未验证 提交 097d0655 编写于 作者: RocketMQ技术号's avatar RocketMQ技术号 提交者: GitHub

Merge pull request #1006 from slgshishen/develop

[RIP-78] Update Example_Filter.md in RocketMQ docs/en
# Filter Example
----------
In most cases, tag is a simple and useful design to select message you want. For example:
In most cases, tag is a simple and useful design to select messages you want. For example:
```java
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("CID_EXAMPLE");
......@@ -28,7 +28,7 @@ SQL feature could do some calculation through the properties you put in when sen
------------
```
## 1.Grammars
## 1 Grammars
RocketMQ only defines some basic grammars to support this feature. You could also extend it easily.
- Numeric comparison, like **>**, **>=**, **<**, **<=**, **BETWEEN**, **=**;
......@@ -43,13 +43,13 @@ Constant types are:
- **NULL**, special constant;
- Boolean, **TRUE** or **FALSE**;
## 2.Usage constraints
## 2 Usage constraints
Only push consumer could select messages by SQL92. The interface is:
```
public void subscribe(finalString topic, final MessageSelector messageSelector)
```
## 3.Producer example
## 3 Producer example
You can put properties in message through method putUserProperty when sending.
```java
......@@ -67,7 +67,7 @@ producer.shutdown();
```
## 4.Consumer example
## 4 Consumer example
Use `MessageSelector.bySql` to select messages through SQL when consuming.
......
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