Spring MVC - Bean不适用于@Autowired

Question

我在使用@Autowired注释将一个在xml文件中定义的数据源bean转换为Spring中的类时遇到了一些麻烦.

有人会知道这里发生了什么吗？似乎*Impl类中的dataSource没有被连线.

道的context.xml

<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.

Answer 1

您的数据源需要在JdbcTemplate中设置(我不认为您这样做).此外,由于您将@Autowired注释放在字段上,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);
    }
}