Java在Eclipse Android应用程序中调试Java

Question

I am new to using eclipse and my first issue is figuring out what the error messages really imply. Trying to hands at Android programming, and trying to follow the example . But when code builds, I have Java errors stopping my code from running, and would appreciate some help in translating this so it makes sense to me in some way. The major problem seems to be in the auto-generated Activity.Java file that comes with my project, but not entirely sure what it is saying I ought to do instead. Thanks in advance.

Exception occurred while saving project preferences: /com.example.android.nfc.simulator.FakeTagsActivity/.settings/org.eclipse.jdt.core.prefs.


org.eclipse.core.internal.resources.ResourceException: A resource already exists on disk 'C:\Development\JavaWorkSpace\UnitedNFCApp\UnitedNFCApp\.settings'.
    at org.eclipse.core.internal.resources.Folder.assertCreateRequirements(Folder.java:47)
    at org.eclipse.core.internal.resources.Folder.create(Folder.java:95)
    at org.eclipse.core.internal.resources.ProjectPreferences$1.run(ProjectPreferences.java:566)
    at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2344)
    at org.eclipse.core.internal.resources.ProjectPreferences.save(ProjectPreferences.java:590)
    at org.eclipse.core.internal.preferences.EclipsePreferences.internalFlush(EclipsePreferences.java:465)
    at org.eclipse.core.internal.resources.ProjectPreferences.flush(ProjectPreferences.java:350)
    at org.eclipse.jdt.internal.core.JavaProject.setOption(JavaProject.java:2953)
    at com.android.ide.eclipse.adt.internal.project.ProjectHelper.checkAndFixCompilerCompliance(ProjectHelper.java:438)
    at com.android.ide.eclipse.adt.internal.project.ProjectHelper.fixProjectClasspathEntries(ProjectHelper.java:343)
    at com.android.ide.eclipse.adt.internal.project.ProjectHelper.fixProject(ProjectHelper.java:261)
    at com.android.ide.eclipse.adt.internal.wizards.newproject.NewProjectCreator.createEclipseProject(NewProjectCreator.java:775)
    at com.android.ide.eclipse.adt.internal.wizards.newproject.NewProjectCreator.createProjectAsync(NewProjectCreator.java:620)
    at com.android.ide.eclipse.adt.internal.wizards.newproject.NewProjectCreator.access$0(NewProjectCreator.java:553)
    at com.android.ide.eclipse.adt.internal.wizards.newproject.NewProjectCreator$2.execute(NewProjectCreator.java:365)
    at org.eclipse.ui.actions.WorkspaceModifyOperation$1.run(WorkspaceModifyOperation.java:106)
    at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2344)
    at org.eclipse.ui.actions.WorkspaceModifyOperation.run(WorkspaceModifyOperation.java:118)
    at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)



eclipse.buildId=I20120608-1400
java.version=1.7.0_05
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_US
Framework arguments:  -product org.eclipse.epp.package.jee.product
Command-line arguments:  -os win32 -ws win32 -arch x86 -product org.eclipse.epp.package.jee.product

Answer 1

请更新您的JDK和ADT，请检查以下链接http://developer.android.com/sdk/installing/installing-adt.html

Answer 2

1.You probably have issues with JAVA_HOME environment variable which you must add within eclipse by clicking on run configurations option located on the toolbar which opens a pop up called ' run configurations' 2 .Under Java application filter find environment tab and add variable - JAVA_HOME plus value -c:\\Java\\jdk or path to jdk.

Then Restart Eclipse

Answer 3

Approach below worked for me:

1. Delete .settings folder or org.eclipse.jdt.core.prefs file in this folder.
2. Restart eclipse
3. If the errors in your project persists you need to find each class with errors and import correct auto-generated R class.