SPI 替换默认值的优先级低于 sqlServerSqlParser,orderBySqlParser,countSqlParser 参数指定的实现，不指定时如果存在SPI实现，即可生效， SPI 可以参考 pagehelper-sqlsource 模块代码。

JSqlParser 默认解析 SQL 会使用临时创建的 Executors.newSingleThreadExecutor()，这里通过 API 跳过了线程池：

CCJSqlParser parser = CCJSqlParserUtil.newParser(statementReader);
parser.withSquareBracketQuotation(true);
return parser.Statement();

JSqlParser 使用线程池的目的是为了防止解析超时，因此如果你遇到过超时的情况，可以引入下面的依赖（通过SPI覆盖了默认实现，超时时间10秒）：

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>sqlparser-timeout</artifactId>
    <version>6.1.0</version>
</dependency>

• Released version 6.1.0, PageHelper provides direct dependency on jsqlparser as intermediate interfaces, allowing default implementation replacement through SPI.
• Upgraded jsqlparser version to 4.7, re-implemented order by, pagination, and count queries.
• Simplified pom.xml configuration, removed shade-embedded jsqlparser approach, and switched to selecting different jsqlparser versions through external dependencies, allowing self-SPI extension.
• jsqlparser parsing no longer uses a thread pool, supporting SPI extension to override SqlParser implementation.
• Changed SqlServer pagination to SqlServerSqlParser interface, added parameter sqlServerSqlParser to override the default value.
• Extracted OrderByParser to OrderBySqlParser interface, added orderBySqlParser parameter to override the default implementation.
• Changed static methods of OrderByParser to regular methods, preparing for future interface changes.
• JSqlParser interface is no longer needed after JDK 8+, removed the interface, and marked the parameter in the documentation (This parameter was used in the early stages to support special configuration for SQL Server). Compatible with jsqlparser 4.7 version. Rui 2023/12/3 15:15.
• Fixed maven-compiler-plugin version to remove warnings and improve build stability. qxo
• Added .vscode to .gitignore for vscode IDE. qxo
• Fixed bug https://github.com/pagehelper/Mybatis-PageHelper/issues/779. chenyuehui

To ensure compatibility with jsqlparser 4.5, 4.7, and possible future versions, a new project called pagehelper-sqlparser has been created. Currently, it provides two implementations: 4.5 and 4.7. To use it, exclude jsqlparser from pagehelper and select one jsqlparser implementation. The current version defaults to using the code from version 4.7. If you want to switch to the 4.5 implementation, follow the configuration steps below:

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>6.1.0</version>
    <exclusions>
        <exclusion>
            <groupId>com.github.jsqlparser</groupId>
            <artifactId>jsqlparser</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>sqlparser4.5</artifactId>
    <version>6.1.0</version>
</dependency>

The priority of replacing default values with SPI is lower than the implementations specified by the sqlServerSqlParser, orderBySqlParser, and countSqlParser parameters. If no specific implementation is specified, the SPI implementation will take effect if available. You can refer to the code in the pagehelper-sqlsource module for SPI implementation examples.

By default, JSqlParser uses a temporarily created Executors.newSingleThreadExecutor() for parsing SQL. Here, the thread pool is bypassed through the API:

CCJSqlParser parser = CCJSqlParserUtil.newParser(statementReader);
parser.withSquareBracketQuotation(true);
return parser.Statement();

The purpose of using a thread pool in JSqlParser is to prevent parsing timeouts. Therefore, if you have encountered timeout situations, you can introduce the following dependency (which overrides the default implementation through SPI with a timeout of 10 seconds):

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>sqlparser-timeout</artifactId>
    <version>6.1.0</version>
</dependency>