Question

我正在构建我的第一个应用程序，并且我对此有点新的但是：

我正在使用HttpURLConnection发送HTTP Get请求。这是我的活动代码：

    import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class HttpGetServletActivity3 extends Activity implements
    OnClickListener {
Button button;
TextView outputText;

public static final String URL =
    "URL";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    findViewsById();

    button.setOnClickListener(this);
}

private void findViewsById() {
    button = (Button) findViewById(R.id.button);
    outputText = (TextView) findViewById(R.id.outputTxt);
}

public void onClick(View view) {
    GetXMLTask task = new GetXMLTask();
    task.execute(new String[] { URL });
}

private class GetXMLTask extends AsyncTask<String, Void, String> {
    @Override
    protected String doInBackground(String... urls) {
        String output = null;
        for (String url : urls) {
            output = getOutputFromUrl(url);
        }
        return output;
    }

    private String getOutputFromUrl(String url) {
        StringBuffer output = new StringBuffer("");
        try {
            InputStream stream = getHttpConnection(url);
            BufferedReader buffer = new BufferedReader(
                    new InputStreamReader(stream));
            String s = "";
            while ((s = buffer.readLine()) != null)
                output.append(s);
        } catch (IOException e1) {
            e1.printStackTrace();
        }
        return output.toString();
    }

    // Makes HttpURLConnection and returns InputStream
    private InputStream getHttpConnection(String urlString)
            throws IOException {
        InputStream stream = null;
        URL url = new URL(urlString);
        URLConnection connection = url.openConnection();

        try {
            HttpURLConnection httpConnection = (HttpURLConnection) connection;
            httpConnection.setRequestMethod("GET");
            httpConnection.connect();

            if (httpConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                stream = httpConnection.getInputStream();
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return stream;
    }

    @Override
    protected void onPostExecute(String output) {
        outputText.setText(output);
    }
}
}

此代码将帮助我显示网站的源代码，并且它正在运行!! 但是，如果我想要一个特定的源代码行怎么办？例如只有第60行？我试图更改以下BuuferedReader块：

BufferedReader buffer = new BufferedReader(
                    new InputStreamReader(stream));
            String s = "";
            while ((s = buffer.readLine()) != null)
                output.append(s);

我写了下面的LineReader，但没有工作：

LineNumberReader lnr = new LineNumberReader(new InputStreamReader(stream));   
            String s = "";
            if (lnr.getLineNumber() == 60){
                output.append(s);
            }

这是做到这一点的方式还是我错过了什么？

Answer 1

您可以使用setLineNumber方法;

lnr.setLineNumber(60)

然后，你可以阅读这行！

Answer 2

如果你试图让你知道的部分代码在边界之间（即。和），那么你可以做类似的事情：

将Stream转换为单个String（我们将其称为结果），然后：

String start = "<body>", end = "</body>";
result = result.substring(result.indexOf(start) + start.length(), result.indexOf(end));

HTTP URL连接：显示特定的网站源代码行

2 个答案: