javax.naming.NameNotFoundException：名称 \[comp/env\] 未绑定在此上下文中。使用 java 调度程序找不到 \[comp\] 错误

Question

新手上路，请多包涵

我想做的是在一段时间后更新我的数据库。所以我正在使用java调度程序和连接池。我不知道为什么，但我的代码只工作一次。它将打印：

 init success
success
javax.naming.NameNotFoundException: Name [comp/env] is not bound in this Context. Unable to find [comp].
    at org.apache.naming.NamingContext.lookup(NamingContext.java:820)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:168)
    at org.apache.naming.SelectorContext.lookup(SelectorContext.java:158)
    at javax.naming.InitialContext.lookup(InitialContext.java:411)
    at test.Pool.main(Pool.java:25)  ---> line 25 is Context envContext = (Context)initialContext.lookup("java:/comp/env");

我不知道为什么它只工作一次。如果我没有在没有 java 调度程序的情况下运行它，我已经对其进行了测试，它工作正常。没有任何错误。如果我使用调度程序运行它，不知道为什么会出现此错误。

希望可以有人帮帮我。

我的连接池代码：

 public class Pool {
public DataSource main() {
    try {
        InitialContext initialContext = new InitialContext();
        Context envContext = (Context)initialContext.lookup("java:/comp/env");
        DataSource datasource = new DataSource();
        datasource = (DataSource)envContext.lookup("jdbc/test");
        return datasource;
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return null;
}

}

我的 web.xml ：

 <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<listener>
    <listener-class> package.test.Pool</listener-class>
</listener>
<resource-ref>
    <description>DB Connection Pooling</description>
    <res-ref-name>jdbc/test</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
</resource-ref>

上下文.xml：

     <?xml version="1.0" encoding="UTF-8"?>
<Context path="/project" reloadable="true">
  <Resource auth="Container"
            defaultReadOnly="false"
            driverClassName="com.mysql.jdbc.Driver"
            factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
            initialSize="0"
            jdbcInterceptors="org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer"
            jmxEnabled="true"
            logAbandoned="true"
            maxActive="300" maxIdle="50"
            maxWait="10000"
            minEvictableIdleTimeMillis="300000"
            minIdle="30"
            name="jdbc/test"
            password="test"
            removeAbandoned="true"
            removeAbandonedTimeout="60"
            testOnBorrow="true"
            testOnReturn="false"
            testWhileIdle="true"
            timeBetweenEvictionRunsMillis="30000"
            type="javax.sql.DataSource"
            url="jdbc:mysql://localhost:3306/database?noAccessToProcedureBodies=true"
            username="root"
            validationInterval="30000"
            validationQuery="SELECT 1"/>
</Context>

我的java调度程序

public class Scheduler extends HttpServlet{

public void init() throws ServletException
{
    System.out.println("init success");
    try{
        Scheduling_test test = new Scheduling_test();
        ScheduledExecutorService executor = Executors.newScheduledThreadPool(100);
        ScheduledFuture future = executor.scheduleWithFixedDelay(test, 1, 60 ,TimeUnit.SECONDS);
    }catch(Exception e){
         e.printStackTrace();
    }
}

}

schedule_test

     public class Scheduling_test extends Thread implements Runnable{
    public void run(){
        Updating updating = new Updating();
        updating.run();
    }
}

更新

public class Updating{

        public void run(){
            ResultSet rs = null;
            PreparedStatement  p = null;
            StringBuilder sb = new StringBuilder();
            Pool pool = new Pool();
            Connection con = null;
            DataSource datasource = null;
            try{
                datasource = pool.main();
                con=datasource.getConnection();
                sb.append("SELECT * FROM database");
                p = con.prepareStatement(sb.toString());
                rs = p.executeQuery();
                rs.close();
                con.close();
                p.close();
                datasource.close();
                System.out.println("success");
         }catch (Exception e){
                e.printStackTrace();
         }
    }