Question

我在设备中运行当前的android项目时遇到了一些麻烦。该项目没有构建错误（使用maven），但是当我运行时会发生此错误：

E/AndroidRuntime(12097): FATAL EXCEPTION: main
E/AndroidRuntime(12097): Process: org.hello, PID: 12097
E/AndroidRuntime(12097): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{org.hello/org.hello.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "org.hello.MainActivity" on path: DexPathList[[zip file "/data/app/org.hello-1.apk"],nativeLibraryDirectories=[/data/app-lib/org.hello-1, /vendor/lib, /system/lib]]
E/AndroidRuntime(12097):        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2124)
E/AndroidRuntime(12097):        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2257)
E/AndroidRuntime(12097):        at android.app.ActivityThread.access$800(ActivityThread.java:139)
E/AndroidRuntime(12097):        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
E/AndroidRuntime(12097):        at android.os.Handler.dispatchMessage(Handler.java:102)
E/AndroidRuntime(12097):        at android.os.Looper.loop(Looper.java:136)
E/AndroidRuntime(12097):        at android.app.ActivityThread.main(ActivityThread.java:5086)
E/AndroidRuntime(12097):        at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(12097):        at java.lang.reflect.Method.invoke(Method.java:515)
E/AndroidRuntime(12097):        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
E/AndroidRuntime(12097):        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
E/AndroidRuntime(12097):        at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime(12097): Caused by: java.lang.ClassNotFoundException: Didn't find class "org.hello.MainActivity" on path: DexPathList[[zip file "/data/app/org.hello-1.apk"],nativeLibraryDirectories=[/data/app-lib/org.hello-1, /vendor/lib, /system/lib]]
E/AndroidRuntime(12097):        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
E/AndroidRuntime(12097):        at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
E/AndroidRuntime(12097):        at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
E/AndroidRuntime(12097):        at android.app.Instrumentation.newActivity(Instrumentation.java:1084)
E/AndroidRuntime(12097):        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2115)
E/AndroidRuntime(12097):        ... 11 more
W/ActivityManager(  916):   Force finishing activity org.hello/.MainActivity

我的MainActivity类是：

package org.hello;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTabHost;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MenuInflater;

public class MainActivity extends FragmentActivity {
    private FragmentTabHost mTabHost;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mTabHost = (FragmentTabHost)findViewById(android.R.id.tabhost);
        mTabHost.setup(this, getSupportFragmentManager(), R.id.realtabcontent);

        mTabHost.addTab(mTabHost.newTabSpec("tab1").setIndicator("Tab1"), Tab1Fragment.class, null);
        mTabHost.addTab(mTabHost.newTabSpec("tab2").setIndicator("Tab2"), Tab2Fragment.class, null);
        mTabHost.addTab(mTabHost.newTabSpec("tab3").setIndicator("Tab3"), Tab3Fragment.class, null);
        mTabHost.addTab(mTabHost.newTabSpec("tab4").setIndicator("Tab4"), Tab4Fragment.class, null);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu_main, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle presses on the action bar items
        switch (item.getItemId()) {
            case R.id.action_search:
                openSearch();
                return true;
            case R.id.action_settings:
                openSettings();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    public void openSearch() {
      //
    }

    public void openSettings() {
      //
    }
}

我的pom.xml是：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>org.hello</groupId>
    <artifactId>basic-tabs</artifactId>
    <version>0.1.0</version>
    <packaging>apk</packaging>

    <properties>
        <!-- use UTF-8 for everything -->
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <android.sdk.path>/home/kleber/android-sdk-linux/</android.sdk.path>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.google.android</groupId>
            <artifactId>android</artifactId>
            <version>4.1.1.4</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
           <groupId>com.google.android</groupId>
           <artifactId>support-v4</artifactId>
           <version>20.0.0</version>
           <scope>system</scope>
           <systemPath>/home/kleber/android-sdk-linux/extras/android/support/v4/android-support-v4.jar</systemPath>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>com.jayway.maven.plugins.android.generation2</groupId>
                <artifactId>android-maven-plugin</artifactId>
                <version>3.9.0-rc.1</version>
                <configuration>
                    <sdk>
                        <platform>19</platform>
                    </sdk>
                    <deleteConflictingFiles>true</deleteConflictingFiles>
                    <undeployBeforeDeploy>true</undeployBeforeDeploy>
                </configuration>
                <extensions>true</extensions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                    <showDeprecation>true</showDeprecation>
                    <showWarnings>true</showWarnings>
                    <executable>/home/kleber/jdk1.7.0_55/bin/javac</executable>
                    <fork>true</fork>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

类MainActivity被放置在我的项目内的正确目录中（与其他项目一样，运行没有问题）。

如果我删除了依赖项support-v4（以及我的代码中从该库中引用的所有内容），运行此项目没有问题。

任何人都可以看到我在这里缺少的东西吗？

ps：有问题的项目是：https://github.com/klebermo/basic_tab2

Answer 1

我记不清楚但是我使用了这个support-v4库时遇到了同样的错误，我甚至没有使用Maven。但是既然你真的非常渴望得到帮助，我认为这可以解决我的问题。如果您有Eclipse（我不了解其他IDE），请转到构建路径并转到Order and Export并在support-v4库中删除或设置Export。

Answer 2

清理项目并删除项目目录下的/gen和/bin文件夹，然后重建它！

Answer 3

您是否尝试过直接在项目中包含jar，看它是否有所作为？

当支持库包含在pom.xml中时，Android项目不会在设备中运行

3 个答案: