Question

我知道有一些关于此的问题，答案似乎是将驱动程序放在Tomcat的lib文件夹中。但是我仍然收到警告。为什么会这样？

这是我的pom.xml：

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.35</version>
    <scope>provided</scope>
</dependency>

在我的Tomcat \ lib文件夹中，我有：

Korays-MacBook-Pro:apache-tomcat-8.0.23 koraytugay$ ls lib/mysql-connector-java-5.1.35-bin.jar 
lib/mysql-connector-java-5.1.35-bin.jar

这是我建立数据库连接的唯一方法：

import java.sql.*;

public class TicketDAO {
    public static void insertTicketToDB(String name)
            throws ClassNotFoundException, SQLException,
            IllegalAccessException, InstantiationException {
        String url = "jdbc:mysql://localhost:3306/";
        String dbName = "ticketsdb";
        String driver = "com.mysql.jdbc.Driver";
        String userName = "";
        String password = "";
        Class.forName(driver).newInstance();
        Connection conn = DriverManager.getConnection(url + dbName, userName, password);
        String insertTableSQL = "INSERT INTO ticket(name) VALUES(?)";
        PreparedStatement preparedStatement = conn.prepareStatement(insertTableSQL);
        preparedStatement.setString(1, name);
        preparedStatement.executeUpdate();
        conn.close();
    }
}

当我关闭Tomcat时，我会看到：

23-Jun-2015 14:31:12.693 WARNING [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [ROOT] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. 

This is very likely to create a memory leak. Stack trace of thread:

我做错了什么？

Answer 1

内存泄漏是由于MySQL的“＃Abandonded connection cleanup thread＆＃39;”所致。该线程从第一个请求开始，并保存对webapp的类加载器的引用。使用classesToInitialize，您也可以防止此内存泄漏。

要防止此特定内存泄漏，您应编辑tomcat / conf / server.xml并更改

<Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />

到

<Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" classesToInitialize="com.mysql.jdbc.NonRegisteringDriver" />

即使mysql连接器在lib文件夹

1 个答案: