Developing enterprise applications based on SpringBoot
1. Set up the enterprise application development environment
- Application architecture: MVC architecture
- Vue realization of front desk development (focus on data display, overall [US])
- Background: SpringBoot (focusing on providing API interface for data access)
- ORM framework: MyBatis Plus
- Data source framework: Druid
- Unit tests: junit
- Build tool: Maven
- The JDK: 1.8
- Runnable package: JAR
2.SpringBoot develops enterprise applications
2.1 New Construction project
2.2 Complete configuration files
pom.xml
Maven does not download dependencies (occasionally)
Reconfigure the remote warehouse in the poM file of the current project
<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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.2</version>
<relativePath/> <! -- lookup parent from repository -->
</parent>
<groupId>cn.com.chinahitech</groupId>
<artifactId>bjmarket</artifactId>
<version>0.0.1 - the SNAPSHOT</version>
<name>bjmarket</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<! Maven repository = maven repository = maven repository = maven repository = maven repository
<repositories>
<repository>
<id>ali-maven</id>
<url>http://maven.aliyun.com/nexus/content/groups/public</url>
<releases>
<enabled>true</enabled>
</releases>
<snapshots>
<enabled>true</enabled>
<updatePolicy>always</updatePolicy>
<checksumPolicy>fail</checksumPolicy>
</snapshots>
</repository>
<repository>
<id>central</id>
<name>Maven Repository Switchboard</name>
<layout>default</layout>
<url>http://repo1.maven.org/maven2</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
<! -- Configure project dependencies -->
<dependencies>
<! -- spring-boot-starter -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<! -- spring boot web -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<! - thymeleaf template - >
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<! -- spring-boot-devtools -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<! Add constructor /setter/getter to entity class runtime -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<! Json object support -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.71</version>
</dependency>
<! -- mybatis plus -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.3.0</version>
</dependency>
<! -- MySQL driver -->
<! -- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.18</version>
</dependency>
<! Druid -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.20</version>
</dependency>
<! -- Use freemarker in code generator -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-freemarker</artifactId>
<version>2.2.2. RELEASE</version>
</dependency>
<! Mybatis -plus -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-generator</artifactId>
<version>3.3.0</version>
</dependency>
<! -- Junit Unit Test -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Copy the codeChange application.properties from the resource file to Application.yml
The 8080 port can be modified by default
server:
port: 8081
spring:
# alias
application:
name: market
aop:
proxy-target-class: true
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.cj.jdbc.Driver
url: JDBC: mysql: / / 192.168.0.104:3306 / market? allowPublicKeyRetrieval=true&useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai&useSSL=false
username: root
password: ROOTroot_1
druid:
validation-query: SELECT 1 FROM DUAL
# initialize the number of connections allocated
initial-size: 10
Retract the connection after 10s with no operation
min-idle: 10
It can hold up to 200 connections at a time
max-active: 200
min-evictable-idle-time-millis: 300000
test-on-borrow: false
test-while-idle: true
time-between-eviction-runs-millis: 30000
pool-prepared-statements: true
max-open-prepared-statements: 100
mybatis-plus:
The package name must be the same as the package name under Java
type-aliases-package: cn.com.chinahitech.bjmarket.*.entity
global-config:
db-config:
id-type: auto
logic-delete-field: flag
logic-delete-value: 1
logic-not-delete-value: 0
configuration:
map-underscore-to-camel-case: true
cache-enabled: false
jdbc-type-for-null: 'null'
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
# config log
logging:
config:
classpath: logback.xml
Copy the codeCreate the log configuration file logback.xml in the resources folder
<configuration>
<! -- Log format -->
<property name="LOG_PATTERN"
value="%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} -%msg%n" />
