• android通过HttpClient与服务器JSON交互


    通过昨天对HttpClient的学习,今天封装了HttpClient类

    代码如下:

    package com.tp.soft.util;
    
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Map;
    
    import org.apache.http.HttpResponse;
    import org.apache.http.HttpStatus;
    import org.apache.http.NameValuePair;
    import org.apache.http.client.ClientProtocolException;
    import org.apache.http.client.HttpClient;
    import org.apache.http.client.entity.UrlEncodedFormEntity;
    import org.apache.http.client.methods.HttpPost;
    import org.apache.http.impl.client.DefaultHttpClient;
    import org.apache.http.message.BasicNameValuePair;
    import org.apache.http.protocol.HTTP;
    
    public class HttpUtil {
        public static String postRequest(String serverPath, Map<String, String> params, String encoding){
            List<NameValuePair> paramPair = new ArrayList<NameValuePair>();
            if(params != null && !params.isEmpty()){
                for(Map.Entry<String, String> entry : params.entrySet()){
                    paramPair.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
                }
            }
            try {
                HttpClient client = new DefaultHttpClient();
                HttpPost post = new HttpPost(serverPath);
                post.setEntity(new UrlEncodedFormEntity(paramPair, HTTP.UTF_8));
                HttpResponse response = client.execute(post);
                if(response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){
                    BufferedReader br = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
                    //数据
                    String reqData = null;
                    String responseData = "";
                    while((reqData = br.readLine()) != null){
                        responseData += reqData;
                    }
                    br.close();
                    return responseData;
                }
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return "postRequest error";
        }
    }

    然后通过调用HttpUtil类来达成与服务器交互

    package com.tp.soft.app;
    
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.view.LayoutInflater;
    import android.view.Menu;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.BaseAdapter;
    import android.widget.ListView;
    import android.widget.TextView;
    
    import com.google.gson.Gson;
    import com.google.gson.reflect.TypeToken;
    import com.tp.soft.entity.User;
    import com.tp.soft.util.HttpUtil;
    
    public class MainActivity extends Activity {
        
        private ListView mListView;
        private TextView mContentTxt;
        private TextView mTimeTxt;
        
        private String serverPath = "http://122.226.178.54:8080/uploadApp/LoginServlet";
        private static final String ENCODING = "utf-8";
        private List<User> userList;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            loadList();
             mListView = (ListView) findViewById(R.id.list_id);
            mListView.setAdapter(new BaseAdapter() {
                
                @Override
                public View getView(int position, View convertView, ViewGroup parent) {
                    if(null == convertView){
                        convertView = LayoutInflater.from(getApplicationContext()).inflate(R.layout.item, null);
                    }
                    
                    TextView textView = (TextView) convertView.findViewById(R.id.contentTxt);
                    textView.setText(userList.get(position).getUsername());
                    return convertView;
                }
                
                @Override
                public long getItemId(int position) {
                    return position;
                }
                
                @Override
                public Object getItem(int position) {
                    return position;
                }
                
                @Override
                public int getCount() {
                    return userList.size();
                }
            });
        }
    
        private List<User> loadList() {
            Map<String, String> params = new HashMap<String, String>();
            String data = HttpUtil.postRequest(serverPath, params, ENCODING);
            userList = new Gson().fromJson(data, new TypeToken<List<User>>() {}.getType());    
            return userList;
        }
    
        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            getMenuInflater().inflate(R.menu.main, menu);
            return true;
        }
    }

    服务器端则采用了servlet

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            response.setCharacterEncoding("utf-8");
            String uname = request.getParameter("uname");
            String pwd = request.getParameter("pwd");
            
            PrintWriter pw = response.getWriter();
            Gson gson = new GsonBuilder().create();
            List<User> userList = new ArrayList<User>();
            User user = new User();
            user.setUsername("zs");
            user.setPassword("1");
            userList.add(user);
            
            User user1 = new User();
            user1.setUsername("lisi");
            user1.setPassword("2");
            userList.add(user1);
            String json = gson.toJson(userList);
            pw.print(json);
        }
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  • 原文地址:https://www.cnblogs.com/tplovejava/p/3919538.html
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