问题
When fetching results from db through springJdbcTemplate, everywhere I have seen that they are passing the new object of RowMapper everytime. Is this required? Or can we just use one object and pass it again and again.
Student student = jdbcTemplateObject.queryForObject(SQL, new Object[] { id }, new StudentRowMapper());
I know this object will be garbage collected later on, but I didn't wanted to create the same object over and over again.
Can I use
Student student = jdbcTemplateObject.queryForObject(SQL, new Object[] { id }, this.studentMapper);
?
Has this any thread safety issue?
回答1:
Why not just create your RowMapper and let Spring manage it? There should be no reason to create a new instance every time. Just autowire in the one managed by Spring. As long as your mapper isn't doing anything non-thread-safe, then should be just fine.
@Component
...RowMapper class...
...
@Service
...WhateverService class...
@Autowired
private RowMapperClass theRowMapper;
public void doSomething() {
Student student = jdbcTemplateObject.queryForObject(SQL, new Object[] { id }, theRowMapper);
}
回答2:
Yes you should be able to reuse the object.
As long as your class is thread safe there is no issue. JdbcTemplate is thread safe by design
来源：https://stackoverflow.com/questions/34951402/can-we-fetch-the-results-using-one-rowmapper-object-instead-of-creating-objects