Spring 测试代码的写法以及一个c3p0的错误

错误信息：

An attempt by a client to checkout a Connection has timed out.

java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
 at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
 at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:65)
 at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:527)
 at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
 at services.callcenter.common.DBUtilHelper.searchToMap(DBUtilHelper.java:278)
 at services.callcenter.test.PersonDaoImplTest.testPersonDaoImpl(PersonDaoImplTest.java:36)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at junit.framework.TestCase.runTest(TestCase.java:154)
 at junit.framework.TestCase.runBare(TestCase.java:127)
 at junit.framework.TestResult$1.protect(TestResult.java:106)
 at junit.framework.TestResult.runProtected(TestResult.java:124)
 at junit.framework.TestResult.run(TestResult.java:109)
 at junit.framework.TestCase.run(TestCase.java:118)
 at junit.framework.TestSuite.runTest(TestSuite.java:208)
 at junit.framework.TestSuite.run(TestSuite.java:203)
 at org.junit.internal.runners.OldTestClassRunner.run(OldTestClassRunner.java:35)
 at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:38)
 at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool@4ac216 -- timeout at awaitAvailable()
 at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1317)
 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)
 ... 22 more
问题原因：

这个问题我在google上搜索了，没有找到有具体的人给出答案。后经过我自己的测试，发现问题原因是配置出错。

是Spring中配置c3p0的时候，有一个配置属性是checkoutTimeout，把这个配置属性去掉就正常了。

 

源代码如下：

Spring配置文件：applicationContext.xml

 xmlns="http://www.springframework.org/schema/beans"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

    class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    
       classpath:jdbc.properties
  
 
 
  
    
    
    
    
    
    
    

    
    
    
    
    
    
    
 
 
 
 
  
 
 
 
 
 
  
   
 
 
  
 
public class DBUtilHelper {

 private DataSource ds;
 
    public void setDs(DataSource ds) {
           this.ds = ds;
   }

    public Map searchToMap(String sql)  {
        Connection conn = null;
        Map result = null;
        QueryRunner run = new QueryRunner();
        ResultSetHandler h = new MapHandler();
     try {
      conn = ds.getConnection();
         result = (Map) run.query(conn,sql, h);
 
     }
     catch (Exception e){
      log.warn(sql);
      log.warn(e.getMessage(),e);
      
     }
     finally {
      try{
       DbUtils.close(conn);
      }
      catch(Exception e){
       log.warn(e.getMessage(),e);
      }
     }

        return result;
    }

}

Junit测试代码如下：

package ***;

import java.util.Map;

import junit.framework.TestCase;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class PersonDaoImplTest extends TestCase{
 
 ApplicationContext ac = null;
 @Test
 public void testPersonDaoImpl() throws Exception {
  DBUtilHelper db=(DBUtilHelper)ac.getBean("DBUtilHelper");
  String sql = "select user_id from ur_users where user_id = 371 ";
  Map m = db.searchToMap(sql);
  System.out.println(m.toString());
  }

 protected void setUp() throws Exception{
  System.out.println("DDDDD");
  ac=new ClassPathXmlApplicationContext("applicationContext.xml");
 }
}

 关于Spring代码的测试，因为Spring采用配置文件来注入某些属性，而Junit在默认的测试情况下，是不会读取这些配置文件的。所以测试Spring类的时候，需要手工指定配置文件，然后通过ClassPathXmlApplicationContext类来加载这些配置信息。

要注意把applicationContext.xml文件以及jdbc.properties文件放到src目录下。

当然，这里的测试代码只是用System.out.println直接打印出来信息，没有采用assert来判断信息，大家就别深究了！