一、問題
MyEclipse怎麼導出可運行的jar包。
二、測試環境
MyEclipse V8.6
三、操作過程
1、java項目沒有導入第三方jar包的情況
這時候打包就比較簡單：
①首先在MyEclipse中打開項目， 右鍵點擊項目，選擇“Export”；
②選擇Java/JAR file，Next；
③Select the resources to export中可以選擇你想要包含的項目文件夾，一些不必要的文件夾就無需放進去了，免得增大空間；
這裏有幾個選項：
* Export generated class files and resources 表示只導出生成的.class文件和其他資源文件
* Export all output folders for checked projects 表示導出選中項目的所有文件夾
* Export java source file and resouces 表示導出的jar包中將包含你的源代碼*.java，如果你不想泄漏源代碼，那麼就不要選這項了
* Export refactorings for checked projects 把一些重構的信息文件也包含進去
在Select the export destination中選擇導出的jar的路徑，Next.
④下一頁可以選擇是否導出那些含有警告warning或者錯誤errors的*.class文件。一般不用理他，Next
⑤下一個頁面裏可以對項目做一些配置。（如果項目沒有引入第三方jar包，這項我們採用系統默認的選項就OK，Main class一定要設置成爲你項目的那個主方法入口類）
* Generate the manifest file是系統幫我們自動生成MANIFEST.MF文件，如果你的項目沒有引用其他class-path，那可以選擇這一項。
* Use existing mainfest from workspace。這是可以選擇我們自定義的.MF文件，格式如上所寫。
* Seal content。要封裝整個jar或者指定的包packet
* Main class。這裏可以選擇你的程序入口，將來打包出來的jar就是你這個入口類的執行結果。
最後Finish，搞定。 ......
2、java項目有導入第三方Jar包的情況
①右擊項目，單擊export=》java=》選第三個,Runnable Jar file (可執行的jar文件),Next。
②選擇launch configuration（程序入口配置），Exportdestination（導出目標）
Library handing： 選擇第一個 引用的jar包會整合到項目中去。
選擇第二個 引用的jar包會單獨放在項目根目錄下（推薦）。
選擇第三個 引用的jar包會單獨放在一個文件夾下，這個文件夾和導出的jar放在同一目錄下，
finish。
四、遇到的問題
（網絡來源）爲什麼export-->runnable jar file的launch configuration沒有東西可以選擇?對於這個問題，網上答案少之又少，我來製造些內容吧。
爲什麼MyEclipse8.5的export-->runnable jar file-->的launch configuration裏面沒有可以選擇的東西了，其實是要把你要打包成jar文件的工程的main方法運行一次，比如main方法在A類裏，運行一次A就有了
我是看見下面這段，試了一下弄出來的，喜歡的人仔細研究一下 Creating a Java application launch configuration
When you choose Run >Run As >Java Application to launch your class, you are running your class using a generic Java Application launch configuration that derives most of the launch parameters from your Java project and your workbench preferences. In some cases,
you will want to override the derived parameters or specify additional arguments.
You do this by creating your own Java Application launch configuration.
Select or from the workbench menu bar. This opens a dialog that lets you create, modify, and delete launch configurations of different types.
Select Java Application in the left hand list of launch configuration types, and press the New button in the toolbar. This will create a new launch configuration for a Java application. The tabs on the right hand side allow you control specific aspects of the
launch.
The Main tab defines the class to be launched. Enter the name of the project containing the class to launch in the project field, and the fully qualified name of the main class in the Main class field. Check the Stop in main checkbox if you want the program
to stop in the main method whenever the program is launched in debug mode.
Note: You do not have to specify a project, but doing so allows a default classpath, source lookup path, and JRE to be chosen.
The Arguments tab defines the arguments to be passed to the application and to the virtual machine (if any). You can also specify the working directory to be used by the launched application.
The JRE tab defines the JRE used to run or debug the application. You can select a JRE from the already defined JREs, or define a new JRE.
The Classpath tab defines the location of class files used when running or debugging an application. By default, the user and bootstrap class locations are derived from the associated project's build path. You may override these settings here.
The Source tab defines the location of source files used to display source when debugging a Java application. By default, these settings are derived from the associated project's build path. You may override these settings here.
The Environment tab defines the environment variable values to use when running or debugging a Java application. By default, the environment is inherited from the Eclipse runtime. You may override or append to the inherited environment.
The Common tab defines general information about the launch configuration. You may choose to store the launch configuration in a specific file and specify which perspectives become active when the launch configuration is launched.