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Personal imitation SSM framework
2022-07-07 05:54:00 【Qingcheng】
Personal imitation SSM frame
1、Pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.wnx.mall.tiny</groupId>
<artifactId>web-my-ssm</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>web-my-ssm</name>
<description> Personal imitation SSM frame </description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!--servlet-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<!--junit-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>test</scope>
</dependency>
<!--mysql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.27</version>
</dependency>
<!--thymeleaf-->
<dependency>
<groupId>org.thymeleaf</groupId>
<artifactId>thymeleaf</artifactId>
<version>3.0.14.RELEASE</version>
</dependency>
<!--lombok-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.22</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>8</source>
<target>8</target>
<!-- Reflection can get the real method name -->
<compilerArgs>
<arg>-parameters</arg>
</compilerArgs>
</configuration>
</plugin>
</plugins>
</build>
</project>
2、Spring The configuration file
Put in resources\applicationContext.xml
<?xml version="1.0" encoding="utf-8"?>
<beans>
<bean id="pmsBrandMapper" class="com.wnx.mall.tiny.mapper.impl.PmsBrandMapperImpl"/>
<bean id="PmsBrandService" class="com.wnx.mall.tiny.service.impl.PmsBrandServiceImpl">
<property name="pmsBrandMapper" ref="pmsBrandMapper"/>
</bean>
<bean id="brand" class="com.wnx.mall.tiny.controller.PmsBrandController">
<property name="fruitService" ref="fruitService"/>
</bean>
</beans>
3、Web.xml To configure
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0">
<!-- Configure context parameters -->
<context-param>
<param-name>view-prefix</param-name>
<param-value>/</param-value>
</context-param>d
<context-param>
<param-name>view-suffix</param-name>
<param-value>.html</param-value>
</context-param>
<!--Spring The location of the configuration file -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>applicationContext.xml</param-value>
</context-param>
</web-app>
4、 Context load listener ContextLoaderListener
be responsible for Create... When the context starts IOC Containers , Then save it to application Scope
package com.wnx.myssm.mylistner;
import com.wnx.myssm.myioc.BeanFactory;
import com.wnx.myssm.myioc.ClassPathXmlApplicationContext;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
/** * Context load listener */
@WebListener
public class ContextLoaderListener implements ServletContextListener {
@Override
public void contextInitialized(ServletContextEvent sce) {
//1. Create... When the context starts IOC Containers , Then save it to application Scope
ServletContext application = sce.getServletContext();
String path = application.getInitParameter("contextConfigLocation");
BeanFactory beanFactory = new ClassPathXmlApplicationContext(path);
application.setAttribute("beanFactory",beanFactory);
}
@Override
public void contextDestroyed(ServletContextEvent sce) {
}
}
5、 Front controller DispatcherServlet
package com.wnx.myssm.mysrpingmvc;
import com.wnx.myssm.myioc.BeanFactory;
import com.wnx.myssm.utils.StringUtil;
import lombok.SneakyThrows;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Method;
import java.lang.reflect.Parameter;
/** * all *.do Your request will enter the Servlet!!! */
@WebServlet("*.do")
public class DispatcherServlet extends ViewBaseServlet {
private BeanFactory beanFactory ;
public DispatcherServlet(){
}
public void init() throws ServletException {
//1.Servlet At the bottom of the build, you will call Init() Method , Integrate ViewBaseServlet, Going to call ViewBaseServlet Of Init()
super.init();
//2. from application Scope to get IOC Containers
ServletContext application = getServletContext();
Object beanFactoryObj = application.getAttribute("beanFactory");
if(beanFactoryObj!=null){
beanFactory = (BeanFactory)beanFactoryObj ;
}else{
throw new RuntimeException("IOC Container acquisition failed ！");
}
}
@SneakyThrows
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1. obtain Bean ID
String servletPath = request.getServletPath();
servletPath = servletPath.substring(1);
int lastDotIndex = servletPath.lastIndexOf(".do") ;
servletPath = servletPath.substring(0,lastDotIndex);
//2. according to ID Take out of the container Bean
Object controllerBeanObj = beanFactory.getBean(servletPath);
//3. Get method name
String operate = request.getParameter("operate");
if(StringUtil.isEmpty(operate)){
operate = "index" ; }
Method[] methods = controllerBeanObj.getClass().getDeclaredMethods();
for (Method method : methods) {
//4. obtain Handler Method object
if (operate.equals(method.getName())) {
Parameter[] parameters = method.getParameters();
Object[] parameterValues = new Object[parameters.length];
//5. complete Controller Method parameter binding
for (int i = 0; i < parameters.length; i++) {
Parameter parameter = parameters[i];
String parameterName = parameter.getName();
if ("request".equals(parameterName)) {
parameterValues[i] = request;
} else if ("response".equals(parameterName)) {
parameterValues[i] = response;
} else if ("session".equals(parameterName)) {
parameterValues[i] = request.getSession();
} else {
String parameterValue = request.getParameter(parameterName);
String typeName = parameter.getType().getName();
Object parameterObj = parameterValue;
if (parameterObj != null) {
if ("java.lang.Integer".equals(typeName)) {
parameterObj = Integer.parseInt(parameterValue);
}
}
if (parameterObj != null) {
if ("java.lang.Long".equals(typeName)) {
parameterObj = Long.parseLong(parameterValue);
}
}
parameterValues[i] = parameterObj;
}
}
//6. Reflection execution method
method.setAccessible(true);
Object returnObj = method.invoke(controllerBeanObj, parameterValues);
//7. The view
String methodReturnStr = (String) returnObj;
if (methodReturnStr.startsWith("redirect:")) {
String redirectStr = methodReturnStr.substring("redirect:".length());
response.sendRedirect(redirectStr);
} else {
super.processTemplate(methodReturnStr, request, response);
}
}
}
}
}
6、 view resolver ViewBaseServlet
package com.wnx.myssm.mysrpingmvc;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.WebContext;
import org.thymeleaf.templatemode.TemplateMode;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class ViewBaseServlet extends HttpServlet {
private TemplateEngine templateEngine;
@Override
public void init() throws ServletException {
// 1. obtain ServletContext object
ServletContext servletContext = this.getServletContext();
// 2. establish Thymeleaf Parser object
ServletContextTemplateResolver templateResolver = new ServletContextTemplateResolver(servletContext);
// 3. Set parameters to the parser object
templateResolver.setTemplateMode(TemplateMode.HTML);
templateResolver.setPrefix(servletContext.getInitParameter("view-prefix"));
templateResolver.setSuffix(servletContext.getInitParameter("view-suffix"));
templateResolver.setCacheTTLMs(60000L);
templateResolver.setCacheable(true);
templateResolver.setCharacterEncoding("utf-8");
// 4. Create template engine object
templateEngine = new TemplateEngine();
// 5. Set the template parser for the template engine object
templateEngine.setTemplateResolver(templateResolver);
}
protected void processTemplate(String templateName, HttpServletRequest req, HttpServletResponse resp) throws IOException {
// 1. Set the content type and character set of the response body
resp.setContentType("text/html;charset=UTF-8");
// 2. establish WebContext object
WebContext webContext = new WebContext(req, resp, getServletContext());
// 3. Process template data
templateEngine.process(templateName, webContext, resp.getWriter());
}
}
7、IOC Container context ClassPathXmlApplicationContext
- abstract Bean factory
package com.wnx.myssm.myioc;
/** * Bean Build factory */
public interface BeanFactory {
Object getBean(String id);
}
- Realization ：ClassPathXmlApplicationContext
package com.wnx.myssm.myioc;
import com.wnx.myssm.utils.StringUtil;
