如何开发一款以太坊（安卓）钱包系列1 - 通过助记词创建账号

这是一张导入钱包账号的截图（导入和创建，其实原理一样），界面仿照ImToken，不过本文将不会介绍UI部分的编写。

This is a screenshot of an imported wallet account (import and creation, in fact, the same principle) with an ImToken interface, but this will not describe the preparation of the UI part.

不过本文中的功能，主要是使用了web3j中椭圆曲线加密及KeyStore文件的生成与解密。

However, the features in this paper are mainly the encryption of elliptical curves in web3j and the generation and decryption of KeyStore files.

bitcoinj 的功能和web3类似，它是比特币协议的Java实现，他实现了 BIP32、BIP44及BIP39 相关协议。

The function of bitcoinj, similar to that of web3, is the realization of Java under the Bitcoin Agreement, which fulfils the BIP32, BIP44 and BIP39 related agreements.

Android使用Gradle来构建，直接在文件中加入：

Android uses Gradle to construct it by adding directly to the document:

提示： 实践中遇到的一个问题，由于bitcoinj 中引入了 加密库， 它包含的文件，会导致在进行Android App Bundle 编译时会出现错误（好像也会导致某些机型没法安装），解决办法是在 build.gradle 加入一下语句，把这个文件在打包时排除掉。 packagingOptions { exclude 'lib/x86_64/darwin/libscrypt.dylib' }

Note: A problem encountered in practice as a result of the introduction of encrypt libraries in bitcoinj, which contain documents that lead to errors in the preparation of Android App Bundle (as if some of the models could not be installed), the solution is to add a statement to the building. gradle and remove this file from the package.

这是目前钱包客户端，最常见的一种为用户常见账号的方式，这里会包含一下几个核心步骤：

This is the current wallet client, the most common type of account for a user, which contains a few core steps:

1. 生成一个随机数种子；
2. 通过随机数种子得到助记词；
3. 通过 种子 + 路径 派生生成私钥；
4. 使用KeyStore保存私钥；
5. 私钥推倒出账号地址。

上述代码中，是入口函数，最终返回的是一个ETHWallet 自定义的钱包实体类，一个实例就对应一个钱包，ETHWallet保存了钱包相关的属性，后面会详细介绍，如果对它序列化保存钱包账号及多个钱包账号管理。

In the above code, which is an entry function, the final return is an ETHWallet self-defined wallet entity category, and one example corresponds to a wallet in which the ETHWallet retains the properties associated with the wallet, which is described in detail at a later stage, if the wallet account number and multiple wallet accounts are managed in a sequenced manner.

关于助记词及私钥的保存，有几点要特别注意，否则有可能和其他钱包无法兼容或导致私钥泄漏。

With regard to the preservation of notes and private keys, there are a number of points where pays particular attention to