Updated FAQ (markdown)

FAQ.md

@@ -97,4 +97,41 @@ Druid is an open source project, hosted on github.com, you can "pull request". s
 (Welcome to join QQ Group: 240619787 for discuss and study Druid)
 
 # 24. How to integrate the Druid connection pool and monitoring in Spring Boot project?
-Use Druid Spring Boot Starter，Documentation：https://github.com/alibaba/druid/tree/master/druid-spring-boot-starter
+Use Druid Spring Boot Starter，Documentation：https://github.com/alibaba/druid/tree/master/druid-spring-boot-starter
+
+# 25. How to add custom WallConfig, Filter in the Spring Boot ?
+
+
+1. add configuration properties
+```xml
+spring.datasource.druid.wall.config.multiStatementAllow=false
+spring.datasource.druid.wall.config.truncateAllow=true
+... other
+```
+2. Use Druid Spring Boot Starter  ```DruidDataSourceBuilder```
+```java
+@Bean
+@ConfigurationProperties("spring.datasource.druid.wall.config")
+public WallConfig wallConfig(){
+    return new WallConfig();
+}
+
+@Bean
+public WallFilter wallFilter(){
+    WallFilter filter = new WallFilter();
+    filter.setConfig(wallConfig());
+    filter.setDbType("mysql");
+    return filter;
+}
+
+@Bean
+public DataSource dataSource(Environment env){
+    DruidDataSource dataSource = DruidDataSourceBuilder
+            .create()
+            .build(env,"spring.datasource.druid.");
+    List<Filter> filters = new ArrayList<>();
+    filters.add(wallFilter());
+    dataSource.setProxyFilters(filters);
+    return dataSource;
+}
+```