Properties in Spring

Properties Injection

• Through XML configuration
• by @PropertySource Configuration
• Propertyplaceholderconfigurer
• Propertysourcesplaceholderconfigurer

Use of Properties

• Using in an XML configuration file
• Using @Value Injection
• Get through environment
• Get through Application.properties

Spring Boot Related

• @ConfigurationProperties
• Configuration priority

The Properties configuration is configured through XML

<context:property-placeholder location ="classpath:sys.properties" />

by @PropertySource Configuration

@PropertySource ("Classpath:sys.properties") @Configurationpublic class Democonfig {}

@PropertySource must be used in conjunction with @Configuration here.

Propertyplaceholderconfigurer

<bean class= "Org.springframework. beans.factory . config. Propertyplaceholderconfigurer ">    <property name=" Locations ">        <list>            <value> classpath:sys.properties</value>        </list>    </property>    <property name= " Ignoreunresolvableplaceholders "value=" true "/>      <!--Here you can configure some properties--></bean>

Java Configuration version

@Beanpublic propertyplaceholderconfigurer propertiess () {    Propertyplaceholderconfigurer PPC = new Propertyplaceholderconfigurer ();    resource[] Resources = new Classpathresource[]{new Classpathresource ("Sys.properties")};    Ppc.setlocations (resources);    Ppc.setignoreunresolvableplaceholders (true);    return PPC;}

Propertysourcesplaceholderconfigurer

<bean class= "Org.springframework. Context.support. Propertysourcesplaceholderconfigurer ">    <property name=" Locations ">        <list>            <value >classpath:sys.properties</value>        </list>    </property>    <property name= " Ignoreunresolvableplaceholders "value=" true "/>    <!--Here you can configure some properties--></bean>

Java Configuration version

@Beanpublic Propertysourcesplaceholderconfigurer Properties () {    Propertysourcesplaceholderconfigurer pspc = new Propertysourcesplaceholderconfigurer ();    resource[] Resources = new Classpathresource[]{new Classpathresource ("Sys.properties")};    Pspc.setlocations (resources);    Pspc.setignoreunresolvableplaceholders (true);    return PSPC;}

Use of Properties in an XML configuration file

<bean id= "xxx" class= "com.demo.Xxx" >      <property name= "url" value= "${mysql.jdbc.url}"/></bean>

Using @Value Injection

@Value ("${demo.jdbc.url}") Private String URL;

Get through environment

It can be used only when using annotations @PropertySource, otherwise it will be null.

@Autowiredprivate Environment Env;public String getUrl () {    return Env.getproperty ("Demo.jdbc.url");}

Get through Application.properties

Demo.database.url=jdbc:mysql:

Spring Boot Related @configurationproperties

Application.properties
Demo.db.url=jdbc:mysql:demo.db.username=testdemo.db.password=123456@configuration@configurationproperties ( prefix = "demo.db") @Datapublic class DataBase {    String URL;    String username;    String password;}

Configuration priority

Java -dspring.profiles.active=env -jar App.jar

If there are two files,application.properties and application-env.properties , then the configuration in the two files will be registered, if there are duplicate keys, Higher priority in the Application-env.properties file.

Summary: startup parameters > application-{env}.properties > application.properties

　　

Properties in Spring