相关类：org.apache.ibatis.executor.CachingExecutor
相关代码：
public <E> List<E> query(MappedStatement ms, Object parameterObject, RowBounds rowBounds, ResultHandler resultHandler) throws SQLException {
BoundSql boundSql = ms.getBoundSql(parameterObject);
CacheKey key = createCacheKey(ms, parameterObject, rowBounds, boundSql);
return query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);
}从CacheKey key = createCacheKey(ms, parameterObject, rowBounds, boundSql);可以看出，当下列四个元素相同时会使用cache：
MappedStatement（一般为xml中定义）、parameterObject（传递给xml的参数）、rowBounds（分页参数）、boundSql（最终sql，由MappedStatement和parameterObject决定）
createCacheKey的代码：
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;
}