java.lang.NoSuchMethodException：org.blacklight.ludocollectibles.servelet.AlbumConfigServlet。<init>（）

Question

当我尝试访问servlet 时，它会给出数据源错误。请有人帮助我，因为这非常重要，我已经坚持了很长一段时间了。以下是错误日志。

package org.blacklight.ludocollectibles.servelet;


import lombok.extern.slf4j.Slf4j;
import org.blacklight.ludocollectibles.utils.RequestUtil;
import org.json.JSONException;
import org.json.JSONObject;

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 javax.sql.DataSource;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.Charset;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.HashMap;

@Slf4j
@WebServlet("album/config")
public class AlbumConfigServlet extends HttpServlet{

    private static final long serialVersionUID = 6941090933264348218L;

    private DataSource dataSource;

    public AlbumConfigServlet(DataSource dataSource) {
        this.dataSource = dataSource;
    }
   
    public JSONObject getAlbumData(int updatedKey) throws Exception{
        JSONObject response = new JSONObject();

        try (Connection conn = dataSource.getConnection();
             PreparedStatement stmt = conn.prepareStatement("select album_id,lbum_name,min_level,rewards,deck_n_card from albums;")) {
            try (ResultSet resultSet = stmt.executeQuery()) {
                while (resultSet.next()) {
                    HashMap<String, Object> keyData = new HashMap<>();
                    keyData.put("album_id", resultSet.getInt(1));
                    keyData.put("album_name", resultSet.getString(2));
                    keyData.put("min_level", resultSet.getInt(3));
                    keyData.put("rewards", resultSet.getObject(4));
                    keyData.put("deck_n_card", resultSet.getObject(5));
                    response.put(String.valueOf(resultSet.getInt(1)), keyData);
                }
            }
        }
        return response;
    }

}

我在数据源初始化时遇到错误。

错误日志-

Starting the App Engine local development server...
Connected to the target VM, address: '127.0.0.1:50461', transport: 'socket'
Sep 05, 2023 1:35:33 PM com.google.appengine.tools.development.SystemPropertiesManager setSystemProperties
INFO: Overwriting system property key 'java.util.logging.config.file', value 'C:\Users\blacklight\AppData\Local\google\ct4j-cloud-sdk\LATEST\google-cloud-sdk\platform\google_appengine\google\appengine\tools\java\config\sdk\logging.properties' with value 'WEB-INF/logging.properties' from 'C:\Users\blacklight\Documents\GitHub\LudoCollectibles\out\artifacts\LudoCollectibles_main_Web_exploded\WEB-INF\appengine-web.xml'
2023-09-05 13:35:33.625:INFO::main: Logging initialized @4681ms to org.eclipse.jetty.util.log.StdErrLog
2023-09-05 13:35:33.715:WARN:oejs.AbstractConnector:main: Ignoring deprecated socket close linger time
Connected to server
2023-09-05 13:35:34.044:INFO:oejs.Server:main: jetty-9.4.51.v20230217; built: 2023-02-17T08:19:37.309Z; git: b45c405e4544384de066f814ed42ae3dceacdd49; jvm 1.8.0_332-b08
2023-09-05 13:35:36.959:INFO:oeja.AnnotationConfiguration:main: Scanning elapsed time=2360ms
2023-09-05 13:35:37.476:INFO:oejsh.ContextHandler:main: Started c.g.a.t.d.j.DevAppEngineWebAppContext@1040be71{LudoCollectibles,/,file:///C:/Users/blacklight/Documents/GitHub/LudoCollectibles/out/artifacts/LudoCollectibles_main_Web_exploded/,AVAILABLE}{C:\Users\blacklight\Documents\GitHub\LudoCollectibles\out\artifacts\LudoCollectibles_main_Web_exploded}
2023-09-05 13:35:37.476:INFO:oejs.session:main: DefaultSessionIdManager workerName=node0
2023-09-05 13:35:37.476:INFO:oejs.session:main: node0 Scavenging disabled
2023-09-05 13:35:37.519:INFO:oejs.AbstractConnector:main: Started NetworkTrafficSelectChannelConnector@2b2948e2{HTTP/1.1, (http/1.1)}{localhost:8080}
2023-09-05 13:35:37.529:INFO:oejs.Server:main: Started @8585ms
Sep 05, 2023 8:05:37 AM com.google.appengine.tools.development.AbstractModule startup
INFO: Module instance collectibles is running at http://localhost:8080/
Sep 05, 2023 8:05:37 AM com.google.appengine.tools.development.AbstractModule startup
INFO: The admin console is running at http://localhost:8080/_ah/admin
Sep 05, 2023 1:35:37 PM com.google.appengine.tools.development.DevAppServerImpl doStart
INFO: Dev App Server is now running
Sep 05, 2023 1:35:39 PM com.google.appengine.tools.development.jetty9.LocalResourceFileServlet doGet
WARNING: No file found for: /favicon.ico
Sep 05, 2023 1:36:11 PM com.google.appengine.tools.development.ApiProxyLocalImpl log
SEVERE: javax.servlet.ServletContext log: unavailable
java.lang.NoSuchMethodException: org.blacklight.ludocollectibles.servelet.AlbumConfigServlet.<init>()
    at java.lang.Class.getConstructor0(Class.java:3110)
    at java.lang.Class.getDeclaredConstructor(Class.java:2206)
    at org.eclipse.jetty.server.handler.ContextHandler$StaticContext.createInstance(ContextHandler.java:2902)
    at org.eclipse.jetty.servlet.ServletContextHandler$Context.createInstance(ServletContextHandler.java:1299)
    at org.eclipse.jetty.server.handler.ContextHandler$StaticContext.createServlet(ContextHandler.java:2919)
    at org.eclipse.jetty.servlet.ServletHolder.newInstance(ServletHolder.java:1202)
    at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:592)
    at org.eclipse.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:486)
    at org.eclipse.jetty.servlet.ServletHolder.prepare(ServletHolder.java:759)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:549)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:571)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:505)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355)
    at com.google.appengine.tools.development.jetty9.DevAppEngineWebAppContext.doScope(DevAppEngineWebAppContext.java:109)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at com.google.appengine.tools.development.jetty9.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:608)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at org.eclipse.jetty.server.Server.handle(Server.java:516)
    at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487)
    at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)
    at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
    at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
    at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.produce(EatWhatYouKill.java:137)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
    at java.lang.Thread.run(Thread.java:750)