<property name="LOG_LEVEL" value="INFO"/>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>${LOG_PATTERN}</pattern>
</encoder>
<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
<level>${LOG_LEVEL}</level>
</filter>
</appender>
<root level="${LOG_LEVEL}">
<appender-ref ref="STDOUT" />
</root>
</configuration>
Copy the code2.3 Importing the Database to Linux
- XFTP upload
- Creating an empty database
- The source command initializes the script
2.4 Use automatic code generation tools
CodeGenerator
Add dependencies and write configurations
Website: baomidou.com/guide/gener…
The configured file given by the teacher: Put it in the Util bag
package cn.com.chinahitech.bjmarket.util;
import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.InjectionConfig;
import com.baomidou.mybatisplus.generator.config.*;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class CodeGenerator {
/** * * read the console contents *
*/
public static String scanner(String tip) {
Scanner scanner = new Scanner(System.in);
StringBuilder help = new StringBuilder();
help.append("Please enter" + tip + "：");
System.out.println(help.toString());
if (scanner.hasNext()) {
String ipt = scanner.next();
if (StringUtils.isNotBlank(ipt)) {
returnipt; }}throw new MybatisPlusException("Please enter the correct one" + tip + "！");
}
public static void main(String[] args) {
// Code generator
AutoGenerator mpg = new AutoGenerator();
// Global configuration
GlobalConfig gc = new GlobalConfig();
String projectPath = System.getProperty("user.dir");
gc.setOutputDir(projectPath + "/src/main/java");
gc.setAuthor("sunjie");
gc.setOpen(false);
mpg.setGlobalConfig(gc);
// Data source configuration
DataSourceConfig dsc = new DataSourceConfig();
dsc.setUrl("JDBC: mysql: / / 192.168.0.104:3306 / market? allowPublicKeyRetrieval=true&useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai&useSSL=false");
dsc.setDriverName("com.mysql.cj.jdbc.Driver");
dsc.setUsername("root");
dsc.setPassword("ROOTroot_1");
mpg.setDataSource(dsc);
/ / package configuration
PackageConfig pc = new PackageConfig();
pc.setModuleName(scanner("Please enter the module name"));
pc.setParent("cn.com.chinahitech.bjmarket");
mpg.setPackageInfo(pc);
// Custom configuration
InjectionConfig cfg = new InjectionConfig() {
@Override
public void initMap(a) {
// to do nothing}};// If the template engine is freemarker
String templatePath = "/templates/mapper.xml.ftl";
// Customize the output configuration
List<FileOutConfig> focList = new ArrayList<>();
// Custom configurations are printed first
focList.add(new FileOutConfig(templatePath) {
@Override
public String outputFile(TableInfo tableInfo) {
// Customize the output file name. If your Entity has a prefix or suffix, note that the XML name will change accordingly!!
return projectPath + "/src/main/resources/mapper/" + pc.getModuleName()
+ "/" + tableInfo.getEntityName() + "Mapper"+ StringPool.DOT_XML; }}); cfg.setFileOutConfigList(focList); mpg.setCfg(cfg);// Configure the template
TemplateConfig templateConfig = new TemplateConfig();
templateConfig.setXml(null);
mpg.setTemplate(templateConfig);
// Policy configuration
StrategyConfig strategy = new StrategyConfig();
strategy.setNaming(NamingStrategy.underline_to_camel);
strategy.setColumnNaming(NamingStrategy.underline_to_camel);
strategy.setEntityLombokModel(true);
strategy.setRestControllerStyle(true);
strategy.setInclude(scanner("Table name, separated by multiple Commas").split(","));
strategy.setControllerMappingHyphenStyle(true);
strategy.setTablePrefix("t_");
mpg.setStrategy(strategy);
mpg.setTemplateEngine(newFreemarkerTemplateEngine()); mpg.execute(); }}Copy the codeAfter the execution:
The module name refers to the name of the automatically generated folder.
Table names refer to the database tables involved.
Generally speaking, a module is generated for each table
Automatic generation:
The Mapper layer is the Dao layer
3. Statistics on the proportion of big data jobs in major cities
The t_PIE table above is the table placed in SQL after big data analysis
Our goal is to export this data in JSON format from the background for the foreground to call and display.
Through the above code generation and a series of operations, we have set up the background framework, the rest of the time to improve the code.
3.1 Not front and background separation
There are both front and back ends in the same project
The background
The Entity and Mapper layers are nicely generated and we don’t need to move them.
