Jar 找不到主方法 - 连接到主类，但无法访问方法 [英] Jar Can't Find Main Method - Connected to main class, but can't access method

问题描述

我一直在 Eclipse 中处理一个项目，除了一些 Ant 问题之外，一切都很顺利.

I've been working on a project in Eclipse and everything's been going smooth except for some Ant issues along the way.

我的代码编译得很好，完全按照我的意愿去做，但是，当它在 jar 中时，我收到错误:

My code compiles perfectly and does exactly what I want it to do, but, when it's in a jar, I get the error:

Exception in thread "main" java.lang.NoSuchMethodError: main

Main 肯定存在于文件中，所以我的猜测是它与文件的构造方式有关.我一直在使用 SuperCSV 来阅读我拥有的一些 Excel 表格，并围绕网站上的示例构建了我的主类:http://supercsv.sourceforge.net/codeExamples_general.html.这是我的改编:

Main definitely exists in the file, so my guess is that it has to do with the way the file is constructed. I've been using SuperCSV to read some excel sheets I have and have constructed my main class around the example from the website: http://supercsv.sourceforge.net/codeExamples_general.html. Here's my adaptation:

ExcelFile.java

package jab.jm.main;

import jab.jm.readers.FileManager;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.net.URL;

import junit.framework.Test;

import org.supercsv.cellprocessor.constraint.StrMinMax;
import org.supercsv.cellprocessor.ift.CellProcessor;
import org.supercsv.io.CsvBeanReader;
import org.supercsv.io.ICsvBeanReader;
import org.supercsv.prefs.CsvPreference;

class ReadingObjects {

    static final CellProcessor[] userProcessors = { null,
            new StrMinMax(0, 100), null, new StrMinMax(0, 100), null,
            new StrMinMax(0, 100), null, null, null, null, null, null, null,
            null, null, null, null, null, null, null, null, null, null, null,
            null, null, null, null, null, new StrMinMax(0, 100), null,
            new StrMinMax(0, 100), null, null, null, null, null, null, null,
            null, null, null, null, null, null, null, null, null, null, null,
            null, null, null, null, null, null, null, null, null };


    public static void main(String[] args) throws Exception {
        ICsvBeanReader inFile = new CsvBeanReader(
                new FileReader(
                        "C:\\Users\\Justian\\workspaces\\LNConnectionCompiler\\src\\jab\\jm\\main\\Fred_Jewell.csv"),
                CsvPreference.EXCEL_PREFERENCE);
        try {
            final String[] header = { "title", "firstName", "middleName",
                    "lastName", "suffix", "email", "email2", "email3",
                    "businessStreet", "businessStreet2", "businessStreet3",
                    "businessCity", "businessState", "businessPostalCode",
                    "businessCountry", "homeStreet", "homeStreet2",
                    "homeStreet3", "homeCity", "homeState", "homePostalCode",
                    "homeCountry", "otherStreet", "otherStreet2",
                    "otherStreet3", "otherCity", "otherState",
                    "otherPostalCode", "otherCountry", "company", "department",
                    "jobTitle", "assistantPhone", "businessFax",
                    "businessPhone", "businessPhone2", "callback", "carPhone",
                    "companyMainPhone", "homeFax", "homePhone", "homePhone2",
                    "isdn", "mobilePhone", "otherFax", "otherPhone", "pager",
                    "primaryPhone", "radioPhone", "TTYTTDPhone", "telex",
                    "assistantName", "birthday", "managerName", "notes",
                    "otherPOBox", "spouse", "webPage", "personalWebPage" };
            ExcelFile file;
            while ((file = inFile.read(ExcelFile.class, header, userProcessors)) != null) {
                if (file.getCompany().indexOf("Jabian") >= 0)
                    System.out.println(file.getFirstName() + " " + file.getLastName());
            }
        } finally {
            inFile.close();
        }

        URL location = ExcelFile.class.getProtectionDomain().getCodeSource().getLocation();
        System.out.println(location.getFile());

