# ============================================================
# 信创基础镜像：Amazon Corretto 8 JDK (Alpine 3.20)
# 支持架构：x86_64, aarch64（鲲鹏）
# 适用场景：Java 微服务基础运行环境
# ============================================================

FROM alpine:3.20

# ============================================================
# 镜像元信息
# ============================================================
LABEL maintainer="lin" \
      description="Amazon Corretto 8 JDK for xinchuang" \
      version="8u422" \
      architecture.multiarch="true"

# ============================================================
# 环境变量
# ============================================================
# Corretto 版本（可通过构建参数覆盖）
ARG CORRETTO_VERSION=8.422.05.1
ARG CORRETTO_SHA256_AMD64=a7b7e2f8c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0
ARG CORRETTO_SHA256_AARCH64=b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9

ENV JAVA_HOME=/usr/lib/jvm/java-1.8.0-amazon-corretto \
    PATH="/usr/lib/jvm/java-1.8.0-amazon-corretto/bin:${PATH}" \
    LANG=en_US.UTF-8 \
    LC_ALL=en_US.UTF-8 \
    TZ=Asia/Shanghai \
    # JVM 默认参数（可通过环境变量覆盖）
    JAVA_OPTS="-XX:+UseG1GC -XX:MaxGCPauseMillis=200 -Djava.security.egd=file:/dev/./urandom"

# ============================================================
# 安装基础依赖 + 配置国内镜像源
# ============================================================
# 使用阿里云镜像源加速（信创环境通常无法直接访问 dl-cdn.alpinelinux.org）
RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories && \
    apk add --no-cache \
        bash \
        curl \
        wget \
        tzdata \
        ca-certificates \
        fontconfig \
        ttf-dejavu \
        busybox-extras \
        procps \
        gzip \
        tar \
        zip \
        unzip \
    && rm -rf /var/cache/apk/*

# ============================================================
# 时区配置
# ============================================================
RUN ln -sf /usr/share/zoneinfo/${TZ} /etc/localtime && \
    echo "${TZ}" > /etc/timezone

# ============================================================
# Locale 配置
# ============================================================
ENV LANG=en_US.UTF-8 \
    LANGUAGE=en_US:en \
    LC_ALL=en_US.UTF-8

# ============================================================
# 安装 Amazon Corretto 8 JDK
# ============================================================
RUN ARCH=$(uname -m) && \
    case "${ARCH}" in \
        x86_64)  CORRETTO_ARCH="x64" ;; \
        aarch64) CORRETTO_ARCH="aarch64" ;; \
        *)       echo "Unsupported architecture: ${ARCH}" && exit 1 ;; \
    esac && \
    wget -q -O /tmp/corretto.tar.gz \
        "https://corretto.aws/downloads/latest/amazon-corretto-${CORRETTO_VERSION}-linux-${CORRETTO_ARCH}-jdk.tar.gz" && \
    mkdir -p /usr/lib/jvm && \
    tar -xzf /tmp/corretto.tar.gz -C /usr/lib/jvm && \
    ln -sf /usr/lib/jvm/amazon-corretto-${CORRETTO_VERSION}-linux-${CORRETTO_ARCH} \
           /usr/lib/jvm/java-1.8.0-amazon-corretto && \
    rm -f /tmp/corretto.tar.gz && \
    java -version

# ============================================================
# 内置健康检查脚本：java-info
# ============================================================
RUN cat > /usr/local/bin/java-info << 'SCRIPT' && chmod +x /usr/local/bin/java-info
#!/bin/bash
echo "========================================="
echo "  Java Environment Info"
echo "========================================="
echo ""
echo "📦 JDK Version:"
java -version 2>&1
echo ""
echo "📁 JAVA_HOME: ${JAVA_HOME}"
echo "🏗️  Architecture: $(uname -m)"
echo "🐧 OS: $(cat /etc/os-release 2>/dev/null | grep PRETTY_NAME | cut -d= -f2 | tr -d '"')"
echo "🕐 Timezone: $(cat /etc/timezone 2>/dev/null || echo 'not set')"
echo ""
echo "💾 Memory:"
free -h 2>/dev/null || echo "  (free command not available)"
echo ""
echo "🔧 JVM System Properties (key ones):"
java -XshowSettings:all 2>&1 | grep -E "(java.home|os.arch|os.name|file.encoding|user.timezone)" | sed 's/^/  /'
echo ""
echo "========================================="
SCRIPT

WORKDIR /app
CMD ["bash"]

import java.util.*;
import java.util.stream.*;

List<Map<String, Object>> users = new ArrayList<>();
users.add(new HashMap<String, Object>() {{ put("id", 1L); put("name", "Alice"); }});
users.add(new HashMap<String, Object>() {{ put("id", 2L); put("name", "Bob"); }});
users.add(new HashMap<String, Object>() {{ put("id", 3L); put("name", "Charlie"); }});

// 基本转换
Map<Long, Map<String, Object>> result = users.stream()
    .collect(Collectors.toMap(
        m -> (Long) m.get("id"),   // key mapper
        m -> m                      // value mapper
    ));

System.out.println(result);
// {1={name=Alice, id=1}, 2={name=Bob, id=2}, 3={name=Charlie, id=3}}