputStream 
  * @param str 
  * 字节流
  */
  String message = "I am iSpirng.";
  StringBufferInputStream sbis = new StringBufferInputStream(message);
  byte[] buf = new byte[1024];
  try{
      int length = sbis.read(buf);
      if(length > 0){
          System.out.println(new String(buf, 0, length, "UTF-8"));
      }
      sbis.close();
  }catch (IOException e){
      e.printStackTrace();
  }

---

   /**
     * 
     * FileReader
     * FileWriter
     * BufferedReader 
     * BufferedWriter 
     * @param File or FileName 生成字节输入流（文件）
     *
     * 字符流，文件拷贝处理
     */
    try {
        FileReader reader = new FileReader("1.txt");
        FileWriter writer = new FileWriter("2.txt");
        BufferedReader bufferedReader = new BufferedReader(reader);
        BufferedWriter bufferedWriter = new BufferedWriter(writer);
        char[] b=new char[1024];
        int len = 0;
        while ((len=bufferedReader.read(b))!=-1){
            bufferedWriter.write(b,0,len);
            System.out.println(new String(b,0,len));
            bufferedWriter.flush();
        }
        bufferedReader.close();
        bufferedWriter.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

---

 /**
   *
   * InputStreamReader
   * OutputStreamWriter
   * BufferedReader
   * BufferedWriter
   * @param File or FileName
   *
   * 字节流转字符流(转换流)，文件拷贝处理
   */
  try {
      InputStreamReader reader = new InputStreamReader(new FileInputStream("1.txt"));
      OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream("2.txt"));
      BufferedReader bufferedReader = new BufferedReader(reader);
      BufferedWriter bufferedWriter = new BufferedWriter(writer);
      char[] b=new char[1024];
      int len = 0;
      while ((len=bufferedReader.read(b))!=-1){
          bufferedWriter.write(b,0,len);
          System.out.println(new String(b,0,len));
          bufferedWriter.flush();
      }
      bufferedReader.close();
      bufferedWriter.close();
      reader.close();
      writer.close();
  } catch (FileNotFoundException e) {
      e.printStackTrace();
  } catch (IOException e) {
      e.printStackTrace();
  }

---

 /**
   *
   * StringReader
   * StringWriter
   * BufferedReader
   * BufferedWriter
   * @param str
   *
   * 字符流，文件拷贝处理
   */
  try {
      String str = "I am iSpring";
      StringReader reader = new StringReader(str);
      StringWriter writer = new StringWriter(str.length());
      BufferedReader bufferedReader = new BufferedReader(reader);
      BufferedWriter bufferedWriter = new BufferedWriter(writer);

      char[] b=new char[1024];
      int len = 0;
      while ((len=bufferedReader.read(b))!=-1){
          bufferedWriter.write(b,0,len);
          System.out.println(new String(b,0,len));
          bufferedWriter.flush();
      }
      bufferedReader.close();
      bufferedWriter.close();
      reader.close();
      writer.close();
  } catch (FileNotFoundException e) {
      e.printStackTrace();
  } catch (IOException e) {
      e.printStackTrace();
  }

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ObjectInputStream
PipedInputStream
SequenceInputStream
参考：https://blog.csdn.net/iispring/article/details/46821033

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PrintStream
PushbackInputStream
参考：https://blog.csdn.net/zhangliangzi/article/details/51226652

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DataInputStream
FilterInputStream
参考：https://blog.csdn.net/u013087513/article/details/52148934

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