java spring framework interview questions

threads are not able to modify objects in the collection that is being traversed by iterator. At the same time, iterator allows the caller to delete elements from the underlying collection, which is not possible for enumeration.What is the difference between 17.HashSet and TreeSet?HashSet is implemented by a hash table, so its elements are unordered. The time complexity of the add (), remove (), contains () method is O (1).On the other hand, TreeSet is implemented by a tree-shaped structure in

I used to have only one Java interview question topic. Now I have divided into the following topics: Java interview questions are of course the focus, all of which are Java programming and directly related to the design. Intelli

Do not write any scopes (that is, access rights) represent friendlyPublic, the largest, the largest scope, within the class, the same package, descendants class, other package can be accessedProtected protection, can be accessed within the class, the same package, descendant classes, but other package cannot accessFriendly friendly, within the class, the same package can be accessed, descendant class, other package cannot accessPrivate, minimal permissions, minimal scope, access within the class

Translation Links: http://www.codeceo.com/article/java-hashmap-value-sort.htmlThe English version: How to Sort HashMap Based on the Values in JavaTranslation Author: Code Rural network – Xiao Feng HashMap in Java is a data structure for storing "key" and "value" information pairs. Unlike array, ArrayList, and linkedlists, it does not maintain the order in which elements are inserted. Therefore, sorting hash

, StringBuilder and StringBufferStorestring constant, which cannot be changed once the object is createdStringBuilder and StringBuffer: String variables, objects can be changedExecution speedstringThread SafetyString,stringbuilder is thread insecure, StringBuffer is thread-safe.Scope of applicationString: Applies to a small number of string operationsStringBuilder: For a single thread, large number of string operationsStringBuffer: For multi-threading, a large number of string operations3. Singl

Transferred from: http://icyfenix.iteye.com/blog/715301The background of this post is tonight to see JE on this posting: http://www.iteye.com/topic/715256, the words written on impulse, if you can, can have other interviewers to analyze their interview questions asked, it may be a very meaningful thing. In the company as a technical interviewer for a few years, from graduating students to work more than 10

the length expands, the hash rules change as well. Let's review the hash formula:index = hashcode (Key) (Length-1) When the original array length is 8 o'clock, the hash operation is done with the 111B (representing the binary 7), and the new array length is 16,hash and 1111B (representing the binary 15). hash results are obviously different . The Java code for rehash is as follows: /** * Transfers all entries from the current table to newtable.

be accessed throughout the class.The ② member variable is created as the object is built, disappears as the object disappears, and exists in the heap memory where the object resides.The ③ member variable has a default initialization value.Local variables:① Local variables are defined only within the local scope, such as within a function, within a statement, and only in the area to which they belong.② local variables exist in the stack memory, the scope of the action ends, and the variable spac

Java and C common technical interview questions 2015 (Continuous updates ...), 2015 updating 1. Differences between overwrite and overload Overload is an Overload. It uses the same name as an existing member to declare attributes or methods, but the parameter list is different from that of the original member. Override is mainly used for method rewriting between

JAVA engineer interview questionsZookeeper I went to a company for an interview today. I felt dizzy with my brains. I didn't make a few algorithm questions. The questions were relatively simple. I should have prepared myself, but the status was not good, after the

Java interview questions Basic knowledge:1. simple principles and applications of the Exception Handling Mechanism in C ++ or Java. When a Java program violates the Java Semantic Rules, the Ja