MyBatis Excutor 拦截器的巧妙用法

@Intercepts({@org.apache.ibatis.plugin.Signature(
  type=Executor.class, 
  method="update", 
  args={MappedStatement.class, Object.class})})
public class SqlInterceptor implements Interceptor

public Object intercept(Invocation invocation) throws Throwable {
  Object[] args = invocation.getArgs();
  MappedStatement ms = (MappedStatement) args[0];
  Object parameter = args[1];
  SqlLog log = new SqlLog();
  Configuration configuration = ms.getConfiguration();
  Object target = invocation.getTarget();
  StatementHandler handler = configuration.newStatementHandler((Executor) target, ms, 
       parameter, RowBounds.DEFAULT, null, null);
  BoundSql boundSql = handler.getBoundSql();
  //记录SQL
  log.setSqlclause(boundSql.getSql());
  //执行真正的方法
  Object result = invocation.proceed();
  //记录影响行数
  log.setResult(Integer.valueOf(Integer.parseInt(result.toString())));
  //记录时间
  log.setWhencreated(new Date());
  //TODO 还可以记录参数，或者单表id操作时，记录数据操作前的状态
  //获取insertSqlLog方法
  ms = ms.getConfiguration().getMappedStatement("insertSqlLog");
  //替换当前的参数为新的ms
  args[0] = ms;
  //insertSqlLog 方法的参数为 log
  args[1] = log;
  //执行insertSqlLog方法
  invocation.proceed();
  //返回真正方法执行的结果
  return result;
}