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Android 如何使用EntityUtils将服务器响应写入TextView？

android

Android 如何使用EntityUtils将服务器响应写入TextView？,android,textview,Android,Textview,为什么在我运行此代码时模拟器会崩溃 TextView servmsg; String data; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.te

为什么在我运行此代码时模拟器会崩溃

    TextView servmsg;
    String data;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test_msg);
        Vars();
        new SendtheData().execute("");
    }

    private void Vars() {
        // TODO Auto-generated method stub
        servmsg = (TextView) findViewById(R.id.tvServerMsg);
    }

    public class SendtheData extends AsyncTask<String, Integer, Void> {

        protected void onPreExecute(String f) {
            // called before doInBackground has started
            f = "f";
        }

        protected Void doInBackground(String... params) {
            // TODO Auto-generated method stub
            HttpClient client = new DefaultHttpClient();
            HttpPost post = new HttpPost(
                    "http://192.168.1.6/androidp2p/process.php");
            try {
                List<NameValuePair> pairs = new ArrayList<NameValuePair>(3);
                pairs.add(new BasicNameValuePair("from", "test4"));
                pairs.add(new BasicNameValuePair("to", ""));
                pairs.add(new BasicNameValuePair("message", ""));
                post.setEntity(new UrlEncodedFormEntity(pairs));
                HttpResponse response = client.execute(post);
                // Convert the response into a String
                HttpEntity resEntity = response.getEntity();

                // Print the response
                data = EntityUtils.toString(resEntity);
                servmsg.setText(data);

                // Write the response to a log file
                if (resEntity != null) {
                    Log.i("RESPONSE", EntityUtils.toString(resEntity));
                }
            } catch (UnsupportedEncodingException uee) {
                uee.printStackTrace();
            } catch (ClientProtocolException cpe) {
                cpe.printStackTrace();
            } catch (IOException ioe) {
                ioe.printStackTrace();
            }
            return null;
        }

        protected void onProgressUpdate(Integer... progress) {
            // called when the background task has made any progress
        }

        protected void onPostExecute() {
            // called after doInBackground has finished
        }

    }
提前谢谢

试过之后 受保护的void onPostExecute（）{ //在doInBackground完成后调用 servmg.setText（数据）； }

这是新的LogCat：

03-27 00:56:24.006: W/dalvikvm(1736): threadid=11: thread exiting with uncaught exception (group=0x40a13300)
03-27 00:56:24.048: E/AndroidRuntime(1736): FATAL EXCEPTION: AsyncTask #1
03-27 00:56:24.048: E/AndroidRuntime(1736): java.lang.RuntimeException: An error occured while executing doInBackground()
03-27 00:56:24.048: E/AndroidRuntime(1736):     at android.os.AsyncTask$3.done(AsyncTask.java:299)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at java.util.concurrent.FutureTask.run(FutureTask.java:137)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at java.lang.Thread.run(Thread.java:856)
03-27 00:56:24.048: E/AndroidRuntime(1736): Caused by: java.lang.IllegalStateException: Content has been consumed
03-27 00:56:24.048: E/AndroidRuntime(1736):     at org.apache.http.entity.BasicHttpEntity.getContent(BasicHttpEntity.java:84)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at org.apache.http.conn.BasicManagedEntity.getContent(BasicManagedEntity.java:100)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at org.apache.http.util.EntityUtils.toString(EntityUtils.java:112)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at org.apache.http.util.EntityUtils.toString(EntityUtils.java:146)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at com.project.keegan.testPrintMsg$SendtheData.doInBackground(testPrintMsg.java:77)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at com.project.keegan.testPrintMsg$SendtheData.doInBackground(testPrintMsg.java:1)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at android.os.AsyncTask$2.call(AsyncTask.java:287)
03-27 00:56:24.048: E/AndroidRuntime(1736):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
下面是我的PHP代码：

<?php

/* connect to database */
$db = mysql_connect("localhost", "root", "root");
if (!$db)
    die('could not connect');

mysql_select_db('androidp2p')
    or die("could not select database");


$from = mysql_real_escape_string($_POST['from']); 
$to = mysql_real_escape_string($_POST['to']);
$message = mysql_real_escape_string($_POST['message']);


if ($_POST['to'])
{
    /* user wants to send a message */
    $query = "INSERT INTO messages (fromuser, touser, message) VALUES ('$from', '$to', '$message')";

    mysql_query($query)
        or die("\n\ndatabase error!\n". mysql_error());

    echo "ok. Messages have been saved.";

}
else
{
    /* user wants to retrieve his messages*/
    $query = "SELECT * FROM messages WHERE touser='$from'";

    $result = mysql_query($query)
        or die("\n\ndatabase error!\n". mysql_error());


    $message_count = mysql_num_rows($result);
    if( $message_count == 0)
    {
        /* no messages*/
        echo "ok. There are no messages.";  
    }
    else
    {
        /* output messages */
        while ($row = mysql_fetch_assoc($result))
        {
            echo "message start\n{$row['fromuser']}\n{$row['message']}\nmessage end\n";
        }


