linker and loader

Java is designed primarily for the embedded domain, for some of the custom classes, consider using the load-on-demand principle, that is, when the program is used to load the class, saving memory consumption, the class loader can be loaded dynamically.If you're just doing web development, you'll rarely have to deal with ClassLoader, but it's essential if you want to learn more about the architecture of the Tomcat server. The so-called ClassLoader, whi

Restart LoaderWhen you use initLoader (), if the loader with the specified ID already exists, it uses this loader. if it does not exist, it will create a new one. but sometimes you want to discard the old data and start new data.To discard old data, you should use restartLoader (). for example, the following SearchView. the implementation of OnQueryTextListener restarts the

Java class loader and parent-parent Delegation Model, java Delegation Class and Class Loader Although the class loader is only used for loading actions of classes, its role in Java programs is far from limited to the class loading stage. for any class, the class loader that loads it needs to establish its The uniquenes

Website address: https://tomcat.apache.org/tomcat-6.0-doc/class-loader-howto.html#Class_Loader_Definitions Class Loader Definitions As indicated in the diagram above, Tomcat 6 creates the following class loaders as it is initialized:As shown in the chart above, Tomcat6 creates the ClassLoader in the following order when initializing: Bootstrap-this class loader c

Oracle SQL * Loader Features analysis Features: SQL * Loader loads data from external files into tables of an Oracle database. it has a powerful data parsing engine that puts little limitation on the format of the data in the datafile. you can use SQL * Loader to do the following: ■ Load data into ss a network. this means that you can run the SQL *

1. System Boot Process:1) Load BIOS hardware information and self-test, and obtain the first bootable device according to the setting2) Read and execute the boot Loader (i.e. Grub,spfdisk, etc.) of the MBR in the first boot device3) Load Kernel,kernerl will start to detect hardware information and load driver based on boot loader settings4) After the hardware driver is successful, kernel will actively call

The virtual machine design team takes the "fully qualified name of a class to obtain a binary byte stream (that is, bytecode) that describes this class" in the class-loading phase, which is implemented outside the Java virtual machine, so that the application can decide for itself how to get the required class. The code module that implements this action is called the class loader. In general, Java virtual machines use Java classes in the following wa

Oracle SQL * Loader architecture 1. SQL * Loader architecture SQL * Loader controls the description of the entire load by an input control file, one or more data files are used as raw data, its detailed composition structure includes Input Datafiles --> Loader Control file, the original data File loaded to the database

Basic concepts of Class Loaders:As the name implies, the ClassLoader (class loader) is used to dynamically load Java classes into a Java virtual machine. This means that when a program needs a class, the ClassLoader adds two of that class to the virtual machine.The tree-like structure of the ClassLoaderThe ClassLoader in Java can be broadly divided into two categories, one for the system, the other for Java application developers. There are three main

Java class is loaded into memory only when needed, and executed by the execution engine of the Java Virtual machine, and the execution engine is divided into four main ways of execution,The first, one-time interpretation of the code, that is, when the bytecode is reproduced in memory, every need will be re-parsed once,Second, instant parsing, which is reproduced into the memory of the bytecode will be parsed cost of machine code, and cached to improve reusability, but more memory consumption,Thi