import org.apache.ibatis.reflection.DefaultReflectorFactory; //导入依赖的package包/类

public Object intercept(Invocation invocation) throws Throwable {

StatementHandler statementHandler = (StatementHandler)invocation.getTarget();

MetaObject metaStatementHandler = MetaObject.forObject(statementHandler, new DefaultObjectFactory(), new DefaultObjectWrapperFactory(), new DefaultReflectorFactory());

RowBounds rowBounds = (RowBounds)metaStatementHandler.getValue("delegate.rowBounds");

if(rowBounds == null || rowBounds == RowBounds.DEFAULT){

return invocation.proceed();

}

if(dialect == null){

Configuration configuration = (Configuration) metaStatementHandler.getValue("delegate.configuration");

Dialect.Type databaseType = null;

String d = configuration.getVariables().getProperty("dialect");

if(d == null || d.trim().equals("")){

throw new IllegalStateException("No property named with 'dialect' defined in mybatis configuration xml file.");

}

try {

databaseType = Dialect.Type.valueOf(d);

} catch (Exception e) {

throw new IllegalStateException(String.format("No such dialect enum defined in class %s.", Dialect.Type.class));

}

switch (databaseType) {

case MYSQL: // MySQL分页

dialect = new MySQLDialect();

break;

case ORACLE: // Oracle分页

dialect = new OracleDialect();

break;

}

if(dialect == null){

throw new IllegalStateException(String.format("No %s dialect found!", databaseType));

}

}

String originalSql = metaStatementHandler.getValue("delegate.boundSql.sql").toString();

metaStatementHandler.setValue("delegate.boundSql.sql", dialect.getLimitSql(originalSql, rowBounds.getOffset(), rowBounds.getLimit()));

metaStatementHandler.setValue("delegate.rowBounds.offset", RowBounds.NO_ROW_OFFSET);

metaStatementHandler.setValue("delegate.rowBounds.limit", RowBounds.NO_ROW_LIMIT);

return invocation.proceed();

}