现有项目仅存build.xml无pom.xml：二者能否互换？能否添加依赖？

二者能否互换？ #

Ant的build.xml和Maven的pom.xml不能直接互换，核心区别在于：

• Ant是过程式构建工具：你得在build.xml里写死构建的每一步操作（比如编译、复制文件、打包Jar），完全手动控制流程。
• Maven是声明式构建工具：你只需要声明项目依赖、基本信息，Maven会自动处理依赖下载、构建流程（编译、测试、打包等），遵循约定好的项目结构。

虽然两者都能完成Java项目的构建，但设计理念和使用方式完全不同，没有直接的转换公式，只能根据需求重新适配。

能不能在这个build.xml里添加依赖？ #

可以添加，但不能像Maven那样只加一行依赖声明，得手动完成以下步骤：
假设你要添加一个名为new-dependency.jar的依赖：

1. 把new-dependency.jar放到项目的libs目录下（和现有Jar放在一起）
2. 修改build.xml的两处内容：
   • 在<manifest>的<attribute name="Class-Path">值里，追加9.9_lib/new-dependency.jar（注意和前面的内容用空格分隔）
   • 在<copy>任务列表的最后，添加一行：<copy file="${dir.buildfile}/libs/new-dependency.jar" todir="${dir.jarfile}/9.9_lib"/>

示例修改后的关键片段 #

<!-- 修改后的Class-Path属性 -->
<attribute name="Class-Path" value=". 9.9_lib/activation.jar ... 9.9_lib/new-dependency.jar"/>

<!-- 新增的copy任务 -->
<copy file="${dir.buildfile}/libs/new-dependency.jar" todir="${dir.jarfile}/9.9_lib"/>

注意事项 #

这个由Eclipse导出的build.xml功能非常单一，只负责打包可执行Jar，没有依赖自动下载、版本管理的能力。如果你的项目需要频繁添加依赖，更高效的方式是：

• 给Ant集成Ivy工具，实现依赖的自动下载和管理
• 把项目转换成Maven项目，使用pom.xml来管理依赖

你提供的原始build.xml内容：

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project default="create_run_jar" name="Create Runnable Jar for Project PM_DEV with libraries in sub-folder">
    <!--this file was created by Eclipse Runnable JAR Export Wizard-->
    <!--ANT 1.7 is required                                        -->
    <!--define folder properties-->
    <property name="dir.buildfile" value="."/>
    <property name="dir.workspace" value="C:/Users/SENIOR/eclipse-workspace"/>
    <property name="dir.jarfile" value="C:/Users/SENIOR/Desktop/9.9"/>
    <target name="create_run_jar">
        <jar destfile="${dir.jarfile}/9.9.jar">
            <manifest>
                <attribute name="Main-Class" value="ui.MainMenuFrame"/>
                <attribute name="Class-Path" value=". 9.9_lib/activation.jar 9.9_lib/apache-mime4j-core-0.8.5.jar 9.9_lib/arial.jar 9.9_lib/commons-beanutils-1.8.2.jar 9.9_lib/commons-digester-2.1.jar 9.9_lib/commons-logging-1.2.jar 9.9_lib/dom4j-1.6.1.jar 9.9_lib/GoodDatePicker-10.3.1.jar 9.9_lib/hamcrest-core-1.3.jar 9.9_lib/itextpdf-5.3.4.jar 9.9_lib/javax.mail-1.6.2.jar 9.9_lib/jcalendar-1.3.3.jar 9.9_lib/jcommon-1.0.23.jar 9.9_lib/jfreechart-1.0.19-experimental.jar 9.9_lib/jfreechart-1.0.19-swt.jar _9.9_lib/jfreechart-1.0.19.jar 9.9_lib/jfreesvg-2.0.jar 9.9_lib/joda-time-2.4-javadoc.jar 9.9_lib/joda-time-2.4-sources.jar 9.9_lib/joda-time-2.4.jar 9.9_lib/junit-4.11.jar 9.9_lib/orsoncharts-1.4-eval-nofx.jar 9.9_lib/orsoncharts-1.5.jar 9.9_lib/orsonpdf-1.6-eval.jar 9.9_lib/orsonpdf-1.7.jar 9.9_lib/poi-3.14.jar 9.9_lib/poi-ooxml-3.14.jar 9.9_lib/poi-ooxml-schemas-3.14.jar 9.9_lib/rs2xml.jar 9.9_lib/servlet.jar 9.9_lib/sqljdbc4.jar 9.9_lib/swingx-1.6.1.jar 9.9_lib/swtgraphics2d.jar 9.9_lib/xmlbeans-2.6.0.jar 9.9_lib/mssql-jdbc-10.2.1.jre8.jar 9.9_lib/sqljdbc42.jar 9.9_lib/AbsoluteLayout.jar 9.9_lib/eclipselink.jar 9.9_lib/javax.persistence_2.1.0.v201304241213.jar 9.9_lib/org.eclipse.persistence.jpa.jpql_2.5.2.v20140319-9ad6abd.jar 9.9_lib/swing-layout-1.0.4.jar 9.9_lib/commons-collections4-4.4.jar 9.9_lib/itext-2.1.7.js8.jar 9.9_lib/jasperreports-6.20.0.jar"/>
            </manifest>
            <fileset dir="${dir.buildfile}/build/classes"/>
        </jar>
        <delete dir="${dir.jarfile}/9.9_lib"/>
        <mkdir dir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/activation.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/apache-mime4j-core-0.8.5.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/arial.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/commons-beanutils-1.8.2.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/commons-digester-2.1.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/commons-logging-1.2.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/dom4j-1.6.1.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/GoodDatePicker-10.3.1.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/hamcrest-core-1.3.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/itextpdf-5.3.4.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/javax.mail-1.6.2.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/jcalendar-1.3.3.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/jcommon-1.0.23.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/jfreechart-1.0.19-experimental.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/jfreechart-1.0.19-swt.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/jfreechart-1.0.19.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/jfreesvg-2.0.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/joda-time-2.4-javadoc.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/joda-time-2.4-sources.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/joda-time-2.4.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/junit-4.11.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/orsoncharts-1.4-eval-nofx.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/orsoncharts-1.5.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/orsonpdf-1.6-eval.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/orsonpdf-1.7.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/poi-3.14.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/poi-ooxml-3.14.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/poi-ooxml-schemas-3.14.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/rs2xml.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/servlet.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/sqljdbc4.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/swingx-1.6.1.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/swtgraphics2d.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/xmlbeans-2.6.0.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/mssql-jdbc-10.2.1.jre8.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/sqljdbc42.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/AbsoluteLayout.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/eclipselink.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/javax.persistence_2.1.0.v201304241213.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/org.eclipse.persistence.jpa.jpql_2.5.2.v20140319-9ad6abd.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/swing-layout-1.0.4.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/commons-collections4-4.4.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/itext-2.1.7.js8.jar" todir="${dir.jarfile}/9.9_lib"/>
        <copy file="${dir.buildfile}/libs/jasperreports-6.20.0.jar" todir="${dir.jarfile}/9.9_lib"/>
    </target>
</project>

内容的提问来源于stack exchange，提问作者ZaneK