spring中xml配置方式和注解annoation方式(包括@autowired和@resource)的区别

xml文件中配置itemSqlParameterSourceProvider是可以的：

<bean id="billDbWriter"
class="com.aa.bb.AABatchWriter">
<property name="dataSource" ref="dataSource" />
<property name="sql"
value="insert into bills(id,user_id,fees,paid_fees,unpaid_fees,pay_status) values(:id,:user.id,:fees,:paidFees,:unpaidFees,:payStatus)" />
<property name="itemSqlParameterSourceProvider"
ref="itemSqlParameterSourceProvider" />

<bean id="itemSqlParameterSourceProvider"
class="org.springframework.batch.item.database.BeanPropertyItemSqlParameterSourceProvider" />

但是假如放到java代码中，用@Resource和@AutoWired都引用不到itemSqlParameterSourceProvider，会报错：

public class AABatchWriter<T> implements ItemWriter<T> {

    @Resource
    BeanPropertyItemSqlParameterSourceProvider itemSqlParameterSourceProvider;

    /* (non-Javadoc)
     * @see org.springframework.batch.item.ItemWriter#write(java.util.List)
     */
    public void write(List<? extends T> items) throws Exception {
        // TODO Auto-generated method stub

    }

}