    }
}

public class ExcelFile {
    private String title, firstName, middleName, lastName, suffix, email,
            email2, email3, businessStreet, businessStreet2, businessStreet3,
            businessCity, businessState, businessPostalCode, businessCountry,
            homeStreet, homeStreet2, homeStreet3, homeCity, homeState,
            homePostalCode, homeCountry, otherStreet, otherStreet2,
            otherStreet3, otherCity, otherState, otherPostalCode, otherCountry,
            company, department, jobTitle, assistantPhone, businessFax,
            businessPhone, businessPhone2, callback, carPhone,
            companyMainPhone, homeFax, homePhone, homePhone2, isdn,
            mobilePhone, otherFax, otherPhone, pager, primaryPhone, radioPhone,
            TTYTTDPhone, telex, assistantName, birthday, managerName, notes,
            otherPOBox, spouse, webPage, personalWebPage;

    public String getTitle() {
        return title;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getMiddleName() {
        return middleName;
    }

    public String getLastName() {
        return lastName;
    }

    public String getSuffix() {
        return suffix;
    }

    public String getEmail() {
        return email;
    }

    public String getEmail2() {
        return email2;
    }

    public String getEmail3() {
        return email3;
    }

    public String getBusinessStreet() {
        return businessStreet;
    }

    public String getBusinessStreet2() {
        return businessStreet2;
    }

    public String getBusinessStreet3() {
        return businessStreet3;
    }

    public String getBusinessCity() {
        return businessCity;
    }

    public String getBusinessState() {
        return businessState;
    }

    public String getBusinessPostalCode() {
        return businessPostalCode;
    }

    public String getBusinessCountry() {
        return businessCountry;
    }

    public String getHomeStreet() {
        return homeStreet;
    }

    public String getHomeStreet2() {
        return homeStreet2;
    }

    public String getHomeStreet3() {
        return homeStreet3;
    }

    public String getHomeCity() {
        return homeCity;
    }

    public String getHomeState() {
        return homeState;
    }

    public String getHomePostalCode() {
        return homePostalCode;
    }

    public String getHomeCountry() {
        return homeCountry;
    }

    public String getOtherStreet() {
        return otherStreet;
    }

    public String getOtherStreet2() {
        return otherStreet2;
    }

    public String getOtherStreet3() {
        return otherStreet3;
    }

    public String getOtherCity() {
        return otherCity;
    }

    public String getOtherState() {
        return otherState;
    }

    public String getOtherPostalCode() {
        return otherPostalCode;
    }

    public String getOtherCountry() {
        return otherCountry;
    }

    public String getCompany() {
        return company;
    }

    public String getDepartment() {
        return department;
    }

    public String getJobTitle() {
        return jobTitle;
    }

    public String getAssistantPhone() {
        return assistantPhone;
    }

    public String getBusinessFax() {
        return businessFax;
    }

    public String getBusinessPhone() {
        return businessPhone;
    }

    public String getBusinessPhone2() {
        return businessPhone2;
    }

    public String getCallBack() {
        return callback;
    }

    public String getCarPhone() {
        return carPhone;
    }

    public String getCompanyMainPhone() {
        return companyMainPhone;
    }

    public String getHomeFax() {
        return homeFax;
    }

    public String getHomePhone() {
        return homePhone;
    }

    public String getHomePhone2() {
        return homePhone2;
    }

    public String getISDN() {
        return isdn;
    }

    public String getMobilePhone() {
        return mobilePhone;
    }

    public String getOtherFax() {
        return otherFax;
    }

    public String getOtherPhone() {
        return otherPhone;
    }

    public String getPager() {
        return pager;
    }

    public String getPrimaryPhone() {
        return primaryPhone;
    }

    public String getRadioPhone() {
        return radioPhone;
    }

    public String getTTYTTDPhone() {
        return TTYTTDPhone;
    }

    public String getTelex() {
        return telex;
    }

    public String getAssistantName() {
        return assistantName;
    }

    public String getBirthday() {
        return birthday;
    }

    public String getManagerName() {
        return managerName;
    }

    public String getNotes() {
        return notes;
    }

    public String getOtherPOBox() {
        return otherPOBox;
    }

    public String getSpouse() {
        return spouse;
    }

    public String getWebPage() {
        return webPage;
    }

    public String getPersonalWebPage() {
        return personalWebPage;
    }

    public void setTitle(final String title) {
        this.title = title;
    }

    public void setFirstName(final String firstName) {
        this.firstName = firstName;
    }

    public void setMiddleName(final String middleName) {
        this.middleName = middleName;
    }

    public void setLastName(final String lastName) {
        this.lastName = lastName;
    }

    public void setSuffix(final String suffix) {
        this.suffix = suffix;
    }

    public void setEmail(final String email) {
        this.email = email;
    }

    public void setEmail2(final String email2) {
        this.email2 = email2;
    }

    public void setEmail3(final String email3) {
        this.email3 = email3;
    }

    public void setBusinessStreet(final String businessStreet) {
        this.businessStreet = businessStreet;
    }

    public void setBusinessStreet2(final String businessStreet2) {
        this.businessStreet2 = businessStreet2;
    }

