/**
*
*
* <pre>
* 查询总数
* </pre>
*
* @author jundong.xu_C
* @param page
* @param parameterObject
* @param mappedStatement
* @param connection
* @throws SQLException
*/
protected void queryTotalRecord(
Page<?> page, Object parameterObject, MappedStatement mappedStatement, Connection connection)
throws SQLException {
BoundSql boundSql = mappedStatement.getBoundSql(parameterObject);
String sql = boundSql.getSql();
String countSql = this.buildCountSql(sql);
if (log.isDebugEnabled()) {
log.debug("分页时, 生成countSql: " + countSql);
}
List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
BoundSql countBoundSql =
new BoundSql(
mappedStatement.getConfiguration(), countSql, parameterMappings, parameterObject);
ParameterHandler parameterHandler =
new DefaultParameterHandler(mappedStatement, parameterObject, countBoundSql);
PreparedStatement pstmt = null;
ResultSet rs = null;
try {
pstmt = connection.prepareStatement(countSql);
parameterHandler.setParameters(pstmt);
rs = pstmt.executeQuery();
if (rs.next()) {
long totalRecord = rs.getLong(1);
int pageSize = page.getPageSize();
int totalPage = (int) (totalRecord + pageSize - 1) / pageSize;
page.setTotalSize(totalRecord);
page.setTotalPage(totalPage);
}
} finally {
if (rs != null)
try {
rs.close();
} catch (Exception e) {
if (log.isWarnEnabled()) {
log.warn("关闭ResultSet时异常.", e);
}
}
if (pstmt != null)
try {
pstmt.close();
} catch (Exception e) {
if (log.isWarnEnabled()) {
log.warn("关闭PreparedStatement时异常.", e);
}
}
}
}
/** 复制BoundSql对象 */
private BoundSql copyFromBoundSql(MappedStatement ms, BoundSql boundSql, String sql) {
BoundSql newBoundSql =
new BoundSql(
ms.getConfiguration(),
sql,
boundSql.getParameterMappings(),
boundSql.getParameterObject());
for (ParameterMapping mapping : boundSql.getParameterMappings()) {
String prop = mapping.getProperty();
if (boundSql.hasAdditionalParameter(prop)) {
newBoundSql.setAdditionalParameter(prop, boundSql.getAdditionalParameter(prop));
}
}
return newBoundSql;
}
private SqlSource getSqlSource(
MappedStatement ms, SqlSource sqlSource, Object parameterObject, boolean isCount) {
if (ms.getSqlSource() instanceof DynamicSqlSource) {
MetaObject msObject = MetaObjectUtils.forObject(ms);
SqlNode sqlNode = (SqlNode) msObject.getValue("sqlSource.rootSqlNode");
MixedSqlNode mixedSqlNode = null;
if (sqlNode instanceof MixedSqlNode) {
mixedSqlNode = (MixedSqlNode) sqlNode;
} else {
List<SqlNode> contents = new ArrayList<SqlNode>(1);
contents.add(sqlNode);
mixedSqlNode = new MixedSqlNode(contents);
}
return new CustomerDynamicSqlSource(ms.getConfiguration(), mixedSqlNode, isCount, dialect);
} else if (sqlSource instanceof ProviderSqlSource) {
return new CustomerProviderSqlSource(
ms.getConfiguration(), (ProviderSqlSource) sqlSource, isCount, dialect);
} else if (!isCount) {
BoundSql boundSql = sqlSource.getBoundSql(parameterObject);
return new StaticSqlSource(
ms.getConfiguration(),
dialect.generatePageSQL(boundSql.getSql()),
MybatisUtils.plusTwoParameterToMapping(ms.getConfiguration(), boundSql));
} else {
BoundSql boundSql = sqlSource.getBoundSql(parameterObject);
return new StaticSqlSource(
ms.getConfiguration(),
dialect.generateCountSQL(boundSql.getSql()),
boundSql.getParameterMappings());
}
}
/**
* 获取总页数
*
* @param conn
* @param orgBoundSql
* @param configuration
* @param mappedStatement
* @return
* @throws SQLException
*/
private int totalCount(
Connection conn,
BoundSql orgBoundSql,
Configuration configuration,
MappedStatement mappedStatement)
throws SQLException {
String orgSql = orgBoundSql.getSql();
StringBuffer sqlBuffer = new StringBuffer(orgSql.length() + 100);
sqlBuffer.append(" SELECT COUNT(0) FROM (").append(orgSql).append(") TEMP ");
logger.debug(" this is countsql : {}", sqlBuffer.toString());
