android客户端从服务器端获取json数据并解析

矫情吗；* 2022-08-02 13:45 161阅读 0赞

首先客户端从服务器端获取json数据

1、利用HttpUrlConnection

/**
     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 block
    10             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 block
    25                 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 ID
    40                         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][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      * @return
    18      */
    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 inStream
    40      * @return
    41      * @throws Exception
    42      */
    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 block
    16                     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UI
    27                     StringBuffer strbuf = new StringBuffer();
    28                     List<HashMap<String, Object>> lists = null;
    29                     try {
    30                         lists = MainActivity.this
    31                                 .parseJson(msg.obj.toString());
    32                     } catch (Exception e) {
    33                         // TODO Auto-generated catch block
    34                         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 block
    46                             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         };

[http_www.nuoter.com_wtserver_resources_upload_13509015004480.jpg]: http://www.nuoter.com/wtserver/resources/upload/13509015004480.jpg