如何获取JAR文件中资源目录内的所有资源？

问题描述 投票：0回答：3

我正在使用 Spring Boot，我想要获取资源。

这是我的目录结构：

├───java
│   └───...
├───resources
│   └───files
│       ├───file1.txt
│       ├───file2.txt
│       ├───file3.txt
│       └───file4.txt

我正在尝试获取 

files
目录中的资源。以下是我为访问这些文件所做的操作：

@Autowired
private ResourceLoader resourceLoader;

...
Stream<Path> walk = Files.walk(Paths.get(resourceLoader.getResource("classpath:files/").getURI()));

当文件位于 

target
目录中时，这可以在本地运行，但是当我从 JAR 文件运行它时找不到这些文件。我该如何解决？我已经检查过这些文件确实存在于位于 
BOOT-INF/classes/files
下的 jar 中。

以下是 maven 如何构建并将资源复制到 JAR 中（我不希望 .txt 文件被过滤）：

<resources>
  <resource>
    <directory>src/main/resources</directory>
    <filtering>true</filtering>
    <excludes>
      <exclude>**/*.txt</exclude>
    </excludes>
  </resource>
  <resource>
    <directory>src/main/resources</directory>
    <filtering>false</filtering>
    <includes>
      <include>**/*.txt</include>
    </includes>
  </resource>
</resources>
java spring java-8
3个回答
8
投票

您可以尝试使用以下代码来读取文件吗？

ResourcePatternResolver resourcePatResolver = new PathMatchingResourcePatternResolver();
Resource[] AllResources = resourcePatResolver.getResources("classpath*:files/*.txt");
 for(Resource resource: AllResources) {
    InputStream inputStream = resource.getInputStream();
    //Process the logic
 }

这不是您所编写的代码的确切解决方案，但它将给出有关要阅读的资源的概述。

0
投票

其他人也遇到了与您相同的问题，他们按照 Sambit 的建议将 ResourceLoader 与 ResourcePatternResolver 结合起来找到了解决方案。请参阅此处查看相同问题的答案：https://stackoverflow.com/a/49826409/6777695

0
投票

下面的示例代码在基于本地 Windows 的开发环境中读取/加载配置为位于 /src/main/resources 项目路径下的 rules/ 文件夹一部分的 Drools 文件，而在基于 Unix 的情况下从应用程序 jar 读取/加载生产环境。

在本地 Windows 开发环境中，使用 org.springframework.core.io.support.ResourcePatternUtils.getResourcePatternResolver 时，加入了使用 java.lang.ClassLoader.getResource(String name) 方法读取/加载文件的方法(ResourceLoader resourcesLoader) 返回 org.springframework.core.io.support.ResourcePatternResolver.getResources(String locationPattern) 部署在基于 Linux 的生产环境中时从应用程序 jar 中读取/加载文件的方法。

Drools 配置

/**
 * @author dinesh.lomte
 */
package com.dl.questioneries.rules.api.config;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.io.FileUtils;
import org.kie.api.KieServices;
import org.kie.api.builder.KieBuilder;
import org.kie.api.builder.KieFileSystem;
import org.kie.api.runtime.KieContainer;
import org.kie.internal.io.ResourceFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.io.support.ResourcePatternUtils;

import com.dl.questioneries.rules.api.exception.SystemException;

import lombok.extern.slf4j.Slf4j;

@Slf4j
@Configuration
public class DroolsConfiguration {

    private final KieServices kieServices = KieServices.Factory.get();
    private ResourceLoader resourceLoader;

    /**
     * 
     * @param resourceLoader
     */
    @Autowired
    public DroolsConfiguration(ResourceLoader resourceLoader) {
        this.resourceLoader = resourceLoader;
    }
    
    /**
     * 
     * @return
     * @throws SystemException
     */
    @Bean
    public KieContainer kieContainer() throws SystemException {

        KieFileSystem kieFileSystem = kieServices.newKieFileSystem();

        File[] files = 
                System.getProperty("os.name").contains("Windows")
                ? loadResourcesOfRulesFromLocalSystem()
                : loadResourcesOfRulesFromJar();
        if (files == null || files.length == 0) {
            String message = "Failed to load the '.drl' files located under resources specific rules folder.";
            log.error(message);
            throw new SystemException(
                    "SYS_ERROR_00001", message, new Exception(message));
        }
        for (File file : files) {
            kieFileSystem.write(ResourceFactory.newFileResource(file));
        }
        log.info("Loaded the configured rule files successfully.");
        KieBuilder Kiebuilder = kieServices.newKieBuilder(kieFileSystem);
        Kiebuilder.buildAll();

        return kieServices.newKieContainer(
                kieServices.getRepository().getDefaultReleaseId());
    }
    
    /**
     * 
     * @return
     */
    private File[] loadResourcesOfRulesFromJar() {
        
        log.info("Loading the configured rule files from Jar.");
        Resource[] resources = null;
        List<File> files = new ArrayList<>();
        try {
            resources = ResourcePatternUtils
                    .getResourcePatternResolver(resourceLoader)
                    .getResources("classpath*:rules/*.drl");
            InputStream inputStream = null;
            File file = null;
            for (Resource resource : resources) {
                try {
                    inputStream = resource.getInputStream();
                    file = File.createTempFile(
                            resource.getFilename().substring(
                                    0, resource.getFilename().length() - 4), 
                            ".drl");
                    FileUtils.copyInputStreamToFile(inputStream, file);
                } finally {
                    inputStream.close();
                }
                log.info("'{}'", resource.getFilename());
                files.add(file);
            }
        } catch (IOException ioException) {
            String message = new StringBuilder(
                    "Failed to load the '.drl' files located under resources specific rules folder.")
                    .append(ioException.getMessage()).toString();
            log.error(message, ioException);
            throw new SystemException(
                    "SYS_ERROR_00001", message, ioException);
        }
        return (File[]) files.toArray(new File[files.size()]);
    }
    
    /**
     * 
     * @return
     */
    private File[] loadResourcesOfRulesFromLocalSystem() {
        
        log.info("Loading the configured rule files from local system.");
        try {
            File files = new File(
                    getClass().getClassLoader().getResource("rules/").getPath());
            return files.listFiles();
        } catch (Exception exception) {
            String message = new StringBuilder(
                    "Failed to load the '.drl' files located under resources specific rules folder.")
                    .append(exception.getMessage()).toString();
            log.error(message, exception);
            throw new SystemException(
                    "SYS_ERROR_00001", message, exception);
        }
    }
}

控制器

/**
 * @author dinesh.lomte
 */
package com.dl.questioneries.rules.api.controller;

import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

import com.dl.questioneries.rules.api.model.Question;

@RestController
public class QuestioneriesRulesController {

    @Autowired
    private KieContainer kieContainer;

    /**
     * 
     * @param question
     * @return
     */
    @PostMapping(path = "/getQuestion", 
            consumes = MediaType.APPLICATION_JSON_VALUE,
            produces = MediaType.APPLICATION_JSON_VALUE)
    public Question fetchQuestion(@RequestBody Question question) {
        
        KieSession kieSession = kieContainer.newKieSession();
        kieSession.insert(question);
        kieSession.fireAllRules(1);
        
        return question;
    }
}
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