PreparedStatement preparedStatement = conn.prepareStatement(sqlBuffer.toString());
Object parameterObject = orgBoundSql.getParameterObject();
BoundSql boundSql =
new BoundSql(
configuration,
sqlBuffer.toString(),
orgBoundSql.getParameterMappings(),
parameterObject);
setParameters(preparedStatement, mappedStatement, boundSql, parameterObject);
ResultSet rs = preparedStatement.executeQuery();
if (rs != null) {
if (rs.next()) {
return rs.getInt(1);
}
}
return 0;
}
/**
* @description TODO
* @createTime 2016-4-19 上午11:20:47
* @fileName CacheInterceptor.java
* @author yaojiamin
*/
private BoundSql createPageBoundSql(CacheHandlerBean cacheHandlerBean, BoundSql boundSql) {
return new BoundSql(
cacheHandlerBean.getMappedStatement().getConfiguration(),
createCountSql(boundSql),
boundSql.getParameterMappings(),
cacheHandlerBean.getParameterObject());
}
private int getCount(
Connection connection,
BoundSql boundSql,
Configuration configuration,
MappedStatement mappedStatement)
throws SQLException {
String countSql = "select count(0) from ( " + boundSql.getSql() + " )"; // 记录统计
PreparedStatement countStmt = connection.prepareStatement(countSql);
BoundSql countBS =
new BoundSql(
configuration,
countSql,
boundSql.getParameterMappings(),
boundSql.getParameterObject());
setParameters(countStmt, mappedStatement, countBS, boundSql.getParameterObject());
ResultSet rs = countStmt.executeQuery();
int count = 0;
if (rs.next()) {
count = rs.getInt(1);
}
rs.close();
countStmt.close();
return count;
}
public Object intercept(Invocation ivk) throws Throwable {
// TODO Auto-generated method stub
if (ivk.getTarget() instanceof RoutingStatementHandler) {
RoutingStatementHandler statementHandler = (RoutingStatementHandler) ivk.getTarget();
BaseStatementHandler delegate =
(BaseStatementHandler) ReflectHelper.getValueByFieldName(statementHandler, "delegate");
MappedStatement mappedStatement =
(MappedStatement) ReflectHelper.getValueByFieldName(delegate, "mappedStatement");
if (mappedStatement.getId().matches(pageSqlId)) { // 拦截需要分页的SQL
BoundSql boundSql = delegate.getBoundSql();
Object parameterObject =
boundSql
.getParameterObject(); // 分页SQL<select>中parameterType属性对应的实体参数，即Mapper接口中执行分页方法的参数,该参数不得为空
if (parameterObject == null) {
throw new NullPointerException("parameterObject尚未实例化！");
} else {
Connection connection = (Connection) ivk.getArgs()[0];
String sql = boundSql.getSql();
String countSql = "select count(0) from (" + sql + ") as tmp_count"; // 记录统计
PreparedStatement countStmt = connection.prepareStatement(countSql);
BoundSql countBS =
new BoundSql(
mappedStatement.getConfiguration(),
countSql,
boundSql.getParameterMappings(),
parameterObject);
setParameters(countStmt, mappedStatement, countBS, parameterObject);
ResultSet rs = countStmt.executeQuery();
int count = 0;
if (rs.next()) {
count = rs.getInt(1);
}
rs.close();
countStmt.close();
// System.out.println(count);
Page page = null;
if (parameterObject instanceof Page) { // 参数就是Page实体
page = (Page) parameterObject;
page.setEntityOrField(true); // 见com.ttsoft.entity.Page.entityOrField 注释
page.setTotalResult(count);
} else { // 参数为某个实体，该实体拥有Page属性
Field pageField = ReflectHelper.getFieldByFieldName(parameterObject, "page");
if (pageField != null) {
page = (Page) ReflectHelper.getValueByFieldName(parameterObject, "page");
if (page == null) page = new Page();
page.setEntityOrField(false); // 见com.ttsoft.entity.Page.entityOrField 注释
page.setTotalResult(count);
ReflectHelper.setValueByFieldName(parameterObject, "page", page); // 通过反射，对实体对象设置分页对象
} else {
throw new NoSuchFieldException(parameterObject.getClass().getName() + "不存在 page 属性！");
}
}
String pageSql = generatePageSql(sql, page);
ReflectHelper.setValueByFieldName(boundSql, "sql", pageSql); // 将分页sql语句反射回BoundSql.