    public void setBusinessStreet3(final String businessStreet3) {
        this.businessStreet3 = businessStreet3;
    }

    public void setBusinessCity(final String businessCity) {
        this.businessCity = businessCity;
    }

    public void setBusinessState(final String businessState) {
        this.businessState = businessState;
    }

    public void setBusinessPostalCode(final String businessPostalCode) {
        this.businessPostalCode = businessPostalCode;
    }

    public void setBusinessCountry(final String businessCountry) {
        this.businessCountry = businessCountry;
    }

    public void setHomeStreet(final String homeStreet) {
        this.homeStreet = homeStreet;
    }

    public void setHomeStreet2(final String homeStreet2) {
        this.homeStreet2 = homeStreet2;
    }

    public void setHomeStreet3(final String homeStreet3) {
        this.homeStreet3 = homeStreet3;
    }

    public void setHomeCity(final String homeCity) {
        this.homeCity = homeCity;
    }

    public void setHomeState(final String homeState) {
        this.homeState = homeState;
    }

    public void setHomePostalCode(final String homePostalCode) {
        this.homePostalCode = homePostalCode;
    }

    public void setHomeCountry(final String homeCountry) {
        this.homeCountry = homeCountry;
    }

    public void setOtherStreet(final String otherStreet) {
        this.otherStreet = otherStreet;
    }

    public void setOtherStreet2(final String otherStreet2) {
        this.otherStreet2 = otherStreet2;
    }

    public void setOtherStreet3(final String otherStreet3) {
        this.otherStreet3 = otherStreet3;
    }

    public void setOtherCity(final String otherCity) {
        this.otherCity = otherCity;
    }

    public void setOtherState(final String otherState) {
        this.otherState = otherState;
    }

    public void setOtherPostalCode(final String otherPostalCode) {
        this.otherPostalCode = otherPostalCode;
    }

    public void setOtherCountry(final String otherCountry) {
        this.otherCountry = otherCountry;
    }

    public void setCompany(final String company) {
        this.company = company;
    }

    public void setDepartment(final String department) {
        this.department = department;
    }

    public void setJobTitle(final String jobTitle) {
        this.jobTitle = jobTitle;
    }

    public void setAssistantPhone(final String assistantPhone) {
        this.assistantPhone = assistantPhone;
    }

    public void setBusinessFax(final String businessFax) {
        this.businessFax = businessFax;
    }

    public void setBusinessPhone(final String businessPhone) {
        this.businessPhone = businessPhone;
    }

    public void setBusinessPhone2(final String businessPhone2) {
        this.businessPhone2 = businessPhone2;
    }

    public void setCallback(final String callback) {
        this.callback = callback;
    }

    public void setCarPhone(final String carPhone) {
        this.carPhone = carPhone;
    }

    public void setCompanyMainPhone(final String companyMainPhone) {
        this.companyMainPhone = companyMainPhone;
    }

    public void setHomeFax(final String homeFax) {
        this.homeFax = homeFax;
    }

    public void setHomePhone(final String homePhone) {
        this.homePhone = homePhone;
    }

    public void setHomePhone2(final String homePhone2) {
        this.homePhone2 = homePhone2;
    }

    public void setIsdn(final String isdn) {
        this.isdn = isdn;
    }

    public void setMobilePhone(final String mobilePhone) {
        this.mobilePhone = mobilePhone;
    }

    public void setOtherFax(final String otherFax) {
        this.otherFax = otherFax;
    }

    public void setOtherPhone(final String otherPhone) {
        this.otherPhone = otherPhone;
    }

    public void setPager(final String pager) {
        this.pager = pager;
    }

    public void setPrimaryPhone(final String primaryPhone) {
        this.primaryPhone = primaryPhone;
    }

    public void setRadioPhone(final String radioPhone) {
        this.radioPhone = radioPhone;
    }

    public void setTTYTTDPhone(final String TTYTTDPhone) {
        this.TTYTTDPhone = TTYTTDPhone;
    }

    public void setTelex(final String telex) {
        this.telex = telex;
    }

    public void setAssistantName(final String assistantName) {
        this.assistantName = assistantName;
    }

    public void setBirthday(final String birthday) {
        this.birthday = birthday;
    }

    public void setManagerName(final String managerName) {
        this.managerName = managerName;
    }

    public void setNotes(final String notes) {
        this.notes = notes;
    }

    public void setOtherPOBox(final String otherPOBox) {
        this.otherPOBox = otherPOBox;
    }

    public void setSpouse(final String spouse) {
        this.spouse = spouse;
    }

    public void setWebPage(final String webPage) {
        this.webPage = webPage;
    }

    public void setPersonalWebPage(final String personalWebPage) {
        this.personalWebPage = personalWebPage;
    }

}

在我看来，这是一个糟糕的结构，但完全有可能，这就是为什么我在编译时不会遇到任何问题.当然，由于它的构造如此不寻常，Ant 可能无法尝试访问它.

