Android简单的获取网络上的json文件

设置网络访问权限

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.wangjialin.internet.json"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".MainActivity"
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>
<uses-sdk android:minSdkVersion="8" />
<!-- 访问internet权限 -->
<uses-permission android:name="android.permission.INTERNET"/>

</manifest>

布局文件：

mian.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<ListView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/listView"
/>
</LinearLayout>

布局文件：

item.xml

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

<TextView
android:layout_width="200dp"
android:layout_height="wrap_content"
android:id="@+id/title"
/>

<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/timelength"
/>
</LinearLayout>

编写主MainActivity文件，具体内容如下：

package com.wangjialin.internet.json;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import com.wangjialin.internet.json.domain.News;
import com.wangjialin.internet.json.service.NewsService;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class MainActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ListView listView = (ListView) this.findViewById(R.id.listView);

String length = this.getResources().getString(R.string.length);
try {
List<News> newes = NewsService.getJSONLastNews();
List<HashMap<String, Object>> data = new ArrayList<HashMap<String,Object>>();
for(News news : newes){
HashMap<String, Object> item = new HashMap<String, Object>();
item.put("id", news.getId());
item.put("title", news.getTitle());
item.put("timelength", length+ news.getTimelength());
data.add(item);
}
SimpleAdapter adapter = new SimpleAdapter(this, data, R.layout.item,
new String[]{"title", "timelength"}, new int[]{R.id.title, R.id.timelength});
listView.setAdapter(adapter);
} catch (Exception e) {
e.printStackTrace();
}
}
}

MainActivity 的核心功能是获取数据并显示数据。

其中获取的数据内的NewsService的具体内容如下：

package com.wangjialin.internet.json.service;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONObject;

import com.wangjialin.internet.json.domain.News;
import com.wangjialin.internet.json.utils.StreamTool;

public class NewsService {

/**
* 获取最新视频资讯
* @return
* @throws Exception
*/
public static List<News> getJSONLastNews() throws Exception{
String path = "http://192.168.1.100:8080/ServerForJSON/NewsListServlet";
HttpURLConnection conn = (HttpURLConnection) new URL(path).openConnection();
conn.setConnectTimeout(5000);
conn.setRequestMethod("GET");
if(conn.getResponseCode() == 200){
InputStream json = conn.getInputStream();
return parseJSON(json);
}
return null;
}

private static List<News> parseJSON(InputStream jsonStream) throws Exception{
List<News> list = new ArrayList<News>();
byte[] data = StreamTool.read(jsonStream);
String json = new String(data);
JSONArray jsonArray = new JSONArray(json);
for(int i = 0; i < jsonArray.length() ; i++){
JSONObject jsonObject = jsonArray.getJSONObject(i);
int id = jsonObject.getInt("id");
String title = jsonObject.getString("title");
int timelength = jsonObject.getInt("timelength");
list.add(new News(id, title, timelength));
}
return list;
}
}

在getJSONLastNews方法中是直接请求搭建好的web服务器，获取JSON输入流后，使用parseJSON方法解析XML数据并最终返回集合数据。

同时在ＮewsService中用到了一个JavaBean，用于封装XML数据，其名称News，具体内容如下所示：

package com.wangjialin.internet.json.domain;

public class News {
private Integer id;
private String title;
private Integer timelength;
public News(){}
public News(Integer id, String title, Integer timelength) {
this.id = id;
this.title = title;
this.timelength = timelength;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public Integer getTimelength() {
return timelength;
}
public void setTimelength(Integer timelength) {
this.timelength = timelength;
}

}