}
}
}
return ivk.proceed();
}
public CacheKey createCacheKey(
MappedStatement ms, Object parameterObject, RowBounds rowBounds, BoundSql boundSql) {
if (closed) throw new ExecutorException("Executor was closed.");
CacheKey cacheKey = new CacheKey();
cacheKey.update(ms.getId());
cacheKey.update(rowBounds.getOffset());
cacheKey.update(rowBounds.getLimit());
cacheKey.update(boundSql.getSql());
List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
if (parameterMappings.size() > 0 && parameterObject != null) {
TypeHandlerRegistry typeHandlerRegistry = ms.getConfiguration().getTypeHandlerRegistry();
if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
cacheKey.update(parameterObject);
} else {
MetaObject metaObject = configuration.newMetaObject(parameterObject);
for (ParameterMapping parameterMapping : parameterMappings) {
String propertyName = parameterMapping.getProperty();
if (metaObject.hasGetter(propertyName)) {
cacheKey.update(metaObject.getValue(propertyName));
} else if (boundSql.hasAdditionalParameter(propertyName)) {
cacheKey.update(boundSql.getAdditionalParameter(propertyName));
}
}
}
}
return cacheKey;
}
public Map setParameter(
MappedStatement ms, Object parameterObject, PageParam page, Dialect dialect) {
BoundSql boundSql = ms.getBoundSql(parameterObject);
Map paramMap = null;
if (parameterObject == null) {
paramMap = new HashMap();
} else if (parameterObject instanceof Map) {
paramMap = (Map) parameterObject;
} else {
paramMap = new HashMap();
boolean hasTypeHandler =
ms.getConfiguration().getTypeHandlerRegistry().hasTypeHandler(parameterObject.getClass());
MetaObject metaObject = MetaObjectUtils.forObject(parameterObject);
if (ms.getSqlSource() instanceof CustomerProviderSqlSource) {
paramMap.put(Const.PROVIDER_OBJECT, parameterObject);
}
if (!hasTypeHandler) {
for (String name : metaObject.getGetterNames()) {
paramMap.put(name, metaObject.getValue(name));
}
}
if (boundSql.getParameterMappings() != null && boundSql.getParameterMappings().size() > 0) {
for (ParameterMapping parameterMapping : boundSql.getParameterMappings()) {
String name = parameterMapping.getProperty();
if (!name.equals(Const.PARAMETER_FIRST)
&& !name.equals(Const.PARAMETER_SECOND)
&& paramMap.get(name) == null) {
if (hasTypeHandler
|| parameterMapping.getJavaType().equals(parameterObject.getClass())) {
paramMap.put(name, parameterObject);
break;
}
}
}
}
}
// 备份原始参数对象
paramMap.put(Const.ORIGINAL_PARAMETER_OBJECT, parameterObject);
// 设置分页参数
Map<String, Object> customerPageParams = dialect.getPageParameter(page);
if (customerPageParams != null) {
for (String key : customerPageParams.keySet()) {
paramMap.put(key, customerPageParams.get(key));
}
}
return paramMap;
}
@Override
public Object intercept(Invocation invocation) throws Throwable {
final MappedStatement mappedStatement = (MappedStatement) invocation.getArgs()[0];
// //拦截需要分页的SQL
//// if (mappedStatement.getId().matches(_SQL_PATTERN)) {
// if (StringUtils.indexOfIgnoreCase(mappedStatement.getId(), _SQL_PATTERN) != -1) {
Object parameter = invocation.getArgs()[1];
BoundSql boundSql = mappedStatement.getBoundSql(parameter);
Object parameterObject = boundSql.getParameterObject();
// 获取分页参数对象
Page<Object> page = null;
if (parameterObject != null) {
page = convertParameter(parameterObject, page);
}
// 如果设置了分页对象，则进行分页
if (page != null && page.getPageSize() != -1) {
if (StringUtils.isBlank(boundSql.getSql())) {
return null;
}
String originalSql = boundSql.getSql().trim();
