@Override protected void doOpen() throws Exception { Map<String, Object> parameters = new HashMap<String, Object>(); if (parameterValues != null) { parameters.putAll(parameterValues); } sqlSession = sqlSessionFactory.openSession(ExecutorType.SIMPLE); // ### ← Open a new session cursor =...
* Set values for a parameter. * This method allows parameters to be added at runtime. * @param String name * @param String[] value */ public void setParameterValues(String name, String[] value) { HashMap<String,String[]> params = (HashMap<String,String[]> :wink: parameterMap; params...
Our last important data structure is the hash table. It’s very useful when you want to quickly look for values. Moreover, understanding the hash table will help us later to understand a common database join operation called thehash join. This data structure is also used by a database to...
在线程是否安全方面,HashMap是线程不安全的,而HashTable是线程安全的,HashTable的大部分方法都被加入Synchronized方法修饰 在效率方面,因为HashTable是方法级别的加锁,所以很影响效率,效率比较低 对null的处理:HashMap可以存储key和value都为null,但是key如果为null只能存一份,HashTable不允许key为null和value为null 底层...
private final Map<String, FirebaseFirestore> instances = new HashMap<>(); } view rawFirestoreMultiDbComponent.javahosted withbyGitHub When you callFirebaseFirestore.getInstance(), it’s actually callingFirestoreMultiDbComponentwith the default database id. ...
public void setParameterValues(String name, String[] value) { HashMap<String,String[]> params = (HashMap<String,String[]> :wink: parameterMap; params.put(name, value); } public Map<String,String[]> getParameterMap() { final Map<String,String[]> parameterMap = this.parameterMap; return ...