spring - Spring 的 JDBCTemplate IllegalArgumentException：需要数据源

Question

好吧，我在配置 Spring 的 JDBCTemplate 以使其正常工作时遇到问题。我正在尝试注入数据源，但它似乎始终为空。这是一个示例代码：

1. 应用程序上下文.xml：

   <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
   <property name="driverClassName" value="org.apache.derby.jdbc.EmbeddedDriver" />
   <property name="url"
       value="jdbc:derby:c:\\Derby\\MyDB\\jsfkickstart;create=true" />
   <property name="username" value="admin" />
   <property name="password" value="admin" />
   </bean>
   
   <bean id="employeeDoa" class="com.kickstart.employeeapp.doa.EmployeeDoa">
       <property name="dataSource" ref="dataSource" />
   </bean>
   

2. web.xml

   <context-param>
   <param-name>contextConfigLocation</param-name>
   <param-value>/WEB-INF/applicationContext.xml</param-value>
   

   <listener>
           <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
   </listener>
   <listener>
           <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
   </listener>
   

3. EmployeeDoa.java

   public class EmployeeDoa implements IEmployeeDoa, IDepartmentDoa {
   private DataSource dataSource;
           public List<Employee> getAllEmployees() {
           JdbcTemplate select = new JdbcTemplate(dataSource);
           return select.query(
                   "SELECT "+
                       "e.ID as empId, "+
                       "e.FIRSTNAME as empFirstName, "+ 
                       "e.LASTNAME as empLastName,  "+
                       "d.ID as depId,  "+
                       "d.NAME as depName, "+
                       "d.LOCATION as depLocation "+
                   "FROM jsfkickstart.Employee e, jsfkickstart.Department d",
                   new EmployeeMapper());
           }
   }
   
   class EmployeeMapper implements RowMapper {
       public Object mapRow(ResultSet rs, int rowNum) throws SQLException {
           Employee emp = new Employee();
           emp.setId(rs.getInt("empId"));
           emp.setFirstName(rs.getString("empFirstName"));
           emp.setLastName(rs.getString("empLastName"));
           Department dep = new Department();
           dep.setId(rs.getShort("depId"));
           dep.setLocation(rs.getString("depLocation"));
           dep.setName(rs.getString("depName"));
           emp.setDepartment(dep);
           return emp;
       }
   }
   

4. 抛出异常：

   Exception in thread "main" java.lang.IllegalArgumentException: Property 'dataSource' is required
   at org.springframework.jdbc.support.JdbcAccessor.afterPropertiesSet(JdbcAccessor.java:134)
   at org.springframework.jdbc.core.JdbcTemplate.<init>(JdbcTemplate.java:142)
   at com.kickstart.employeeapp.doa.EmployeeDoa.addEmployee(EmployeeDoa.java:29)
   

有谁知道我该如何解决这个问题？如果我在问题中遗漏了任何重要信息，请告诉我。

谢谢你。

Answer 1

我实际上是一个非常愚蠢的例外。setDataSource() 的主体是空的，即我没有将 dataSource 分配给任何东西，因此它始终为空。

愚蠢的我！！！