// 得到总记录数
page.setCount(
SQLHelper.getCount(originalSql, null, mappedStatement, parameterObject, boundSql, log));
// 分页查询 本地化对象 修改数据库注意修改实现
String pageSql = SQLHelper.generatePageSql(originalSql, page, DIALECT);
// if (log.isDebugEnabled()) {
// log.debug("PAGE SQL:" + StringUtils.replace(pageSql, "\n", ""));
// }
invocation.getArgs()[2] = new RowBounds(RowBounds.NO_ROW_OFFSET, RowBounds.NO_ROW_LIMIT);
BoundSql newBoundSql =
new BoundSql(
mappedStatement.getConfiguration(),
pageSql,
boundSql.getParameterMappings(),
boundSql.getParameterObject());
// 解决MyBatis 分页foreach 参数失效 start
if (Reflections.getFieldValue(boundSql, "metaParameters") != null) {
MetaObject mo = (MetaObject) Reflections.getFieldValue(boundSql, "metaParameters");
Reflections.setFieldValue(newBoundSql, "metaParameters", mo);
}
// 解决MyBatis 分页foreach 参数失效 end
MappedStatement newMs =
copyFromMappedStatement(mappedStatement, new BoundSqlSqlSource(newBoundSql));
invocation.getArgs()[0] = newMs;
}
// }
return invocation.proceed();
}
/**
* 对SQL参数(?)设值, 参考org.apache.ibatis.executor.parameter.DefaultParameterHandler。
*
* @param ps 表示预编译的 SQL 语句的对象。
* @param mappedStatement MappedStatement
* @param boundSql SQL
* @param parameterObject 参数对象
* @throws java.sql.SQLException 数据库异常
*/
@SuppressWarnings("unchecked")
public static void setParameters(
PreparedStatement ps,
MappedStatement mappedStatement,
BoundSql boundSql,
Object parameterObject)
throws SQLException {
ErrorContext.instance()
.activity("setting parameters")
.object(mappedStatement.getParameterMap().getId());
List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
if (parameterMappings != null) {
Configuration configuration = mappedStatement.getConfiguration();
TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
MetaObject metaObject =
parameterObject == null ? null : configuration.newMetaObject(parameterObject);
for (int i = 0; i < parameterMappings.size(); i++) {
ParameterMapping parameterMapping = parameterMappings.get(i);
if (parameterMapping.getMode() != ParameterMode.OUT) {
Object value;
String propertyName = parameterMapping.getProperty();
PropertyTokenizer prop = new PropertyTokenizer(propertyName);
if (parameterObject == null) {
value = null;
} else if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
value = parameterObject;
} else if (boundSql.hasAdditionalParameter(propertyName)) {
value = boundSql.getAdditionalParameter(propertyName);
} else if (propertyName.startsWith(ForEachSqlNode.ITEM_PREFIX)
&& boundSql.hasAdditionalParameter(prop.getName())) {
value = boundSql.getAdditionalParameter(prop.getName());
if (value != null) {
value =
configuration
.newMetaObject(value)
.getValue(propertyName.substring(prop.getName().length()));
}
} else {
value = metaObject == null ? null : metaObject.getValue(propertyName);
}
@SuppressWarnings("rawtypes")
TypeHandler typeHandler = parameterMapping.getTypeHandler();
if (typeHandler == null) {
throw new ExecutorException(
"There was no TypeHandler found for parameter "
+ propertyName
+ " of statement "
+ mappedStatement.getId());
}
typeHandler.setParameter(ps, i + 1, value, parameterMapping.getJdbcType());
}
}
}
}
private void ensureNoOutParams(MappedStatement ms, Object parameter, BoundSql boundSql) {
if (ms.getStatementType() == StatementType.CALLABLE) {
for (ParameterMapping parameterMapping : boundSql.getParameterMappings()) {
if (parameterMapping.getMode() != ParameterMode.IN) {
throw new ExecutorException(
"Caching stored procedures with OUT params is not supported. Please configure useCache=false in "
+ ms.getId()
+ " statement.");
}
}
}
}
private void handleLocallyCachedOutputParameters(
MappedStatement ms, CacheKey key, Object parameter, BoundSql boundSql) {
if (ms.getStatementType() == StatementType.CALLABLE) {
final Object cachedParameter = localOutputParameterCache.getObject(key);
if (cachedParameter != null && parameter != null) {
final MetaObject metaCachedParameter = MetaObject.forObject(cachedParameter);
final MetaObject metaParameter = MetaObject.forObject(parameter);
for (ParameterMapping parameterMapping : boundSql.getParameterMappings()) {
if (parameterMapping.getMode() != ParameterMode.IN) {
final String parameterName = parameterMapping.getProperty();
final Object cachedValue = metaCachedParameter.getValue(parameterName);
metaParameter.setValue(parameterName, cachedValue);
}
}
}
}
}
public void handleOutputParameters(CallableStatement cs) throws SQLException {
final Object parameterObject = parameterHandler.getParameterObject();
final MetaObject metaParam = configuration.newMetaObject(parameterObject);
final List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
for (int i = 0; i < parameterMappings.size(); i++) {
final ParameterMapping parameterMapping = parameterMappings.get(i);
if (parameterMapping.getMode() == ParameterMode.OUT
|| parameterMapping.getMode() == ParameterMode.INOUT) {
if (ResultSet.class.equals(parameterMapping.getJavaType())) {
handleRefCursorOutputParameter(
(ResultSet) cs.getObject(i + 1), parameterMapping, metaParam);
} else {
final TypeHandler<?> typeHandler = parameterMapping.getTypeHandler();
metaParam.setValue(parameterMapping.getProperty(), typeHandler.getResult(cs, i + 1));
}
}
}
}
@Override
protected BoundSql getCountBoundSql(Object parameterObject) {
DynamicContext context = new DynamicContext(configuration, parameterObject);
rootSqlNode.apply(context);
SqlSourceBuilder sqlSourceParser = new SqlSourceBuilder(configuration);
Class<?> parameterType = parameterObject == null ? Object.class : parameterObject.getClass();
SqlSource sqlSource =
sqlSourceParser.parse(context.getSql(), parameterType, context.getBindings());
BoundSql boundSql = sqlSource.getBoundSql(parameterObject);
sqlSource =
new StaticSqlSource(
configuration, parser.getCountSql(boundSql.getSql()), boundSql.getParameterMappings());
boundSql = sqlSource.getBoundSql(parameterObject);
// 设置条件参数
for (Map.Entry<String, Object> entry : context.getBindings().entrySet()) {
boundSql.setAdditionalParameter(entry.getKey(), entry.getValue());
}
return boundSql;
}
/**
* 获取一个Mybatis运行时调用的SQL和参数
*
* @param ms
* @param parameterObject
* @return
*/
public static MyBatisSql getMyBatisSql(MappedStatement ms, Object parameterObject) {
MyBatisSql ibatisSql = new MyBatisSql();
BoundSql boundSql = ms.getBoundSql(parameterObject);
ibatisSql.setSql(boundSql.getSql());
List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
if (parameterMappings != null) {
Object[] parameterArray = new Object[parameterMappings.size()];
MetaObject metaObject =
parameterObject == null ? null : MetaObject.forObject(parameterObject);
for (int i = 0; i < parameterMappings.size(); i++) {
ParameterMapping parameterMapping = parameterMappings.get(i);
if (parameterMapping.getMode() != ParameterMode.OUT) {
Object value;
String propertyName = parameterMapping.getProperty();
PropertyTokenizer prop = new PropertyTokenizer(propertyName);