        /* clear messages */
        $query = "DELETE FROM messages WHERE touser='$from'";

        mysql_query($query)
            or die("\n\ndatabase error!\n". mysql_error());


        echo "ok. Cleared all messages.";       
    }
}


?>

公共类发送数据扩展异步任务{
受保护的void onPreExecute（字符串f）{
//在doInBackground开始之前调用
f=“f”；
}
受保护的字符串doInBackground（字符串…参数）{
//TODO自动生成的方法存根
字符串数据=null；
HttpClient=new DefaultHttpClient（）；
HttpPost=新的HttpPost(
"http://192.168.1.6/androidp2p/process.php");
试一试{
列表对=新的ArrayList（3）；
添加（新的BasicNameValuePair（“from”，“test4”））；
添加（新的BasicNameValuePair（“to“，”）；
添加（新的BasicNameValuePair（“message”和“”）；
setEntity（新的UrlEncodedFormEntity（对））；
HttpResponse response=client.execute（post）；
//将响应转换为字符串
HttpEntity当前性=response.getEntity（）；
//打印响应
数据=EntityUtils.toString（最近性）；
//将响应写入日志文件
if（最近性！=null）{
Log.i（“响应”，EntityUtils.toString（resEntity））；
}
}捕获（不支持的编码异常uee）{
uee.printStackTrace（）；
}捕获（客户端协议异常cpe）{
printStackTrace（）；
}捕获（ioe异常ioe）{
ioe.printStackTrace（）；
}
返回数据；
}
受保护的void onProgressUpdate（整数…进度）{
//在后台任务取得任何进展时调用
}
受保护的void onPostExecute（字符串数据）{
if（null！=数据）
{
servmg.setText（数据）；
}否则{
//处理错误
}
}
}


您可以更改
异步任务
，实现如下。始终在
AsyncTask
的
onPsotExecute
方法中处理结果。希望这会有所帮助

另外，如果我可以添加的话，服务器的响应有3个字段，
“收件人、发件人和信息”。什么是最好的方式，把每一个这些
他们自己的文本视图


从PHP页面返回的响应，您可以使其成为
JSON
响应，并使用android
JSONParser
从客户端解析该
JSON
响应，您的响应可能如下
“{status:'200'，statusMessage:'success or as your wish'，data{to:'value'，from:'value'，message your message}”
谢谢。它已将消息打印到屏幕上。但是有一件事，就像@K所说的，您必须注释掉Log.i（“RESPONSE”，EntityUtils.toString（resEntity）），代码才能工作
在从
doInBackground
方法返回之前执行此操作。是否也可以回答问题的第二部分。。。。服务器的响应有3个字段，“收件人、发件人和消息”。什么是最好的方式来把它们放到自己的文本视图中？好的，谢谢。我对JSONParser一无所知，但如果这是最简单的方法，我会检查一下。 
<?php

/* connect to database */
$db = mysql_connect("localhost", "root", "root");
if (!$db)
    die('could not connect');

mysql_select_db('androidp2p')
    or die("could not select database");


$from = mysql_real_escape_string($_POST['from']); 
$to = mysql_real_escape_string($_POST['to']);
$message = mysql_real_escape_string($_POST['message']);


if ($_POST['to'])
{
    /* user wants to send a message */
    $query = "INSERT INTO messages (fromuser, touser, message) VALUES ('$from', '$to', '$message')";

    mysql_query($query)
        or die("\n\ndatabase error!\n". mysql_error());

    echo "ok. Messages have been saved.";

}
else
{
    /* user wants to retrieve his messages*/
    $query = "SELECT * FROM messages WHERE touser='$from'";

    $result = mysql_query($query)
        or die("\n\ndatabase error!\n". mysql_error());


    $message_count = mysql_num_rows($result);
    if( $message_count == 0)
    {
        /* no messages*/
        echo "ok. There are no messages.";  
    }
    else
    {
        /* output messages */
        while ($row = mysql_fetch_assoc($result))
        {
            echo "message start\n{$row['fromuser']}\n{$row['message']}\nmessage end\n";
        }


        /* clear messages */
        $query = "DELETE FROM messages WHERE touser='$from'";

        mysql_query($query)
            or die("\n\ndatabase error!\n". mysql_error());


        echo "ok. Cleared all messages.";       
    }
}


?>

public class SendtheData extends AsyncTask<String, Integer, String> {

    protected void onPreExecute(String f) {
        // called before doInBackground has started
        f = "f";
    }

    protected String doInBackground(String... params) {
        // TODO Auto-generated method stub
        String data = null;
        HttpClient client = new DefaultHttpClient();
        HttpPost post = new HttpPost(
                "http://192.168.1.6/androidp2p/process.php");
        try {
            List<NameValuePair> pairs = new ArrayList<NameValuePair>(3);
            pairs.add(new BasicNameValuePair("from", "test4"));
            pairs.add(new BasicNameValuePair("to", ""));
            pairs.add(new BasicNameValuePair("message", ""));
            post.setEntity(new UrlEncodedFormEntity(pairs));
            HttpResponse response = client.execute(post);
            // Convert the response into a String
            HttpEntity resEntity = response.getEntity();

            // Print the response
            data = EntityUtils.toString(resEntity);

            // Write the response to a log file
            if (resEntity != null) {
                Log.i("RESPONSE", EntityUtils.toString(resEntity));
            }
        } catch (UnsupportedEncodingException uee) {
            uee.printStackTrace();
        } catch (ClientProtocolException cpe) {
            cpe.printStackTrace();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }
        return data;
    }

    protected void onProgressUpdate(Integer... progress) {
        // called when the background task has made any progress
    }

    protected void onPostExecute(String data) {
        if(null != data)
        {
            servmsg.setText(data);
        }else{
            //handle Error
        }

    }

}