Android中处理Json数据

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1.Android中解析Json

JSON数据格式，在Android中被广泛运用于客户端和网络(或者说服务器)通信，非常有必要系统的了解学习。
恰逢本人最近对json做了一个简单的学习，特此总结一下，以飨各位。
为了文章简明清晰，尽量多列点，少废话。
参考文档：http://www.ietf.org/rfc/rfc4627.txt?number=4627

1.JSON解析
(1).解析Object之一:

"url""http://www.cnblogs.com/qianxudetianxia"

1

new "url"

1

{:,:}

　　解析方法:

JSONObject demoJson = JSONObject(jsonString);

String name = demoJson.getString();

String version = demoJson.getString();

System.out.println(+name++version);

(3).解析Array之一:

"number"

1

new "number"(int i=0; i<numberList.length(); i++){

System.out.println(numberList.getInt(i));

}

　　(4).解析Array之二:

"number"

1

//嵌套数组遍历

JSONObject demoJson = JSONObject(jsonString);

JSONArray numberList = demoJson.getJSONArray();

forint 0//获取数组中的数组

0

1

{:[{:},{:}]}

　　解析方法:

new "mobile"(i=; i<numberList.length(); i++){

"name"

1

"url""url"

1

"{""}"1

1

{

: {

: 800,

: 600,

: ,

: {

: <code string"="" style="white-space: pre-wrap; margin: 0px !important; padding: 0px !important; border-radius: 0px !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 2em !important; outline: 0px !important; overflow: visible !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-family: 'Courier New', Consolas, 'Bitstream Vera Sans Mono', Courier, monospace !important; color: blue !important; background-image: none !important;">"http://www.example.com/image/481989943""Height""Width""100"

"IDs"}

}

b.Array实例:

[

"precision""zip""Latitude""Longitude""Address""""City""SAN FRANCISCO""State""CA""Zip""94107""Country""US"

{

:,

: 37.371991,

: -122.026020,

: ,

: }

]

3.小结
很简单，很基础，积水方能成江，累砖才可筑楼。

2.Android利用Gson解析嵌套多层的Json

首先先讲一个比较简单点的例子(最简单的我就不讲啦，网上很多)，帮助新手理解Gson的使用方法：
               比如我们要解析一个下面这种的Json：
               String json = {"a":"100","b":[{"b1":"b_value1","b2":"b_value2"},{"b1":"b_value1","b2":"b_value2"}]，"c":{"c1":"c_value1","c2":"c_value2"}}
            首先我们需要定义一个序列化的Bean，这里采用内部类的形式，看起来会比较清晰一些：
            public class JsonBean {
                     public String a;
                     public List<B> b;
                     public C c;

                     public static class B {
                              public String b1;
                              public String b2;
                     }

                     public static class C {
                              public String c1;
                              public String c2;
                     }
            }
         很多时候大家都是不知道这个Bean是该怎么定义，这里面需要注意几点：
         1、内部嵌套的类必须是static的，要不然解析会出错；
         2、类里面的属性名必须跟Json字段里面的Key是一模一样的；
         3、内部嵌套的用[]括起来的部分是一个List，所以定义为 public List<B> b，而只用{}嵌套的就定义为 public C c，
               具体的大家对照Json字符串看看就明白了，不明白的我们可以互相交流，本人也是开发新手！
            Gson gson = new Gson();
            java.lang.reflect.Type type = new TypeToken<JsonBean>() {}.getType();
            JsonBean jsonBean = gson.fromJson(json, type);
            然后想拿数据就很简单啦，直接在jsonBean里面取就可以了！
   如果需要解析的Json嵌套了很多层，同样可以可以定义一个嵌套很多层内部类的Bean，需要细心的对照Json字段来定义哦。

