利用SHA-1算法通过JavaSwing实现获取文件消息摘要程序

0.前言

该程序要用到eclipse中的swt插件来实现可视化编程
插件的安装及使用操作可在我这一篇博客中获取
https://blog.csdn.net/leon9dragon/article/details/91864590

（非常简便，2分钟就能安装完了，而且可视化编程十分好用,强烈推荐）

下图是最终实现的效果

1.代码实现

package com.blog.sha;

import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JTextField;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import java.awt.Font;
import java.awt.Color;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.security.MessageDigest;
import java.awt.event.ActionEvent;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.security.MessageDigest;




public class testSHA extends JFrame {

	private JPanel contentPane;
	private JTextField pathField;
	private JTextField shaField;
	
	
	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					testSHA frame = new testSHA();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public testSHA() {
		setTitle("\u6D88\u606F\u6458\u8981\u754C\u9762");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 450, 300);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		pathField = new JTextField();
		pathField.setBounds(69, 67, 211, 21);
		contentPane.add(pathField);
		pathField.setColumns(10);
		
		JButton chooseBton = new JButton("\u9009\u62E9\u6587\u4EF6");
		chooseBton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				chooseaction(arg0);
			}
		});
		chooseBton.setBounds(290, 66, 93, 23);
		contentPane.add(chooseBton);
		
		shaField = new JTextField();
		shaField.setEditable(false);
		shaField.setBounds(113, 138, 311, 21);
		contentPane.add(shaField);
		shaField.setColumns(10);
		
		JButton comfirmBton = new JButton("\u786E\u8BA4");
		comfirmBton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				confirmaction(arg0);
			}
		});
		comfirmBton.setBounds(10, 137, 93, 23);
		contentPane.add(comfirmBton);
		
		JLabel label = new JLabel("\u8F93\u51FA\u6587\u4EF6\u7684\u6D88\u606F\u6458\u8981");
		label.setForeground(Color.RED);
		label.setFont(new Font("黑体", Font.BOLD, 15));
		label.setBounds(186, 113, 167, 15);
		contentPane.add(label);
	}
	
	
	//选择文件事件
	public void chooseaction(ActionEvent arg0){
		JFileChooser fileChooser=new JFileChooser("C:/Users/Administrator/Desktop");//默认搜寻路径,可根据自己的需要进行修改
		if(fileChooser.showOpenDialog(null)==JFileChooser.APPROVE_OPTION){
			pathField.setText(fileChooser.getSelectedFile().getPath());//获取文本框给出的文件路径
		}
	}
	
	//确认事件，输出文件消息摘要
	public void confirmaction(ActionEvent arg0){
		//首先获取加密文件的路径
		String filePath = null;
		filePath = pathField.getText();//取的要进行加密的文件的路径
		File shaFile = null;//定义要获取摘要的文件
		try {
			 shaFile = new File(filePath);
	         if(!shaFile.exists()) {	        	 
	            JOptionPane.showMessageDialog(null, "请先选择文件");
	            throw  new NullPointerException("SHA file is empty");
	         }			
			shaField.setText(testSHA.encrypt(shaFile));
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
	
    //摘要算法名称, SHA-1, SHA-256, SHA-512
    private final static String ALGORITHM = "SHA-1"; 
    // 提取字节数组的SHA，data是待提取字节数组
    public static String encrypt(byte[] data) throws Exception {
        //获取SHA摘要算法实例
        MessageDigest messageDigest = MessageDigest.getInstance(ALGORITHM);
        //计算消息摘要
        byte[] bytes = messageDigest.digest(data);
        //返回16进制格式字符串
        return byte2Hex(bytes);
    }
     
    //提取字符的SHA，data是待提取字符串
    public static String encrypt(String data) throws Exception {
        return encrypt(data.getBytes());
    }
 
    //提取数据流的SHA，inputStream是待提取数据流
    public static String encrypt(InputStream inputStream) throws Exception {
        //获取SHA摘要算法实例
        MessageDigest messageDigest = MessageDigest.getInstance(ALGORITHM);
        //计算消息摘要
        byte[] bytes = new byte[1024];
        while (inputStream.read(bytes) != -1) {
            messageDigest.update(bytes);
        }
        //返回16进制格式字符串
        return byte2Hex(messageDigest.digest());
    }
     
    //提取文件的SHA，file是待提取文件
    public static String encrypt(File file) throws Exception {
        return encrypt(new FileInputStream(file));
    }
   
	//将byte转为16进制
    private static String byte2Hex(byte[] bytes) {
        StringBuilder data = new StringBuilder(bytes.length);
        for (byte b : bytes) {
            data.append(Integer.toHexString((b >> 4) & 0xf)); //高4位
            data.append(Integer.toHexString(b & 0xf)); //低4位
        }
        return data.toString();
    }
 

}

2.运行效果

1）选择文件

2）点击确认后，输出消息摘要