What we need to improve is the Service layer and the Controller layer.
The Controller layer calls the Service layer, which calls the Mapper layer, which accesses the database
The service layer
The Service layer calls the Mapper layer.
“Interface”
public interface IPieService extends IService<Pie> {
/** * Query all big data job information *@return* /
List<Pie> getCityDatas(a);
}
Copy the code“Implementation”
@Service
public class PieServiceImpl extends ServiceImpl<PieMapper.Pie> implements IPieService {
@Resource
private PieMapper pieMapper;
@Override
// Access the database to execute the query
public List<Pie> getCityDatas(a) {
//1 encapsulates the QueryWrapper object
QueryWrapper<Pie> wrapper=new QueryWrapper<>();
//2 Perform query
List<Pie> pieList=pieMapper.selectList(wrapper);
returnpieList; }}Copy the codeThe controller layer
The Controller layer calls the Service layer
@RestController
@RequestMapping("/pie")
public class PieController {
@Resource
private IPieService pieService;
@RequestMapping(value = "/getCityData")
@ResponseBody
public String getCityData(a){
Map<String,Object> map=new HashMap<>();
try {
// 1 calls the service layer to perform the query
List<Pie> cityDatas = pieService.getCityDatas();
//2 Data is encapsulated successfully
map.put("status"."200");
map.put("data",cityDatas);
}catch (Exception e){
//2 Failed to encapsulate data
map.put("status"."500");
map.put("errorMsg"."Error:"+e.getMessage());
}
// Return the package as Jason data
returnJSON.toJSONString(map); }}Copy the codeModify the main class
The main class is now:
@SpringBootApplication
@MapperScan("cn.com.chinahitech.bjmarket.*.mapper")// To add a packet sweep declaration, scan all mapper, namely the DAO package
public class BjmarketApplication {
public static void main(String[] args) { SpringApplication.run(BjmarketApplication.class, args); }}Copy the coderun
The port is 8081. The goal behind the scenes is to get json data
As I provide an address: http://localhost:8081/pie/getCityData (interface)
You can call this address and get the corresponding JSON data
The front desk to show
Template page: Place it under Template
It needs to be called by Controller
Configure static js
-
Put pie.html in the template directory
-
Put the js file in the static directory
Create a new js file in the static directory of the resource directory and put the js file in it
Controller is changed to display page
@Controller
@RequestMapping("/pie")
public class PieController {
// omit existing code
@RequestMapping(value="/show")
public String show(a){
return "pie"; //pie is the name of the pie.html page}}Copy the codeDelete the target generated last time before testing, otherwise the previous code will be executed. * * * *
Test results:
3.2 Separation of front and background
To separate the front from the back, we do not need the pages in the template directory or the js in the static directory.
That is to say, the above project does not do anything about the foreground, is a pure background, meaning is to give you an address, you can get data from.
So the foreground developer can use WebStorm to create a foreground project.
The final compilation will also result in such a file
- Backend program: BjMarket (SpringBoot+MyBatis Plus) — IDEA
- Front-end program: Piesite (Vue based on Ajax implementation) – WebSTORM
Resolve cross-domain access issues
No longer in the same project no cross domain means the same IP and port
Execute pie.html alone
No pie chart appears.
How to solve
Controller in the back end
Add the cross domain access annotation @crossorigin to the Controller class
Exceptions are origin’s problem
@Controller
@RequestMapping("/pie")
@CrossOrigin<----------------- add comments -------->public class PieController {
@Resource
private IPieService pieService;
@RequestMapping(value = "/getCityData")
@ResponseBody
public String getCityData(a){
Map<String,Object> map=new HashMap<>();
try{...Copy the codeRestarting the service
Note: The port is occupied
Type the command in the command window: netstat – ano | findstr searches, 8080 (8080 into their occupied ports),
Then enter the command to stop the process: Taskkill/PID 14076 /f To stop the process one by one. This method is more troublesome, the following is simple.
The test results
The deployment of
SpringBoot daemon package –jar
Double click package (you may want to delete the Java files in the test folder before packaging, otherwise it may make an error)
