Question

我通过以下属性动态创建DataSource来连接到mysql数据库，它工作正常，但过了一段时间它一直给我错误＆＃34;无法获取JDBC连接＆＃34;。

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Too many connections
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.Util.getInstance(Util.java:408)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3970)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3906)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:873)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1710)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2253)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2284)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2083)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    at sun.reflect.GeneratedConstructorAccessor39.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328)
    at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:310)
    at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:732)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:664)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:479)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131)

它已在Tomcat环境中托管在AWS中。 DB位于AWS的RDS中。

更新：
引起：

ArrayList<String> app = new ArrayList<>();
app.add("C:\\Windows\\System32\\rundll32.exe");
app.add("SHELL32.DLL,ShellExec_RunDLL");
app.add(file.getAbsolutePath());

// Args are passed by windows when it launches the "More Sends" jar
for (int i = 0; args != null && i < args.length; i++) {
    app.add(args[i]);
}

ProcessBuilder b = new ProcessBuilder(app);
// The logger thread hangs till the called process does not die... not ideal
 // log(
    b.start()
// )
;

Answer 1

我从你的堆栈跟踪中学到了什么，你有太多的连接问题导致无法建立任何新的连接。解决方案很简单 - 你必须设置连接池（c3p0很受欢迎）并指定池连接。
请参阅this如何设置c3p0连接并进行基本调整

也不要忘记{/ 3}}

祝你好运

Answer 2

对我来说，通过确保在使用后立即正确关闭所有会话来解决问题。

SpringBoot：GenericJDBCException：无法获取JDBC连接

2 个答案: