Spring Boot命令行启动添加参数的三种方式

java -jar xxx.jar --server.port=8081

java -jar xxx.jar abc def

java -jar -Dserver.port=8081 xxx.jar

@Component
public class ComponentDB {
    @Autowired
    private ApplicationArguments applicationArguments;
    public final  String driverClassName = "com.mysql.cj.jdbc.Driver";
    //private final  String url = "jdbc:mysql://localhost:3306/test?serverTimezone=Asia/Shanghai&useSSL=false&allowPublicKeyRetrieval=true";
    @Bean
    DataSource dataSource(){
        System.out.println("# 非选项参数数量: " + applicationArguments.getNonOptionArgs().size());
        System.out.println("# 选项参数数量: " + applicationArguments.getOptionNames().size());
        System.out.println("# 非选项参具参数:");
        applicationArguments.getNonOptionArgs().forEach(System.out::println);
        System.out.println("# 选项参数具体参数:");
        applicationArguments.getOptionNames().forEach(optionName ->{
            System.out.println("--" + optionName + "=" + applicationArguments.getOptionValues(optionName));
        });
        System.out.println("**************************");
        String dbUrl = applicationArguments.getOptionValues("url").get(0);
        String url = "jdbc:mysql://"+dbUrl+"?serverTimezone=Asia/Shanghai&useSSL=false&allowPublicKeyRetrieval=true";
        String name = applicationArguments.getOptionValues("name").get(0);
        String pass = applicationArguments.getOptionValues("pass").get(0);
        return DataSourceBuilder.create()
                .url(url)
                .username(name)
                .password(pass)
                .driverClassName(driverClassName).build();
    }
}

java -jar springboottest-0.0.1-SNAPSHOT.jar --url=localhost:3306/test --name=root --pass=root aaa bbb

@RestController
public class TestController {
    @Value("${server.port}")
    private String serverPort;
}

String systemServerPort = System.getProperty("server.port");

public interface ApplicationArguments {  
/**  * 原始参数数组（未经过处理的参数）  */  
String[] getSourceArgs();  
/**  * 选项参数名称  */  
Set<String> getOptionNames(); 
/**  * 根据名称校验是否包含选项参数  */  
boolean containsOption(String name);  
/**  * 根据名称获得选项参数  */  
List<String> getOptionValues(String name);  
/**  * 获取非选项参数列表  */  
List<String> getNonOptionArgs();
}
 

public ConfigurableApplicationContext run(String... args) { 
 try {    ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);    // ...    prepareContext(context, environment, listeners, // ...  } catch (Throwable ex) {    // ...  }  return context;}

public class DefaultApplicationArguments implements ApplicationArguments {
    private final Source source;
    private final String[] args;
    public DefaultApplicationArguments(String... args) {
        Assert.notNull(args, "Args must not be null");
        this.source = new Source(args);
        this.args = args;
    }
    public String[] getSourceArgs() {
        return this.args;
    }
    public Set<String> getOptionNames() {
        String[] names = this.source.getPropertyNames();
        return Collections.unmodifiableSet(new HashSet(Arrays.asList(names)));
    }
    public boolean containsOption(String name) {
        return this.source.containsProperty(name);
    }
    public List<String> getOptionValues(String name) {
        List<String> values = this.source.getOptionValues(name);
        return values != null ? Collections.unmodifiableList(values) : null;
    }
    public List<String> getNonOptionArgs() {
        return this.source.getNonOptionArgs();
    }
    private static class Source extends SimpleCommandLinePropertySource {
        Source(String[] args) {
            super(args);
        }
        public List<String> getNonOptionArgs() {
            return super.getNonOptionArgs();
        }
        public List<String> getOptionValues(String name) {
            return super.getOptionValues(name);
        }
    }
}

public SimpleCommandLinePropertySource(String... args) {
		super(new SimpleCommandLineArgsParser().parse(args));
	}

public CommandLineArgs parse(String... args) {
		CommandLineArgs commandLineArgs = new CommandLineArgs();
		for (String arg : args) {
			if (arg.startsWith("--")) {
				String optionText = arg.substring(2);
				String optionName;
				String optionValue = null;
				int indexOfEqualsSign = optionText.indexOf('=');
				if (indexOfEqualsSign > -1) {
					optionName = optionText.substring(0, indexOfEqualsSign);
					optionValue = optionText.substring(indexOfEqualsSign + 1);
				}
				else {
					optionName = optionText;
				}
				if (optionName.isEmpty()) {
					throw new IllegalArgumentException("Invalid argument syntax: " + arg);
				}
				commandLineArgs.addOptionArg(optionName, optionValue);
			}
			else {
				commandLineArgs.addNonOptionArg(arg);
			}
		}
		return commandLineArgs;
	}

private void prepareContext(ConfigurableApplicationContext context, ConfigurableEnvironment environment,SpringApplicationRunListeners listeners, ApplicationArguments applicationArguments, Banner printedBanner) 
{  // ...  
ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();  
// 通过beanFactory将ApplicationArguments的对象注入Spring容器  beanFactory.registerSingleton("springApplicationArguments", applicationArguments);  
// ...}