Programmer Think

JDBC overview Data persistence Persistence: save data to a power down storage device for later use. In most cases, especially for enterprise applications, data persistence means saving the data in memory to the hard disk for "solidification", and the implementation process of persistence is mostly completed through various relat ...

Maven Eclipse Eclipse provides a good plug-in   m2eclipse   , the plug-in can integrate Maven and Eclipse. Maven is included in the latest Eclipse. Let's open windows - > preferences. If so, the following screen will appear: Here are some features of m2eclipse: You can run Maven's target files on the Eclipse environment.You can ...

inherit Commonness extraction In inheritance, a subclass is a parent, that is, a subclass can be treated as a parent For example, the parent class is an employee, the child class is a lecturer, and the lecturer is an employee Define parent class: (the definition of ordinary class is the same) public class parent class name{ //...... } D ...

catalogue 1, Problem description 2, Specific code 3, Specific operation 1, Problem description Merge multiple input files, eliminate the duplicate contents, and output the duplicated contents to one file.         Main idea: according to the process characteristics of reduce, the input value set will be automatically ...

IO flow learning (II) - the overall framework and use of IO flow Stream operation I/O is the abbreviation of input/output, that is, the data transmission between processing devices, and the transmission process is called "flow"; And java provides standard methods to read and write data, and the input and output is for programs ( ...

① Traversal mode and concept of binary tree Preorder traversal: traverse according to the head left right method, first output the head, then output the left, and finally output the right.                 According to the above figure, the preceding traversal should ...

1. Team members and task assignment classfull nametaskNetwork 2014LAN suyuResponsible for coding related work: coding specification, object-oriented design, function designNetwork 2014Liu YuhengResponsible for writing blog related work: preliminary investigation, blog production 2. Preliminary investigation (taking Jingdong Mall interface ...

JavaDay04 Java environment construction JDK download and installation Uninstall the original environment and configure the JDK Delete the original environment variable, system – > environment variable – > java_ Home file location where the value is found – > delete – > then delete the environment variable ...

try catch finally For all java developers, closing resources in a finally block of code is a familiar approach. Part of exception handling is to ensure that all kinds of resources in the code block are closed and effectively released. Once the code in the try catch statement block throws an exception, the previous workflow will change. try { ...

Implementation of multithreading 1. Inherit Thread class     (1) define a class to inherit Thread and override the run() method;     (2) create subclass objects of Thread class;     (3) call start() to start a new thread. //The main thread and the custom thread execute concurrently public class th ...