import lombok.SneakyThrows;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;
public class ClassPathXmlApplicationContext implements BeanFactory {
private Map<String,Object> beanMap = new HashMap<>();
@SneakyThrows
public ClassPathXmlApplicationContext(){
this("applicationContext.xml");
}
@SneakyThrows
public ClassPathXmlApplicationContext(String path){
if(StringUtil.isEmpty(path)){
throw new RuntimeException("IOC The container's configuration file does not specify ..."); }
//1. according to Resource Under the table of contents applicationContext.xml, Construct document objects
InputStream inputStream = getClass().getClassLoader().getResourceAsStream(path);
DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder() ;
Document document = documentBuilder.parse(inputStream);
//2. Scan all Bean label
NodeList beanNodeList = document.getElementsByTagName("bean");
for(int i = 0 ; i<beanNodeList.getLength() ; i++){
Node beanNode = beanNodeList.item(i);
if(beanNode.getNodeType() == Node.ELEMENT_NODE){
//1. according to Bean label , Construct objects from reflections
Element beanElement = (Element)beanNode ;
String beanId = beanElement.getAttribute("id");
String className = beanElement.getAttribute("class");
Class beanClass = Class.forName(className);
Object beanObj = beanClass.newInstance() ;
//2. Deposit in Map Containers
beanMap.put(beanId , beanObj) ;
}
}
//3. assemble bean Dependencies between
for(int i = 0 ; i<beanNodeList.getLength() ; i++){
Node beanNode = beanNodeList.item(i);
if(beanNode.getNodeType() == Node.ELEMENT_NODE) {
Element beanElement = (Element) beanNode;
String beanId = beanElement.getAttribute("id");
NodeList beanChildNodeList = beanElement.getChildNodes();
for (int j = 0; j < beanChildNodeList.getLength() ; j++) {
//4. Take the dependent from the container Bean Inject into the dependent Bean in
Node beanChildNode = beanChildNodeList.item(j);
if(beanChildNode.getNodeType()==Node.ELEMENT_NODE && "property".equals(beanChildNode.getNodeName())){
Element propertyElement = (Element) beanChildNode;
String propertyName = propertyElement.getAttribute("name");
String propertyRef = propertyElement.getAttribute("ref");
Object refObj = beanMap.get(propertyRef);
Object beanObj = beanMap.get(beanId);
Class beanClazz = beanObj.getClass();
Field propertyField = beanClazz.getDeclaredField(propertyName);
propertyField.setAccessible(true);
propertyField.set(beanObj,refObj);
}
}
}
}
}
/** * according to ID obtain Bean * @param id ID * @return Bean */
@Override
public Object getBean(String id) {
return beanMap.get(id);
}
}
8、 Configure character encoding filter
package com.wnx.myssm.myfilter;
import com.wnx.myssm.utils.StringUtil;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
/** * Character encoding filter Filter *.do Request */
@WebFilter(urlPatterns = {
"*.do"},initParams = {
@WebInitParam(name = "encoding",value = "UTF-8")})
public class CharacterEncodingFilter implements Filter {
private String encoding = "UTF-8";
@Override
public void init(FilterConfig filterConfig) throws ServletException {
String encodingStr = filterConfig.getInitParameter("encoding");
if(StringUtil.isNotEmpty(encodingStr)){
encoding = encodingStr ;
}
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
((HttpServletRequest)servletRequest).setCharacterEncoding(encoding);
filterChain.doFilter(servletRequest,servletResponse);
}
@Override
public void destroy() {
}
}
9、 Persistence layer frame BaseMapper
package com.wnx.mall.tiny.mapper;
import com.wnx.myssm.mymapper.ConnUtil;
import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
public abstract class BaseMapper<T> {
private final String DRIVER = "com.mysql.cj.jdbc.Driver";
private final String URL = "jdbc:mysql://localhost:3306/mall?useUnicode=true&characterEncoding=utf-8&useSSL=false";
private final String USER = "root";
private final String PWD = "root" ;
private Connection conn ;
private PreparedStatement psmt ;
private ResultSet rs ;
private Class entityClass ;
public BaseMapper(){
//1. Get program runtime ,T The type of actual reference .
