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preface

In SpringBoot, we often read configuration file values. What are the ways to read configuration file values? Follow the author to see!

Use @value annotations

Prepare two configuration files named application.properties and application.yml

  • properties
userproperties.name=gongj===properties
userproperties.age=11===properties
userproperties.sex=12===properties
userproperties.email=[email protected]===properties
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  • yml
useryml:
  name: gongjie
  age: 23
  sex: 1
  email: 111@163.com
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  • test
    @Value("${userproperties.name}")
    private String name;
    @Value("${userproperties.age}")
    private String age;
    @Value("${userproperties.sex}")
    private String sex;
    @Value("${userproperties.email}")
    private String email;

    @Value("${useryml.name}")
    private String nameyml;
    @Value("${useryml.age}")
    private String ageyml;
    @Value("${useryml.sex}")
    private String sexyml;
    @Value("${useryml.email}")
    private String emailyml;

    @Test
    public void testValue(a){
    
        System.out.println("name=" + name + "，age=" + age + "，sex=" 
        + sex + , "email" + email);
        
       System.out.println("nameyml=" + nameyml + ", ageyml =" + ageyml 
       + ", sexyml =" + sexyml + ", emailyml" + emailyml);
    }
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Use the @configurationProperties annotation

  • properties
@Component
@ConfigurationProperties(prefix = "userproperties")
public class ReadPropertiesValue {
    private String name;
    private String age;
    private String email;
    private String sex;

    @Override
    public String toString(a) {
        return "ReadPropertiesValue{" +
                "name='" + name + '\' ' +
                ", age=" + age +
                ", email='" + email + '\' ' +
                ", sex=" + sex +
                '} ';
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public void setSex(String sex) {
        this.sex = sex; }}Copy the code

Prefix: specifies the prefix of the key name in the configuration file.

Note: The @Component modifier is not used on the ReadPropertiesValue class. Is not available in the container. Need to start the class add @ EnableConfigurationProperties (ReadPropertiesValue. Class) will be registered into the container.

  • yml
@Component
@ConfigurationProperties(prefix = "useryml")
public class ReadYmlValue {
    private String name;
    private String age;
    private String email;
    private String sex;

    @Override
    public String toString(a) {
        return "ReadYmlValue{" +
                "name='" + name + '\' ' +
                ", age=" + age +
                ", email='" + email + '\' ' +
                ", sex=" + sex +
                '} ';
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public void setSex(String sex) {
        this.sex = sex; }}Copy the code
  • test
    @Autowired
    ReadPropertiesValue readPropertiesValue;
    @Autowired
    ReadYmlValue readYmlValue;
    @Test
    public void readPropertiesValueTest(a){
        System.out.println(readPropertiesValue.toString());
        System.out.println(readYmlValue.toString());
    }
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3, Use Environment

Note: This is done by dependency injection directly into the Evnironment object and then using environment.getProperty(” key name “) to read the corresponding value.

  • Coding test
@Autowired
Environment environment;

@Test
public void environmentTest(a){

    System.out.println(environment.getProperty("userproperties.name") 
    + "= =" + environment.getProperty("userproperties.age") + "= =" + 
    environment.getProperty("userproperties.sex") + "= =" + 
    environment.getProperty("userproperties.email"));

    System.out.println(environment.getProperty("useryml.name") + "= =" 
    + environment.getProperty("useryml.age") + "= =" + 
    environment.getProperty("useryml.sex") + "= =" + 
    environment.getProperty("useryml.email"));

}
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Properties and application.yml are all read from the default configuration files. But these two files are certainly not the only ones in the company’s official development. There is usually a custom configuration file, and this is the time to specify the load configuration file.

Read from the definition configuration file

Create configValue.properties and configValue.yml configuration files

  • configValue.properties
userconfigvalueproperties.name=yuanjConfigValue
userconfigvalueproperties.age=11ConfigValue
userconfigvalueproperties.sex=12ConfigValue
userconfigvalueproperties.email=[email protected]
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  • yml
userconfigvalueyml:
  name: yuanjconfigvalueyml
  age: 11configvalueyml
  sex: 12configvalueyml
  email: 3333@163.comconfigvalueyml
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Use @propertysource + @Value

  • readpropertiesThe file content
@Component
@PropertySource(value = "classpath:configValue.properties")
public class ReadPropertiesByValue {

    @Value("${userconfigvalueproperties.name}")
    public String name;
    @Value("${userconfigvalueproperties.age}")
    public String age;
    @Value("${userconfigvalueproperties.sex}")
    public String sex;
    @Value("${userconfigvalueproperties.email}")
    public String email;

    @Override
    public String toString(a) {
        return "ReadPropertiesByValue{" +
                "name='" + name + '\' ' +
                ", age='" + age + '\' ' +
                ", sex='" + sex + '\' ' +
                ", email='" + email + '\' ' +
                '} '; }}Copy the code

The @propertysource annotation configures a property, value: that specifies the location of the configuration file.

