android app通过Geth RPC接口实现远程调用

记录一下APP怎么通过以太坊的RPC接口实现远程调用。此过程的环境为Window7和Android studio2.2.3。以web3_clientVersion为例。更多用法参考Geth JSON-RPC和Management APIs。首先启动geth私有链并设定RPC端口geth --identity “blossom” --rpc --rpccorsdomain “*” --datadir “%cd%” --port “30303” --rpcapi “personal,db,eth,net,web3,miner” --networkid 66666 --rpcport 8545 console 2>geth.txtAndroid studio新建项目并添加.jar包。jar包下载布局如下：

<Button
android:id="@+id/showView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="getBlock"/>

<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/textview"/>

MainActivity如下：package com.ethereum;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.TextView;import org.alexd.jsonrpc.JSONRPCException;import org.alexd.jsonrpc.JSONRPCHttpClient;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;public class MainActivity extends AppCompatActivity implements View.OnClickListener{

private Button showButton;
private TextView textview;

public static final int SHOW = 0;

private Handler handler = new Handler() {

public void handleMessage(Message msg) {
switch (msg.what) {
case SHOW:
String a = (String) msg.obj;
textview.setText(a);
}
}
};

[@Override](/user/Override)
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textview=(TextView)findViewById(R.id.textview);
showButton = (Button) findViewById(R.id.showView);
showButton.setOnClickListener(this);
}

[@Override](/user/Override)
public void onClick(View v) {
if(v.getId() == R.id.showView) {
show();
}
}

private void show() {
new Thread(new Runnable() {
[@Override](/user/Override)
public void run() {
try {
String url = "http://10.0.2.2:8545";
JSONRPCHttpClient client = new JSONRPCHttpClient(url);
Map<String, Object> map = new HashMap();
List paramsList = new ArrayList();
map.put("json-rpc", "2.0");
map.put("method", "web3_clientVersion");
map.put("params", paramsList);
map.put("id", "67");
String st = client.callString("web3_clientVersion", map);
Message msg = new Message();
msg.what =SHOW;
msg.obj = st;
handler.sendMessage(msg);
} catch (JSONRPCException e) {
e.printStackTrace();
}
}
}).start();
}

}添加权限：<uses-permission android:name="android.permission.INTERNET"/>点击Button以后结果：