mybatis- abnormal module

1 Overview

In this paper, we share the abnormal module MyBatis, the corresponding  exceptions package. As shown below:

In the  "exhausted MyBatis source code parsing - List Project structure"  , a brief introduction to this module are as follows:

MyBatis defines proprietary PersistenceException and TooManyResultsException exception.

In fact, not only in MyBatis  exceptions under-cladding abnormal, in other packages are also abnormal, the entire class diagram as follows:

Below, we look at one by one package abnormalities seen in the past.

2.  exceptions Package

2.1 IbatisException

org.apache.ibatis.exceptions.IbatisException Achieve RuntimeException class, the base class IBatis exception. code show as below:

@Deprecated public class IbatisException extends RuntimeException { private static final long serialVersionUID = 3880206998166270511L; public IbatisException() { super(); } public IbatisException(String message) { super(message); } public IbatisException(String message, Throwable cause) { super(message, cause); } public IbatisException(Throwable cause) { super(cause); } }

• 实际上，IbatisException 已经在 2015 年被废弃，取代它的是 PersistenceException 类。

2.2 PersistenceException

org.apache.ibatis.exceptions.PersistenceException ，继承 IbatisException 类，目前 MyBatis 真正的异常基类。代码如下：

public class PersistenceException extends IbatisException { private static final long serialVersionUID = -7537395265357977271L; public PersistenceException() { super(); } public PersistenceException(String message) { super(message); } public PersistenceException(String message, Throwable cause) { super(message, cause); } public PersistenceException(Throwable cause) { super(cause); } }

2.2.1 ExceptionFactory

org.apache.ibatis.exceptions.ExceptionFactory ，异常工厂。代码如下：

public class ExceptionFactory { private ExceptionFactory() { // Prevent Instantiation } /** * 包装异常成 PersistenceException * * @param message 消息 * @param e 发生的异常 * @return PersistenceException */ public static RuntimeException wrapException(String message, Exception e) { return new PersistenceException(ErrorContext.instance().message(message).cause(e).toString(), e); } }

2.3 TooManyResultsException

org.apache.ibatis.exceptions.TooManyResultsException ，继承 PersistenceException 类，查询返回过多结果的异常。期望返回一条，实际返回了多条。代码如下：

public class TooManyResultsException extends PersistenceException { private static final long serialVersionUID = 8935197089745865786L; public TooManyResultsException() { super(); } public TooManyResultsException(String message) { super(message); } public TooManyResultsException(String message, Throwable cause) { super(message, cause); } public TooManyResultsException(Throwable cause) { super(cause); } }

3. parsing 包

3.1 ParsingException

org.apache.ibatis.parsing.ParsingException ，继承 PersistenceException 类，解析异常。代码如下：

public class ParsingException extends PersistenceException { private static final long serialVersionUID = -176685891441325943L; public ParsingException() { super(); } public ParsingException(String message) { super(message); } public ParsingException(String message, Throwable cause) { super(message, cause); } public ParsingException(Throwable cause) { super(cause); } }

3. 其它包

实际上，我们会看到其他包，会和 parsing 包一样，都会定义其独有的异常类。但是，代码都是相同的。所以，这里就简单整理如下：

• reflection 包：ReflectionException
• logging 包：LogException
• builder 包：BuilderException、IncompleteElementException
• scripting 包：ScriptingException
• binding 包：BindingException
• type Package: TypeException
• session Package: SqlSessionException
• cache 包: CacheException
• transaction 包：TransactionException
• datasource 包：DataSourceException
• executor 包：ResultMapException、ExecutorException、BatchExecutorException
• plugin 包：PluginException