# cd 到 maker/java 根目錄
mvn clean compile package

 <!-- ip2region  -->
        <dependency>
            <groupId>org.lionsoul</groupId>
            <artifactId>ip2region</artifactId>
            <version>2.6.3</version>
        </dependency>

/**
 * 全局獲取HttpServletRequest、HttpServletResponse的工具類
 */
public class HttpContextUtil {

    private HttpContextUtil() {

    }

    public static HttpServletRequest getHttpServletRequest() {
        return ((ServletRequestAttributes) Objects.requireNonNull(RequestContextHolder.getRequestAttributes())).getRequest();
    }

    public static HttpServletResponse getHttpServletResponse() {
        return ((ServletRequestAttributes) Objects.requireNonNull(RequestContextHolder.getRequestAttributes())).getResponse();
    }
}

public class IPUtil {

    private static final String UNKNOWN = "unknown";

    protected IPUtil() {

    }

    /**
     * 獲取 IP地址
     * 使用 Nginx等反向代理軟件， 則不能通過 request.getRemoteAddr()獲取 IP地址
     * 如果使用了多級反向代理的話，X-Forwarded-For的值并不止一個，而是一串IP地址，
     * X-Forwarded-For中第一個非 unknown的有效IP字符串，則為真實IP地址
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return "0:0:0:0:0:0:0:1".equals(ip) ? "127.0.0.1" : ip;
    }

}

public class AddressUtil {

    public static String dbPath = "src/main/resources/ip2region/ip2region.xdb";

    public static String region = "UNKOWN";

    //方法一：完全基于文件的查詢
    public static String getInfoByFie(String ip) throws IOException {
        // 1、創(chuàng)建 searcher 對象
        Searcher searcher = null;
        try {
            searcher = Searcher.newWithFileOnly(dbPath);
        } catch (IOException e) {
            System.out.printf("failed to create searcher with `%s`: %s\n", dbPath, e);
            return "";
        }

        // 2、查詢
        try {
            //ip = "119.39.183.117";
            long sTime = System.nanoTime();
            region = searcher.searchByStr(ip);
            long cost = TimeUnit.NANOSECONDS.toMicros((long) (System.nanoTime() - sTime));
            System.out.printf("{region: %s, ioCount: %d, took: %d μs}\n", region, searcher.getIOCount(), cost);
        } catch (Exception e) {
            System.out.printf("failed to search(%s): %s\n", ip, e);
        }


        return region;
        // 備注：并發(fā)使用，每個線程需要創(chuàng)建一個獨立的 searcher 對象單獨使用。
    }

    //方法二：緩存 VectorIndex 索引
    //我們可以提前從 xdb 文件中加載出來 VectorIndex 數(shù)據(jù)，然后全局緩存，
    // 每次創(chuàng)建 Searcher 對象的時候使用全局的 VectorIndex 緩存可以減少一次固定的 IO 操作，從而加速查詢，減少 IO 壓力。
    public static String getInfoByVectorIndex(String ip) throws IOException {

        // 1、從 dbPath 中預先加載 VectorIndex 緩存，并且把這個得到的數(shù)據(jù)作為全局變量，后續(xù)反復使用。
        byte[] vIndex;
        try {
            vIndex = Searcher.loadVectorIndexFromFile(dbPath);
        } catch (Exception e) {
            System.out.printf("failed to load vector index from `%s`: %s\n", dbPath, e);
            return "";
        }

        // 2、使用全局的 vIndex 創(chuàng)建帶 VectorIndex 緩存的查詢對象。
        Searcher searcher;
        try {
            searcher = Searcher.newWithVectorIndex(dbPath, vIndex);
        } catch (Exception e) {
            System.out.printf("failed to create vectorIndex cached searcher with `%s`: %s\n", dbPath, e);
            return "";
        }

        // 2、查詢
        try {
            //ip = "119.39.183.117";
            long sTime = System.nanoTime();
            region = searcher.searchByStr(ip);
            long cost = TimeUnit.NANOSECONDS.toMicros((long) (System.nanoTime() - sTime));
            System.out.printf("{region: %s, ioCount: %d, took: %d μs}\n", region, searcher.getIOCount(), cost);
        } catch (Exception e) {
            System.out.printf("failed to search(%s): %s\n", ip, e);
        }

        return region;
        // 備注：每個線程需要單獨創(chuàng)建一個獨立的 Searcher 對象，但是都共享全局的制度 vIndex 緩存。
    }

    //方法三：緩存整個 xdb 數(shù)據(jù)
    //我們也可以預先加載整個 ip2region.xdb 的數(shù)據(jù)到內存，
    //然后基于這個數(shù)據(jù)創(chuàng)建查詢對象來實現(xiàn)完全基于文件的查詢，類似之前的 memory search。
    public static String getInfoByBuffer(String ip) throws IOException {

        // 1、從 dbPath 中預先加載 VectorIndex 緩存，并且把這個得到的數(shù)據(jù)作為全局變量，后續(xù)反復使用。
        byte[] vIndex;
        try {
            vIndex = Searcher.loadVectorIndexFromFile(dbPath);
        } catch (Exception e) {
            System.out.printf("failed to load vector index from `%s`: %s\n", dbPath, e);
            return "";
        }

        // 2、使用全局的 vIndex 創(chuàng)建帶 VectorIndex 緩存的查詢對象。
        Searcher searcher;
        try {
            searcher = Searcher.newWithVectorIndex(dbPath, vIndex);
        } catch (Exception e) {
            System.out.printf("failed to create vectorIndex cached searcher with `%s`: %s\n", dbPath, e);
            return "";
        }

        // 2、查詢
        try {
            //ip = "119.39.183.117";
            long sTime = System.nanoTime();
            String region = searcher.searchByStr(ip);
            long cost = TimeUnit.NANOSECONDS.toMicros((long) (System.nanoTime() - sTime));
            System.out.printf("{region: %s, ioCount: %d, took: %d μs}\n", region, searcher.getIOCount(), cost);
        } catch (Exception e) {
            System.out.printf("failed to search(%s): %s\n", ip, e);
        }


        return region;
        // 備注：每個線程需要單獨創(chuàng)建一個獨立的 Searcher 對象，但是都共享全局的制度 vIndex 緩存。
    }

    public static void main(String[] args) throws IOException {
        //1、完全基于文件查詢
        String info1 = AddressUtil.getInfoByFie("203.15.235.101");
        System.out.println(info1);
        //2、緩存VectorIndex索引
        String info2 = AddressUtil.getInfoByVectorIndex("203.15.235.101");
        System.out.println(info2);
        //3、緩存整個xdb文件
        String info3 = AddressUtil.getInfoByVectorIndex("203.15.235.101");
        System.out.println(info3);
    }
}