Update source/target JDK version to 1.8 and update documents

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

README.md

@@ -49,9 +49,9 @@ Below is a simple demo that guides new users to use Sentinel in just 3 steps. It
 
 ### 1. Add Dependency
 
-**Note:** Sentinel Core requires Java 7 or later.
+**Note:** Sentinel requires JDK 1.8 or later.
 
-If your're using Maven, just add the following dependency in `pom.xml`.
+If you're using Maven, just add the following dependency in `pom.xml`.
 
 ```xml
 <!-- replace here with the latest version -->

pom.xml

@@ -53,8 +53,8 @@
 
         <!-- Build -->
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <java.source.version>1.7</java.source.version>
-        <java.target.version>1.7</java.target.version>
+        <java.source.version>1.8</java.source.version>
+        <java.target.version>1.8</java.target.version>
         <java.encoding>UTF-8</java.encoding>
         <maven.compiler.version>3.8.0</maven.compiler.version>
         <maven.surefire.version>2.22.1</maven.surefire.version>

sentinel-adapter/sentinel-api-gateway-adapter-common/pom.xml

@@ -12,11 +12,6 @@
     <artifactId>sentinel-api-gateway-adapter-common</artifactId>
     <packaging>jar</packaging>
 
-    <properties>
-        <java.source.version>1.7</java.source.version>
-        <java.target.version>1.7</java.target.version>
-    </properties>
-
     <dependencies>
         <dependency>
             <groupId>com.alibaba.csp</groupId>

sentinel-adapter/sentinel-motan-adapter/pom.xml

@@ -20,6 +20,7 @@
             <groupId>com.alibaba.csp</groupId>
             <artifactId>sentinel-core</artifactId>
         </dependency>
+
         <dependency>
             <groupId>com.weibo</groupId>
             <artifactId>motan-core</artifactId>
@@ -33,18 +34,5 @@
             <scope>provided</scope>
         </dependency>
     </dependencies>
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven.compiler.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                    <encoding>${java.encoding}</encoding>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
+
 </project>

sentinel-adapter/sentinel-reactor-adapter/README.md

@@ -1,7 +1,5 @@
 # Sentinel Reactor Adapter
 
-> Note: this module requires Java 8 or later version.
-
 Sentinel provides integration module for [Reactor](https://projectreactor.io/).
 
 Add the following dependency in `pom.xml` (if you are using Maven):

sentinel-adapter/sentinel-spring-cloud-gateway-adapter/README.md

@@ -1,7 +1,5 @@
 # Sentinel Spring Cloud Gateway Adapter
 
-> Note: this module requires Java 8 or later version.
-
 Sentinel provides integration module with Spring Cloud Gateway.
 The integration module is based on the Sentinel Reactor Adapter.
 

sentinel-adapter/sentinel-spring-webflux-adapter/README.md

@@ -1,7 +1,5 @@
 # Sentinel Spring WebFlux Adapter
 
-> Note: this module requires Java 8 or later version.
-
 Sentinel provides integration module with Spring WebFlux, so reactive web applications can also leverage Sentinel's flow control
 and circuit breaking to achieve reliability. The integration module is based on the Sentinel Reactor Adapter.
 

sentinel-benchmark/pom.xml

@@ -40,22 +40,11 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <jmh.version>1.21</jmh.version>
-        <javac.target>1.8</javac.target>
         <uberjar.name>benchmarks</uberjar.name>
     </properties>
 
     <build>
         <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven.compiler.version}</version>
-                <configuration>
-                    <compilerVersion>${javac.target}</compilerVersion>
-                    <source>${javac.target}</source>
-                    <target>${javac.target}</target>
-                </configuration>
-            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-pmd-plugin</artifactId>

sentinel-cluster/pom.xml

@@ -13,9 +13,6 @@
     <description>The parent module of Sentinel cluster server</description>
 
     <properties>
-        <java.source.version>1.7</java.source.version>
-        <java.target.version>1.7</java.target.version>
-
         <netty.version>4.1.31.Final</netty.version>
     </properties>
 

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/processor/RequestProcessorProvider.java

@@ -59,11 +59,7 @@ public final class RequestProcessorProvider {
     }
 
     static void addProcessorIfAbsent(int type, RequestProcessor processor) {
-        // TBD: use putIfAbsent in JDK 1.8.
-        if (PROCESSOR_MAP.containsKey(type)) {
-            return;
-        }
-        PROCESSOR_MAP.put(type, processor);
+        PROCESSOR_MAP.putIfAbsent(type, processor);
     }
 
     static void addProcessor(int type, RequestProcessor processor) {

sentinel-dashboard/pom.xml

@@ -13,8 +13,6 @@
     <packaging>jar</packaging>
 
     <properties>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
         <spring.boot.version>2.0.5.RELEASE</spring.boot.version>
         <curator.version>4.0.1</curator.version>
     </properties>
@@ -158,15 +156,6 @@
                 </executions>
             </plugin>
 
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <configuration>
-                    <source>${maven.compiler.source}</source>
-                    <target>${maven.compiler.target}</target>
-                </configuration>
-            </plugin>
-
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-deploy-plugin</artifactId>

sentinel-demo/pom.xml

@@ -12,11 +12,6 @@
     <packaging>pom</packaging>
     <name>sentinel-demo</name>
 
-    <properties>
-        <java.source.version>1.8</java.source.version>
-        <java.target.version>1.8</java.target.version>
-    </properties>
-
     <modules>
         <module>sentinel-demo-basic</module>
         <module>sentinel-demo-dynamic-file-rule</module>

sentinel-demo/sentinel-demo-apollo-datasource/pom.xml

