如何在Eclipse中导入已有Java项目并开展调试开发工作？

Don’t worry—this is totally manageable, even if you’re not a regular developer. Let’s walk through each step clearly to get your project up and running in Eclipse for editing, running, and debugging:

1. Create a Java Project Linked to Your Existing Files #

First, we’ll set up Eclipse to use your existing file structure instead of copying files (so changes you make in Eclipse edit your original code directly):

• Open Eclipse and go to File > New > Java Project.
• Enter a project name (like DTNSim—pick anything you prefer).
• Uncheck Use default location, then click Browse and select your root directory /media/sf_shared/one_1.4.1. Click Finish.

2. Mark Your Source Code Folders #

Eclipse needs to know which folders contain your .java files. Let’s configure that:

• Right-click your project in the Project Explorer and go to Build Path > Configure Build Path.
• Switch to the Source tab, then click Add Folder.
• Select all folders with .java files (e.g., core/, applications/, gui/, input/—skip folders like lib/ or doc/ unless they have source code). Click OK.
• To avoid confusion with pre-compiled .class files:
  • Expand each source folder in the Source tab, select Excluded, then click Edit.
  • Click Add, type *.class, and click OK twice. This tells Eclipse to ignore compiled files.
• Click Apply and Close to save these settings.

3. Include Your Configuration Files #

Your root folder has .txt config files your app needs. Let’s make sure Eclipse can access them:

• If you don’t see the .txt files in the Project Explorer, go to Window > Preferences > General > Workspace and check Show linked resources to make them visible.
• To ensure the app can find these files when running: Later, we’ll set the working directory to your root folder (step 4).

4. Set Up the Main Class for Running & Debugging #

Your main class is DTNSim.java in the core folder. Let’s configure Eclipse to run it:

• Navigate to core > DTNSim.java in the Project Explorer.
• Right-click the file and select Run As > Java Application. Eclipse will create a run configuration automatically.
• If you get errors about missing libraries (from the lib/ folder):
  • Right-click your project, go to Build Path > Add External Archives.
  • Select all .jar files in /media/sf_shared/one_1.4.1/lib/ and click Open.
• To fix config file access issues:
  • Go to Run > Run Configurations, select your DTNSim configuration.
  • Switch to the Arguments tab, then under Working Directory, select Other and browse to /media/sf_shared/one_1.4.1. Click Apply.

5. Run and Debug Your App #

• Run normally: Click the green "Run" button (▶️) in the toolbar, or right-click DTNSim.java and choose Run As > Java Application.
• Debug:
  • Click the left margin of any source file to set a breakpoint (a blue dot will appear).
  • Right-click DTNSim.java and select Debug As > Java Application. Eclipse will switch to the Debug perspective, where you can step through code, inspect variables, and fix issues.
• If Eclipse doesn’t pick up your changes: Go to Project > Clean, select your project, and click Clean to force a recompile.

Quick Troubleshooting #

• Red error markers? Check the Problems tab in Eclipse—common fixes include adding missing libraries or adjusting source folder settings.
• App can’t find config files? Double-check the working directory in your run configuration (step 4).

内容的提问来源于stack exchange，提问作者Miguel.G