从网页返回字符串-android失败

我正在尝试使用以下代码从网站检索字符串：

// webgrabber starts here
public String getPage() {
    // lets format the icaos the user is interested in
    icaos = etICAO1.getText().toString() + " "
            + etICAO2.getText().toString() + " "
            + etICAO3.getText().toString() + " "
            + etICAO4.getText().toString() + " "
            + etICAO5.getText().toString() + " "
            + etICAO6.getText().toString() + " "
            + etICAO7.getText().toString() + " "
            + etICAO8.getText().toString() + " ";

    //now lets format the webaddress
    finalWebAddress = websitePart1 + icaos + websitePart2;
    //try to get the data
    Toast.makeText(getApplicationContext(),
                    "Collecting data from " + finalWebAddress, Toast.LENGTH_LONG).show();
    try {
        HttpURLConnection con = (HttpURLConnection) new URL(finalWebAddress)
                .openConnection();
        con.connect();

        if (con.getResponseCode() == HttpURLConnection.HTTP_OK) {
            return inputStreamToString(con.getInputStream());
        } else {
            Toast.makeText(getApplicationContext(),
                        "No Internet connection detected.  Please fix your connection and try again.", Toast.LENGTH_LONG).show();
            return null;
        }
    } catch (IOException ex) {
        return null;
    }
}

private String inputStreamToString(InputStream in) throws IOException {
    BufferedReader bufferedReader = new BufferedReader(
            new InputStreamReader(in));
    StringBuilder stringBuilder = new StringBuilder();
    String line = null;

    while ((line = bufferedReader.readLine()) != null) {
        stringBuilder.append(line + "\n");
    }

    bufferedReader.close();
    //set the TV to the weather we returned
    return stringBuilder.toString();
}

使用以下代码从Onclick调用getPage（）：

if (v == ibGrabber) {           
    getPage();
    tvWeather.setText(getPage());
}

当我点击按钮时，我从logcat获得以下信息：

11-22 08:18:51.780: E/AndroidRuntime(11637): FATAL EXCEPTION: main
11-22 08:18:51.780: E/AndroidRuntime(11637): android.os.NetworkOnMainThreadException
11-22 08:18:51.780: E/AndroidRuntime(11637):    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1118)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at java.net.InetAddress.getAllByName(InetAddress.java:214)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:315)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpEngine.connect(HttpEngine.java:310)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:289)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:239)
11-22 08:18:51.780: E/AndroidRuntime(11637):    at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:80)

11-22 08:18:51.780:E/AndroidRuntime（11637）：致命异常：main
11-22 08:18:51.780:E/AndroidRuntime（11637）：android.os.NetworkOnMainThreadException
11-22 08:18:51.780:E/AndroidRuntime（11637）：在android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork（StrictMode.java:1118）
11-22 08:18:51.780:E/AndroidRuntime（11637）：位于java.net.InetAddress.lookupHostByName（InetAddress.java:385）
11-22 08:18:51.780:E/AndroidRuntime（11637）：位于java.net.InetAddress.getAllByNameImpl（InetAddress.java:236）
11-22 08:18:51.780:E/AndroidRuntime（11637）：位于java.net.InetAddress.getAllByName（InetAddress.java:214）
11-22 08:18:51.780:E/AndroidRuntime（11637）：位于libcore.net.http.HttpConnection.（HttpConnection.java:70）
11-22 08:18:51.780:E/AndroidRuntime（11637）：位于libcore.net.http.HttpConnection.（HttpConnection.java:50）
11-22 08:18:51.780:E/AndroidRuntime（11637）：在libcore.net.http.HttpConnection$Address.connect（HttpConnection.java:340）
11-22 08:18:51.780:E/AndroidRuntime（11637）：在libcore.net.http.HttpConnectionPool.get（HttpConnectionPool.java:87）
11-22 08:18:51.780:E/AndroidRuntime（11637）：在libcore.net.http.HttpConnection.connect（HttpConnection.java:128）上
11-22 08:18:51.780:E/AndroidRuntime（11637）：位于libcore.net.http.HttpEngine.openSocketConnection（HttpEngine.java:315）
11-22 08:18:51.780:E/AndroidRuntime（11637）：位于libcore.net.http.HttpEngine.connect（HttpEngine.java:310）
11-22 08:18:51.780:E/AndroidRuntime（11637）：位于libcore.net.http.HttpEngine.sendSocketRequest（HttpEngine.java:289）
11-22 08:18:51.780:E/AndroidRuntime（11637）：位于libcore.net.http.HttpEngine.sendRequest（HttpEngine.java:239）
11-22 08:18:51.780:E/AndroidRuntime（11637）：在libcore.net.http.HttpURLConnectionImpl.connect（HttpURLConnectionImpl.java:80）

有人能帮我检索这个字符串并在我的文本视图中设置值吗

谢谢,

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Andy使用AsynTask来完成与网络相关的任务

Android不允许在主线程上进行网络调用。您需要使用Aysnc任务。有关如何使用异步任务的更多详细信息，请参阅以下链接

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谢谢您的链接。我已经看过async任务，但它在博客上声明该任务只能运行一次。如果用户多次单击图像按钮，我希望能够在需要时多次运行该任务。我如何管理它呢？所以每次您想要运行异步任务时，都要创建它的新实例并调用execute方法。