# 构建阶段
FROM maven:3.9.9-eclipse-temurin-21 AS builder
WORKDIR /app

# 先复制 pom，缓存依赖（关键优化）
COPY pom.xml .
RUN mvn dependency:go-offline -B

COPY src ./src
RUN mvn clean package -DskipTests

# 运行阶段
FROM eclipse-temurin:21-jre
WORKDIR /app

# 复制jar（稳定写法）
COPY --from=builder /app/target/*.jar app.jar

EXPOSE 8080

# 启动时加JVM参数，集群更稳定
ENTRYPOINT ["java", "-jar", "-Xms512m", "-Xmx512m", "app.jar"]