区块链常用数据库leveldb用java来实现常规操作的方法

<dependency>
		<groupId>org.iq80.leveldb</groupId>
		<artifactId>leveldb-api</artifactId>
		<version>0.10</version>
	</dependency>
	<dependency>
		<groupId>org.iq80.leveldb</groupId>
		<artifactId>leveldb</artifactId>
		<version>0.10</version>
	</dependency>

DBFactory factory = new Iq80DBFactory();
	Options options = new Options();
	options.createIfMissing(true);
	//folder 是db存储目录
	DB db = factory.open(new File(folder), options);

//levelDB 的api存储都是字节数组 所以这里需要转成字节数组
	db.put(Iq80DBFactory.bytes(key), Iq80DBFactory.bytes(value));

byte[] bytes = db.get(Iq80DBFactory.bytes(key));
	String value = Iq80DBFactory.asString(bytes);

//删除
	db.delete(Iq80DBFactory.bytes(key));
	
	//更改 重新put新的key - value即可
	db.put(Iq80DBFactory.bytes(key), Iq80DBFactory.bytes(value));

	public LinkedHashMap<String, String> iteratorDb() {
    DBIterator iterator = db.iterator();
    LinkedHashMap<String, String> linkedHashMap = new LinkedHashMap<>();
    while (iterator.hasNext()) {
      Map.Entry<byte[], byte[]> next = iterator.next();
      String key = Iq80DBFactory.asString(next.getKey());
      String value = Iq80DBFactory.asString(next.getValue());
      linkedHashMap.put(key, value);
    }
    return linkedHashMap;
  }

@ResponseBody
  @GetMapping("/generate")
  public ResponeEntity generate(Long count) {
    DB db = levelDb.getDb();
    //创建批量处理
    WriteBatch batch = db.createWriteBatch();
    for (int i = 0; i < count; i++) {
      String uuid = UUID.randomUUID().toString();
      batch.put(Iq80DBFactory.bytes(uuid), Iq80DBFactory.bytes(uuid));
    }
    //执行写入
    db.write(batch);
    return buildRespone(null);
  }

@ResponseBody
  @GetMapping("/getLevel")
  public ResponeEntity getLevel(String key) {
    byte[] bytes = db.get(Iq80DBFactory.bytes(key));
    String value = Iq80DBFactory.asString(bytes);
    return buildRespone(value);
  }