springboot implements jar operation and copies resources files to the specified directory

1. Requirements

During the project development process, all resources in the project resources/static/ directory need to be copied to the specified directory. . In the company project, video files need to be downloaded. Since the download has an html page, the corresponding static resource files are used to load the multi-channel video, such as js, css.jwplayer, jquery.js and other files

The path of the jar generated by maven is different from the path of the usually released project, so when reading the path, the path of the jar is obtained, and the file path in the jar cannot be obtained

2. Idea

Based on For my needs, the idea of ??copying is to first obtain the file list in the resources/static/blog directory, and then copy the files to the specified location in a loop through the list (the relative paths need to be consistent)

Because the project will It is classified into a jar package, so the traditional directory file copying method cannot be used. Spring Resource is required here:

Resource interface, which is simply the abstract access interface for resources of the entire Spring framework. It inherits from the InputStreamSource interface. Subsequent articles will analyze it in detail.

Method description of Resource interface:

##exists() Determine whether the resource exists, true means it exists. isReadable()Determine whether the content of the resource is readable. It should be noted that when the result is true, its content may not really be readable, but if it returns false, its content must not be readable. isOpen() Determine whether the underlying resource represented by the current Resource has been opened. If true is returned, it can only be read once and then closed to avoid resource leakage; This method is mainly aimed at InputStreamResource. In the implementation class, only its return result is true, and the others are false. getURL()Returns the URL corresponding to the current resource. An exception will be thrown if the current resource cannot be resolved into a URL. For example, ByteArrayResource cannot be parsed into a URL. getURI()Returns the URI corresponding to the current resource. An exception will be thrown if the current resource cannot be resolved into a URI. getFile()Returns the File corresponding to the current resource. contentLength()Returns the length of the current resource contentlastModified()Returns the current The last modification time of the underlying resource represented by Resource. createRelative()Create a new resource based on the relative path of the resource. [Creating relative path resources is not supported by default]getFilename()Get the file name of the resource. getDescription()Returns the descriptor of the underlying resource of the current resource, which is usually the full path of the resource (actual file name or actual URL address). getInputStream()Get the input stream represented by the current resource. Except for the InputStreamResource implementation class, other Resource implementation classes will return a brand new InputStream every time they call the getInputStream() method.

Method	Description

Get the Resource list, I need to get the resources through the ResourceLoader interface, here I chose

org.springframework.core.io.support.PathMatchingResourcePatternResolver

3. Implementation code

/**
     * 只復(fù)制下載文件中用到的js
     */
    private void copyJwplayer() {
        //判斷指定目錄下文件是否存在
        ApplicationHome applicationHome = new ApplicationHome(getClass());
        String rootpath = applicationHome.getSource().getParentFile().toString();
        String realpath=rootpath+"/vod/jwplayer/";   //目標(biāo)文件
        String silderrealpath=rootpath+"/vod/jwplayer/silder/";   //目標(biāo)文件
        String historyrealpath=rootpath+"/vod/jwplayer/history/";   //目標(biāo)文件
        String jwplayerrealpath=rootpath+"/vod/jwplayer/jwplayer/";   //目標(biāo)文件
        String layoutrealpath=rootpath+"/vod/jwplayer/res/layout/";   //目標(biāo)文件
        /**
         * 此處只能復(fù)制目錄中的文件，不能多層目錄復(fù)制（目錄中的目錄不能復(fù)制，如果循環(huán)復(fù)制目錄中的目錄則會提示cannot be resolved to URL because it does not exist）
         */
        //不使用getFileFromClassPath()則報(bào)[static/jwplayerF:/workspace/VRSH265/target/classes/static/jwplayer/flvjs/] cannot be resolved to URL because it does not exist
        //jwplayer
        File fileFromClassPath = FreeMarkerUtil.getFileFromClassPath("/static/jwplayer/");  //復(fù)制目錄
        FreeMarkerUtil.BatCopyFileFromJar(fileFromClassPath.toString(),realpath);
        //silder
        File flvjspath = FreeMarkerUtil.getFileFromClassPath("/static/jwplayer/silder/");  //復(fù)制目錄
        FreeMarkerUtil.BatCopyFileFromJar(flvjspath.toString(),silderrealpath);
        //history
        File historypath = FreeMarkerUtil.getFileFromClassPath("/static/jwplayer/history/");  //復(fù)制目錄
        FreeMarkerUtil.BatCopyFileFromJar(historypath.toString(),historyrealpath);
        //jwplayer
        File jwplayerpath = FreeMarkerUtil.getFileFromClassPath("/static/jwplayer/jwplayer/");  //復(fù)制目錄
        FreeMarkerUtil.BatCopyFileFromJar(jwplayerpath.toString(),jwplayerrealpath);
        //layout
        File layoutpath = FreeMarkerUtil.getFileFromClassPath("/static/jwplayer/res/layout/");  //復(fù)制目錄
        FreeMarkerUtil.BatCopyFileFromJar(layoutpath.toString(),layoutrealpath);
    }

