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();
}
}