如何用Java程序代替Notepad++的文字处理和Powershell

在上篇文章 如何备份微信朋友圈的视频照片 中，我们下载到exported_sns.json文件之后，用Notepad++做文字处理然后再用一个Powershell程序来做批量下载。

由于Notepad++里面的文字处理有些复杂，我在想能不能用一个Java程序来统一处理呢？

尝试了一下，发现不太复杂，Java果然处理各种事情都比较方便。程序如下：

注意在RegExp里面，必须用四个反斜杠\\\\代表一个反斜杠\

package com.pwc;

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.ArrayList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class WechatMomentDownload {
    
    public static String jsonFile = "C:\\Download\\exported_sns_gary.json";
    public static String outputFolder = "C:\\Download\\gary_pic\\";

    public static void main(String[] args) throws IOException {
        BufferedReader reader = null;
        String sLine = "";
        String sContent = "";
        String sLink = "";
        URL url = null;
        String outputFile = "";
        ArrayList<String> aLink = new ArrayList<String>();
        String Regex1 = "CDATA\\[http\\:\\\\\\/\\\\\\/(sh)?mmsns([^]]*)\\/0\\]";
        
        reader = new BufferedReader(
                new InputStreamReader(new FileInputStream(new File(jsonFile)), "UTF-8"));
        if (reader != null) {
            while ((sLine = reader.readLine()) != null) {
                sContent = sContent + sLine;
            }
            reader.close();
        }
        
        Pattern pattern = Pattern.compile(Regex1);
        Matcher matcher = pattern.matcher(sContent);
        int count = 0;
        
        System.out.println("Start processing...");
        while(matcher.find()) {
            count++;
            sLink = sContent.substring(matcher.start() + 6, matcher.end() - 1);
            sLink = sLink.replaceAll("\\\\/", "/");
            aLink.add(sLink);
         }
        
        System.out.println(count + " pictures were found");
        
        for (String sLinkTemp : aLink) {
            url = new URL(sLinkTemp);
            DataInputStream dataInputStream = new DataInputStream(url.openStream());
            
            outputFile = outputFolder + count + ".jpg";
            FileOutputStream fileOutputStream = new FileOutputStream(new File(outputFile));
            ByteArrayOutputStream output = new ByteArrayOutputStream();

            System.out.println("Downloading " + sLinkTemp + " to file " + outputFile);
            
            byte[] buffer = new byte[1024];
            int length;
 
            while ((length = dataInputStream.read(buffer)) > 0) {
                output.write(buffer, 0, length);
            }
            fileOutputStream.write(output.toByteArray());
            dataInputStream.close();
            fileOutputStream.close();
        
            count--;
        }
        
        System.out.println("End of processing...");
    }
}