This, in my mind, is a poor construction, but it is entirely possible and that's why I don't run into any issues compiling. Of course, because it's such an unusual construction, Ant may be having trouble trying to access it.

请注意，ExcelFile.Java 包含非公共类 ReadingObjects，该类包含 main 方法.我的理论是，因为 ExcelFile.java 不一定是包含 main 方法的类，所以我遇到了问题

让我知道你们的想法.我愿意试一试.

Let me know what you guys think. I'm willing to give things a shot.

非常感谢！

-贾斯汀

这是我的构建文件:

<?xml version="1.0" ?>

<project name="ServerJar" default="dist" basedir=".">
    <description>
        Builds client files into .jar
    </description>
    <!-- [build variables] -->
    <property name="src" location="src" />
    <property name="build" location="build" />
    <property name="dist" location="dist" />
    <property name="lib" location="lib" />
    <!-- [path to packages] -->
    <path id="master-classpath">
        <fileset dir="${lib}">
            <include name="*.jar"/>
        </fileset>
    </path>


    <target name="init">
        <!-- makes time stamp to be used in jar name -->
        <tstamp />
        <!-- creates build directory structure -->
        <mkdir dir="${build}" />
    </target>

    <target name="compile" depends="init" description="Compiles the source">
        <!-- compiles the java code from ${src} into ${build} -->
        <!-- <javac srcdir="${src}" destdir="${build}" /> -->
        <javac destdir= "${build}">
            <src path="${src}"/>
            <classpath refid="master-classpath"/>
        </javac>
    </target>

    <target name="dist" depends="compile" description="Generates distributable">
    <!-- creates the distribution directory -->
        <mkdir dir="${dist}/lib" />

        <!-- puts everything in ${build} into the jar file -->
        <jar jarfile="${dist}/lib/CC-${DSTAMP}.jar" basedir="${build}">
            <manifest>
                <attribute name="Main-Class" value="jab.jm.main.ExcelFile" />
            </manifest>
        </jar>

        <!-- makes a jar file for quick test execution -->
        <jar jarfile="${dist}/lib/CC.jar" basedir="${build}">
            <manifest>
                <attribute name="Main-Class" value="jab.jm.main.ExcelFile" />
            </manifest>
        </jar>
    </target>

    <target name="clean" description="Cleans up the extra build files">
        <!-- deletes the ${build} and ${dist} directories -->
        <delete dir="${build}" />
        <delete dir="${dist}" />
    </target>
</project>

没有运气.也许我们可以考虑将我的一个文件重组为两个?

我对此有点紧张，因为我不知道 SuperCSV 需要什么样的格式.

I'm a little nervous about that because I don't know what kind of format SuperCSV requires.

推荐答案

-cp(和 -classpath)参数在以下情况下被忽略使用 -jar 参数.您需要在 JAR 的 MANIFEST.MF 文件的 Class-Path 属性中指定它.

The -cp (and -classpath) arguments are ignored when using -jar argument. You need to specify it in the Class-Path attribute of JAR's MANIFEST.MF file.

我的蚂蚁有点生锈，但它就像那些线:

My ant is a bit rusty, but it's something like those lines:

<attribute name="Class-Path" value="${dist.classpath}"/>

<小时>

更新 根据您的评论，您想知道如何直接使用 Eclipse 而不是使用 Ant 来执行此操作.首先，您需要使用 Ctrl+F11 运行建议的 main() 方法，然后右键单击该项目，选择 Export > RunnableJAR 文件(注意Runnable"部分，这很重要！).然后，在向导中，您必须从列表中选择相同的启动配置(如有必要，选择库处理)，然后单击完成.这样，Eclipse 会在生成 MANIFEST 文件时自动考虑构建路径详细信息.

---

Update as per your comments you'd like to know how to do this directly with Eclipse instead of hassling with Ant. First, you need to run the proposed main() method using Ctrl+F11 and then rightclick the project, choose Export > Runnable JAR file (note "Runnable" part, this is important!). Then, in the Wizard you have to choose the same Launch configuration from the list (and if necessary choose library handling) and then click Finish. This way Eclipse will take the buildpath details automagically into account when generating the MANIFEST file.

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