mysql p6spy druid 启动报错

报错信息

java.lang.NullPointerException: null
	at com.alibaba.druid.wall.WallFilter.init(WallFilter.java:132) ~[druid-1.2.6.jar:1.2.6]
	at com.alibaba.druid.pool.DruidDataSource.init(DruidDataSource.java:830) ~[druid-1.2.6.jar:1.2.6]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_251]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_251]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_251]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_251]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeCustomInitMethod(AbstractAutowireCapableBeanFactory.java:1925) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1867) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1795) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1307) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1227) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:886) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:790) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:540) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1341) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1181) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:556) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1307) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1227) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1514) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1409) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:207) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeanByName(AbstractAutowireCapableBeanFactory.java:453) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:527) ~[spring-context-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:497) ~[spring-context-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:650) ~[spring-context-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:228) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:318) ~[spring-context-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1425) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) [spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) [spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) [spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:897) [spring-beans-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879) [spring-context-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551) [spring-context-5.2.14.RELEASE.jar:5.2.14.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) [spring-boot-2.3.10.RELEASE.jar:2.3.10.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:755) [spring-boot-2.3.10.RELEASE.jar:2.3.10.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.3.10.RELEASE.jar:2.3.10.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:402) [spring-boot-2.3.10.RELEASE.jar:2.3.10.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.3.10.RELEASE.jar:2.3.10.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1247) [spring-boot-2.3.10.RELEASE.jar:2.3.10.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1236) [spring-boot-2.3.10.RELEASE.jar:2.3.10.RELEASE]

yml

datasource:
    driver-class-name: com.p6spy.engine.spy.P6SpyDriver
    url: jdbc:p6spy:mysql://127.0.0.1:3306/xxxxx?useUnicode=true&characterEncoding=utf8&useSSL=false&allowPublicKeyRetrieval=true&autoReconnect=true&serverTimezone=GMT%2B8
    username: root
    password: xxxxx
    type: com.alibaba.druid.pool.DruidDataSource
    druid:
      # 下面为连接池的补充设置，应用到上面所有数据源中
      # 初始化连接数大小，最小，最大
      initial-size: 5
      min-idle: 5
      max-active: 20
      # 配置获取连接等待超时的时间
      max-wait: 30000
      # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
      time-between-eviction-runs-millis: 60000
      # 配置一个连接在池中最小生存的时间，单位是毫秒
      min-evictable-idle-time-millis: 300000
      # 验证数据库连接的有效性
      validation-query: select '1' from dual
      test-while-idle: true
      test-on-borrow: false
      test-on-return: false
      # 打开PSCache，并且指定每个连接上PSCache的大小
      pool-prepared-statements: true
      max-open-prepared-statements: 20
      max-pool-prepared-statement-per-connection-size: 20
      # 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
      filters: stat,wall,slf4j
      # 合并多个DruidDataSource的监控数据
      use-global-data-source-stat: true
      connection-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
      stat-view-servlet:
        login-username: admin
        login-password: admin
        url-pattern: /druid/*
        allow: 127.0.0.1
        reset-enable: false
        # 必须启用，要不会404
        enabled: true

定位错误（druid源码）

com.alibaba.druid.wall.WallFilter.init

public synchronized void init(DataSourceProxy dataSource) {
        if (dataSource == null) {
            LOG.error("dataSource should not be null");
        } else {
            if (this.dbTypeName == null || this.dbTypeName.trim().length() == 0) {
                if (dataSource.getDbType() != null) {
                    this.dbTypeName = dataSource.getDbType();
                } else {
                    this.dbTypeName = JdbcUtils.getDbType(dataSource.getRawJdbcUrl(), "");
                }
            }

            if (this.dbTypeName == null) {
                this.dbTypeName = JdbcUtils.getDbType(dataSource.getUrl(), (String)null);
            }

            DbType dbType = DbType.of(this.dbTypeName);
            switch(dbType) {
            case mysql:
            case oceanbase:
            case drds:
            case mariadb:
            case h2:
            case presto:
                if (this.config == null) {
                    this.config = new WallConfig("META-INF/druid/wall/mysql");
                }

                this.provider = new MySqlWallProvider(this.config);
                break;
            case oracle:
            case ali_oracle:
            case oceanbase_oracle:
                if (this.config == null) {
                    this.config = new WallConfig("META-INF/druid/wall/oracle");
                }

                this.provider = new OracleWallProvider(this.config);
                break;
            case sqlserver:
            case jtds:
                if (this.config == null) {
                    this.config = new WallConfig("META-INF/druid/wall/sqlserver");
                }

                this.provider = new SQLServerWallProvider(this.config);
                break;
            case postgresql:
            case edb:
            case polardb:
                if (this.config == null) {
                    this.config = new WallConfig("META-INF/druid/wall/postgres");
                }

                this.provider = new PGWallProvider(this.config);
                break;
            case db2:
                if (this.config == null) {
                    this.config = new WallConfig("META-INF/druid/wall/db2");
                }

                this.provider = new DB2WallProvider(this.config);
                break;
            case sqlite:
                if (this.config == null) {
                    this.config = new WallConfig("META-INF/druid/wall/sqlite");
                }

                this.provider = new SQLiteWallProvider(this.config);
                break;
            case clickhouse:
                if (this.config == null) {
                    this.config = new WallConfig("META-INF/druid/wall/clickhouse");
                }

                this.provider = new ClickhouseWallProvider(this.config);
                break;
            default:
                throw new IllegalStateException("dbType not support : " + dbType + ", url " + dataSource.getUrl());
            }

            this.provider.setName(dataSource.getName());
            this.inited = true;
        }
    }

显然this.dbTypeName为null，从源码分析可知因为我们配置了p6spy，jdbc的url上添加了:p6spy导致druid无法匹配对应dbType，所以只需要手动配置下数据库类型即可,我用的是mysql，所以添加datasource.druid.dbType = mysql即

  ...
  datasource:
    driver-class-name: com.p6spy.engine.spy.P6SpyDriver
    url: jdbc:p6spy:mysql://127.0.0.1:3306/xxxxx?useUnicode=true&characterEncoding=utf8&useSSL=false&allowPublicKeyRetrieval=true&autoReconnect=true&serverTimezone=GMT%2B8
    username: root
    password: xxxxx
    type: com.alibaba.druid.pool.DruidDataSource
    druid:
      db-type: mysql
      ...

这样显式定义dbType就能解决问题