Question

我对android很新。我正在尝试构建一个基本应用程序，以便了解＆＃34; android应用程序从服务器读取数据＆＃34;。为了了解关于android的http连接，我创建了这个应用程序观看视频教程，我有两个java类。

HttpExample.java类，

package com.raveen.testingthree;

import android.app.Activity;
import android.os.Bundle;
import android.os.StrictMode;
import android.view.View;
import android.widget.TextView;

public class HttpExample extends Activity {

TextView httpStuff;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
            .detectAll().penaltyLog().build();
    StrictMode.setThreadPolicy(policy);
    super.onCreate(savedInstanceState);
    httpStuff = (TextView) findViewById(R.id.tvHttp);
    GetMethodHttp test = new GetMethodHttp();
    String returned;
    try {
        returned = test.getInternetData();
        httpStuff.setText(returned);
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}



}

和getmethodhttp.java类，

package com.raveen.testingthree;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URI;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

public class GetMethodHttp {

public String getInternetData () throws Exception{
    BufferedReader in = null;
    String data = null;

    try{
        HttpClient client = new DefaultHttpClient();
        URI website = new URI("http://www.google.com");
        HttpGet request = new HttpGet();
        request.setURI(website);
        HttpResponse responce = client.execute(request);

        in = new BufferedReader(new InputStreamReader(responce.getEntity().getContent()));
        StringBuffer sb = new StringBuffer("");
        String line = "";
        String newLine = System.getProperty("line.separator");

        while((line = in.readLine()) != null){
            sb.append(line + newLine);

        }
        in.close();
        data = sb.toString();
        return data;

    } finally {
        if (in != null){
            try{
                in.close();
                return data;
            } catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}

}

这是我的AndroidManifest，

<uses-sdk
    android:minSdkVersion="15"
    android:targetSdkVersion="22" />

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".HttpExample"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

</application>


</manifest>

和我的布局xml，

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<ScrollView
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <TextView
        android:id="@+id/tvHttp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Loading Data"
        android:textSize="20dp"
         />
</ScrollView>

</LinearLayout>

现在当我在模拟器上运行它或我的Android手机没有显示时..只是一个空白的白色布局是可见的..我在这里做错了什么？

（我正在使用eclipse进行编程）

Answer 1

首先，您不应更改策略以强制主线程上的网络调用，而是使用Async task。

如果你想阅读html内容，那么使用允许解析html的jsoup。如果你想从webservice读取数据，那么试试VOLLEY Library。这样可以节省你的时间，提高工作效率和可追溯性。

Android，从互联网应用程序接收数据不起作用

1 个答案: