新建 Maven Project，项目结构：
修改 pom.xml 文件，引入依赖：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.mk</groupId> <artifactId>cmd-tree</artifactId> <version>1.0.0</version> <description>列出指定目录的结构</description> <properties> <commons-lang3.version>3.10</commons-lang3.version> <logback-classic.version>1.2.3</logback-classic.version> <lombok.version>1.18.12</lombok.version> </properties> <dependencies> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-lang3</artifactId> <version>${commons-lang3.version}</version> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>${logback-classic.version}</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>${lombok.version}</version> <optional>true</optional> </dependency> </dependencies> <build> <plugins> <!-- http://maven.apache.org/plugins/index.html --> <!-- http://maven.apache.org/plugins/maven-shade-plugin/examples/executable-jar.html --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-shade-plugin</artifactId> <version>3.2.1</version> <executions> <execution> <phase>package</phase> <goals> <goal>shade</goal> </goals> <configuration> <transformers> <!-- To create an executable uber JAR, one simply needs to set the main class that serves as the application entry point --> <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer"> <mainClass>com.mk.Application</mainClass> </transformer> </transformers> </configuration> </execution> </executions> </plugin> </plugins> </build> </project>/cmd-tree/src/main/resources/logback.xml 日志配置文件：
<?xml version="1.0" encoding="UTF-8"?> <configuration scan="true" scanPeriod="60 seconds" debug="false"> <!-- 输出到控制台 --> <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> <encoder> <pattern>%msg%n</pattern> </encoder> </appender> <!-- 基于大小以及时间的轮转策略 --> <!-- 参考：http://www.logback.cn/04%E7%AC%AC%E5%9B%9B%E7%AB%A0Appenders.html --> <appender name="ROLLING" class="ch.qos.logback.core.rolling.RollingFileAppender"> <!-- 要写入文件的名称。如果文件不存在，则新建。 --> <!-- <file>${USER_HOME}/logback.log</file> --> <file>logback.log</file> <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy"> <fileNamePattern>%d{yyyyMMdd}/logback-%d{yyyy-MM-dd}.%i.log</fileNamePattern> <maxFileSize>1000KB</maxFileSize> <!-- 最多保留多少数量的归档文件，将会异步删除旧的文件。 --> <maxHistory>30</maxHistory> <!-- 所有归档文件总的大小。当达到这个大小后，旧的归档文件将会被异步的删除。 --> <totalSizeCap>10MB</totalSizeCap> </rollingPolicy> <encoder> <!-- <pattern>%d{HH:mm:ss.SSS} %-5level [%-10thread] %logger - %msg%n</pattern> --> <pattern>%msg%n</pattern> </encoder> </appender> <!-- 日志输出级别 --> <root level="info"> <appender-ref ref="ROLLING" /> <appender-ref ref="STDOUT" /> </root> </configuration>/cmd-tree/src/main/java/com/mk/Application.java 主类
package com.mk; import java.io.File; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Scanner; import org.apache.commons.lang3.StringUtils; import lombok.extern.slf4j.Slf4j; @Slf4j public class Application { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); String pathname = null; try { System.out.format("Please input the location (default is %s): ", System.getProperty("user.dir")); pathname = scanner.nextLine(); } catch (Exception e) { log.error("ERROR! EXCEPTION: {}", e); scanner.close(); System.exit(0); } if (StringUtils.isBlank(pathname)) { pathname = System.getProperty("user.dir"); } File root = new File(pathname); if (!root.exists()) { log.info("{} does not exist.", pathname); System.exit(0); } Map<String, Integer> counters = listFiles(root, 0, null); log.info("\nTotal directories: {}", counters.get("directories")); log.info("Total files: {}", counters.get("files")); } /** * * @param root 目录 * @param deep 初始值 0 * @param counters 初始值 <code>null</code> * @return 返回两个计数器。第一个记录文件夹总数，键值 <code>directories</code>；第二个记录文件总数，键值 <code>files</code> */ private static Map<String, Integer> listFiles(File root, int deep, Map<String, Integer> counters) { if (counters == null) { counters = new HashMap<>(); counters.put("directories", 0); counters.put("files", 0); } deep++; String indentation = ""; for (int i = 0; i < deep; i++) { indentation = indentation.concat(" "); } indentation = "|".concat(indentation.substring(1)); File[] files = root.listFiles(); List<File> sortedFiles = new ArrayList<>(); List<File> sortedDirectories = new ArrayList<>(); for (File file : files) { if (file.isDirectory()) { sortedDirectories.add(file); } else { sortedFiles.add(file); } } counters.put("files", counters.get("files") + sortedFiles.size()); indentation = indentation.replace("+", "|").replaceAll("-", " "); for (File file : sortedFiles) { log.info("{}{}", indentation, file.getName()); } counters.put("directories", counters.get("directories") + sortedDirectories.size()); indentation = indentation.replace("|", "+").replaceAll(" ", "-"); for (File file : sortedDirectories) { log.info("{}{}", indentation, file.getName()); listFiles(file, deep, counters); } return counters; } }使用 Maven 打包之后，执行命令 java -jar cmd-tree-1.0.0.jar，如果不输入目录，则统计当前目录：
G:\Eclipse\eclipse-workspace-spring-boot-20191129\cmd-tree\target>java -jar cmd-tree-1.0.0.jar Please input the location (default is G:\Eclipse\eclipse-workspace-spring-boot-20191129\cmd-tree\target): | cmd-tree-1.0.0.jar | logback.log | original-cmd-tree-1.0.0.jar +---classes | logback.xml +-------com +-----------mk | Application.class +-------META-INF | MANIFEST.MF +-----------maven +---------------com.mk +-------------------cmd-tree | pom.properties | pom.xml +---generated-sources +-------annotations +---maven-archiver | pom.properties +---maven-status +-------maven-compiler-plugin +-----------compile +---------------default-compile | createdFiles.lst | inputFiles.lst +-----------testCompile +---------------default-testCompile | inputFiles.lst +---test-classes Total directories: 17 Total files: 12