maven dependency:

        <dependency>
            <groupId>org.fusesource.leveldbjni</groupId>
            <artifactId>leveldbjni-all</artifactId>
            <version>1.8</version>
        </dependency>

测试代码实现, 很简单就不多阐述了.

package com.qshuai.singleton;

import org.iq80.leveldb.CompressionType;
import org.iq80.leveldb.DB;
import org.iq80.leveldb.DBIterator;
import org.iq80.leveldb.Options;

import java.io.File;
import java.io.IOException;

import static org.fusesource.leveldbjni.JniDBFactory.asString;
import static org.fusesource.leveldbjni.JniDBFactory.factory;

public class DBTest {
    public static void main(String[] args) {
        Options utxoOptions = new Options();
        utxoOptions.createIfMissing(true);
        utxoOptions.compressionType(CompressionType.SNAPPY);
        utxoOptions.writeBufferSize(800 * 1048576); // 800MB cache for write buffer
        utxoOptions.cacheSize(0);

        DB ldb = null;
        try {
            ldb = factory.open(new File("testdb"), utxoOptions);
        } catch (IOException e) {
            e.printStackTrace();
        }

        // less value
        ldb.put(("120000" + "00").getBytes(), new byte[2]);

        String prefix = "120099";
        ldb.put((prefix + "01").getBytes(), new byte[2]);
        ldb.put((prefix + "02").getBytes(), new byte[2]);
        ldb.put((prefix + "03").getBytes(), new byte[2]);
        ldb.put((prefix + "04").getBytes(), new byte[2]);
        ldb.put((prefix + "05").getBytes(), new byte[2]);

        // great value
        ldb.put(("999999" + "00").getBytes(), new byte[2]);

        // [first target] to [the last]
        System.out.println("[first target] to [the last]");
        DBIterator iterator = ldb.iterator();
        try {
            for (iterator.seek(prefix.getBytes()); iterator.hasNext(); iterator.next()) {
                String key = asString(iterator.peekNext().getKey());
                String value = asString(iterator.peekNext().getValue());
                System.out.println(key + " = " + value);
            }
        } finally {

        }

        // [first target] to [last target]
        System.out.println("\n[first target] to [last target]");
        DBIterator it = ldb.iterator();
        try {
            for (it.seek(prefix.getBytes()); it.hasNext(); it.next()) {
                if (!equalPrefix(it.peekNext().getKey(), prefix.getBytes()))
                    break;
                String key = asString(it.peekNext().getKey());
                String value = asString(it.peekNext().getValue());
                System.out.println(key + " = " + value);
            }
        } finally {

        }
    }

    public static boolean equalPrefix(byte[] src, byte[] target) {
        if (src.length < target.length)
            return false;

        for (int i = 0; i <target.length; i++) {
            if (src[i] != target[i])
                return false;
        }

        return true;
    }
}