Java圖片與byte數組相互轉化

Java圖片與byte數組相互轉化

圖片與byte數組相互轉化的工具類：

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;

import javax.imageio.stream.FileImageInputStream;
import javax.imageio.stream.FileImageOutputStream;

public class Test {

	/**
	 * 圖片轉化爲byte數組
	 * @param path
	 * @return
	 */
	public byte[] image2byte(String path){
		byte[] data = null;
		FileImageInputStream input = null;
		try {
			input = new FileImageInputStream(new File(path));
			ByteArrayOutputStream output = new ByteArrayOutputStream();
			byte[] buf = new byte[1024];
			int numBytesRead = 0;
			while ((numBytesRead = input.read(buf)) != -1) {
				output.write(buf, 0, numBytesRead);
			}
			data = output.toByteArray();
			output.close();
			input.close();
		} catch (FileNotFoundException ex1) {
			ex1.printStackTrace();
		} catch (IOException ex1) {
			ex1.printStackTrace();
		}
		return data;
	}
    
	/**
	 * byte數組轉化爲圖片
	 * @param data
	 * @param path
	 */
	public void byte2image(byte[] data,String path){
		if(data.length<3||path.equals("")) {
			return;
		}
		try{
			FileImageOutputStream imageOutput = new FileImageOutputStream(new File(path));
			imageOutput.write(data, 0, data.length);
			imageOutput.close();
			System.out.println("Make Picture success,Please find image in " + path);
		} catch(Exception ex) {
			System.out.println("Exception: " + ex);
			ex.printStackTrace();
		}
	}
	
	/**
	 * byte數組到16進制字符串
	 * @param data
	 * @return
	 */
	public String byte2string(byte[] data){
		if(data==null||data.length<=1) {
			return "0x";
		}
		if(data.length>200000) {
			return "0x";
		}
		StringBuffer sb = new StringBuffer();
		int buf[] = new int[data.length];
		//byte數組轉化成十進制
		for(int k=0;k<data.length;k++){
			buf[k] = data[k]<0?(data[k]+256):(data[k]);
		}
		//十進制轉化成十六進制
		for(int k=0;k<buf.length;k++){
			if(buf[k]<16) {
				sb.append("0"+Integer.toHexString(buf[k]));
			} else {
				sb.append(Integer.toHexString(buf[k]));
			}
		}
		return "0x"+sb.toString().toUpperCase();
	} 
}