标签: classnotfoundexception

我正在尝试创建一个Web服务并在Tomcat上使用它.我正在学习本教程.

我正在使用Eclipse Europa.

但是当我尝试启动服务器时,它会返回以下错误:

java.lang.ClassNotFoundException: org.apache.catalina.core.ThreadLocalLeakPreventionListener
    at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
    at org.apache.tomcat.util.digester.ObjectCreateRule.begin(ObjectCreateRule.java:205)
    at org.apache.tomcat.util.digester.Rule.begin(Rule.java:153)
    at org.apache.tomcat.util.digester.Digester.startElement(Digester.java:1356)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:504)
    at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:182)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1320)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2732)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:625)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:488)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:812)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:741)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1208)
    at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:525)
    at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1642)
    at org.apache.catalina.startup.Catalina.load(Catalina.java:524)
    at org.apache.catalina.startup.Catalina.load(Catalina.java:562)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:262)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:430)

我正在尝试使用Android注释框架,因为它看起来非常强大.我完全坚持基于它配置我的第一个项目.我遵循了wiki的每一步,但是在构建之后它不会生成任何文件.

所以当我从清单中请求生成的类时:

<activity android:name=".MyActivity_"
   android:label="@string/app_name">

我得到一个例外:

java.lang.ClassNotFoundException

我的活动与维基中的活动完全相同:

@EActivity(R.layout.main)
public class MyActivity extends Activity {

    @ViewById
    EditText myInput;

    @ViewById(R.id.myTextView)
    TextView textView;

    @Click
    void myButton() {
         String name = myInput.getText().toString();
         textView.setText("Hello "+name);
    }
}

有任何想法吗？

编辑:刚刚找到一个目录".apt_generated",但它在构建后是空的.

我在IntelliJ工作并使用maven.我有一个使用JSONObject的类,我已导入它

import org.json.JSONObject;

在一个方法中我使用它如下:

    JSONObject documentObj = null;
    try {
        documentObj = new JSONObject(document);
    } catch (Exception e) {
        throw new RuntimeException("Failed to convert JSON String document into a JSON Object.", e);
    }

我在pom.xml文件中也有依赖项

    <dependency>
        <groupId>org.json</groupId>
        <artifactId>json</artifactId>
        <version>20090211</version>
    </dependency>

我可以"mvn clean package"这段代码,一切都成功构建.但是当我尝试运行它时,我得到"Error:java.lang.ClassNotFoundException:org.json.JSONObject".

还有什么我在这里不见了吗？

谢谢!

我开始使用servlets在eclipse中开发一个java web应用程序,并在我的localhost上使用tomcat服务器进行测试.我已经在tomcat中部署了应用程序,但是当我尝试在浏览器中加载目标URL时,我得到以下堆栈跟踪:

Jul 31, 2013 2:58:31 PM org.apache.catalina.core.ApplicationContext log
INFO: Marking servlet ImageServlet as unavailable
Jul 31, 2013 2:58:31 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Allocate exception for servlet ImageServlet
java.lang.ClassNotFoundException: test.ImageServlet
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:527)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:509)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:137)
        at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1144)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:865)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:136)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1852)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)  

ImageServlet类非常清楚地位于我的eclipse工作区的myproject/src/test文件夹中,其中myproject是eclipse项目的名称,test是包.

web.xml位于myproject/web/WEB-INF/web.xml中,myproject.xml位于myproject/myproject.xml

web.xml的内容是:

<?xml version="1.0"?> …

突然间,我忙着我的应用程序超过一个星期了:

11-12 07:59:17.860    1653-1653/nl.test.myapp E/AndroidRuntime? FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{nl.test.MyApp/nl.test.MyApp.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "nl.test.myapp.MainActivity" on path: DexPathList[[zip file "/data/app/nl.test.myapp-2.apk"],nativeLibraryDirectories=[/data/app-lib/nl.test.myapp-2, /system/lib]]
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2137)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
        at android.app.ActivityThread.access$600(ActivityThread.java:141)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:5103)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:525)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
        at dalvik.system.NativeStart.main(Native Method)
 Caused by: java.lang.ClassNotFoundException: Didn't find class "nl.test.myapp.MainActivity" on path: DexPathList[[zip file "/data/app/nl.test.MyApp-2.apk"],nativeLibraryDirectories=[/data/app-lib/nl.test.MyApp-2, /system/lib]]
        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
        at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2128)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
        at android.app.ActivityThread.access$600(ActivityThread.java:141)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) …

