欢迎大家加入我的知识星球！
前几天把服务器上的mysql服务端卸载了，用宝塔面板安装了新的mysql，安装完成后使用mysql的客户端可以正常连接，但就是tomcat中跑的java项目怎么也连不上，一直报数据库连接失败！
尝试了很多办法，比如设置root账号权限、允许远程连接，结果报错一直没消除，搞的人心情极度郁闷！
完整报错信息如下：
Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:
** BEGIN NESTED EXCEPTION **
com.mysql.jdbc.CommunicationsException
MESSAGE: Communications link failure due to underlying exception:
** BEGIN NESTED EXCEPTION **
javax.net.ssl.SSLHandshakeException
MESSAGE: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
STACKTRACE:
javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.ssl.alerts.getSSLException(alerts.java:192)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1868)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:276)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:270)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1338)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:154)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:868)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:804)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:998)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1294)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1321)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1305)
at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:72)
at com.mysql.jdbc.MysqlIO.negotiateSSLConnection(MysqlIO.java:3982)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1293)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2775)
at com.mysql.jdbc.Connection.
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:146)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:195)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:184)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockonSuccess(BasicResourcePool.java:1073)
at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:385)
at sun.security.validator.PKIXValidator.enginevalidate(PKIXValidator.java:292)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:326)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:231)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:126)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1320)
... 22 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:196)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:268)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:380)
... 28 more
** END NESTED EXCEPTION **
后来仔细查看了日志，发现了一句关键的信息：
unable to find valid certification path to requested target
看着像是证书的问题，百度上翻了一下，果然找到对口的文章，问题得以解决！
java连接MySQL时报错，unable to find valid certification path to requested target-布布扣-bubuko.comjava连接mysql报错信息 05-Dec-2020 13:56:59.027 严重 [localhost-startStop-1] org.apache.catalina.core.StandardContext.filterStart 启动过滤器异常 java.lang.RuntimeExce ...http://www.bubuko.com/infodetail-3701588.html
mysql的配置信息
jdbcUrl = jdbc:mysql://127.0.0.1:3306/wawaji?characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true
user = root
password =root
错误解决
将jdbcUrl中的useSSL去掉即可，修改之后为
jdbcUrl = jdbc:mysql://127.0.0.1:3306/wawaji?characterEncoding=utf8&zeroDateTimeBehavior=convertToNull user = root password =root
欢迎大家加入我的知识星球！
