IO流--图片拷贝

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/Caiaixiong/article/details/85251115

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * 图片拷贝
 * 1. 图片读取到字节数组
 * 2. 字节数组写出文件
 */
public class IOUtils {
	
	public static void main(String[] args) {
		byte[] datas = fileToByteArray("p.png");
		System.out.println(datas.length);
		byteArrayToFile(datas,"p-byte.png");
	}
	/**
	 * 1. 图片读取到字节数组
	 * 1）图片到程序  FileInputStream
	 * 2） 程序到字节数组	ByteArrayOutputStream
	 * @return 
	 */
	public static byte[] fileToByteArray(String filePath){
		File src = new File(filePath);
		InputStream is = null;
		ByteArrayOutputStream baos = null;
		try {
			is = new FileInputStream(src);
			baos = new ByteArrayOutputStream();
			byte[] flush = new byte[1024*10];
			int len = -1;
			while((len = is.read(flush))!=-1){
				baos.write(flush, 0, len);
			}
			baos.flush();
			return baos.toByteArray();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if(is!=null){
				try {
					is.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		return null;
	}
	
	/**
	 * 2. 字节数组写出到图片
	 * 1) 字节数组到程序 ByteArrayInputStream
	 * 2) 程序到文件 FileOutputStream
	 */
	public static void byteArrayToFile(byte[] src,String filePath){
		File dest = new File(filePath);
		InputStream is = null;
		OutputStream os = null;
		
		try {
			is = new ByteArrayInputStream(src);
			os = new FileOutputStream(dest);
			byte[] flush = new byte[1024];
			int len = -1;
			while((len=is.read(flush))!=-1){
				os.write(flush,0,len);
			}
			os.flush();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if(os!=null){
				try {
					os.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		
		
	}
}