我在使用@Autowired注释将一个在xml文件中定义的数据源bean导入Spring的类时遇到了一些麻烦。
有人知道这里发生了什么吗?似乎* Impl类中的dataSource没有被连线。
道context.xml中
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:8889/spring" />
<property name="username" value="user" />
<property name="password" value="1234" />
</bean>
PersonDaoImpl.java
public class PersonDaoImpl implements PersonDao {
@Autowired
private DataSource dataSource;
private JdbcTemplate jdbcTemplate = new JdbcTemplate();
public DataSource getDataSource() {
return dataSource;
}
public void setDataSource(DataSource dataSource) {
System.out.println("SETTING DATA SOURCE");
this.dataSource = dataSource;
}
public List<Person> getPersonList() {
// TODO Auto-generated method stub
return null;
}
public void savePerson(Person person) {
// TODO Auto-generated method stub
}
public Person getPersonById(int id) {
System.out.println("Getting Person: " + id);
return null;
}
@Override
public int getPersonCount(){
String sql = "SELCECT COUNT(*) FROM PERSON";
jdbcTemplate.setDataSource(getDataSource());
int count = jdbcTemplate.queryForInt(sql);
System.out.println("Count of Person: " + count);
return count;
}
public JdbcTemplate getJdbcTemplate() {
return jdbcTemplate;
}
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
}
......最后,例外。
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalArgumentException: No DataSource specified
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:894)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
java.lang.IllegalArgumentException: No DataSource specified
org.springframework.util.Assert.notNull(Assert.java:112)
org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:97)
org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:382)
org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:456)
org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:464)
org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:472)
org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:477)
org.springframework.jdbc.core.JdbcTemplate.queryForInt(JdbcTemplate.java:486)
com.myPackage.rest.dao.impl.PersonDaoImpl.getPersonCount(PersonDaoImpl.java:50)
com.myPackage.rest.HomeController.home(HomeController.java:36)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:212)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:126)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:96)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:617)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:900)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:827)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
任何帮助都会非常感激,欢呼。
答案 0 :(得分:5)
您的数据源需要在JdbcTemplate中设置(我不认为您这样做)。此外,由于您在字段上放置了@Autowired
注释,我认为它不会使用setter,因此这就是为什么不调用setDataSource方法的原因。由于您的异常表明您调用了jdbcTemplate.execute且dataSource为null,因此这是有道理的。
如果你看这里:http://static.springsource.org/spring/docs/current/spring-framework-reference/html/jdbc.html有一个自动装配数据源的例子,但想法是:
public class MyDao {
private JdbcTemplate jdbcTemplate;
@Autowired
public void setDataSource(DataSource dataSource) {
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
}
答案 1 :(得分:1)
是的,多亏了这两个回复,我有这个工作。
dao-context(如上所述,添加了此内容):
<bean id="personDao" class="com.mypackage.rest.dao.impl.PersonDaoImpl">
<property name="dataSource" ref="dataSource"/>
</bean>
Impl class
@Repository
public class PersonDaoImpl implements PersonDao {
private JdbcTemplate jdbcTemplate;
@Autowired
public void setDataSource(DataSource dataSource) {
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
public int getPersonCount(){
String sql = "select count(*) from person";
return jdbcTemplate.queryForInt(sql);
}
}
我错过的另一个重要部分是Controller中的Dependency Injected Impl实例。
@Controller
public class HomeController {
@Autowired
private PersonDao personDao;
@RequestMapping(value = "/", method = RequestMethod.GET)
public String home(Locale locale, Model model) {
int personCount = personDao.getPersonCount();
model.addAttribute("personCount", personCount );
return "home";
}
}
答案 2 :(得分:0)
需要将impl类标记为spring处理:
@Repository
public class PersonDaoImpl implements PersonDao {
现在如果正在使用spring package扫描,它会找到这个类并处理所有@Autowired注释