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当我尝试运行一个程序时,出现“太多连接”错误,该程序要求使用tomcat库实现的连接池进行连接,在大约50次连接后失败,这里是错误:Java - MySQL不关闭连接
Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection, message from server: "Too many connections"
这里的主类,它有一个循环,在这里执行连接
public static void main(String[] args) throws Exception{
SimplePoolExample ex = new SimplePoolExample();
int cont = 100;
while (cont > 0)
{
ex.test();
System.out.println(cont);
cont--;
}
}
是执行一个简单的查询测试()函数
public void test() throws Exception
{
Connection con = getConnection();
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery("select * from actor");
while (rs.next()) {
System.out.println(rs.getString("actor_id") +" "+ rs.getString("first_name")+" "+ rs.getString("last_name"));
}
rs.close();
st.close();
} finally {
if (con!=null) try {
con.close();
}
catch (SQLException ignore) {
System.out.println("***SQL EXC" + ignore.getMessage());
}
}
}
,并询问从一个连接池
public Connection getConnection() throws SQLException
{
DataSource datasource = new DataSource();
datasource.setPoolProperties(p);
Connection con = null;
con = datasource.getConnection();
return con;
}
编辑的连接的getConnection()类:这里是连接池设置:
public void setPoolProperties()
{
p.setUrl("jdbc:mysql://localhost:3306/sakila");
p.setDriverClassName("com.mysql.jdbc.Driver");
p.setUsername("user");
p.setPassword("pwd");
p.setJmxEnabled(true); // utilities to manage JVM
p.setTestWhileIdle(false); // test idle connections
p.setTestOnBorrow(true); //
p.setValidationQuery("SELECT 1"); // any test requires it
p.setTestOnReturn(false);
p.setValidationInterval(30000); // cada cuanto hace test
p.setTimeBetweenEvictionRunsMillis(30000); // how often check idle and abandoned conn
p.setMaxActive(50);
p.setInitialSize(10);
p.setMaxWait(50);
p.setRemoveAbandonedTimeout(60); // OJO: max query last
p.setMinEvictableIdleTimeMillis(30000); // time to consider a conn idle
p.setMaxIdle(10);
p.setMinIdle(10);
p.setLogAbandoned(true); // log stack traces .. overhead
p.setRemoveAbandoned(true); //abandoned timeout ...
p.setJdbcInterceptors(
"org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;"+
"org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer");
}
连接池支持多少个连接?您可能希望将其限制为小于MySql可支持的连接数的最大连接数。 – alfasin
我更新了帖子的池设置,我认为它被限制为MySql支持的最大连接数(默认为151) – Jose