java - ResourcePool 无法从其主要工厂或来源获取资源

Question

我正在尝试使用 jdbcTemplate 连接到 Java 中的数据库，但出现以下错误。我用 Google 搜索了很长时间，发现的所有解决方案都没有解决我的问题。我尝试了几种不同的数据库(SQLServer 和 MySQL)，但都没有用。

SEVERE: Servlet.service() for servlet [Faces Servlet] in context with path [/promotion-handler-admin] threw exception [Could not open JDBC Connection for transaction; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database!] with root cause
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:1319)
    at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
    at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
    at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:202)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:371)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:335)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:105)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:622)
    ...

这是我的属性文件:

app.driverClassName=net.sourceforge.jtds.jdbc.Driver
app.url=jdbc:sqlserver://myUrl:port;databaseName=my_database
app.username=myUsername
app.password=myPassword

webapp/WEB-INF/applicationContext-database.xml:

<beans:bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
    destroy-method="close">
    <beans:property name="driverClass" value="${app.driverClassName}" />
    <beans:property name="jdbcUrl"
        value="${app.url}" />
    <beans:property name="user" value="${app.username}" />
    <beans:property name="password" value="${app.password}" />
    <beans:property name="acquireIncrement" value="5" />
    <beans:property name="idleConnectionTestPeriod" value="600" />
    <beans:property name="maxPoolSize" value="10" />
    <beans:property name="maxStatements" value="5" />
    <beans:property name="minPoolSize" value="3" />
    <beans:property name="preferredTestQuery" value="select 1 from DUAL" />
</beans:bean>

<!-- TRANSACTION_MANAGERS -->
<!-- See http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/transaction.html -->

<!-- Default -->
<beans:bean id="transactionManager"
    class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <beans:property name="dataSource" ref="dataSource" />
</beans:bean>

DAO 类:

@Repository
public class CampaignDAO {
    private JdbcTemplate jdbcTemplate;

    @Resource(name = "dataSource")
    public void setDataSource(DataSource dataSource) {
        this.jdbcTemplate = new JdbcTemplate(dataSource);
    }

public List<Campaign> getCampaignList() {
    Long start = System.currentTimeMillis();

    List<Campaign> queryList;

    try {
        queryList = jdbcTemplate.query("SELECT * FROM campaign", new RowMapper<Campaign>() {
            public Campaign mapRow(ResultSet rs, int line) throws SQLException {
                Campaign campaign = new Campaign();
                campaign.setId(rs.getLong("id"));
                campaign.setExtraInfo(rs.getString("extra_info"));
                campaign.setBeginTime(rs.getDate("begin_time"));
                campaign.setEndTime(rs.getDate("end_time"));

                return campaign;

            }
        });
    } finally {
         ...
    }
    return queryList;
}

Answer 1

对于将来发现此问题的任何人。我做错的是我使用的是 jtds 驱动程序，但我忘了在 url 中添加它。所以在我的属性文件中我应该做的是:

app.url=jdbc:jtds:sqlserver://myUrl:port;databaseName=my_database