2023-09-05 13:36:11.471:WARN:oejs.HttpChannel:qtp695682681-21: /album/config
javax.servlet.ServletException: org.blacklight.ludocollectibles.servelet.AlbumConfigServlet==org.blacklight.ludocollectibles.servelet.AlbumConfigServlet@be111c00{jsp=null,order=-1,inst=true,async=false,src=ANNOTATION:org.blacklight.ludocollectibles.servelet.AlbumConfigServlet,STARTED}
    at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:650)
    at org.eclipse.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:486)
    at org.eclipse.jetty.servlet.ServletHolder.prepare(ServletHolder.java:759)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:549)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:571)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:505)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355)
    at com.google.appengine.tools.development.jetty9.DevAppEngineWebAppContext.doScope(DevAppEngineWebAppContext.java:109)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at com.google.appengine.tools.development.jetty9.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:608)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at org.eclipse.jetty.server.Server.handle(Server.java:516)
    at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487)
    at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)
    at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
    at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
    at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.produce(EatWhatYouKill.java:137)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
    at java.lang.Thread.run(Thread.java:750)
Caused by: 
java.lang.NoSuchMethodException: org.blacklight.ludocollectibles.servelet.AlbumConfigServlet.<init>()
    at java.lang.Class.getConstructor0(Class.java:3110)
    at java.lang.Class.getDeclaredConstructor(Class.java:2206)
    at org.eclipse.jetty.server.handler.ContextHandler$StaticContext.createInstance(ContextHandler.java:2902)
    at org.eclipse.jetty.servlet.ServletContextHandler$Context.createInstance(ServletContextHandler.java:1299)
    at org.eclipse.jetty.server.handler.ContextHandler$StaticContext.createServlet(ContextHandler.java:2919)
    at org.eclipse.jetty.servlet.ServletHolder.newInstance(ServletHolder.java:1202)
    at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:592)
    at org.eclipse.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:486)
    at org.eclipse.jetty.servlet.ServletHolder.prepare(ServletHolder.java:759)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:549)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:571)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:505)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355)
    at com.google.appengine.tools.development.jetty9.DevAppEngineWebAppContext.doScope(DevAppEngineWebAppContext.java:109)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at com.google.appengine.tools.development.jetty9.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:608)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at org.eclipse.jetty.server.Server.handle(Server.java:516)
    at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487)
    at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)
    at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
    at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
    at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.produce(EatWhatYouKill.java:137)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
    at java.lang.Thread.run(Thread.java:750)
Sep 05, 2023 1:38:53 PM com.google.appengine.tools.development.jetty9.LocalResourceFileServlet doGet
WARNING: No file found for: /openapi/v2

Answer 1

java.lang.NoSuchMethodException：org.blacklight.ludocollectibles.servelet.AlbumConfigServlet.()

意味着您需要一个无参数构造函数

public AlbumConfigServlet() {
}

顺便说一句：不要直接在 servlet 中使用数据源。了解三层架构