3.Android从服务器端获取并解析Json

转自：http://www.cnblogs.com/qingblog/archive/2012/10/23/2735026.html

首先客户端从服务器端获取json数据

1、利用HttpUrlConnection

 1 /** 2      * 从指定的URL中获取数组 3      * @param urlPath 4      * @return 5      * @throws Exception 6      */ 7     public static String readParse(String urlPath) throws Exception {   8                ByteArrayOutputStream outStream = new ByteArrayOutputStream();   9                byte[] data = new byte[1024];  10                 int len = 0;  11                 URL url = new URL(urlPath);  12                 HttpURLConnection conn = (HttpURLConnection) url.openConnection();  13                 InputStream inStream = conn.getInputStream();  14                 while ((len = inStream.read(data)) != -1) {  15                     outStream.write(data, 0, len);  16                 }  17                 inStream.close();  18                 return new String(outStream.toByteArray());//通过out.Stream.toByteArray获取到写的数据  19             }

2、利用HttpClient

 1 /** 2      * 访问数据库并返回JSON数据字符串 3      *  4      * @param params 向服务器端传的参数 5      * @param url 6      * @return 7      * @throws Exception 8      */ 9     public static String doPost(List<NameValuePair> params, String url)10             throws Exception {11         String result = null;12         // 获取HttpClient对象13         HttpClient httpClient = new DefaultHttpClient();14         // 新建HttpPost对象15         HttpPost httpPost = new HttpPost(url);16         if (params != null) {17             // 设置字符集18             HttpEntity entity = new UrlEncodedFormEntity(params, HTTP.UTF_8);19             // 设置参数实体20             httpPost.setEntity(entity);21         }22 23         /*// 连接超时24         httpClient.getParams().setParameter(25                 CoreConnectionPNames.CONNECTION_TIMEOUT, 3000);26         // 请求超时27         httpClient.getParams().setParameter(CoreConnectionPNames.SO_TIMEOUT,28                 3000);*/29         // 获取HttpResponse实例30         HttpResponse httpResp = httpClient.execute(httpPost);31         // 判断是够请求成功32         if (httpResp.getStatusLine().getStatusCode() == 200) {33             // 获取返回的数据34             result = EntityUtils.toString(httpResp.getEntity(), "UTF-8");35         } else {36             Log.i("HttpPost", "HttpPost方式请求失败");37         }38 39         return result;40     }

其次Json数据解析：
json数据：[{"id":"67","biaoTi":"G","logo":"http://www.nuoter.com/wtserver/resources/upload/13508741845270.png","logoLunbo":"http://www.nuoter.com/wtserver/resources/upload/13509015004480.jpg","yuanJia":"0","xianJia":"0"},{"id":"64","biaoTi":"444","logo":"http://www.nuoter.com/wtserver/resources/upload/13508741704400.png","logoLunbo":"http://172.16.1.75:8080/wtserver/resources/upload/13508741738500.png","yuanJia":"0","xianJia":"0"},{"id":"62","biaoTi":"jhadasd","logo":"http://www.nuoter.com/wtserver/resources/upload/13508741500450.png","logoLunbo":"http://172.16.1.75:8080/wtserver/resources/upload/13508741557450.png","yuanJia":"1","xianJia":"0"}]

 1 /** 2      * 解析 3      *  4      * @throws JSONException 5      */ 6     private static ArrayList<HashMap<String, Object>> Analysis(String jsonStr) 7             throws JSONException { 8         /******************* 解析 ***********************/ 9         JSONArray jsonArray = null;10         // 初始化list数组对象11         ArrayList<HashMap<String, Object>> list = new ArrayList<HashMap<String, Object>>();12         jsonArray = new JSONArray(jsonStr);13         for (int i = 0; i < jsonArray.length(); i++) {14             JSONObject jsonObject = jsonArray.getJSONObject(i);15             // 初始化map数组对象16             HashMap<String, Object> map = new HashMap<String, Object>();17             map.put("logo", jsonObject.getString("logo"));18             map.put("logoLunbo", jsonObject.getString("logoLunbo"));19             map.put("biaoTi", jsonObject.getString("biaoTi"));20             map.put("yuanJia", jsonObject.getString("yuanJia"));21             map.put("xianJia", jsonObject.getString("xianJia"));22             map.put("id", jsonObject.getInt("id"));23             list.add(map);24         }25         return list;26     }

