老师，学习到后面，前面的就忘记了，这正常吗

家人们，踩坑啊，如果是jdk8之后的版本，JDK 8 中有关反射相关的功能自从 JDK 9 开始就已经被限制了，为了兼容原先的版本，需要在运行项目时添加 --add-opens java.base/java.lang=ALL-UNNAMED 选项来开启这种默认不被允许的行为，在那个VM options里，具体的报错信息如下：

Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain) throws java.lang.ClassFormatError accessible: module java.base does not "opens java.lang" to unnamed module @595b007d

老师 1.png 2.png这六张图片课程资料是没有的 要在哪里取呀
课程资料只有微信图片

我在配置类里面也配置登录和登录页的权限了，为啥访问的时候还是报403

他是怎么做到每五个数就换行的，不是很理解

老师，我在进行高可用部署的时候，可以正常运行，并且其他服务也可以正常运行，但是eureka的服务端会爆如下错误(请您有时间的话可以解答一下)：

2023-12-30T20:06:53.437+08:00 ERROR 46409 --- [et_localhost-18] c.n.e.cluster.ReplicationTaskProcessor   : Network level connection to peer localhost; retrying after delay

jakarta.ws.rs.ProcessingException: org.apache.http.conn.HttpHostConnectException: Connect to localhost:8761 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused

at org.glassfish.jersey.apache.connector.ApacheConnector.apply(ApacheConnector.java:531) ~[jersey-apache-connector-3.1.2.jar:na]

at org.glassfish.jersey.client.ClientRuntime.invoke(ClientRuntime.java:300) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.lambda$invoke$0(JerseyInvocation.java:662) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.call(JerseyInvocation.java:697) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.lambda$runInScope$3(JerseyInvocation.java:691) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.internal.Errors.process(Errors.java:292) ~[jersey-common-3.1.2.jar:na]

at org.glassfish.jersey.internal.Errors.process(Errors.java:274) ~[jersey-common-3.1.2.jar:na]

at org.glassfish.jersey.internal.Errors.process(Errors.java:205) ~[jersey-common-3.1.2.jar:na]

at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:390) ~[jersey-common-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.runInScope(JerseyInvocation.java:691) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.invoke(JerseyInvocation.java:661) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation$Builder.method(JerseyInvocation.java:439) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation$Builder.post(JerseyInvocation.java:345) ~[jersey-client-3.1.2.jar:na]

at com.netflix.eureka.transport.Jersey3ReplicationClient.submitBatchUpdates(Jersey3ReplicationClient.java:116) ~[eureka-core-jersey3-2.0.1.jar:2.0.1]

at com.netflix.eureka.cluster.ReplicationTaskProcessor.process(ReplicationTaskProcessor.java:80) ~[eureka-core-2.0.1.jar:2.0.1]

at com.netflix.eureka.util.batcher.TaskExecutors$BatchWorkerRunnable.run(TaskExecutors.java:190) ~[eureka-core-2.0.1.jar:2.0.1]

at java.base/java.lang.Thread.run(Thread.java:842) ~[na:na]

Caused by: org.apache.http.conn.HttpHostConnectException: Connect to localhost:8761 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused

at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:156) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:376) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:393) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:236) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:72) ~[httpclient-4.5.14.jar:4.5.14]

at org.glassfish.jersey.apache.connector.ApacheConnector.apply(ApacheConnector.java:483) ~[jersey-apache-connector-3.1.2.jar:na]

... 16 common frames omitted

Caused by: java.net.ConnectException: Connection refused

at java.base/sun.nio.ch.Net.pollConnect(Native Method) ~[na:na]

at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:672) ~[na:na]

at java.base/sun.nio.ch.NioSocketImpl.timedFinishConnect(NioSocketImpl.java:554) ~[na:na]

at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:602) ~[na:na]

at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327) ~[na:na]

at java.base/java.net.Socket.connect(Socket.java:633) ~[na:na]

at org.apache.http.conn.socket.PlainConnectionSocketFactory.connectSocket(PlainConnectionSocketFactory.java:75) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:142) ~[httpclient-4.5.14.jar:4.5.14]

... 25 common frames omitted

a啊？

import java.awt.*;
import javax.swing.*;

public class BallGame extends JFrame {

    Image ball = Toolkit.getDefaultToolkit().getImage("images/ball.png");
    Image desk = Toolkit.getDefaultToolkit().getImage("images/desk.png");

    //绘制窗口
    public void paint(Graphics g){
        System.out.println("窗口被画了一次！");
        g.drawImage(desk,0,0,null);
        g.drawImage(ball,200,200,null);

        //实现动画每秒绘制窗口25次
        while(true){
            repaint();

            try {
                Thread.sleep(40);   //1s=1000ms，1000/40=25，每秒画25次。
            } catch (InterruptedException e) {
                //throw new RuntimeException(e);
                e.printStackTrace();
            }
        }
    }

    //创建窗口
    void launchFrame(){
        setSize(856,501);
        setLocation(100,100);
        setVisible(true);
    }

    public static void main(String[] args){

        System.out.println("我的小游戏开始啦");

        BallGame game = new BallGame();
        game.launchFrame();

    }

}

加入while(true){}之后，程序出现卡死情况，窗口无法正常绘制。

运行程序：

停止：

我这个dubbo启动后就一直访问不到，查看日志发现他一直走得是docker网络，怎么解决呢？

安装jre如图显示

图片的问题嘛?

那想问一下 工程中更推荐使用Resource注解 还是 用Service那些注解

public Vehicle getVehicle(){

22        System.out.println("给你一个交通工具！");

23        return null;

24    }

这个有点没明白，格式是修饰符+类名+方法名+形参列表+……。

这是什么方法命名啊？有这种格式吗

这个查询用and只能查询一条数据  不能查询多条