Type genericType = getClass().getGenericSuperclass();
Type[] actualTypeArguments = ((ParameterizedType) genericType).getActualTypeArguments();
Type actualType = actualTypeArguments[0];
// 2. Construct the T Class object of
try {
entityClass = Class.forName(actualType.getTypeName());
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
/** * Get database connection * @return A database connection */
private Connection getConn(){
return ConnUtil.getConn();
}
/** * Release database related resources * @param rs Result set object * @param psmt Precompiled statement object * @param conn Database connection */
private void close(ResultSet rs, PreparedStatement psmt, Connection conn){
try {
if (rs != null) {
rs.close();
}
if(psmt!=null){
psmt.close();
}
if(conn!=null && !conn.isClosed()){
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
/*** * Placeholders for preprocessing statement objects ? Set parameters * @param psmt Preprocess the statement object * @param params Parameters * @throws SQLException SQL abnormal */
private void setParams(PreparedStatement psmt , Object... params) throws SQLException {
if(params!=null && params.length>0){
for (int i = 0; i < params.length; i++) {
psmt.setObject(i+1,params[i]);
}
}
}
/*** * Perform database update operation * @param sql Database operation SQL * @param params Update parameters * @return Rows affected */
protected int executeUpdate(String sql , Object... params){
boolean insertFlag = false ;
try {
conn = getConn();
psmt = conn.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);
setParams(psmt,params);
int count = psmt.executeUpdate() ;
rs = psmt.getGeneratedKeys();
if(rs.next()){
return ((Long)rs.getLong(1)).intValue();
}
return count ;
} catch (SQLException e) {
e.printStackTrace();
}finally {
close(rs,psmt,conn);
}
return 0;
}
/** * Give... By reflection technology obj Object's property Attribute propertyValue value * @param obj object model * @param property model Field * @param propertyValue model value */
private void setValue(Object obj , String property , Object propertyValue){
//1. Get the class of the object
Class clazz = obj.getClass();
try {
//2. Get the member variable according to the member variable name
Field field = clazz.getDeclaredField(property);
//3. Reflection assignment
if(field!=null){
field.setAccessible(true);
field.set(obj,propertyValue);
}
} catch (Exception e) {
e.printStackTrace();
}
}
/** * Execute complex queries , Returns, for example, statistical results * @param sql Database operation SQL * @param params Update parameters * @return An array of objects */
protected Object[] executeComplexQuery(String sql , Object... params){
try {
//1. Execute the query
conn = getConn() ;
psmt = conn.prepareStatement(sql);
setParams(psmt,params);
rs = psmt.executeQuery();
//2. Construct column containers
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
Object[] columnValueArr = new Object[columnCount];
//3. The query results are put into the column container
if(rs.next()){
for(int i = 0 ; i<columnCount;i++){
Object columnValue = rs.getObject(i+1);
columnValueArr[i]=columnValue;
}
//4. Return column container
return columnValueArr ;
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
close(rs,psmt,conn);
}
return null ;
}
/** * Execute the query , Returns a single entity object * @param sql Database operation SQL * @param params Query parameters * @return Entity Model */
protected T load(String sql , Object... params){
try {
//1. Query operation
conn = getConn() ;
psmt = conn.prepareStatement(sql);
setParams(psmt,params);
rs = psmt.executeQuery();
//2. Object Assignment
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
if(rs.next()){
T entity = (T)entityClass.newInstance();
for(int i = 0 ; i<columnCount;i++){
String columnName = rsmd.getColumnName(i+1);
//3. The transformation of hump naming
while (columnName.contains("_")) {
int index = columnName.indexOf("_");
String target = columnName.substring(index + 1, index + 2);
columnName = columnName.replace(("_" + target), target.toUpperCase());
}
Object columnValue = rs.getObject(i+1);
setValue(entity,columnName,columnValue);
}
//3. Returns the object
return entity ;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
close(rs,psmt,conn);
}
return null ;
}
/*** * Execute the query , return List * @param sql Database operation SQL * @param params Query parameters * @return Set of entities List */
protected List<T> executeQuery(String sql , Object... params){
