java - redisTemplate @Resource 不适用于 Spring Framework

Question

我正在构建一个 Web 应用程序，它使用 Spring Framework 4.1.3 并将 Jersey 用于 RESTful Web 服务。

我想连接到 Redis 服务器，我正在使用 Spring Data Redis 和 Jedis 驱动程序。

这是我的 Beans.xml 文件的样子:

<!-- Jedis ConnectionFactory -->
<bean id="jedisConnFactory"
    class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
    p:host-name="server" p:port="6379" p:use-pool="true" 
/>

<!-- redis template definition -->
<bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate"
    p:connection-factory-ref="jedisConnFactory" 
/>

这是访问Redis服务器的Servlet:

import javax.annotation.Resource;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.ListOperations;
import org.springframework.data.redis.core.RedisTemplate;

@Path("/")
public class RoutesServlet {

    @Autowired
    private RedisTemplate<String, String> template;


    // inject the template as ListOperations
    @Resource(name="redisTemplate")
    private ListOperations<String, String> listOps;

    @GET
    @Produces("text/plain")
    public String index() {

        listOps.leftPush("user", "name");
    ...

此时我得到一个 NullPointerException。我猜 @Resource 注释由于某种原因不能正常工作。有什么想法吗？

更新:

这是我的完整 Beans.xml 文件:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    xmlns:p="http://www.springframework.org/schema/p"
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd ">

    <!-- Initialization for data source -->
    <!--bean id="dataSource" class="db.mysql.DBConn"> </bean -->

    <bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/insider" />
        <property name="username" value="root" />
        <property name="password" value="" />
        <property name="jmxEnabled" value="true" />
        <property name="testWhileIdle" value="false" />
        <property name="testOnBorrow" value="true" />
        <property name="validationQuery" value="SELECT 1" />
        <property name="testOnReturn" value="false" />
        <property name="validationInterval" value="30000" />
        <property name="timeBetweenEvictionRunsMillis" value="30000" />
        <property name="maxActive" value="100" />
        <property name="initialSize" value="10" />
        <property name="maxWait" value="10000" />
        <property name="removeAbandonedTimeout" value="60" />
        <property name="minEvictableIdleTimeMillis" value="30000" />
        <property name="minIdle" value="10" />
        <property name="logAbandoned" value="true" />
        <property name="removeAbandoned" value="true" />
        <property name="jdbcInterceptors"
            value="org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer" />
    </bean>

    <!-- Definition for categoryJDBCTemplate bean -->
    <bean id="categoryJDBCTemplate" class="db.mysql.CategoryJDBCTemplate">
        <property name="dataSource" ref="dataSource" />
    </bean>

    <!-- Definition for itemJDBCTemplate bean -->
    <bean id="itemJDBCTemplate" class="db.mysql.ItemJDBCTemplate">
        <property name="dataSource" ref="dataSource" />
    </bean>

    <!-- Definition for userJDBCTemplate bean -->
    <bean id="userJDBCTemplate" class="db.mysql.UserJDBCTemplate">
        <property name="dataSource" ref="dataSource" />
    </bean>

    <!-- Definition for reviewJDBCTemplate bean -->
    <bean id="reviewJDBCTemplate" class="db.mysql.ReviewJDBCTemplate">
        <property name="dataSource" ref="dataSource" />
    </bean>

    <!-- Jedis ConnectionFactory -->
    <bean id="jedisConnFactory"
        class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
        p:host-name="server" p:port="6379" p:use-pool="true" 
    />

    <!-- redis template definition -->
    <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate"
        p:connection-factory-ref="jedisConnFactory" 
    />

</beans>

Answer 1

我相信很简单，名称为 redisTemplate 的 bean 的类型为 RedisTemplate。检索 ListOperations 的一种方法是执行以下操作:

public class RedisExample {
    // Just use the RedisTemplate - don't inject the ListOperations
    private final RedisTemplate<String, String> redisTemplate;

    // Use constructor injection (preferred over field injection)
    @Autowired
    public RedisExample(final RedisTemplate<String, String> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    public void addLink(String userId, URL url) {
        // Here is the trick:
        // You can either retrieve the ListOperations this way
        ListOperations<String, String> listOps = redisTemplate.opsForList();
        listOps.leftPush(userId, url.toExternalForm());

        // or, you can retrieve it this way
        redisTemplate.boundListOps(userId).leftPush(url.toExternalForm());
    }
}

该示例表明您应该注入(inject)一个名为 redisTemplate 的 ListOperations bean。由于没有这样的 bean，因此注入(inject)失败。只需删除 @Resource 注释(和字段)并使用上述代码即可。