java lang reflect method

) Only.These two days to look at the understanding of the JVM this book, recommended to advanced Java programmers to see, to you understand Java's underlying and operating mechanism hasA big help.Nonsense don't want to talk about. Into the topic:First understand the specific concepts:Java's JVM memory can be divided into 3 zones: heap, stack (stack), and method areaHeap Area:1. All objects are stored, each

/ArrayListdupinvokespecial # // Method java/util/ArrayList." ":()Vastore_aload_invokeinterface #, // InterfaceMethod java/util/List.iterator:()Ljava/util/Iterator;astore_goto aload_invokeinterface #, // InterfaceMethod java/util/Iterator.next:()Ljava/lang/Object;popaload

object:New HashMap (map);This will allow the normal initialization of the.The principle of two-bracket notation:The first layer of parentheses actually defines an internal anonymous class (Anonymous Inner Class), and the second layer of parentheses is actually an instance initialization block (instance initializer block), which is executed when the inner anonymous class is constructed. This block is called "instance initialization blocks" because they are defined within the scope of an instance

of the a1 object, but do not want the data of the a2 object to be changed, it will not affect A1. The clone () method is the simplest and most efficient method.Next we will implement the clone method of.Java code Public class A implements Cloneable { Public String name; Public Object clone (){ A o = null; Try { O = (A) super. clone (); } Catch (CloneNotSupportedException e ){ E. printStackTrace

are interested in is findMonitorDeadlockedThreads. If you have used Java 6, the corresponding method is findDeadlockedThreads. The difference between the two is that findDeadlockedThreads can also detect the deadlock caused by the owner locks (java. util. concurrent), while findMonitorDeadlockedThreads can only detect monitor locks (for example, synchronous bloc

received in the form of keyboard input.3) JUnit can implement a single method to invoke execution, because it cannot take advantage of myeclipse, so we traverse all the methods in the Myjunit program and decide whether to invoke execution of the method by judging whether the @mytest annotation is declared.Here's how to implement @mytest annotations in any directory running:You need to enter the absolute pa

file: javap test. You can see:D: "javacode" bin> javap TestCompiled from "test. Java"Class test extends java. Lang. object {Test ();}See the default constructor automatically added by the compiler! E. If only a constructor with parameters is created, the compiler will not automatically add a constructor without parameters! F. In each constructor, if the overload

converted, and String. valueOf (Object. These methods are analyzed one by one. Method 1: Use the Object # toString () method. See the following example: Object object = getObject (); System. out. PRintln (object. toString (); in this method, Because java. lang. the public

direct interfaces of this typeThe type name appears in the Java class file and in the JVM as a full valid name. In the Java source code, the full valid name is added by the class's owning package name plus a ".", plus the class nameComposition For example, the owning package for class Object is Java.lang, and its full name is Java.lang.Object, but in the class file, all the "." have beenThe slash "/" inste

). In Maven, control whether output is by using Debug or DebugLevel in the plug-in maven-compiler-plugin (the default is true). The local variable table is JAVAP, as follows: Non-static method localvariabletable: Start Length Slot Name Signature 0 1 0 this LT; 0 1 1 count J 0 1 3 name ljava/lang/string; static method localvariablet

" Java.lang.ClassCastException:java.util.ArrayList cannot is cast to java.lang.String principle Exploration The sees the result above and wonders what the generic method eventually converts after the type erase, and the compiled class file for the reverse-compiled static generic method is as follows: Compiled from ' Test.java ' public class Test {public test (); code:0: Aload_0 1:invokespecial #1//

);//release pointer using free Free(Char_result);returnString_result;//If you use Java 16 binary conversion, it should also be possible, write with C 16 binary conversion too troublesome //jclass class_handledata = (*env)->findclass (env, "Com/hengbao/util/handledata"); //tem_method = (*env)->getstaticmethodid (env, Class_handledata, "BytesToHexString1", "([B) ljava/lang/string;"); //jobject O

second challenge to the Java For-each loop: The following code example throws a Concurrentmodificationexception exception. Here we use standard iterator and For-each loops to iterate through the ArrayList, then delete the elements, and you need to figure out which piece of code will throw Concurrentmodificationexception, why? Please note that the answer may be two, none, or one of them. Copy Code code as follows: Package test; Import

Today I studied the reflection mechanism of Java, here to make a note. Basic step: Get the Class object first, and then use the object to get the method. Just look at the code. The reflection mechanism will be better understood in the light of the final results of this article. The class that will be reflected: Package com.gzy.reflect; public class reflect {pr

Package CN. classes; Public class person {Private string name;Private int age; Public String getname (){Return name;} Public void setname (string name ){This. Name = Name;} Public int getage (){Return age;} Public void setage (INT age ){This. Age = age;} @ OverridePublic String tostring (){Return "person [name =" + name + ", age =" + age + "]";} } Package CN. test; Import CN. classes. person; Public class test{// In this case, an empty constructor must exist in the class.Public static void main

Since sun launched Java, it has made every effort to make it all-encompassing. Therefore, since its development, Java has been divided into three main parts by application: j2se, j2-and J2EE, this is the Sun ONE (Open Net Environment) system. J2se is the standard version of Java2 and is mainly used for programming desktop application software. j2se is mainly used for embedded system development, such as mob

Java Foundation System.getproperty () method Daquan1 Public Static voidMain (string[] args) {2System.out.println ("Java Version number:" + system.getproperty ("java.version"));//Java version number3SYSTEM.OUT.PRINTLN ("Java Provider name:" + system.getproperty ("Java.vendor

supplemental action in case the user forgets to "close" the resource, the FileInputStream, FileOutputStream, connection classes in the JDK use this "technology", The following code is excerpted from the FileInputStream class[Java]View Plaincopy /** * Ensures that a * Called when there is no more references to it. * * @exception IOException If an I/O error occurs. * @see Java.io.fileinputstream#close () */ protected Void Finalize ()

audio devices, sound file readers andWriters, or audio format converters. Solution 3Use the sound class in Java 3D. This is an abstract definition of a sound resource. Each specific sound object can use the sound method. The class relationship of the sound class is as follows:Java. Lang. Object+-Javax. Media. j3d. scenegraphobject+-Javax. Media. j3d. Node+-Javax

The example in this article describes a method for Java to randomly generate a name and corresponding pinyin. Share to everyone for your reference. as follows: Package com.cn.wangk.util.name; Import Java.util.Random; Import Com.cn.wangk.util.StrTools; public class Chinesename {string[] sname = new string[95]; string[] Name = new string[79]; Private String Names; Private String Pid; Public