最后数据适配：

1、TextView

 1 /** 2  * readParse（String）从服务器端获取数据 3  * Analysis（String）解析json数据 4  */ 5     private void resultJson() { 6         try { 7             allData = Analysis(readParse(url)); 8             Iterator<HashMap<String, Object>> it = allData.iterator(); 9             while (it.hasNext()) {10                 Map<String, Object> ma = it.next();11                 if ((Integer) ma.get("id") == id) {12                     biaoTi.setText((String) ma.get("biaoTi"));13                     yuanJia.setText((String) ma.get("yuanJia"));14                     xianJia.setText((String) ma.get("xianJia"));15                 }16             }17         } catch (JSONException e) {18             e.printStackTrace();19         } catch (Exception e) {20             e.printStackTrace();21         }22     }

2、ListView：

 1 /** 2      * ListView 数据适配 3      */ 4     private void product_data(){  5         List<HashMap<String, Object>> lists = null; 6         try { 7             lists = Analysis(readParse(url));//解析出json数据 8         } catch (Exception e) { 9             // TODO Auto-generated catch block10             e.printStackTrace();11         }12         List<HashMap<String, Object>> data = new ArrayList<HashMap<String,Object>>();13         for(HashMap<String, Object> news : lists){14             HashMap<String, Object> item = new HashMap<String, Object>();15             item.put("chuXingTianShu", news.get("chuXingTianShu"));16             item.put("biaoTi", news.get("biaoTi"));17             item.put("yuanJia", news.get("yuanJia"));18             item.put("xianJia", news.get("xianJia"));19             item.put("id", news.get("id"));20             21             try {22                 bitmap = ImageService.getImage(news.get("logo").toString());//图片从服务器上获取23             } catch (Exception e) {24                 // TODO Auto-generated catch block25                 e.printStackTrace();26             }27             if(bitmap==null){28                 Log.i("bitmap", ""+bitmap);29                 Toast.makeText(TravelLine.this, "图片加载错误", Toast.LENGTH_SHORT)30                 .show();                                         // 显示图片编号31             }32             item.put("logo",bitmap);33             data.add(item);34         }35              listItemAdapter = new MySimpleAdapter1(TravelLine.this,data,R.layout.a_travelline_item,36                         // 动态数组与ImageItem对应的子项37                         new String[] { "logo", "biaoTi",38                                 "xianJia", "yuanJia", "chuXingTianShu"},39                         // ImageItem的XML文件里面的一个ImageView,两个TextView ID40                         new int[] { R.id.trl_ItemImage, R.id.trl_ItemTitle,41                                 R.id.trl_ItemContent, R.id.trl_ItemMoney,42                                 R.id.trl_Itemtoday});43                 listview.setAdapter(listItemAdapter);44                 //添加点击   45                 listview.setOnItemClickListener(new OnItemClickListener() {    46                     public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,   47                             long arg3) {   48                         login_publicchannel_trl_sub(arg2);49                     }   50                 });51     }

