@value 字面量 SpEL & 动态刷新实例

spring-boot/002-properties-value/pom.xml

@@ -11,5 +11,10 @@
 
     <artifactId>002-properties-value</artifactId>
 
-
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+    </dependencies>
 </project>

spring-boot/002-properties-value/src/main/java/com/git/hui/boot/properties/value/Application.java

@@ -1,15 +1,26 @@
 package com.git.hui.boot.properties.value;
 
+import com.git.hui.boot.properties.value.config.ConfigProperties;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
 
 /**
  * @author yihui
  * @date 2021/6/2
  */
+@RestController
 @SpringBootApplication
 public class Application {
+    @Autowired
+    private ConfigProperties configProperties;
 
+    @GetMapping("show")
+    public String showProperties() {
+        return configProperties.toJsonStr();
+    }
 
     public static void main(String[] args) {
         SpringApplication.run(Application.class);

spring-boot/002-properties-value/src/main/java/com/git/hui/boot/properties/value/config/ConfigProperties.java

@@ -1,6 +1,8 @@
 package com.git.hui.boot.properties.value.config;
 
+import com.alibaba.fastjson.JSONObject;
 import com.git.hui.boot.properties.value.model.Jwt;
+import lombok.Data;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.core.env.Environment;
@@ -14,6 +16,7 @@
  * @author yihui
  * @date 2021/6/2
  */
+@Data
 @Component
 public class ConfigProperties {
 
@@ -47,6 +50,24 @@ public class ConfigProperties {
     @Value("${auth.jwt.tt}")
     private Jwt tt;
 
+    @Value("1+2")
+    private String a;
+
+    @Value("#{1+2}")
+    private String b;
+
+    /**
+     * 配置注入 + 前缀
+     */
+    @Value("prefix_${auth.jwt.token}")
+    private String c;
+
+    /**
+     * spel表达式
+     */
+    @Value("#{randomService.randUid()}")
+    private String rid;
+
     @Autowired
     private Environment environment;
 
@@ -55,4 +76,8 @@ public void init() {
         System.out.println("token: " + token + "\nexpire:" + expire + "\nno:" + no + "\nwhiteList:" + whiteList +
                 "\nblackList:" + Arrays.asList(blackList) + "\ntt:" + tt);
     }
+
+    public String toJsonStr() {
+        return JSONObject.toJSONString(this);
+    }
 }

spring-boot/002-properties-value/src/main/java/com/git/hui/boot/properties/value/config/dynamic/AnoValueRefreshPostProcessor.java

@@ -0,0 +1,144 @@
+package com.git.hui.boot.properties.value.config.dynamic;
+
+import com.alibaba.fastjson.JSONObject;
+import javafx.util.Pair;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessorAdapter;
+import org.springframework.context.ApplicationEvent;
+import org.springframework.context.EnvironmentAware;
+import org.springframework.context.event.EventListener;
+import org.springframework.core.env.Environment;
+import org.springframework.stereotype.Component;
+import org.springframework.util.PropertyPlaceholderHelper;
+
+import java.lang.reflect.Field;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * 配置的动态刷新
+ *
+ * @author yihui
+ * @date 2021/6/7
+ */
+@Component
+public class AnoValueRefreshPostProcessor extends InstantiationAwareBeanPostProcessorAdapter implements EnvironmentAware {
+    private Map<String, FieldPair> mapper = new HashMap<>();
+    private Environment environment;
+
+    @Override
+    public boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException {
+        processMetaValue(bean);
+        return super.postProcessAfterInstantiation(bean, beanName);
+    }
+
+    /**
+     * 扫描bean的所有属性，并获取@MetaVal修饰的属性
+     *
+     * @param bean
+     */
+    private void processMetaValue(Object bean) {
+        Class clz = bean.getClass();
+        if (!clz.isAnnotationPresent(RefreshValue.class)) {
+            return;
+        }
+
+        try {
+            for (Field field : clz.getDeclaredFields()) {
+                if (field.isAnnotationPresent(Value.class)) {
+                    Value val = field.getAnnotation(Value.class);
+                    Pair<String, String> pair = pickPropertyKey(val.value());
+                    mapper.put(pair.getKey(), new FieldPair(bean, field, val, pair.getValue()));
+                }
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+            System.exit(-1);
+        }
+    }
+
+    /**
+     * 实现一个基础的配置文件参数动态刷新支持
+     *
+     * @param value
+     * @return
+     */
+    private Pair<String, String> pickPropertyKey(String value) {
+        int start = value.indexOf("$") + 2;
+        int middle = value.indexOf(":", start);
+        int end = value.indexOf("}", start);
+
+        String key;
+        String defaultValue;
+        if (middle > 0 && middle < end) {
+            // 包含默认值
+            key = value.substring(start, middle);
+            defaultValue = value.substring(middle + 1, end);
+        } else {
+            // 不包含默认值
+            key = value.substring(start, end);
+            defaultValue = null;
+        }
+        return new Pair<>(key, defaultValue);
+    }
+
+    @Override
+    public void setEnvironment(Environment environment) {
+        this.environment = environment;
+    }
+
+    @Data
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static class FieldPair {
+        private static PropertyPlaceholderHelper propertyPlaceholderHelper = new PropertyPlaceholderHelper("${", "}");
+
+        Object bean;
+        Field field;
+        Value value;
+        String defaultVal;
+
+        public void updateValue(Environment environment) throws IllegalAccessException {
+            boolean access = field.isAccessible();
+            if (!access) {
+                field.setAccessible(true);
+            }
+
+            String val = value.value();
+            if (defaultVal != null) {
+                val = value.value().replace(":" + defaultVal, "");
+            }
+
+            String updateVal = propertyPlaceholderHelper.replacePlaceholders(val, environment::getProperty);
+            field.set(bean, JSONObject.parseObject(updateVal, field.getType()));
+            field.setAccessible(access);
+        }
+    }
+
+    public static class ConfigUpdateEvent extends ApplicationEvent {
+        String key;
+
+        /**
+         * Create a new {@code ApplicationEvent}.
+         *
+         * @param source the object on which the event initially occurred or with
+         *               which the event is associated (never {@code null})
+         */
+        public ConfigUpdateEvent(Object source, String key) {
+            super(source);
+            this.key = key;
+        }
+    }
+
+    @EventListener
+    public void updateConfig(ConfigUpdateEvent configUpdateEvent) throws IllegalAccessException {
+        FieldPair pair = mapper.get(configUpdateEvent.key);
+        if (pair != null) {
+            pair.updateValue(environment);
+        }
+    }
+}