  • Read the contents of the YML file
@Component
@PropertySource(value = "classpath:configValue.yml")
public class ReadYmlByValue {
    
    @Value("${userconfigvalueyml.name}")
    public String name;
    @Value("${userconfigvalueyml.age}")
    public String age;
    @Value("${userconfigvalueyml.sex}")
    public String sex;
    @Value("${userconfigvalueyml.email}")
    public String email;

    @Override
    public String toString(a) {
        return "ReadYmlByValue{" +
                "name='" + name + '\' ' +
                ", age='" + age + '\' ' +
                ", sex='" + sex + '\' ' +
                ", email='" + email + '\' ' +
                '} '; }}Copy the code
@Autowired
ReadPropertiesByValue readPropertiesByValue;

@Autowired
ReadYmlByValue readYmlByValue;

@Test
public void readPropertiesByValue(a){
    System.out.println(readPropertiesByValue.toString());
    System.out.println(readYmlByValue.toString());
}
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Use @propertysource + @ConfigurationProperties

  • properties
@Component
@ConfigurationProperties(prefix = "userconfigvalueproperties")
@PropertySource(value = { "classpath:configValue.properties" })
public class ReadPropertiesConfigValue {
    private String name;
    private String age;
    private String email;
    private String sex;

    @Override
    public String toString(a) {
        return "ReadPropertiesConfigValue{" +
                "name='" + name + '\' ' +
                ", age='" + age + '\' ' +
                ", email='" + email + '\' ' +
                ", sex='" + sex + '\' ' +
                '} ';
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public void setSex(String sex) {
        this.sex = sex; }}Copy the code
  • yml
@Component
@ConfigurationProperties(prefix = "userconfigvalueyml")
@PropertySource(value = { "classpath:configValue.yml" }, factory = CommPropertyResourceFactory.class)
public class ReadYmlConfigValue {
    private String name;
    private String age;
    private String email;
    private String sex;

    @Override
    public String toString(a) {
        return "ReadYmlConfigValue{" +
                "name='" + name + '\' ' +
                ", age='" + age + '\' ' +
                ", email='" + email + '\' ' +
                ", sex='" + sex + '\' ' +
                '} ';
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public void setSex(String sex) {
        this.sex = sex; }}Copy the code

Since @propertysource is not yamL readable, we need to modify it.

import org.springframework.boot.env.YamlPropertySourceLoader;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.support.DefaultPropertySourceFactory;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.core.io.support.PropertySourceFactory;
import org.springframework.lang.Nullable;

import java.io.IOException;
import java.util.List;
import java.util.Optional;

public class CommPropertyResourceFactory implements PropertySourceFactory {

@Override
publicPropertySource<? > createPropertySource(@Nullable String name, EncodedResource
        resource) throws IOException {
    String resourceName = Optional.ofNullable(name).orElse(resource.getResource().getFilename());
    if (resourceName.endsWith(".yml") || resourceName.endsWith(".yaml")) { List<org.springframework.core.env.PropertySource<? >> yamlSources =new YamlPropertySourceLoader().load(resourceName, resource.getResource());
        return yamlSources.get(0);
    } else {
        return newDefaultPropertySourceFactory() .createPropertySource(name, resource); }}}Copy the code

When you need to read YAML, add the factory parameter

@PropertySource(value = { "classpath:configValue.yml" }, factory = CommPropertyResourceFactory.class)
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  • test
   //=========== specifies the configuration file to load
    @Autowired
    ReadPropertiesConfigValue readPropertiesConfigValue;

    @Autowired
    ReadYmlConfigValue readYmlConfigValue;

    @Test
    public void readPropertiesConfigValueTest(a){
        System.out.println(readPropertiesConfigValue.toString());
        System.out.println(readYmlConfigValue.toString());
    }
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