对于有图片的要重写适配器

 1 package com.nuoter.adapterUntil; 2  3  4 import java.util.HashMap; 5 import java.util.List; 6  7  8 import android.content.Context; 9 import android.graphics.Bitmap;10 import android.graphics.BitmapFactory;11 import android.graphics.Paint;12 import android.net.Uri;13 import android.view.LayoutInflater;14 import android.view.View;15 import android.view.ViewGroup;16 import android.widget.BaseAdapter;17 import android.widget.ImageView;18 import android.widget.LinearLayout;19 import android.widget.TextView;20 21 22 public class MySimpleAdapter1 extends BaseAdapter {  23     private LayoutInflater mInflater;  24     private List<HashMap<String, Object>> list;  25     private int layoutID;  26     private String flag[];  27     private int ItemIDs[];  28     public MySimpleAdapter1(Context context, List<HashMap<String, Object>> list,  29             int layoutID, String flag[], int ItemIDs[]) {  30         this.mInflater = LayoutInflater.from(context);  31         this.list = list;  32         this.layoutID = layoutID;  33         this.flag = flag;  34         this.ItemIDs = ItemIDs;  35     }  36     @Override  37     public int getCount() {  38         // TODO Auto-generated method stub  39         return list.size();  40     }  41     @Override  42     public Object getItem(int arg0) {  43         // TODO Auto-generated method stub  44         return 0;  45     }  46     @Override  47     public long getItemId(int arg0) {  48         // TODO Auto-generated method stub  49         return 0;  50     }  51     @Override  52     public View getView(int position, View convertView, ViewGroup parent) {  53         convertView = mInflater.inflate(layoutID, null);  54        // convertView = mInflater.inflate(layoutID, null);  55         for (int i = 0; i < flag.length; i++) {//备注1  56             if (convertView.findViewById(ItemIDs[i]) instanceof ImageView) {  57                 ImageView imgView = (ImageView) convertView.findViewById(ItemIDs[i]);  58                 imgView.setImageBitmap((Bitmap) list.get(position).get(flag[i]));///////////关键是这句!!!!!!!!!!!!!!!59  60             }else if (convertView.findViewById(ItemIDs[i]) instanceof TextView) {  61                 TextView tv = (TextView) convertView.findViewById(ItemIDs[i]);  62                 tv.setText((String) list.get(position).get(flag[i]));  63             }else{64                 //...备注2 65             }  66         }  67         //addListener(convertView); 68         return convertView;  69     }  70 71 /*    public void addListener(final View convertView) {72         73         ImageView imgView = (ImageView)convertView.findViewById(R.id.lxs_item_image);74         75         76  77     } */78 79 }

对于图片的获取，json解析出来的是字符串url："logoLunbo":http://www.nuoter.com/wtserver/resources/upload/13509015004480.jpg 从url获取图片

ImageService工具类

 1 package com.nuoter.adapterUntil; 2  3 import java.io.ByteArrayOutputStream; 4 import java.io.InputStream; 5 import java.net.HttpURLConnection; 6 import java.net.URL; 7  8 import android.graphics.Bitmap; 9 import android.graphics.BitmapFactory;10 11 12 public class ImageService {13     14     /**15      * 获取网络图片的数据16      * @param path 网络图片路径17      * @return18      */19     public static Bitmap getImage(String path) throws Exception{20         21         /*URL url = new URL(imageUrl);   22         HttpURLConnection conn = (HttpURLConnection) url.openConnection();   23         InputStream is = conn.getInputStream();   24         mBitmap = BitmapFactory.decodeStream(is);*/25         Bitmap bitmap= null;26         URL url = new URL(path);27         HttpURLConnection conn = (HttpURLConnection) url.openConnection();//基于HTTP协议连接对象28         conn.setConnectTimeout(5000);29         conn.setRequestMethod("GET");30         if(conn.getResponseCode() == 200){31             InputStream inStream = conn.getInputStream();32             bitmap = BitmapFactory.decodeStream(inStream);33         }34         return bitmap;35     }36     37     /**38      * 读取流中的数据 从url获取json数据39      * @param inStream40      * @return41      * @throws Exception42      */43     public static byte[] read(InputStream inStream) throws Exception{44         ByteArrayOutputStream outStream = new ByteArrayOutputStream();45         byte[] buffer = new byte[1024];46         int len = 0;47         while( (len = inStream.read(buffer)) != -1){48             outStream.write(buffer, 0, len);49         }50         inStream.close();51         return outStream.toByteArray();52     }53 54 55 }

