我试着用Jmeter强调我的应用程序。当我没有同步我的两个方法时，我有多个错误，如下所示：
声明已结束。 或
22:43:40,669 ERROR [stderr] (http-localhost-127.0.0.1-8080-106) java.sql.SQLException: Error
22:43:40,669 ERROR [stderr] (http-localhost-127.0.0.1-8080-106) at org.jboss.jca.adapters.jdbc.WrappedConnection.checkException(WrappedConnection.java:1643)
22:43:40,670 ERROR [stderr] (http-localhost-127.0.0.1-8080-106) at org.jboss.jca.adapters.jdbc.WrappedStatement.checkException(WrappedStatement.java:1262)
22:43:40,670 ERROR [stderr] (http-localhost-127.0.0.1-8080-106) at org.jboss.jca.adapters.jdbc.WrappedResultSet.checkException(WrappedResultSet.java:4063)
22:43:40,670 ERROR [stderr] (http-localhost-127.0.0.1-8080-106) at org.jboss.jca.adapters.jdbc.WrappedResultSet.next(WrappedResultSet.java:1866)
22:43:40,671 ERROR [stderr] (http-localhost-127.0.0.1-8080-106) at fr.formation.dao.DaoImpl.getAllPersonnes(DaoImpl.java:275)
或
java.sql.SQLException: The result set is closed.
或
Caused by: java.lang.NullPointerException
22:43:40,992 ERROR [stderr] (http-localhost-127.0.0.1-8080-73) at com.mysql.jdbc.ResultSetImpl.checkColumnBounds(ResultSetImpl.java:825)
22:43:40,993 ERROR [stderr] (http-localhost-127.0.0.1-8080-73) at com.mysql.jdbc.ResultSetImpl.getInt(ResultSetImpl.java:2710)
22:43:40,993 ERROR [stderr] (http-localhost-127.0.0.1-8080-73) at com.mysql.jdbc.ResultSetImpl.getInt(ResultSetImpl.java:2846)
22:43:40,993 ERROR [stderr] (http-localhost-127.0.0.1-8080-73) at org.jboss.jca.adapters.jdbc.WrappedResultSet.getInt(WrappedResultSet.java:1073)
22:43:40,993 ERROR [stderr] (http-localhost-127.0.0.1-8080-73) ... 23 more
22:43:40,993 ERROR [stderr] (http-localhost-127.0.0.1-8080-184) java.sql.SQLException: The result set is closed.
22:43:40,994 ERROR [stderr] (http-localhost-127.0.0.1-8080-184) at org.jboss.jca.adapters.jdbc.WrappedResultSet.checkState(WrappedResultSet.java:4081)
22:43:40,994 ERROR [stderr] (http-localhost-127.0.0.1-8080-184) at org.jboss.jca.adapters.jdbc.WrappedResultSet.getInt(WrappedResultSet.java:1065)
我的代码：
public List<PersonneDao> getAllPersonnes() throws SQLException{
List<PersonneDao> liste = new ArrayList<PersonneDao>();
ResultSet rs = null ;
PreparedStatement preparedStatement = null;
try {
connection = ConnectionUtil.getInstance().getConnection();
preparedStatement = (PreparedStatement) connection.prepareStatement("select * from personne");
rs = preparedStatement.executeQuery();
while (rs.next()) {
PersonneDao user = new PersonneDao();
user.setId (rs.getInt("id"));
user.setNom (rs.getString("nom"));
user.setPrenom(rs.getString("prenom"));
user.setEmail(rs.getString("email"));
liste.add(user);
}
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}finally{
if (rs != null) {
try {
rs.close();
} catch (SQLException sqlex) {
// ignore, as we can't do anything about it here
}
rs = null;
}
if (preparedStatement != null) {
try {
preparedStatement.close();
} catch (SQLException sqlex) {
// ignore, as we can't do anything about it here
}
preparedStatement = null;
}
if (connection != null) {
try {
ConnectionUtil.getInstance().close(connection);
} catch (SQLException sqlex) {
// ignore, as we can't do anything about it here
}
connection = null;
}
}
return liste;
}
}
和
public class ConnectionUtil {
private DataSource dataSource;
private static ConnectionUtil instance = new ConnectionUtil();
private ConnectionUtil() {
try {
Context initContext = new InitialContext();
dataSource = (DataSource) initContext.lookup("java:/dsFormationJSP");
} catch (NamingException e) {
e.printStackTrace();
}
}
public static ConnectionUtil getInstance() {
return instance;
}
public Connection getConnection() throws SQLException {
Connection connection = dataSource.getConnection();
return connection;
}
public void close(Connection connection) throws SQLException {
if (connection != null && !connection.isClosed()) {
connection.close();
}
connection = null;
}
}
我使用Jboss AS 7.1和这个conf
<datasource jta="false" jndi-name="java:/dsFormationJSP" pool-name="dsFormationJSP" enabled="true" use-ccm="false">
<connection-url>jdbc:mysql://localhost:3306/base_personne</connection-url>
<driver-class>com.mysql.jdbc.Driver</driver-class>
<driver>mysql-connector-java-5.1.30-bin.jarcom.mysql.jdbc.Driver_5_1</driver>
<pool>
<min-pool-size>50</min-pool-size>
<max-pool-size>70</max-pool-size>
<prefill>true</prefill>
</pool>
<security>
<user-name>root</user-name>
<password>root</password>
</security>
<validation>
<validate-on-match>false</validate-on-match>
<background-validation>false</background-validation>
</validation>
<timeout>
<blocking-timeout-millis>50000</blocking-timeout-millis>
<idle-timeout-minutes>5</idle-timeout-minutes>
</timeout>
<statement>
<share-prepared-statements>false</share-prepared-statements>
</statement>
</datasource>
当我同步这两种方法时，没关系。我通常不需要（它是数据库和jboss的本机机制）。谢谢你的帮助。
答案 0 :(得分：0)
connection中的getAllPersonnes()似乎是一个字段，而不是局部变量。这意味着当并发运行时，一次执行可能会覆盖另一次执行的连接，这可能导致使用相同连接执行两次。
例如：
connection，connection，无论哪种方法完成，首先会在另一方完成之前关闭连接。关闭连接会关闭依赖语句和结果集，从而导致错误。
您需要将connection更改为方法内的局部变量，这样就不会被其他线程覆盖。