if (parameterObject == null) {
value = null;
} else if (ms.getConfiguration()
.getTypeHandlerRegistry()
.hasTypeHandler(parameterObject.getClass())) {
value = parameterObject;
} else if (boundSql.hasAdditionalParameter(propertyName)) {
value = boundSql.getAdditionalParameter(propertyName);
} else if (propertyName.startsWith(ForEachSqlNode.ITEM_PREFIX)
&& boundSql.hasAdditionalParameter(prop.getName())) {
value = boundSql.getAdditionalParameter(prop.getName());
if (value != null) {
value =
MetaObject.forObject(value)
.getValue(propertyName.substring(prop.getName().length()));
}
} else {
value = metaObject == null ? null : metaObject.getValue(propertyName);
}
parameterArray[i] = value;
}
}
ibatisSql.setParameters(parameterArray);
}
return ibatisSql;
}
/**
* 查询总纪录数。
*
* @param sql SQL语句
* @param connection 数据库连接
* @param mappedStatement mapped
* @param parameterObject 参数
* @param boundSql boundSql
* @return 总记录数
* @throws SQLException sql查询错误
*/
public static int getCount(
final String sql,
final Connection connection,
final MappedStatement mappedStatement,
final Object parameterObject,
final BoundSql boundSql)
throws SQLException {
final String countSql = "select count(1) from (" + sql + ")";
PreparedStatement countStmt = null;
ResultSet rs = null;
try {
countStmt = connection.prepareStatement(countSql);
BoundSql countBS =
new BoundSql(
mappedStatement.getConfiguration(),
countSql,
boundSql.getParameterMappings(),
parameterObject);
SQLHelp.setParameters(countStmt, mappedStatement, countBS, parameterObject);
rs = countStmt.executeQuery();
int count = 0;
if (rs.next()) {
count = rs.getInt(1);
}
logger.debug("Pagination TotalCount SQL: " + countSql);
return count;
} finally {
if (rs != null) {
rs.close();
}
if (countStmt != null) {
countStmt.close();
}
if (connection != null) {
connection.close();
}
}
}
public void setParameters(PreparedStatement ps) throws SQLException {
ErrorContext.instance()
.activity("setting parameters")
.object(mappedStatement.getParameterMap().getId());
List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
if (parameterMappings != null) {
MetaObject metaObject =
parameterObject == null ? null : configuration.newMetaObject(parameterObject);
for (int i = 0; i < parameterMappings.size(); i++) {
ParameterMapping parameterMapping = parameterMappings.get(i);
if (parameterMapping.getMode() != ParameterMode.OUT) {
Object value;
String propertyName = parameterMapping.getProperty();
if (boundSql.hasAdditionalParameter(
propertyName)) { // issue #448 ask first for additional params
value = boundSql.getAdditionalParameter(propertyName);
} else if (parameterObject == null) {
value = null;
} else if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
value = parameterObject;
} else {
value = metaObject == null ? null : metaObject.getValue(propertyName);
}
TypeHandler typeHandler = parameterMapping.getTypeHandler();
if (typeHandler == null) {
throw new ExecutorException(
"There was no TypeHandler found for parameter "
+ propertyName
+ " of statement "
+ mappedStatement.getId());
}
JdbcType jdbcType = parameterMapping.getJdbcType();
if (value == null && jdbcType == null) jdbcType = configuration.getJdbcTypeForNull();
typeHandler.setParameter(ps, i + 1, value, jdbcType);
}
}
}
}
/**
* 获取总记录数
*
* @param sql 原始sql语句
* @param conn
* @param ms
* @param boundSql
* @return
* @throws SQLException
*/
private int getTotalCount(String sql, Connection conn, MappedStatement ms, BoundSql boundSql)