上面也将从url处获取网络数据写在了工具类ImageService中方面调用，因为都是一样的。

当然也可以在Activity类中写一个获取服务器图片的函数（当用处不多时）

 1  /* 2  3      * 从服务器取图片 4      * 参数：String类型 5      * 返回：Bitmap类型 6  7      */ 8  9     public static Bitmap getHttpBitmap(String urlpath) {10         Bitmap bitmap = null;11         try {12             //生成一个URL对象13             URL url = new URL(urlpath);14             //打开连接15             HttpURLConnection conn = (HttpURLConnection)url.openConnection();16 //            conn.setConnectTimeout(6*1000);17 //            conn.setDoInput(true);18             conn.connect();19             //得到数据流20             InputStream inputstream = conn.getInputStream();21             bitmap = BitmapFactory.decodeStream(inputstream);22             //关闭输入流23             inputstream.close();24             //关闭连接25             conn.disconnect();26         } catch (Exception e) {27             Log.i("MyTag", "error:"+e.toString());28         }29         return bitmap;30     }

调用：

 1 public ImageView pic; 2 ..... 3 ..... 4 allData=Analysis(readParse(url)); 5 Iterator<HashMap<String, Object>> it=allData.iterator(); 6 while(it.hasNext()){ 7 Map<String, Object> ma=it.next(); 8 if((Integer)ma.get("id")==id) 9 {10 logo=(String) ma.get("logo");11 bigpic=getHttpBitmap(logo);12 }13 }14 pic.setImageBitmap(bigpic);

另附下载数据很慢时建立子线程并传参：

 1 new Thread() { 2             @Override 3             public void run() { 4                 // 参数列表 5                 List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); 6                 nameValuePairs.add(new BasicNameValuePair("currPage", Integer 7                         .toString(1))); 8                 nameValuePairs.add(new BasicNameValuePair("pageSize", Integer 9                         .toString(5)));10                 try {11                     String result = doPost(nameValuePairs, POST_URL);                    12                     Message msg = handler.obtainMessage(1, 1, 1, result);13                     handler.sendMessage(msg);                     // 发送消息14                 } catch (Exception e) {15                     // TODO Auto-generated catch block16                     e.printStackTrace();17                 }18             }19         }.start();20 21         // 定义Handler对象22         handler = new Handler() {23             public void handleMessage(Message msg) {24                 switch (msg.what) {25                 case 1:{26                     // 处理UI27                     StringBuffer strbuf = new StringBuffer();28                     List<HashMap<String, Object>> lists = null;29                     try {30                         lists = MainActivity.this31                                 .parseJson(msg.obj.toString());32                     } catch (Exception e) {33                         // TODO Auto-generated catch block34                         e.printStackTrace();35                     }36                     List<HashMap<String, Object>> data = new ArrayList<HashMap<String,Object>>();37                     for(HashMap<String, Object> news : lists){38                         HashMap<String, Object> item = new HashMap<String, Object>();39                         item.put("id", news.get("id"));40                         item.put("ItemText0", news.get("name"));41                         42                         try {43                             bitmap = ImageService.getImage(news.get("logo").toString());44                         } catch (Exception e) {45                             // TODO Auto-generated catch block46                             e.printStackTrace();47                         }48                         if(bitmap==null){49                             Log.i("bitmap", ""+bitmap);50                             Toast.makeText(MainActivity.this, "图片加载错误", Toast.LENGTH_SHORT)51                             .show();                                         // 显示图片编号52                         }53                         item.put("ItemImage",bitmap);54                         data.add(item);55                     }56                     57                     //生成适配器的ImageItem <====> 动态数组的元素，两者一一对应58                     MySimpleAdapter saImageItems = new MySimpleAdapter(MainActivity.this, data, 59                             R.layout.d_travelagence_item, 60                             new String[] {"ItemImage", "ItemText0", "ItemText1"}, 61                             new int[] {R.id.lxs_item_image, R.id.lxs_item_text0, R.id.lxs_item_text1});62                     //添加并且显示63                     gridview.setAdapter(saImageItems);64                 }65                     break;66                 default:67                     break;68                 }69                 70                 71             }72         };

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