how to create immutable class in java

Inner class:1, the inner class defined in a class, the instantiation of the inner class is constructed with the method defined by the perimeter class, the inner class object has an implicit reference to the perimeter

concurrent code more readable and reduces the occurrence of errors. 　　Despite all these advantages, immutability has some drawbacks, for example, it is not without cost. Because the string is immutable, it generates a large number of temporary objects and escape objects, which can put pressure on the garbage collector. Java designers have considered that storing string literals in a constant pool is a solu

[Problem Solving] error: shouldnotreachhere () [sorting] Blog type: Android Android If you create a class that contains the main () method in the android project and right-click the class to run the class, the following error is reported:# A fatal error has been detected by the

external class, which needs to be accessed by an object-level object.You cannot declare any static member in a non-static inner class.Inner classes can be called to each other, for example: access to member-internal classes1 class A {2 // B, C can call each other 3 class B {} 4 class C {} 5 }An object of a

Java reflection Class -- class, java reflection -- Class Let's first look at the functions provided by reflection: The reflection mechanism provides the function to determine the data type, parse the class structure, and obtain in

the sine/cosine/tangent of a double type argumentTodegrees ()/toradians (): Return angle/radiansRandom (): Returns the stochastic numbertwo , Character class:　　The Character class is used to manipulate a single character, and the Character class wraps the value of a primitive type char in an object:CharCH ='a';//Unicode Character RepresentationCharUnichar ='\u03

First, ArraysFor the tool class for array manipulation, some methods for array sorting and binary searching are provided.Common methods:1. public static string toString (Int[] a): Converts an array of type int to a string.Converted to a string after the output form: ([element 1, Element 2, Element 3 ...]), arrays overrides the ToString method at the bottom.2, public static void sort (int[] a): Sorts the specified array of type int in ascending order o

this string object is returned. Three, immutable class An immutable string has a great advantage: The compiler can set the string to be shared. Immutable class strings have an important advantage-they are not shared references. So, Ja