List<T> list = new ArrayList<>();
try {
//1. Execute the query
conn = getConn() ;
psmt = conn.prepareStatement(sql);
setParams(psmt,params);
rs = psmt.executeQuery();
//2. Object Assignment
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
while(rs.next()){
T entity = (T)entityClass.newInstance();
for(int i = 0 ; i<columnCount;i++){
String columnName = rsmd.getColumnName(i+1);
//3. The transformation of hump naming
while (columnName.contains("_")) {
int index = columnName.indexOf("_");
String target = columnName.substring(index + 1, index + 2);
columnName = columnName.replace(("_" + target), target.toUpperCase());
}
Object columnValue = rs.getObject(i+1);
setValue(entity,columnName,columnValue);
}
//4. Add to collection
list.add(entity);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
close(rs,psmt,conn);
}
//5. Back to the assembly
return list ;
}
}
10、 Transaction control TransactionManager
package com.wnx.myssm.mytransaction;
import com.wnx.myssm.mymapper.ConnUtil;
import java.sql.Connection;
import java.sql.SQLException;
public class TransactionManager {
// Open transaction
public static void beginTrans() throws SQLException {
ConnUtil.getConn().setAutoCommit(false);
}
// Commit transaction
public static void commit() throws SQLException {
Connection conn = ConnUtil.getConn();
conn.commit();
ConnUtil.closeConn();
}
// Roll back the transaction
public static void rollback() throws SQLException {
Connection conn = ConnUtil.getConn();
conn.rollback();
ConnUtil.closeConn();
}
}
11、 Thread knowledge
Use a connection Connection To say things , One request corresponds to one thread . Rewrite the get database connection class
- ConnUtil
package com.wnx.myssm.mymapper;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class ConnUtil {
private static ThreadLocal<Connection> threadLocal = new ThreadLocal<>();
private static final String DRIVER = "com.mysql.cj.jdbc.Driver";
private static final String URL = "jdbc:mysql://localhost:3306/javaweb?useUnicode=true&characterEncoding=utf-8&useSSL=false&allowPublicKeyRetrieval=true";
private static final String USER = "root";
private static final String PWD = "root";
/** * Create database connection * @return Back to database connection */
private static Connection createConn() {
try {
Class.forName(DRIVER);
return DriverManager.getConnection(URL, USER, PWD);
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
return null;
}
/** * Get database connection * @return Database connection */
public static Connection getConn() {
//1. If there is a connection with a local thread , Create a .
Connection conn = threadLocal.get();
if (conn == null) {
conn = createConn();
threadLocal.set(conn);
}
return threadLocal.get();
}
/** * Close database connection * @throws SQLException SQL abnormal */
public static void closeConn() throws SQLException {
Connection conn = threadLocal.get();
if(conn==null){
return ;
}
if(!conn.isClosed()){
conn.close();
threadLocal.set(null);
}
}
}
Once something goes wrong , Let the current database connection rollback immediately .
- OpenSessionInViewFilter
package com.wnx.myssm.myfilter;
import com.wnx.myssm.mytransaction.TransactionManager;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;
import java.sql.SQLException;
@WebFilter("*.do")
public class OpenSessionInViewFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
try{
TransactionManager.beginTrans();
System.out.println(" Open transaction ....");
filterChain.doFilter(servletRequest, servletResponse);
TransactionManager.commit();
System.out.println(" Commit transaction ...");
}catch (Exception e){
e.printStackTrace();
try {
TransactionManager.rollback();
System.out.println(" Roll back the transaction ....");
} catch (SQLException ex) {
ex.printStackTrace();
}
}
}
@Override
public void destroy() {
}
}
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原生小程序 之 input切换 text与password类型
cf：C. Column Swapping【排序 + 模拟】
PTA 天梯赛练习题集 L2-004 搜索树判断
Red hat install kernel header file
往图片添加椒盐噪声或高斯噪声
Hcip seventh operation
Paper reading [MM21 pre training for video understanding challenge:video captioning with pre training techniqu]
线性回归
Opensergo is about to release v1alpha1, which will enrich the service governance capabilities of the full link heterogeneous architecture
产业金融3.0：“疏通血管”的金融科技
《HarmonyOS实战—入门到开发，浅析原子化服务》
bat 批示处理详解
Randomly generate session_ id
话说SQLyog欺骗了我！
[daily training -- Tencent selected 50] 235 Nearest common ancestor of binary search tree
驱动开发中platform设备驱动架构详解