报错具体信息：
"C:\Program Files\Java\jdk1.8.0_201\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\idea\IntelliJ IDEA 2020.2.1\lib\idea_rt.jar=57710:D:\idea\IntelliJ IDEA 2020.2.1\bin" -Dfile.encoding=UTF-8 -classpath "D:\idea\IntelliJ IDEA 2020.2.1\lib\idea_rt.jar;D:\idea\IntelliJ IDEA 2020.2.1\plugins\junit\lib\junit5-rt.jar;D:\idea\IntelliJ IDEA 2020.2.1\plugins\junit\lib\junit-rt.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\rt.jar;D:\idea\jdbcDemo\untitled1\target\test-classes;D:\idea\jdbcDemo\untitled1\target\classes;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\junit\junit\4.11\junit-4.11.jar;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\mysql\mysql-connector-java\5.1.17\mysql-connector-java-5.1.17.jar;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\org\springframework\spring-core\4.3.17.RELEASE\spring-core-4.3.17.RELEASE.jar;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\org\springframework\spring-beans\4.3.17.RELEASE\spring-beans-4.3.17.RELEASE.jar;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\org\springframework\spring-jdbc\4.3.17.RELEASE\spring-jdbc-4.3.17.RELEASE.jar;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\org\springframework\spring-tx\4.3.17.RELEASE\spring-tx-4.3.17.RELEASE.jar;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\commons-logging\commons-logging\1.2\commons-logging-1.2.jar;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\com\mchange\c3p0\0.9.5.2\c3p0-0.9.5.2.jar;D:\apache-maven-3.6.1-bin\apache-maven-3.6.1\Maven-respostory\com\mchange\mchange-commons-java\0.2.11\mchange-commons-java-0.2.11.jar" com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 StudentTest,test
十二月 26, 2020 9:34:29 下午 com.mchange.v2.log.MLog
信息: MLog clients using java 1.4+ standard logging.
十二月 26, 2020 9:34:29 下午 com.mchange.v2.c3p0.C3P0Registry
信息: Initializing c3p0-0.9.5.2 [built 08-December-2015 22:06:04 -0800; debug? true; trace: 10]
十二月 26, 2020 9:34:29 下午 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource
信息: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, contextClassLoaderSource -> caller, dataSourceName -> 1hge1dbae186s3k91m7wdey|2db0f6b2, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> null, extensions -> {}, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, forceSynchronousCheckins -> false, forceUseNamedDriverClass -> false, identityToken -> 1hge1dbae186s3k91m7wdey|2db0f6b2, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> null, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 15, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 3, numHelperThreads -> 3, preferredTestQuery -> null, privilegeSpawnedThreads -> false, properties -> {}, propertyCycle -> 0, statementCacheNumDeferredCloseThreads -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, userOverrides -> {}, usesTraditionalReflectiveProxies -> false ]
十二月 26, 2020 9:34:59 下午 com.mchange.v2.resourcepool.BasicResourcePool
警告: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@327339f3 -- 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 (30). Last acquisition attempt exception:
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getDriver(DriverManager.java:315)
at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:285)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:161)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:161)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:147)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:202)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125)
at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1870)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)
十二月 26, 2020 9:34:59 下午 com.mchange.v2.resourcepool.BasicResourcePool
警告: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@4acae9ba -- 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 (30). Last acquisition attempt exception:
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getDriver(DriverManager.java:315)
at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:285)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:161)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:161)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:147)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:202)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125)
at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1870)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)
十二月 26, 2020 9:34:59 下午 com.mchange.v2.resourcepool.BasicResourcePool
警告: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@4d41cee is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests.
十二月 26, 2020 9:34:59 下午 com.mchange.v2.resourcepool.BasicResourcePool
警告: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@4d41cee is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests.
十二月 26, 2020 9:34:59 下午 com.mchange.v2.resourcepool.BasicResourcePool
警告: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@388b5283 -- 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 (30). Last acquisition attempt exception:
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getDriver(DriverManager.java:315)
at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:285)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:161)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:161)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:147)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:202)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125)
at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1870)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)
十二月 26, 2020 9:34:59 下午 com.mchange.v2.resourcepool.BasicResourcePool
警告: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@4d41cee is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests.
org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database!
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:80)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:478)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:488)
at util.StudentDaoImpl.queryAllStudents(StudentDaoImpl.java:56)
at StudentTest.test(StudentTest.java:14)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)
Caused by: java.sql.SQLException: Connections could not be acquired from the underlying database!
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:118)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:692)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:140)
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
... 27 more
Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1469)
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:644)
at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:554)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutAndMarkConnectionInUse(C3P0PooledConnectionPool.java:758)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:685)
... 30 more
Caused by: java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getDriver(DriverManager.java:315)
at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:285)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:161)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:161)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:147)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:202)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125)
at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1870)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)
Process finished with exit code -1
报错原因：创建的不是JavaWeb项目
解决方法：创建JavaWeb项目并迁移代码
1.创建JavaWeb项目
File-New-Project-Maven-勾选Create from archetype-选择webapp-next
根据自己的项目填写信息，注意Maven目录的填写
2.解决pom依赖
把原项目pom文件中的dependency复制到新项目的pom文件中，并刷新新项目的maven jar包，能看到dependencies出现了需要的包
3.迁移代码和配置文件
Com.hisoft.pojo存放实体类Student
Com.hisoft.dao进行数据库交互
Com.hisoft.utils是工具类
C3p3-config.xml放在main/resource中
4.运行测试代码
成功ヾ(◍°∇°◍)ﾉﾞ
其实这个挺憨憨的，项目类型创建错了
如果出现问题，可以根据报错提示进行查找，常见的问题有：
1.c3p0配置文件没有放在src下面
2.数据库最大连接数不够，修改mysql的最大连接数
查看最大连接数：
show variables like '%max_connections%'
修改最大连接数据：
set global max_connections=1000
3.换jdbc的驱动jar包
查看mysql版本命令：show variables like '%version%'
4.配置文件地址不对，配置文件中的换连接地址
5.数据库连接密码错了
6.项目类型创建错误