IO流知识点+（文件上传、下载+压缩文件等）

一 常见IO介绍

1 根据数据流向分类

        输入流：把数据从其他设备读取到内存，以InputStream,Reader结尾

        输出流：把数据从内存中写出到其他设备，以OutputStream、Writer结尾

2 根据数据类型分类

        字节流：已字节为单位，读写数据，以InputStream和OutputStream结尾

        字符流：以字符为单位，读写数据，以Reader和Writer结尾

3 根据IO流的角色不同

        节点流：可以从或向一个特定的地方（节点）读写数据

        处理流：是对一个已经存在的流进行连接和封装，通过所封装的流的功能调用实现数据读写

4 常用的节点流

        文 件 FileInputStream FileOutputStrean FileReader FileWriter 文件进行处理的节点流。
        字符串 StringReader StringWriter 对字符串进行处理的节点流。
        数 组 ByteArrayInputStream ByteArrayOutputStream CharArrayReader CharArrayWriter 对数组进行处理的节点流（对应的不再是文件，而是内存中的一个数组）。
        管 道 PipedInputStream、PipedOutputStream、PipedReader、PipedWriter对管道进行处理的节点流。
5 常用处理流

        缓冲流：BufferedInputStream、BufferedOutputStream、BufferedReader、BufferedWriter—增加缓冲功能，避免频繁读写硬盘。
        转换流：InputStreamReader、OutputStreamReader—实现字节流和字符流之间的转换。
        对象流：ObjectInputStream、ObjectOutputStream–提供直接读写Java对象功能

二 文件管理案例（上传、下载、压缩等）

2.1 文件上传

1 阿里云OSS学习+上传案例https://blog.csdn.net/ytyDaMoTou/article/details/1249098432 使用spring-file-storage实现文件上传https://blog.csdn.net/ytyDaMoTou/article/details/128893435

2.2 文件压缩

2.1 文件压缩功能实现代码https://blog.csdn.net/ytyDaMoTou/article/details/124910011

2.3 文件下载

2.1 springboot案例实现文件下载https://blog.csdn.net/ytyDaMoTou/article/details/125529059

三 文件base64编码（代码工具类）

package com.gztpay.utils;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class Base64Image {
	
	 public static void main(String[] args) {
		    // 测试从Base64编码转换为图片文件
		    String strImg = "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";
		    GenerateImage(strImg, "D:\\wangyc.jpg");
		     
		    // 测试从图片文件转换为Base64编码
		    System.out.println(GetImageStr("d:\\wangyc.jpg"));
		  }
		 
		  public static String GetImageStr(String imgFilePath) {// 将图片文件转化为字节数组字符串，并对其进行Base64编码处理
		    byte[] data = null;
		     
		    // 读取图片字节数组
		    try {
		      InputStream in = new FileInputStream(imgFilePath);
		      data = new byte[in.available()];
		      in.read(data);
		      in.close();
		    } catch (IOException e) {
		      e.printStackTrace();
		    }
		     
		    // 对字节数组Base64编码
		    BASE64Encoder encoder = new BASE64Encoder();
		    return encoder.encode(data);// 返回Base64编码过的字节数组字符串
		  }
		 
		  public static boolean GenerateImage(String imgStr, String imgFilePath) {// 对字节数组字符串进行Base64解码并生成图片
		    if (imgStr == null) // 图像数据为空
		      return false;
		    BASE64Decoder decoder = new BASE64Decoder();
		    try {
		      // Base64解码
		      byte[] bytes = decoder.decodeBuffer(imgStr);
		      for (int i = 0; i < bytes.length; ++i) {
		        if (bytes[i] < 0) {// 调整异常数据
		          bytes[i] += 256;
		        }
		      }
		      // 生成jpeg图片
		      OutputStream out = new FileOutputStream(imgFilePath);
		      out.write(bytes);
		      out.flush();
		      out.close();
		      return true;
		    } catch (Exception e) {
		      return false;
		    }
		  }

}