如何在Spring Boot Maven项目的测试方法中获取命令行参数

一、规范项目结构调整 #

Spring Boot+Maven项目需遵循标准结构，同时修正主类的Spring Boot启动逻辑（使用CommandLineRunner更符合控制台应用规范）：

1. Maven构建配置（pom.xml） #

<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.0</version>
        <relativePath/>
    </parent>
    <groupId>com.example</groupId>
    <artifactId>xml-tag-checker</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>xml-tag-checker</name>
    <description>Console app to validate XML tag structure</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <mainClass>com.example.xmltagchecker.XmlTagChecker</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

2. 主类重构（XmlTagChecker.java） #

实现CommandLineRunner接口，Spring Boot启动后自动执行参数处理逻辑：

package com.example.xmltagchecker;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import java.util.ArrayList;
import java.util.List;

@SpringBootApplication
public class XmlTagChecker implements CommandLineRunner {

    public static void main(String[] args) {
        SpringApplication.run(XmlTagChecker.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        if (args.length == 0) {
            System.out.println("请传入待验证的字符串作为命令行参数");
            return;
        }
        String input = args[0];
        System.out.println(determineXml(input));
    }

    public String determineXml(String input) {
        int n = input.length();
        char[] array = input.toCharArray();

        List<String> leftTag = new ArrayList<>();
        List<String> rightTag = new ArrayList<>();

        int current = 0, start = 0;
        int leftcount = 0, rightcount = 0;
        boolean isLeftTag = false, isRightTag = false;

        while (current < n) {
            if (current < n && array[current] == '<') {
                current++;
                if (array[current] == '/') {
                    isRightTag = true;
                    isLeftTag = false;
                    start = current + 1;
                } else {
                    if (rightcount > 0)
                        return "Invalid";
                    isLeftTag = true;
                    isRightTag = false;
                    start = current;
                }

                while (current < n && array[current] != '>') {
                    current++;
                }

                if (current < n && array[current] == '>') {
                    if (isLeftTag) {
                        leftTag.add(input.substring(start, current));
                        leftcount++;
                    } else {
                        rightTag.add(input.substring(start, current));
                        rightcount++;
                    }
                    current++;
                }
            } else {
                while (current < n && array[current] != '<') {
                    current++;
                }
            }
        }

        if (leftcount != rightcount)
            return "Invalid";

        int size = leftcount;
        for (int i = 0; i < size; i++) {
            int right = i;
            int left = size - 1 - i;
            if (!rightTag.get(right).equals(leftTag.get(left)))
                return "Invalid";
        }

        return "Valid";
    }
}

二、测试类参数传递解决方案 #

针对测试方法的参数需求，提供两种实用方案：

方案1：单元测试直接指定用例（推荐） #

直接构造不同场景的输入参数，覆盖有效、无效、边界情况：

package com.example.xmltagchecker;

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

class XmlTagCheckerTest {

    private final XmlTagChecker checker = new XmlTagChecker();

    @Test
    void testValidXmlTags() {
        String input = "<Design><Code>hello world</Code></Design>";
        assertEquals("Valid", checker.determineXml(input));
    }

    @Test
    void testInvalidUnbalancedTags() {
        String input = "<Design><Code>hello world</Design>";
        assertEquals("Invalid", checker.determineXml(input));
    }

    @Test
    void testInvalidWrongOrderTags() {
        String input = "<Design><Code>hello world</Design></Code>";
        assertEquals("Invalid", checker.determineXml(input));
    }

    @Test
    void testInvalidRightTagFirst() {
        String input = "</Design><Design>hello</Design>";
        assertEquals("Invalid", checker.determineXml(input));
    }
}

方案2：从命令行传递参数给测试 #

通过JVM参数传递测试输入，模拟实际运行场景：

package com.example.xmltagchecker;

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

class XmlTagCheckerCommandLineTest {

    private final XmlTagChecker checker = new XmlTagChecker();

    @Test
    void testWithCommandLineArg() {
        // 读取JVM参数，运行测试时需添加：-Dtest.input="<Design><Code>hello</Code></Design>"
        String input = System.getProperty("test.input");
        assertNotNull(input, "请通过JVM参数-Dtest.input传入测试字符串");
        assertEquals("Valid", checker.determineXml(input));
    }
}

运行该测试的Maven命令：

mvn test -Dtest.input="<Design><Code>hello world</Code></Design>"

三、控制台运行验证 #

打包并执行应用：

# 打包应用
mvn clean package

# 运行jar包并传入参数
java -jar target/xml-tag-checker-0.0.1-SNAPSHOT.jar "<Design><Code>hello world</Code></Design>"

预期输出：

Valid

内容的提问来源于stack exchange，提问作者Vaibhav