javascript - Android 为 Node.js 服务器抛出 FileNotFoundException

Question

我正在尝试将我的 Android 应用程序连接到 Node.js 服务器。对于 URL，我使用了 ifconfig 并发现是 192.168.1.33，因此我在端口 3030 上启动了服务器。

当我从浏览器打开192.168.1.33:3030时，成功获取JSON结果但是当我在 app 中执行相同操作时，它会抛出:

09-09 13:14:38.176  28693-28725/com.example.pournima.loginform W/System.err﹕ java.io.FileNotFoundException: http://192.168.1.33:3030
09-09 13:14:38.184  28693-28725/com.example.pournima.loginform W/System.err﹕ at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:197)
09-09 13:14:38.184  28693-28725/com.example.pournima.loginform W/System.err﹕ at com.example.pournima.loginform.RetreiveStuff.doInBackground(RetreiveStuff.java:43)
09-09 13:14:38.184  28693-28725/com.example.pournima.loginform W/System.err﹕ at com.example.pournima.loginform.RetreiveStuff.doInBackground(RetreiveStuff.java:18)
09-09 13:14:38.184  28693-28725/com.example.pournima.loginform W/System.err﹕ at android.os.AsyncTask$2.call(AsyncTask.java:288)
09-09 13:14:38.184  28693-28725/com.example.pournima.loginform W/System.err﹕ at java.util.concurrent.FutureTask.run(FutureTask.java:237)
09-09 13:14:38.184  28693-28725/com.example.pournima.loginform W/System.err﹕ at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
09-09 13:14:38.184  28693-28725/com.example.pournima.loginform W/System.err﹕ at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
09-09 13:14:38.184  28693-28725/com.example.pournima.loginform W/System.err﹕ at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
09-09 13:14:38.185  28693-28725/com.example.pournima.loginform W/System.err﹕ at java.lang.Thread.run(Thread.java:818)
09-09 13:14:38.185  28693-28693/com.example.pournima.loginform D/RESULT :﹕ [ 09-09 13:14:38.218  1089: 1235 V/AlarmManager ]
send {1a636348, *alarm*:com.domobile.applock/.service.LockService}

node.js 命令提示符显示:

Error: invalid json
at parse (/home/mayur/intern/node_modules/body-parser/lib/types/json.js:79:15)
at /home/mayur/intern/node_modules/body-parser/lib/read.js:102:18
at done (/home/mayur/intern/node_modules/body-parser/node_modules/raw-body/index.js:248:14)
at IncomingMessage.onEnd (/home/mayur/intern/node_modules/body-parser/node_modules/raw-body/index.js:294:7)
at IncomingMessage.g (events.js:199:16)
at IncomingMessage.emit (events.js:104:17)
at _stream_readable.js:908:16
at process._tickCallback (node.js:355:11)

我的onCreate():

  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    bt  = (Button) findViewById(R.id.login);
    bt.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            tv = (TextView) findViewById(R.id.UserName);
            String username = tv.getText().toString();
            RetreiveStuff rs = new RetreiveStuff();
            try {
                String a =  rs.execute(username).get();
                Log.d("RESULT : ", a);
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                e.printStackTrace();
            }
        }
    });
}

RetreiveStuff.java:

package com.example.pournima.loginform;


public class RetreiveStuff extends AsyncTask<String,Void,String>{

@Override
protected void onPostExecute(String s) {
    super.onPostExecute(s);

}

@Override
protected String doInBackground(String ... params) {

    StringBuilder sb = new StringBuilder();
    try {
        URL url = new URL("http://192.168.1.33:3030");
        String username = params[0];
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        con.setDoOutput(true);
        con.setRequestMethod("POST");
        con.setRequestProperty("Content-Type", "application/json");
        OutputStream os = con.getOutputStream();
        String toPass = "{\"username\" : \"" + username + "\" }";
        Log.d("String passed : " , toPass);
        os.write(username.getBytes());
        os.flush();

        BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
        String line = "";
        while((line = reader.readLine())!=null){
            sb.append(line + '\n');
        }
        reader.close();

    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    return sb.toString();

}
}

服务器.js:

var app = require('express')(); // Express App include
var http = require('http').Server(app); // http server
var mysql = require('mysql'); // Mysql include
var bodyParser = require("body-parser"); // Body parser for fetch posted data
var connection = mysql.createConnection({ // Mysql Connection
host : 'localhost',
user : 'root',
password : 'mayur',
database : 'mayur',
});

app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

app.post('/',function(req,res){

connection.query("SELECT * from login where username= ? ", req.body.username ,function(err, rows, fields){
    if(rows.length!=0){
        res.json(rows);

    }else{
        var data = 'No users Found..';
        res.json(data);
    }
});
});

app.get('/',function(req,res){

res.json("You have called get");
});
app.listen(3030);

Answer 1

您仅将 JSON 输出到日志中。您还需要将其传递给请求。

您的代码:

OutputStream os = con.getOutputStream();
String toPass = "{\"username\" : \"" + username + "\" }";
Log.d("String passed : " , toPass);
os.write(username.getBytes());
os.flush();

修复:

OutputStream os = con.getOutputStream();
String toPass = "{\"username\" : \"" + username + "\" }";
Log.d("String passed : " , toPass);
os.write(toPass.getBytes());
os.flush();

修复线路:

os.write(toPass.getBytes());