为什么以下代码会导致ClassNotFoundException？

public class App02 {

    public static class A {
    }

    public static void main(String[] args) throws ClassNotFoundException {

        try {
            System.out.println("A.class.getCanonicalName() = " + A.class.getCanonicalName());
            Class c = Class.forName("tests.App02.A"); //error on this line
            System.out.println(c.getName());
        }

        catch(Exception e) {
            e.printStackTrace();
        }
    }
}

输出:

A.class.getCanonicalName() = tests.App02.A
java.lang.ClassNotFoundException: tests.App02.A
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:190)
    at tests.App02.main(App02.java:15)

我有一个在Eclipse中启动的Java Maven项目,几天就开始工作,然后在IntelliJ IDEA中导入它,再过几天就开始工作了.

IDEA和via shell中的正常运行/执行确实有效,但不是Debug.

当我单击调试的Bug图标时,它会打开URLClassLoader.java文件并指向Line"抛出新的ClassNotFoundException(name)"并暂停Debug,如果我单击Resume Debug,它会显示几个不属于我的类项目.我可以无限地单击Resume Button,它会在连续循环中反复显示相同的类,ClassNotFoundException并且不会调试我的源代码.

如果我单击Build - > Rebuild Project,它会在Debug图标中显示"Hot Swap failed myClassname:schema change not not implemented; myClassname:Operation不支持VM"

在变量下的调试窗口中,它显示:"框架不可用"

IntelliJ IDEA中的这个项目的调试以前工作过,现在有什么问题吗？

我希望看到已在ActiveMQ队列中排队的消息内容.我打开了web-console.(http:// localhost:8161/admin/queues.jsp)并点击了队列消息的message-id.它在"消息详细信息"窗口中给出了以下错误,而不是给出消息内容.

"javax.jms.JMSException:无法从内容构建正文.可序列化的类不可用于代理.原因:java.lang.ClassNotFoundException:"

这个异常的原因是什么？我需要做些什么来摆脱这个？

我FileProvider在我的应用程序中使用。像往常一样，我<Provider>在AndroidManifest.xml文件中声明了标签，如下所示。

<provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="com.jk.android.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
</provider>

当我在具有lollipop版本的android设备上运行它时，它工作正常。当我在kitkat版本上尝试时，它显示以下错误：

FATAL EXCEPTION: main
              Process: com.jk.android.perfectphotoeditor2018, PID: 24992
              java.lang.RuntimeException: Unable to get provider android.support.v4.content.FileProvider: java.lang.ClassNotFoundException: Didn't find class "android.support.v4.content.FileProvider" on path: DexPathList[[zip file "/data/app/com.jk.android.perfectphotoeditor2018-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.jk.android.perfectphotoeditor2018-2, /system/lib]]
                  at android.app.ActivityThread.installProvider(ActivityThread.java:5071)
                  at android.app.ActivityThread.installContentProviders(ActivityThread.java:4648)
                  at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4588)
                  at android.app.ActivityThread.access$1500(ActivityThread.java:151)
                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1290)
                  at android.os.Handler.dispatchMessage(Handler.java:102)
                  at android.os.Looper.loop(Looper.java:136)
                  at android.app.ActivityThread.main(ActivityThread.java:5299)
                  at java.lang.reflect.Method.invokeNative(Native Method)
                  at java.lang.reflect.Method.invoke(Method.java:515)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:932)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:748)
                  at dalvik.system.NativeStart.main(Native Method)
               Caused by: java.lang.ClassNotFoundException: Didn't find class …

我是 Spring Boot 空间的新手。我正在按照教程学习创建 OAuth 身份验证服务器。

配置AuthorizationServerConfig.java讲师时，从包“org.springframework.security.oauth2.server.authrization.config”导入“ProviderSettings”类

但是，我没有从该特定包中获得该类。

我缺少任何依赖项吗？或者该课程现在不可用？

参考文献 1：错误点。无法解析符号 ProviderSettings

@Bean
    public ProviderSettings providerSettings(){
        return ProviderSettings.builder()
                .issuer("http://auth-server:9000")
                .build();
    }

参考2：pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>np.com.oskarshrestha</groupId>
    <artifactId>Oauth-authorization-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>Oauth-authorization-server</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency> …