尝试用Tomcat启动Liferay时，我得到了以下Java ConnectException：连接被拒绝。有什么建议吗？ 发送到服务器的最后一个数据包是0毫秒前的。 位于com.mysql.jdbc.Connection.createNewIO（Connection.java:2820） 位于com.mysql.jdbc.Connection（Connection.java:1553） 位于com.mysql.jdbc.NonRegisteringDriver.connect（NonRegisteringDriver.java:285） 位于com.mchange.v2.c3p0.DriverManagerDataSource.getConnection（DriverManagerDataSource.java:134） 位于com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection（WrapperConnectionPoolDataSource.java:182） 位于com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.AcquisiteSource（C3P0PooledConnectionPool.java:148） 位于com.mchange.v2.resourcepool.BasicResourcePool.doAcquire（basicResourceSourcePool.java:1014） 在com.mchange.v2.resourcepool.BasicResourcePool.access$800（BasicResourcePool.java:32） 位于com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run（BasicResourcePool.java:1810） 位于com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run（ThreadPoolAsynchronousRunner.java:547） 14:23:57798警告[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0][BasicResourcePool:1841]com.mchange.v2.resourcepool.basicResourceSourcePool$AcquireTask@2a391af--获取尝试失败！！！清算未决收购。在尝试获取所需的新资源时，我们未能成功获取超过允许的最大获取尝试次数（3）。上次采集尝试异常： com.mysql.jdbc.CommunicationsException:由于基础异常导致的通信链路故障：

**开始嵌套异常**

Last packet sent to the server was 0 ms ago.
        at com.mysql.jdbc.Connection.createNewIO(Connection.java:2820)
        at com.mysql.jdbc.Connection.<init>(Connection.java:1553)
        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
        at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
        at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
        at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:148)
        at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
        at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
        at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
        at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
14:23:57,798 WARN  [com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0][BasicResourcePool:1841] com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@2a391af -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (3). Last acquisition attempt exception: 
com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: 

java.net.ConnectException
信息：Verbindungsaufbau abgelehnt
堆栈跟踪：
java.net.ConnectException:Verbindungsaufbau abgelehnt
位于java.net.PlainSocketImpl.socketConnect（本机方法）
位于java.net.AbstractPlainSocketImpl.doConnect（未知源）
位于java.net.AbstractPlainSocketImpl.connectToAddress（未知源）
位于java.net.AbstractPlainSocketImpl.connect（未知源）
位于java.net.socksocketimpl.connect（未知源）
位于java.net.Socket.connect（未知源）
位于java.net.Socket.connect（未知源）
位于java.net.Socket。（未知源）
位于java.net.Socket。（未知源）
位于com.mysql.jdbc.StandardSocketFactory.connect（StandardSocketFactory.java:256）
在com.mysql.jdbc.MysqlIO上（MysqlIO.java:271）
在com.mysql.jdbc.Connection.createNewIO上（Connection.java:2744）
位于com.mysql.jdbc.Connection（Connection.java:1553）
位于com.mysql.jdbc.NonRegisteringDriver.connect（NonRegisteringDriver.java:285）
位于com.mchange.v2.c3p0.DriverManagerDataSource.getConnection（DriverManagerDataSource.java:134）
位于com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection（WrapperConnectionPoolDataSource.java:182）
位于com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.AcquisiteSource（C3P0PooledConnectionPool.java:148）
位于com.mchange.v2.resourcepool.BasicResourcePool.doAcquire（basicResourceSourcePool.java:1014）
在com.mchange.v2.resourcepool.BasicResourcePool.access$800（BasicResourcePool.java:32）
位于com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run（BasicResourcePool.java:1810）
位于com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run（ThreadPoolAsynchronousRunner.java:547）

听起来像是MySQL连接问题。检查数据库连接设置、用户名/密码、url等。应如下所示：

java.net.ConnectException
MESSAGE: Verbindungsaufbau abgelehnt

STACKTRACE:

java.net.ConnectException: Verbindungsaufbau abgelehnt


at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:271)
    at com.mysql.jdbc.Connection.createNewIO(Connection.java:2744)
    at com.mysql.jdbc.Connection.<init>(Connection.java:1553)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
    at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:148)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
    at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
    at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
    at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)

jdbc.default.driverClassName=org.gjt.mm.mysql.Driver
jdbc.default.url=jdbc:mysql://127.0.0.1/lportal
jdbc.default.username=mysqluser
jdbc.default.password=mysqlpass

常见URL如下所示：

java.net.ConnectException
MESSAGE: Verbindungsaufbau abgelehnt

STACKTRACE:

java.net.ConnectException: Verbindungsaufbau abgelehnt


at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:271)
    at com.mysql.jdbc.Connection.createNewIO(Connection.java:2744)
    at com.mysql.jdbc.Connection.<init>(Connection.java:1553)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
    at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:148)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
    at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
    at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
    at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)

jdbc.default.driverClassName=org.gjt.mm.mysql.Driver
jdbc.default.url=jdbc:mysql://127.0.0.1/lportal
jdbc.default.username=mysqluser
jdbc.default.password=mysqlpass

---

你能将你的语言设置为英语并重新触发异常吗？你有mysql运行吗？错误消息说Liferay无法连接到mysql。因此，要么您的数据库连接没有正确配置（如Artem Khojoyan所建议的），要么根本不存在/运行。