Java对比两个文件的差异，并且输出新文件与旧文件的差异行数

Posted 2022-01-28 白发随你去

Java对比两个文件的差异，并且输出新文件与旧文件的差异、行数

@Test
    void contextLoads() 
        try 
            compareTwoFile("E:\\\\test1.txt", "E:\\\\test2.txt");
         catch (IOException e) 
            e.printStackTrace();
        
    

/**
     * 对比两个文件的差异，并且输出新文件与旧文件的差异
     *
     * @param oldFile 旧的文件
     * @param newFile 当前新文件
     * @throws IOException 异常
     */
    public static void compareTwoFile(String oldFile, String newFile) throws IOException 

        File fileOld = new File(oldFile);
        File fileNew = new File(newFile);

        FileInputStream inputStream1 = new FileInputStream(fileOld);
        int size1 = inputStream1.available();
        byte[] buffer1 = new byte[size1];
        inputStream1.read(buffer1);
        inputStream1.close();
        String fileOldStr = new String(buffer1, "UTF-8");

        FileInputStream inputStream2 = new FileInputStream(fileNew);
        int size2 = inputStream2.available();
        byte[] buffer2 = new byte[size2];
        inputStream2.read(buffer2);
        inputStream2.close();
        String fileNewStr = new String(buffer2, "UTF-8");

        if (fileNewStr.equals(fileOldStr))
            System.out.println("两个文件完全相同！");
            return;
        

        String[] oldSplit = fileOldStr.split("\\n");
        String[] newSplit = fileNewStr.split("\\n");


        if (newSplit != null && oldSplit != null) 
            //旧文件
            System.out.println("================旧文件===================");
            for (int i = 0; i < oldSplit.length; i++) 
                if (!oldSplit[i].equals(newSplit[i])) 
                    System.out.println(i + ":" + oldSplit[i]);
                
            

            //新文件
            System.out.println("================新文件===================");
            for (int i = 0; i < newSplit.length; i++) 
                if (i < oldSplit.length) 
                    if (!newSplit[i].equals(oldSplit[i])) 
                        System.out.println(i + ":" + newSplit[i]);
                    
                 else 
                    System.out.println(i + ":" + newSplit[i]);
                
            
        
    

对比结果：

================旧文件===================
13:
17:111111111111111111aaaaaaaaa1111
================新文件===================
13:aaaaaaaeeeeeeeee
17:1111111111111111111111