4. Tool class FreeMarkerUtil

package com.aio.util;

import org.apache.commons.io.FileUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;

import java.io.*;

/**
 * @author:hahaha
 * @creattime:2021-12-02 10:33
 */

public class FreeMarkerUtil {

   
    /**
     * 復(fù)制path目錄下所有文件
     * @param path  文件目錄 不能以/開頭
     * @param newpath 新文件目錄
     */
    public static void BatCopyFileFromJar(String path,String newpath) {
        if (!new File(newpath).exists()){
            new File(newpath).mkdir();
        }
        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        try {
            //獲取所有匹配的文件
            Resource[] resources = resolver.getResources(path+"/*");
            //打印有多少文件
            for(int i=0;i<resources.length;i++) {
                Resource resource=resources[i];
                try {
                    //以jar運(yùn)行時，resource.getFile().isFile() 無法獲取文件類型，會報(bào)異常，抓取異常后直接生成新的文件即可；以非jar運(yùn)行時，需要判斷文件類型，避免如果是目錄會復(fù)制錯誤，將目錄寫成文件。
                    if(resource.getFile().isFile()) {
                        makeFile(newpath+"/"+resource.getFilename());
                        InputStream stream = resource.getInputStream();
                        write2File(stream, newpath+"/"+resource.getFilename());
                    }
                }catch (Exception e) {
                    makeFile(newpath+"/"+resource.getFilename());
                    InputStream stream = resource.getInputStream();
                    write2File(stream, newpath+"/"+resource.getFilename());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    /**
     * 創(chuàng)建文件
     * @param path  全路徑 指向文件
     * @return
     */
    public static boolean makeFile(String path) {
        File file = new File(path);
        if(file.exists()) {
            return false;
        }
        if (path.endsWith(File.separator)) {
            return false;
        }
        if(!file.getParentFile().exists()) {
            if(!file.getParentFile().mkdirs()) {
                return false;
            }
        }
        try {
            if (file.createNewFile()) {
                return true;
            } else {
                return false;
            }
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
    }
    /**
     * 輸入流寫入文件
     *
     * @param is
     *            輸入流
     * @param filePath
     *            文件保存目錄路徑
     * @throws IOException
     */
    public static void write2File(InputStream is, String filePath) throws IOException {
        OutputStream os = new FileOutputStream(filePath);
        int len = 8192;
        byte[] buffer = new byte[len];
        while ((len = is.read(buffer, 0, len)) != -1) {
            os.write(buffer, 0, len);
        }
        os.close();
        is.close();
    }
    /**
    *處理異常報(bào)錯（springboot讀取classpath里的文件，解決打jar包java.io.FileNotFoundException: class path resource cannot be opened）
    **/
    public static File getFileFromClassPath(String path){
        File targetFile = new File(path);
        if(!targetFile.exists()){
            if(targetFile.getParent()!=null){
                File parent=new File(targetFile.getParent());
                if(!parent.exists()){
                    parent.mkdirs();
                }
            }
            InputStream initialStream=null;
            OutputStream outStream =null;
            try {
                Resource resource=new ClassPathResource(path);
                //注意通過getInputStream，不能用getFile
                initialStream=resource.getInputStream();
                byte[] buffer = new byte[initialStream.available()];
                initialStream.read(buffer);
                outStream = new FileOutputStream(targetFile);
                outStream.write(buffer);
            } catch (IOException e) {
            } finally {
                if (initialStream != null) {
                    try {
                        initialStream.close(); // 關(guān)閉流
                    } catch (IOException e) {
                    }
                }
                if (outStream != null) {
                    try {
                        outStream.close(); // 關(guān)閉流
                    } catch (IOException e) {
                    }
                }
            }
        }
        return targetFile;
    }
}

5. Effect

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