Servlet에서 org.json을 사용하면 java.lang.ClassNotFoundException이 발생합니다. org.json.JSONException

일부 JSON 객체를 보내기 위해 서블릿을 개발하려고하는데 몇 가지 예외가 있습니다. 나는 jar 파일을 추가 할 필요가 있다고 믿지만 어느 것이 확실하지 않다. 다음은 내가 수입 모두와 함께의 doGet 방법입니다 :Servlet에서 org.json을 사용하면 java.lang.ClassNotFoundException이 발생합니다. org.json.JSONException

import java.io.IOException; 
import java.io.PrintWriter; 

import javax.servlet.ServletException; 
import javax.servlet.annotation.WebServlet; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 

import org.json.JSONException; 
import org.json.JSONObject; 

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
    response.setContentType("application/json"); 
    PrintWriter out = response.getWriter(); 

    JSONObject obj = new JSONObject(); 
    try { 
     obj.put("name", "jad"); 
    } catch (JSONException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
    out.println(obj.toString()); 
}

이 내 콘솔입니다 :

SEVERE: A child container failed during start 
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/CarpoolServer]] 
    at java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source) 
    at java.util.concurrent.FutureTask.get(Unknown Source) 
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123) 
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:800) 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) 
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) 
    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source) 
    at java.util.concurrent.FutureTask.run(Unknown Source) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) 
    at java.lang.Thread.run(Unknown Source) 
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/CarpoolServer]] 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154) 
    ... 7 more 
Caused by: java.lang.NoClassDefFoundError: org/json/JSONException 
    at java.lang.Class.getDeclaredFields0(Native Method) 
    at java.lang.Class.privateGetDeclaredFields(Unknown Source) 
    at java.lang.Class.getDeclaredFields(Unknown Source) 
    at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106) 
    at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:261) 
    at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:140) 
    at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:67) 
    at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:405) 
    at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:881) 
    at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:369) 
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) 
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90) 
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5269) 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 
    ... 7 more 
Caused by: java.lang.ClassNotFoundException: org.json.JSONException 
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1713) 
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1558) 
    ... 21 more 

May 03, 2013 6:16:01 PM org.apache.catalina.core.ContainerBase startInternal 
SEVERE: A child container failed during start 
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]] 
    at java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source) 
    at java.util.concurrent.FutureTask.get(Unknown Source) 
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123) 
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:302) 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443) 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:732) 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 
    at org.apache.catalina.startup.Catalina.start(Catalina.java:684) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
    at java.lang.reflect.Method.invoke(Unknown Source) 
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:322) 
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:456) 
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]] 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154) 
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) 
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) 
    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source) 
    at java.util.concurrent.FutureTask.run(Unknown Source) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) 
    at java.lang.Thread.run(Unknown Source) 
Caused by: org.apache.catalina.LifecycleException: A child container failed during start 
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131) 
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:800) 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 
    ... 7 more 

May 03, 2013 6:16:01 PM org.apache.catalina.startup.Catalina start 
SEVERE: Catalina.start: 
org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]] 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154) 
    at org.apache.catalina.startup.Catalina.start(Catalina.java:684) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
    at java.lang.reflect.Method.invoke(Unknown Source) 
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:322) 
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:456) 
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]] 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154) 
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:732) 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 
    ... 7 more 
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]] 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154) 
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443) 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 
    ... 9 more 
Caused by: org.apache.catalina.LifecycleException: A child container failed during start 
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131) 
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:302) 
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 
    ... 11 more

출처

2013-05-03 Jad

코드를 어떻게 컴파일합니까? 누락 된 jar 파일은 컴파일 할 때 classpath에 있습니다. –

@JBNizet 라이브러리 (json-jena.jar)가 Tomcat 런타임에 포함되어 있다고 가정하고 있습니까? –

ctrl-shift-T를 사용하고 누락 된 클래스 이름을 입력하십시오. 프로젝트보기에서 항아리를 찾은 다음이 항아리가 웹 프로젝트의 WEB-INF/lib 아래에 있는지 확인하십시오. WEB-INF/lib에있는 모든 jar는 컴파일 클래스 경로에 있고 webapp의 런타임 클래스 경로에 있습니다. 프로젝트의 빌드 경로에서 항아리를 찾을 수도 있습니다. 빌드 경로에서 제거하고 WEB-INF/lib에 추가하십시오. –

이클립스의 배포 어셈블리에 java-json.jar를 추가합니다.

enter image description here

출처

2013-05-03 15:19:50

그것은 일했습니다! 고맙습니다! 내 브라우저에 URL을 쓸 때 브라우저에 나타나는 json 객체 문자열 대신 다운로드 할 파일을 얻습니다. 그게 정상인가요? – Jad

@Jad 그는 JB에게 정말 감사드립니다. 응답에 contenttype을 설정했기 때문에 다운로드를 받으 셨다고 생각합니다. 재미로만 시도하지 말고 사용해보십시오. 시험 후에도 그걸 다시 설정하고 싶을 것입니다. –

네가 맞다 – Jad

Servlet에서 org.json을 사용하면 java.lang.ClassNotFoundException이 발생합니다. org.json.JSONException

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