public Object intercept(Invocation invocation) throws Throwable {
StatementHandler handler = (StatementHandler) invocation.getTarget();
MetaObject metaObject = MetaObject.forObject(handler);
Page page = pageByMetaObject(metaObject);
if (page == null || (page.getPageCount() == 0 && page.getPageSize() == 0))
return invocation.proceed();
Configuration configuration = (Configuration) metaObject.getValue("delegate.configuration");
BoundSql orgBoundSql = (BoundSql) metaObject.getValue("delegate.boundSql");
if (page.getCount() == 0) {
MappedStatement mappedStatement =
(MappedStatement) metaObject.getValue("delegate.mappedStatement");
page.setCount(
totalCount(
(Connection) invocation.getArgs()[0], orgBoundSql, configuration, mappedStatement));
}
metaObject.setValue(
"delegate.boundSql.sql",
searchDialectByDbTypeEnum(configuration, page)
.spellPageSql(orgBoundSql.getSql(), page.getOffset(), page.getLimit()));
logger.debug("pagination sql : {}", handler.getBoundSql().getSql());
return invocation.proceed();
}
public Object intercept(Invocation invocation) throws Throwable {
StatementHandler statementHandler = (StatementHandler) invocation.getTarget();
BoundSql boundSql = statementHandler.getBoundSql();
String sql = tryConvertSql(boundSql);
if (StringUtils.isNotEmpty(sql)) {
Reflections.setFieldValue(boundSql, "sql", sql);
}
return invocation.proceed();
}
private void pagination(Invocation invocation, StatementHandler target) throws SQLException {
final MetaObject metaStatementHandler = getMetaObject(target);
final BoundSql boundSql = target.getBoundSql();
Page<?> page = PAGE_THREAD_LOCAL.get();
if (page == null) {
page = findPageParameter(boundSql.getParameterObject());
}
// 如果传入的参数中有分页对象且sql语句中有select，才做分页处理
String sql = boundSql.getSql().toLowerCase();
if (sql.startsWith("select") && page != null) {
// 采用物理分页后，就不需要mybatis的内存分页了，所以重置下面的两个参数
metaStatementHandler.setValue("delegate.rowBounds.offset", RowBounds.NO_ROW_OFFSET);
metaStatementHandler.setValue("delegate.rowBounds.limit", RowBounds.NO_ROW_LIMIT);
// 设置分页对象里的总记录数和总页数
Connection connection = (Connection) invocation.getArgs()[0];
MappedStatement mappedStatement =
(MappedStatement) metaStatementHandler.getValue("delegate.mappedStatement");
if (page.isCountTotal()) {
int recordsTotal = getTotalCount(sql, connection, mappedStatement, boundSql);
page.setTotalNum(recordsTotal);
}
// 最后重写sql
String pageSql = buildPageSql(sql, page);
metaStatementHandler.setValue("delegate.boundSql.sql", pageSql);
}
}
@Override
public Object intercept(Invocation invocation) throws Throwable {
StatementHandler statementHandler = (StatementHandler) invocation.getTarget();
ParameterHandler parameterHandler = statementHandler.getParameterHandler();
BoundSql boundSql = statementHandler.getBoundSql();
MetaObject metaStatementHandler =
MetaObject.forObject(
statementHandler, DEFAULT_OBJECT_FACTORY, DEFAULT_OBJECT_WRAPPER_FACTORY);
RowBounds rowBounds = (RowBounds) metaStatementHandler.getValue("delegate.rowBounds");
// 没有分页参数
if (rowBounds == null || rowBounds == RowBounds.DEFAULT) {
return invocation.proceed();
}
Configuration configuration =
(Configuration) metaStatementHandler.getValue("delegate.configuration");
Dialect dialect = DialectFactory.buildDialect(configuration);
String originalSql = (String) metaStatementHandler.getValue("delegate.boundSql.sql");
// 获取总记录数
Page<?> page = (Page<?>) rowBounds;
String countSql = dialect.getCountString(originalSql);
Connection connection = (Connection) invocation.getArgs()[0];
int total = getTotal(parameterHandler, connection, countSql);
page.setTotalCount(total);
// 设置物理分页语句
metaStatementHandler.setValue(
"delegate.boundSql.sql",
dialect.getLimitString(originalSql, page.getOffset(), page.getLimit()));
// 屏蔽mybatis原有分页
metaStatementHandler.setValue("delegate.rowBounds.offset", RowBounds.NO_ROW_OFFSET);
metaStatementHandler.setValue("delegate.rowBounds.limit", RowBounds.NO_ROW_LIMIT);
if (logger.isDebugEnabled()) {
logger.debug("分页SQL : " + boundSql.getSql());
}
return invocation.proceed();
}
@Override
@SuppressWarnings({"unchecked", "rawtypes"})
public Object intercept(Invocation invocation) throws Throwable {
if (invocation.getTarget() instanceof StatementHandler) { // 控制SQL和查询总数的地方
Page page = pageThreadLocal.get();
Order order = orderThreadLocal.get();
RoutingStatementHandler handler = (RoutingStatementHandler) invocation.getTarget();
StatementHandler delegate = (StatementHandler) ReflectUtil.getFieldValue(handler, "delegate");
BoundSql boundSql = delegate.getBoundSql();
if (page == null) { // 不是分页查询
if (order != null) {
String orderSql = buildOrderSql(order, boundSql.getSql());
ReflectUtil.setFieldValue(boundSql, "sql", orderSql);
}
return invocation.proceed();
}
Connection connection = (Connection) invocation.getArgs()[0];
prepareAndCheckDatabaseType(connection); // 准备数据库类型
if (page.getTotalPage() > -1) {
if (log.isTraceEnabled()) {
log.trace("已经设置了总页数, 不需要再查询总数.");
}
} else {
Object parameterObj = boundSql.getParameterObject();
MappedStatement mappedStatement =
(MappedStatement) ReflectUtil.getFieldValue(delegate, "mappedStatement");
queryTotalRecord(page, parameterObj, mappedStatement, connection);
}
String sql = boundSql.getSql();
if (order != null) {
sql = buildOrderSql(order, sql);
}
String pageSql = buildPageSql(page, sql);
if (log.isDebugEnabled()) {
log.debug("分页时, 生成分页pageSql: " + pageSql);
}
ReflectUtil.setFieldValue(boundSql, "sql", pageSql);
return invocation.proceed();
} else { // 查询结果的地方
try {
// 获取是否有分页Page对象
Page<?> page = findPageObject(invocation.getArgs()[1]);
// 获取是否有排序Order对象
Order order = findOrderObject(invocation.getArgs()[1]);
if (order != null) {
orderThreadLocal.set(order);
}
if (page == null) {
if (log.isTraceEnabled()) {
log.trace("没有Page对象作为参数, 不是分页查询.");
}
return invocation.proceed();
} else {
if (log.isTraceEnabled()) {
log.trace("检测到分页Page对象, 使用分页查询.");
}
}
// 设置真正的parameterObj
invocation.getArgs()[1] = extractRealParameterObject(invocation.getArgs()[1]);
pageThreadLocal.set(page);
Object resultObj = invocation.proceed(); // Executor.query(..)
if (resultObj instanceof List) {
/* @SuppressWarnings({ "unchecked", "rawtypes" }) */
page.setDatas((List) resultObj);
}
return resultObj;
} finally {
pageThreadLocal.remove();
orderThreadLocal.remove();
}
}
}