spring-boot/002-properties-value/src/main/java/com/git/hui/boot/properties/value/config/dynamic/DynamicRest.java

@@ -0,0 +1,44 @@
+package com.git.hui.boot.properties.value.config.dynamic;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.MapPropertySource;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @author yihui
+ * @date 2021/6/7
+ */
+@RestController
+public class DynamicRest {
+    @Autowired
+    ApplicationContext applicationContext;
+    @Autowired
+    ConfigurableEnvironment environment;
+    @Autowired
+    RefreshConfigProperties refreshConfigProperties;
+
+    @GetMapping(path = "dynamic/update")
+    public RefreshConfigProperties updateEnvironment(String key, String value) {
+        String name = "applicationConfig: [classpath:/application-dynamic.yml]";
+        MapPropertySource propertySource = (MapPropertySource) environment.getPropertySources().get(name);
+        Map<String, Object> source = propertySource.getSource();
+        Map<String, Object> map = new HashMap<>(source.size());
+        map.putAll(source);
+        map.put(key, value);
+        environment.getPropertySources().replace(name, new MapPropertySource(name, map));
+
+        applicationContext.publishEvent(new AnoValueRefreshPostProcessor.ConfigUpdateEvent(this, key));
+        return refreshConfigProperties;
+    }
+
+    @GetMapping(path = "dynamic/show")
+    public RefreshConfigProperties show() {
+        return refreshConfigProperties;
+    }
+}

spring-boot/002-properties-value/src/main/java/com/git/hui/boot/properties/value/config/dynamic/RefreshConfigProperties.java

@@ -0,0 +1,27 @@
+package com.git.hui.boot.properties.value.config.dynamic;
+
+import lombok.Data;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+/**
+ * 演示动态配置刷新
+ *
+ * @author yihui
+ * @date 2021/6/7
+ */
+@Data
+@Component
+@RefreshValue
+public class RefreshConfigProperties {
+
+    @Value("${xhh.dynamic.name}")
+    private String name;
+
+    @Value("${xhh.dynamic.age:18}")
+    private Integer age;
+
+    @Value("${xhh.dynamic.other:test}")
+    private String other;
+
+}

spring-boot/002-properties-value/src/main/java/com/git/hui/boot/properties/value/config/dynamic/RefreshValue.java

@@ -0,0 +1,13 @@
+package com.git.hui.boot.properties.value.config.dynamic;
+
+import java.lang.annotation.*;
+
+/**
+ * @author yihui
+ * @date 2021/6/7
+ */
+@Target({ElementType.TYPE})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface RefreshValue {
+}

spring-boot/002-properties-value/src/main/java/com/git/hui/boot/properties/value/service/RandomService.java

@@ -0,0 +1,20 @@
+package com.git.hui.boot.properties.value.service;
+
+import org.springframework.stereotype.Service;
+
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * @author yihui
+ * @date 2021/6/7
+ */
+@Service
+public class RandomService {
+    private AtomicInteger cnt = new AtomicInteger(1);
+
+    public String randUid() {
+        return cnt.getAndAdd(1) + "_" + UUID.randomUUID().toString();
+    }
+
+}

spring-boot/002-properties-value/src/main/resources/application-dynamic.yml

@@ -0,0 +1,3 @@
+xhh:
+  dynamic:
+    name: 一灰灰blog

spring-boot/002-properties-value/src/main/resources/application.yml

@@ -7,4 +7,7 @@ auth:
       - 100
       - 200
       - 300
-    tt: token:tt_token; expire:1622616888888
+    tt: token:tt_token; expire:1622616888888
+spring:
+  profiles:
+    active: dynamic