Solo 开发指南

h2 是内存数据库么 我先服务器崩了之后 h2 的数据库中的内容还能找回来不

按照上述步骤，git clone 后用 mvn jetty:run 运行报错，错误信息应该是说连接 mysql 失败，难道要先装 mysql 吗？不是说集成了 mysql 在项目发布的文件里吗？第一次尝试 solo，谁能帮忙解答一下？谢谢。打印信息如下：

[INFO ]-[2019-06-23 10:38:10]-[com.zaxxer.hikari.HikariDataSource:110]: HikariPool-1 - Starting...

[ERROR]-[2019-06-23 10:38:11]-[com.zaxxer.hikari.pool.HikariPool:574]: HikariPool-1 - Exception during pool initialization.
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
        at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
        ...
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:347)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        ... 72 more
Caused by: java.net.ConnectException: Connection refused (Connection refused)
        at java.base/java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399)
        at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242)
        at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224)
        at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:403)
        at java.base/java.net.Socket.connect(Socket.java:591)
        at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155)
        at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65)
        ... 75 more
[ERROR]-[2019-06-23 10:38:11]-[org.b3log.solo.service.InitService:186]: Check tables failed, please make sure database existed and database configuration [jdbc.*] in local.props is correct [msg=Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.]
​

安装并启动了 mysql 后，接下来修改 root@localhost 密码为 12345

mysql 在安装后会创建一个 root@locahost 账户(这是 mysql 本地登录的账号。MySQL8.0 为远程连接 root@% 和本地连接 root@locahost 提供了不同的密码验证方式。)，并且把本地连接初始的密码放到了/var/log/mysqld.log 文件中；用 cat /var/log/mysqld.log | grep password 命令查看初始密码。

[root@VM_0_11_centos solo]# cat /var/log/mysqld.log | grep password


2019-06-23T03:35:57.941668Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: n=Ti,P4?J(uE
​

注：上面 n=Ti,P4?J(uE 就是初始密码。

使用初始密码登录 mysql

[root@VM_0_11_centos solo]# mysql -uroot -p


Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 12
Server version: 8.0.16 MySQL Community Server - GPL

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
​

mysql 的 root 用户的验证方式变了。从下面命令结果可以看出 root 的用户的加密方式为 caching_sha2_passoword,而 navicat 连接所用的方式为 native_password。

mysql> use mysql

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A

Database changed
mysql> select host, user, plugin from user;
+-----------+------------------+-----------------------+
| host      | user             | plugin                |
+-----------+------------------+-----------------------+
| %         | root             | mysql_native_password |
| localhost | mysql.infoschema | caching_sha2_password |
| localhost | mysql.session    | caching_sha2_password |
| localhost | mysql.sys        | caching_sha2_password |
| localhost | root             | caching_sha2_password |
+-----------+------------------+-----------------------+
5 rows in set (0.00 sec)
​

下面开始修改密码操作，但是直接用 alter 命令改还不行，因为 123456 密太简单，不满足密码策略，查看密码策略命令如下：

mysql> SHOW VARIABLES LIKE 'validate%';

+--------------------------------------+--------+

| Variable_name                        | Value  |
+--------------------------------------+--------+
| validate_password.check_user_name    | ON     |
| validate_password.dictionary_file    |        |
| validate_password.length             | 8      |
| validate_password.mixed_case_count   | 1      |
| validate_password.number_count       | 1      |
| validate_password.policy             | MEDIUM |
| validate_password.special_char_count | 1      |
+--------------------------------------+--------+
7 rows in set (0.01 sec)
​

需要把 validate_password.check_user_name 改为 OFF，validate_password.length 改为 1，validate_password.policy 改为 LOW。命令如下：

mysql> set global validate_password.check_user_name=0;
Query OK, 0 rows affected (0.00 sec)

mysql> set global validate_password.length=1;
Query OK, 0 rows affected (0.00 sec)

mysql> set global validate_password.policy=0;
Query OK, 0 rows affected (0.00 sec)

mysql> SHOW VARIABLES LIKE 'validate%';

+--------------------------------------+-------+
| Variable_name                        | Value |
+--------------------------------------+-------+
| validate_password.check_user_name    | OFF   |
| validate_password.dictionary_file    |       |
| validate_password.length             | 4     |
| validate_password.mixed_case_count   | 1     |
| validate_password.number_count       | 1     |
| validate_password.policy             | LOW   |
| validate_password.special_char_count | 1     |
+--------------------------------------+-------+
7 rows in set (0.00 sec)

​

然后才可以开始改密码了：（本地和远程的都改为 123456）

mysql> alter user'root'@'localhost' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.01 sec)

mysql> ALTER USER 'root'@'%' IDENTIFIED by '123456';
Query OK, 0 rows affected (0.01 sec)

mysql> ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '123456';
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
​

 org.xml.sax.SAXParseException; systemId: file:/usr/local/apache-tomcat-9.0.14/webapps/solo/META-INF/context.xml; lineNumber: 3; columnNumber: 1; Premature end of file.
​

这个文件有点问题，你看下是不是有损坏之类的。