springboot学习笔记一

application.properties中的属性

local.ip=192.168.1.118local.port=8080#配置的引入name=springbootapp.name=this is ${name}ds.url=jdbc:mysql://localhost:3306/testds.driver=com.mysql.jdbc.Driverds.username=rootds.password=root#注入集合list.hosts[0]=192.168.1.2list.hosts[1]=192.168.1.3list.hosts[2]=192.168.1.4

读取application.properties中属性的方式

package da.test;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Value;import org.springframework.core.env.Environment;import org.springframework.stereotype.Component;@Componentpublic class UserConifg {    @Autowired    private Environment env;    @Value("${local.port}")    private String localPort;    // 可以类型转换    @Value("${local.port}")    private Integer localPort2;    // 直接赋值 不用在配置里面    // @Value默认要有配置项，配置项可以为空，如果没有配置项，则可以给默认值    @Value("${tomcat.port:9090}")    private String tomcatPort;    // 测试获取application.properties的值    public void show() {        System.out.println("local ip=" + env.getProperty("local.ip"));        // 类型转换成Integer型        System.out.println("local port=" + env.getProperty("local.port", Integer.class));        System.out.println("local port=" + localPort);        System.out.println("local port=" + localPort2);        System.out.println("name=" + env.getProperty("name"));        System.out.println("appname=" + env.getProperty("app.name"));        System.out.println("tomcat port=" + tomcatPort);        // 下面的为null        // System.out.println("tomcat port=" + env.getProperty("tomcat.port"));    }}

读取application.properties中的属性，并转换为集合形式

package da.test;import java.util.ArrayList;import java.util.List;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.stereotype.Component;/** * private List<String> hosts声明的名字要和list.hosts[0]的名字对应 */@Component@ConfigurationProperties("list")public class CollectionConfig {    private List<String> hosts = new ArrayList<>();    public void show() {        System.out.println("=============CollectionConfig===============");        System.out.println("hosts=" + hosts);    }    public List<String> getHosts() {        return hosts;    }    public void setHosts(List<String> hosts) {        this.hosts = hosts;    }}

读取带前缀的属性，通过set方法自动注入

package da.test;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.stereotype.Component;@Component@ConfigurationProperties(prefix = "ds")public class DsConfig {    private String url;    private String driver;    private String username;    private String password;    public void show() {        System.out.println("=============DsConfig=============");        System.out.println("url=" + url);        System.out.println("driveClass=" + driver);        System.out.println("username=" + username);        System.out.println("password=" + password);    }    public String getUrl() {        return url;    }    public void setUrl(String url) {        this.url = url;    }    public String getDriver() {        return driver;    }    public void setDriver(String driver) {        this.driver = driver;    }    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getPassword() {        return password;    }    public void setPassword(String password) {        this.password = password;    }}

读取application.properties配置的方式1

package da.test;import org.springframework.beans.factory.annotation.Value;import org.springframework.context.annotation.PropertySource;import org.springframework.stereotype.Component;/** * @PropertySource 可以加载一个外部配置，同时写几个可以加多个外部配置 */@Component@PropertySource("classpath:config/db.properties")// @PropertySource("file:/e:/temp/db.properties")public class DbConfig {    @Value("${db.url}")    private String url;    @Value("${db.class}")    private String driveClass;    public void show() {        System.out.println("=============DbConfig=============");        System.out.println("url=" + url);        System.out.println("driveClass=" + driveClass);    }}

读取application.properties配置的方式2
说明：这里的application.properties改名为app.properties了

启动测试文件

package da.test;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.context.ConfigurableApplicationContext;/** *  * 默认的配置的名字可以通过--spring.config.name来指定，只需要指定文件的名字，不需要指定拓展的后缀 * * 默认的配置的路径可以通过--spring.config.location来指定。比如：--spring.config.location=classpath * :config/application.properties */@SpringBootApplicationpublic class Springboot01Application {    public static void main(String[] args) {        ConfigurableApplicationContext context = SpringApplication.run(Springboot01Application.class, args);        context.getBean(UserConifg.class).show();        context.getBean(DbConfig.class).show();        context.getBean(DsConfig.class).show();        context.getBean(CollectionConfig.class).show();    }}