一文彻底搞定VSCode Java环境配置(解决JDK版本总对不上)

# 查看Java版本
java -version
# 查看JDK安装路径（Linux/macOS）
/usr/libexec/java_home -V
# Windows用户可通过环境变量确认JAVA_HOME
echo %JAVA_HOME%

{
  "java.home": "/Library/Java/JavaVirtualMachines/jdk-17.jdk/Contents/Home"
}

{
  "java.project.sourcePaths": ["src"],
  "java.project.outputPath": "bin",
  "java.runtime.version": "17"
}

// JDK 8 引入的Lambda表达式
List names = Arrays.asList("Alice", "Bob");
names.forEach(name -> System.out.println("Hello, " + name));

{
  "java.home": "/path/to/your/jdk-17"
}

<!-- .idea/misc.xml（IntelliJ）中project JDK配置 -->
<component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="false">
  <output url="file://$PROJECT_DIR$/out" />
</component>

Exception in thread "main" java.lang.UnsupportedClassVersionError: 
com/example/Service has been compiled by a more recent version of the Java Runtime (class file version 55.0), 
this version of the Java Runtime only recognizes class file versions up to 52.0

java -version

javac -version

which java

{
  "java.home": "/Library/Java/JavaVirtualMachines/jdk-17.jdk/Contents/Home",
  "java.configuration.runtimes": [
    {
      "name": "JavaSE-17",
      "path": "/Library/Java/JavaVirtualMachines/jdk-17.jdk/Contents/Home"
    }
  ]
}

export JAVA_HOME=/path/to/project/jdk
./gradlew build

export JAVA_HOME=$HOME/.sdkman/candidates/java/17.0.9-tem
./gradlew build # 使用JDK 17构建项目

java -version
javac -version

<properties>
  <java.version>11</java.version>
  <maven.compiler.release>11</maven.compiler.release>
</properties>

"java.home": "C:\\Program Files\\Java\\jdk-17"

<properties>
  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  <maven.compiler.source>17</maven.compiler.source>
  <maven.compiler.target>17</maven.compiler.target>
</properties>

WARNING: Running version OpenJDK 17, but project is targeting Java 11

<properties>
    <java.version>17</java.version>
    <maven.compiler.source>17</maven.compiler.source>
    <maven.compiler.target>17</maven.compiler.target>
</properties>

<properties>
  <!-- 确保字节码兼容JDK 8 -->
  <maven.compiler.source>1.8</maven.compiler.source>
  <maven.compiler.target>1.8</maven.compiler.target>
</properties>

logEntry := map[string]interface{}{
    "level":   "info",
    "msg":     "user login successful",
    "user_id": 12345,
    "ts":      time.Now().UTC(),
}
jsonLog, _ := json.Marshal(logEntry)
fmt.Println(string(jsonLog))