@@ -12,8 +12,6 @@
   <artifactId>sentinel-demo-apollo-datasource</artifactId>
 
   <properties>
-    <java.source.version>1.8</java.source.version>
-    <java.target.version>1.8</java.target.version>
     <log4j2.version>2.9.1</log4j2.version>
     <slf4j.version>1.7.25</slf4j.version>
   </properties>

sentinel-demo/sentinel-demo-dubbo/pom.xml

@@ -50,18 +50,4 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven.compiler.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                    <encoding>${java.encoding}</encoding>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
 </project>

sentinel-demo/sentinel-demo-dynamic-file-rule/pom.xml

@@ -30,19 +30,4 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <finalName>sentinel-demo-dynamic-file-rule</finalName>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven.compiler.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                    <encoding>${java.encoding}</encoding>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
 </project>

sentinel-demo/sentinel-demo-etcd-datasource/pom.xml

@@ -12,37 +12,19 @@
     <artifactId>sentinel-demo-etcd-datasource</artifactId>
 
     <dependencies>
-
         <dependency>
             <groupId>com.alibaba.csp</groupId>
             <artifactId>sentinel-core</artifactId>
         </dependency>
-
         <dependency>
             <groupId>com.alibaba.csp</groupId>
             <artifactId>sentinel-datasource-etcd</artifactId>
         </dependency>
 
-
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>fastjson</artifactId>
         </dependency>
-
     </dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven.compiler.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                    <encoding>${java.encoding}</encoding>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
 </project>

sentinel-demo/sentinel-demo-motan/pom.xml

@@ -50,19 +50,4 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven.compiler.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                    <encoding>${java.encoding}</encoding>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
-
 </project>

sentinel-demo/sentinel-demo-nacos-datasource/pom.xml

@@ -37,18 +37,4 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven.compiler.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                    <encoding>${java.encoding}</encoding>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
 </project>

sentinel-demo/sentinel-demo-parameter-flow-control/pom.xml

@@ -11,11 +11,6 @@
 
     <artifactId>sentinel-demo-parameter-flow-control</artifactId>
 
-    <properties>
-        <java.source.version>1.8</java.source.version>
-        <java.target.version>1.8</java.target.version>
-    </properties>
-
     <dependencies>
         <dependency>
             <groupId>com.alibaba.csp</groupId>

sentinel-demo/sentinel-demo-rocketmq/pom.xml

@@ -19,18 +19,4 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven.compiler.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                    <encoding>${java.encoding}</encoding>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
 </project>

sentinel-demo/sentinel-demo-spring-cloud-gateway/pom.xml

@@ -11,11 +11,6 @@
 
     <artifactId>sentinel-demo-spring-cloud-gateway</artifactId>
 
-    <properties>
-        <java.source.version>1.8</java.source.version>
-        <java.target.version>1.8</java.target.version>
-    </properties>
-
     <dependencies>
         <dependency>
             <groupId>org.springframework.cloud</groupId>

sentinel-demo/sentinel-demo-zookeeper-datasource/pom.xml

@@ -54,19 +54,4 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven.compiler.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                    <encoding>${java.encoding}</encoding>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
-
 </project>

sentinel-extension/sentinel-datasource-consul/README.md

@@ -3,8 +3,6 @@
 Sentinel DataSource Consul provides integration with Consul. The data source leverages blocking query (backed by
 long polling) of Consul.
 
-> **NOTE**: This module requires JDK 1.8 or later.
-
 ## Usage
 
 To use Sentinel DataSource Consul, you could add the following dependency:

sentinel-extension/sentinel-datasource-etcd/README.md

@@ -3,8 +3,6 @@
 Sentinel DataSource Etcd provides integration with etcd so that etcd
 can be the dynamic rule data source of Sentinel. The data source uses push model (watcher).
 
-> **NOTE**: This module requires JDK 1.8 or later.
-
 To use Sentinel DataSource Etcd, you should add the following dependency:
 
 ```xml

sentinel-extension/sentinel-datasource-redis/README.md

@@ -2,7 +2,7 @@
 
 Sentinel DataSource Redis provides integration with Redis. The data source leverages Redis pub-sub feature to implement push model (listener).
 
-The data source uses [Lettuce](https://lettuce.io/) as the Redis client internal. Requires JDK 1.8 or later.
+The data source uses [Lettuce](https://lettuce.io/) as the Redis client, which requires JDK 1.8 or later.
 
 > **NOTE**: Currently we do not support Redis Cluster now.
 

sentinel-extension/sentinel-datasource-zookeeper/pom.xml

@@ -13,8 +13,6 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.source.version>1.7</java.source.version>
-        <java.target.version>1.7</java.target.version>
         <zookeeper.version>3.4.14</zookeeper.version>
         <curator.version>4.0.1</curator.version>
         <curator.test.version>2.12.0</curator.test.version>

sentinel-logging/sentinel-logging-slf4j/pom.xml

@@ -13,8 +13,6 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.source.version>1.7</java.source.version>
-        <java.target.version>1.7</java.target.version>
         <slf4j.version>1.7.25</slf4j.version>
         <slf4j-test.version>1.2.0</slf4j-test.version>
     </properties>