cannot be found on object of type xx.CacheExpressionRootObject

0 环境

系统环境：win10
编辑器：IDEA

1 前言->环境搭建

1-1 pom依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.8.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>org.javaboy</groupId>
    <artifactId>chapter09-cacheredis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>chapter09-cacheredis</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-cache</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

1-2 properties(redis的基本配置以及缓存名的配置)

spring.redis.host=127.0.0.1
spring.redis.password=123456
spring.redis.port=6379
spring.redis.database=0

spring.cache.cache-names=c1

1-3 Application启动项添加

1-4 自定义KeyGenerator

@Component
public class MyKeyGen implements KeyGenerator {

    @Override
    public Object generate(Object o, Method method, Object... objects) {
        return method.getName()+":"+ Arrays.toString(objects);
    }

1-5 service层

@Service
//@CacheConfig(cacheNames = "c1")
public class BookService {
//    key = "#methodName"
//    key = "#method.name"
//    key = "#caches[0]"
//    key = "#args[0]"
//    @Cacheable(cacheNames = "c1",key = "#caches[0]")
    @Cacheable(cacheNames = "c1",key = "'myKeyGen'")
    public Book getUserById(Integer id){
        System.out.println("book>>>>>>" + id);
        Book book = new Book();
        book.setId(id);
        return book;
    }

}

1-6 单元测试

    @Autowired
    BookService bookService;

    @Test
    public void contextLoads() {

        Book book = bookService.getUserById(1);
        Book book1 = bookService.getUserById(1);
        System.err.println("book --->>" + book);
        System.err.println("book1 --->>" + book1);

    }

2 报错

key = "''" (需要内嵌一下单引号 不然会报错)