throws SQLException {
int start = sql.indexOf("from");
if (start == -1) {
throw new RuntimeException("statement has no 'from' keyword");
}
int stop = sql.indexOf("order by");
if (stop == -1) {
stop = sql.length();
}
String countSql = "select count(0) " + sql.substring(start, stop);
BoundSql countBoundSql =
new BoundSql(
ms.getConfiguration(),
countSql,
boundSql.getParameterMappings(),
boundSql.getParameterObject());
ParameterHandler parameterHandler =
new DefaultParameterHandler(ms, boundSql.getParameterObject(), countBoundSql);
PreparedStatement stmt = null;
ResultSet rs = null;
int count = 0;
try {
stmt = conn.prepareStatement(countSql);
// 通过parameterHandler给PreparedStatement对象设置参数
parameterHandler.setParameters(stmt);
rs = stmt.executeQuery();
if (rs.next()) {
count = rs.getInt(1);
}
} finally {
CloseableUtil.closeQuietly(rs);
CloseableUtil.closeQuietly(stmt);
}
return count;
}
public Object intercept(Invocation ivk) throws Throwable {
if (ivk.getTarget() instanceof RoutingStatementHandler) {
RoutingStatementHandler statementHandler = (RoutingStatementHandler) ivk.getTarget();
BaseStatementHandler delegate =
(BaseStatementHandler) ReflectHelper.getValueByFieldName(statementHandler, "delegate");
MappedStatement mappedStatement =
(MappedStatement) ReflectHelper.getValueByFieldName(delegate, "mappedStatement");
if (mappedStatement.getId().matches(pageSqlId)) { // 拦截需要分页的SQL
BoundSql boundSql = delegate.getBoundSql();
Object parameterObject =
boundSql
.getParameterObject(); // 分页SQL<select>中parameterType属性对应的实体参数，即Mapper接口中执行分页方法的参数,该参数不得为空
if (parameterObject == null) {
throw new NullPointerException("parameterObject尚未实例化！");
} else {
long count = 0;
String sql = "";
try {
Connection connection = (Connection) ivk.getArgs()[0];
sql = boundSql.getSql();
String countSql = "";
if ("mysql".equals(dialect)) {
countSql = "select count(1) from (" + sql + ") as tmp_count"; // 记录统计
} else if ("oracle".equals(dialect)) {
countSql = "select count(1) from (" + sql + ") tmp_count"; // 记录统计
}
PreparedStatement countStmt = connection.prepareStatement(countSql);
BoundSql countBS =
new BoundSql(
mappedStatement.getConfiguration(),
countSql,
boundSql.getParameterMappings(),
parameterObject);
setParameters(countStmt, mappedStatement, countBS, parameterObject);
ResultSet rs = countStmt.executeQuery();
if (rs.next()) {
count = rs.getLong(1);
}
rs.close();
countStmt.close();
} catch (Exception e) {
throw new RuntimeException("分页查询无法获取总记录数", e);
}
Pagination page = null;
if (parameterObject instanceof Pagination) { // 参数就是Pagination实体
page = (Pagination) parameterObject;
page.setTotalRows(count);
} else { // 参数为某个实体，该实体拥有Page属性
Field pageField = ReflectHelper.getFieldByFieldName(parameterObject, "pagination");
if (pageField != null) {
page = (Pagination) ReflectHelper.getValueByFieldName(parameterObject, "pagination");
if (page == null) page = new Pagination();
page.setTotalRows(count);
ReflectHelper.setValueByFieldName(
parameterObject, "pagination", page); // 通过反射，对实体对象设置分页对象
} else {
throw new NoSuchFieldException(
parameterObject.getClass().getName() + "不存在 pagination 属性！");
}
}
String pageSql = generatePageSql(sql, page);
ReflectHelper.setValueByFieldName(boundSql, "sql", pageSql); // 将分页sql语句反射回BoundSql.
}
}
}
return ivk.proceed();
}
@Override
public List<ParameterMapping> getPageParameterMapping(
Configuration configuration, BoundSql boundSql) {
return boundSql.getParameterMappings();
}