Java 使用try with resources/close this";“准备好的报表”;在“a”中;最后";条款
我正在sonarqube上运行我的JDBC代码。我的代码有问题Java 使用try with resources/close this";“准备好的报表”;在“a”中;最后";条款,java,spring,jdbc,Java,Spring,Jdbc,我正在sonarqube上运行我的JDBC代码。我的代码有问题 try (final Connection connection = DatabaseConnectionProvider.createConnection(configuration)) { PreparedStatement statement = connection.prepareStatement( "SELECT 1 FROM `todo_items` WHERE
try (final Connection connection = DatabaseConnectionProvider.createConnection(configuration)) {
PreparedStatement statement = connection.prepareStatement(
"SELECT 1 FROM `todo_items` WHERE `id` = ? LIMIT 1;");
statement.setLong(1, id);
ResultSet resultSet = statement.executeQuery();
if (!resultSet.next()) {
return false;
}
statement = connection.prepareStatement("UPDATE `todo_items` SET `checked` = ? WHERE id = ?;");
statement.setBoolean(1, checked);
statement.setLong(2, id);
statement.executeUpdate();
return true;
}
它说在3号线和9号线有拦截器问题
使用try with resources或在“finally”子句中关闭此“PreparedStatement”。我不明白这一点。您可以使用内部try with resources,因为您在内部有两个不同的prepared语句:
try (final Connection connection = DatabaseConnectionProvider.createConnection(configuration)) {
try(PreparedStatement statement = connection.prepareStatement("SELECT 1 FROM `todo_items` WHERE `id` = ? LIMIT 1;")) {
statement.setLong(1, id);
ResultSet resultSet = statement.executeQuery();
if (!resultSet.next()) {
return false;
}
}
try(PreparedStatement statement = connection.prepareStatement("UPDATE `todo_items` SET `checked` = ? WHERE id = ?;")) {
statement.setBoolean(1, checked);
statement.setLong(2, id);
statement.executeUpdate();
return true;
}
}
小优化是可能的(请注意,try(…)
中存在2个可自动关闭的s):
您不必查询数据库中是否存在行,因为更新的行数通常由
executeUpdate()
返回。实际返回值可能取决于JDBC驱动程序的实现(尽管JDBC规范对此非常清楚).您已经有了一个连接的try with resource
。请将准备好的语句也放在其中。如果您尝试JdbcTemplate,您可以用更少的样板文件来解决这个问题。您已经在使用Spring。我对您为什么不使用该类感到不解。您应该将数据源和Instance集中起来启动时在SpringBean工厂中初始化池。
try (final Connection connection = DatabaseConnectionProvider.createConnection(configuration);
PreparedStatement statement = connection.prepareStatement("UPDATE `todo_items` SET `checked` = ? WHERE id = ?;")) {
statement.setBoolean(1, checked);
statement.setLong(2, id);
return statement.executeUpdate() > 0;
}