face recognition java

overflow zone 2, how HashMap in Java is implemented We can understand it as " array of list ". HashMap is actually implemented as a linear array, so the container that can be understood to store the data is a linear array.So how does a linear array implement key-value pairs to access data? Here HashMap has to do some processing.1. First hashmap inside a static inner class entry is implemented. Its important attributes are key,

verification) We understand the role of this module as a facet, telling us that it is a functional module. We can think of it as a facet. To put it bluntly, we write a class. Write a method in this class that deals with the same effect in the core business.We also need to know two keyword:　connection point (Joinpoint), a simple understanding is the method defined in the tangent module. Is the method in the definition class above.　pointcut (Pointcut). Is the collection of connection points, whic

, synchronization: Hashtable is thread-safe, that is, synchronous, and HashMap is a line program is not secure, not synchronous.2. HashMap allows the existence of a null key with multiple null value.3, the Hashtable key and value are not allowed to be null.V. Short S1 = 1; S1 = s1 + 1; Is it wrong? short S1 = 1; S1 + = 1; Is it wrong?Short S1 = 1; S1 = s1 + 1; not compiled correctly, 1 int integer, s1=s1+1 automatically transformed to int type and then assigned to S1, the result is int type; sho

separately? An example is described.For:Assume that data is shared between threads. For example, the data being written may be read by another thread. Or the data being read may have been written by another thread, then this data is shared data. Synchronous access is required.When an application invokes a method on an object that takes a very long time to run, and does not want the program to wait for the method to return. Asynchronous programming should be used, and in very many cases the asyn

the semantics of synchronized; If a thread enters a synchronized block that is protected by a monitor that the thread already owns, it allows the thread to continue and does not release the lock when the thread exits the second (or subsequent) synchronized block. The lock is released only when the thread exits the first synchronized block that the monitor protects when it enters.2. When a thread enters an synchronized instance method of an object, does the other thread have access to other meth

First, the Java Foundation:1, the difference between abstract class and interface:2. Which method is called by the set set and the Map collection when the repetition is removed? Are the results the same?3. Copy the contents of the D:\\java folder into the e:\\4. The difference between sleep () and wait ()5, there are several ways to close the threadSecond, the Web Foundation1, why the servlet is designed to

Break in Java can only jump out of the current loop, and to jump out of multiple loops you can label the label:Cases: PublicclassStepovermultiloop { Public StaticvoidMain (string[] args) {intcount = 0; OK: for(int i = 0; i for(intj = 0; J if((i + j) = = Ten) {System. out. println (++count); BreakOK;}}}}}How to jump out of multiple loops in Java face question

**Record some Java written exams, and interview with less certain questions:The difference between 1,string,stringbuffer,stringbuilder2,servlet is a single instance or multi-instance3,hashmap4,hibernate, the three object states of the session5,javascript closure, JS get form There are also sessions in 6,web, where the SessionID is allocated, the session expires when the browser is closed, and SessionID also exists in the client's cookie,When it shuts

the time is less than the interrupt () force interrupt.The role of Thread.Sleep (0) is "triggering the operating system to immediately re-compete with the CPU".③ Use range:wait,notify and Notifyall can only be used in synchronous control methods or synchronization control blocks, and sleep can be used anywhereSynchronized (x) {X.notify ()or wait ()}④sleep must catch exceptions , while Wait,notify and notifyall do not need to catch exceptions2. Differences between HashMap and Hashtable in

1. What is the Java data type?2. What is the package type for Java?3. What is the difference between a basic type and a package type?The base type can only be passed by value, and the corresponding wrapper class is passed by reference.The base type is created on the stack, and all object types are created on the heap.The default values are different.The encapsulation class appears to make it easier to use s

Java Face Test-javaweb Chapter seven 61,JDBC the basic steps to access a database.1, load Driver2, get the connection object through the DriverManager object connection3, getting the session through the Connection object4, through the session of data additions and deletions to check, packaging objects5, close the resource 62, tell me the difference between preparedstatement and statement.1, efficiency: pr

JavaBasic1. Where Java is different from other languagesA: The biggest feature of Java is its platform independence, the Java compiler compiled Java source code into bytecode and then the JVM is responsible for interpreting execution, for the world's most popular platform has its corresponding Jvm,

improves the reusability of the application Controller: When the user clicks the Submit button in the Web page, the controller accepts the request and invokes the appropriate model to process the request. The corresponding view is then called according to the result of the processing to display the results of the processing. MVC process: First the controller accepts the user's request, invokes the corresponding model for business processing, and returns the data to the controller. The

method is not executed by default and requires the Proceedingjoinpoint pair to be used by the target object's method for execution. What is the difference between 50.JDBC, Ibatis (MyBatis), and hibernate?A: ①JDBC programming process fixed, while the SQL statement and Java code mixed together, often need to piece together SQL statements, details are cumbersome;②ibatis (MyBatis) It's not exactly an ORM framework, because MyBatis requires programme

design what knowledge points:The concept of hashingMethods of solving collisions in HashMapThe application of Equals () and hashcode (), and their importance in HashMapThe benefits of immutable objectsHashMap Multi-threaded conditional competitionResize the HashMapSummarizeHow the HashMap worksHashMap based on the hashing principle, we store and retrieve objects through the put () and get () methods. When we pass a key-value pair to the put () method, it calls the Hashcode () method of the Key

Iii. Open Source FrameworkWhat is Mybaties? Mybaties is an excellent persistence layer framework that supports common SQL queries, stored procedures, and advanced mappings. Mybaties eliminates the manual setting of almost all JDBC code and parameters and the retrieval of the result set. Mybaties uses simple XML or annotations for configuration and raw mapping, mapping interfaces and Java POJOs (Plan old Java