WSO2CEP siddhi无法在事件执行计划中解析substr扩展函数

Question

我试图通过SiddhiManger获取ExectuionPlanRuntime，如下所示

public static ExecutionPlanRuntime getExecutionPlanRuntime(String plan) {
        return new SiddhiManager().createExecutionPlanRuntime(plan);
}

String计划有一个表达式，它通过str:substr WSO2CEP函数扩展名提取一个值，如下所示

define stream PROBE_DATA(speed string);
from PROBE_DATA[ convert(str:substr(speed, '(\d*)' ), 'int') > 30]
insert into ostream;

但是我得到了ExecutionPlanValidationException，说明 substr既不是函数也不是执行计划中的聚合属性

org.wso2.siddhi.query.api.exception.ExecutionPlanValidationException: substr is neither a function nor an aggregated attribute in execution plan "ce1873e8-9247-4d16-a8ee-f9146e1e8c79"
    at org.wso2.siddhi.core.util.parser.ExecutionPlanParser.parse(ExecutionPlanParser.java:127) ~[siddhi-core-3.0.2.jar:na]
    at org.wso2.siddhi.core.SiddhiManager.createExecutionPlanRuntime(SiddhiManager.java:51) ~[siddhi-core-3.0.2.jar:na]
    at org.wso2.siddhi.core.SiddhiManager.createExecutionPlanRuntime(SiddhiManager.java:59) ~[siddhi-core-3.0.2.jar:na]
    at com.test.utils.SiddhiUtils.getExecutionPlanRuntime(SiddhiUtils.java:82) ~[SiddhiUtils.class:na]
Caused by: org.wso2.siddhi.core.exception.ExecutionPlanCreationException: substr is neither a function nor an aggregated attribute
    at org.wso2.siddhi.core.util.parser.QueryParser.parse(QueryParser.java:111) ~[siddhi-core-3.0.2.jar:na]
    at org.wso2.siddhi.core.util.parser.ExecutionPlanParser.parse(ExecutionPlanParser.java:117) ~[siddhi-core-3.0.2.jar:na]
    ... 110 common frames omitted
Caused by: org.wso2.siddhi.core.exception.ExecutionPlanCreationException: substr is neither a function nor an aggregated attribute
    at org.wso2.siddhi.core.util.parser.ExpressionParser.parseExpression(ExpressionParser.java:292) ~[siddhi-core-3.0.2.jar:na]
    at org.wso2.siddhi.core.util.parser.ExpressionParser.parseExpression(ExpressionParser.java:319) ~[siddhi-core-3.0.2.jar:na]
    at org.wso2.siddhi.core.util.parser.ExpressionParser.parseExpression(ExpressionParser.java:123) ~[siddhi-core-3.0.2.jar:na]
    at org.wso2.siddhi.core.util.parser.SingleInputStreamParser.generateProcessor(SingleInputStreamParser.java:129) ~[siddhi-core-3.0.2.jar:na]
    at org.wso2.siddhi.core.util.parser.SingleInputStreamParser.parseInputStream(SingleInputStreamParser.java:86) ~[siddhi-core-3.0.2.jar:na]
    at org.wso2.siddhi.core.util.parser.InputStreamParser.parse(InputStreamParser.java:51) ~[siddhi-core-3.0.2.jar:na]
    at org.wso2.siddhi.core.util.parser.QueryParser.parse(QueryParser.java:64) ~[siddhi-core-3.0.2.jar:na]
    ... 111 common frames omitted

但是，WSO2CEP控制台的相同ExecutionPlan是有效的，如下图所示。

以下是我的siddhi pom依赖

    <dependency>
        <groupId>org.wso2.siddhi</groupId>
        <artifactId>siddhi-core</artifactId>
        <version>${siddhi.version}</version>
        <exclusions>
            <exclusion>
                <artifactId>log4j</artifactId>
                <groupId>org.apache.log4j.wso2</groupId>
            </exclusion>
            <exclusion>
                <artifactId>quartz</artifactId>
                <groupId>org.quartz-scheduler.wso2</groupId>
            </exclusion>
            <exclusion>
                <artifactId>slf4j-simple</artifactId>
                <groupId>org.slf4j</groupId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.wso2.siddhi</groupId>
        <artifactId>siddhi-query-api</artifactId>
        <version>${siddhi.version}</version>
        <exclusions>
            <exclusion>
                <artifactId>log4j</artifactId>
                <groupId>org.apache.log4j.wso2</groupId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.wso2.siddhi</groupId>
        <artifactId>siddhi-query-compiler</artifactId>
        <version>${siddhi.version}</version>
        <exclusions>
            <exclusion>
                <artifactId>log4j</artifactId>
                <groupId>org.apache.log4j.wso2</groupId>
            </exclusion>
        </exclusions>
    </dependency>

WSO2CEP服务器是版本4.0.0，它使用的siddhi lib是版本3.0.2，但我已经尝试了版本3.0.2,3.0.3和最新的版本3.1.2 for my app client，all of all他们没有帮助，并得到了与上述相同的例外。

我是否错过了为我的应用客户端设置的内容可以识别siddhi功能扩展？

Answer 1

substr是一个返回属性的函数。因此，它不能在from语句中应用;相反，它必须在select语句中应用。请参阅下面的示例查询：

from inputStream 
select symbol, str:substr(symbol, 4) as substring  
insert into outputStream;