600字范文 > android端获取Tomcat服务器端json数据并通过listview显示

android端获取Tomcat服务器端json数据并通过listview显示

时间：2019-07-14 00:41:17

大体描述：

大体意思是用eclipse ee创建一个Javaweb项目,该项目能从MySQL数据库中获取user表的数据，将数据封装成json格式，将此项目发布到本地Tomcat服务器，在android端获取刚才的json数据，并用listview显示。废话不多说下面直接开始。

Tomcat服务器端

很简单，建立一个servlet用来处理数据，再建一个数据库工具类，我这里是DatabaseUtil.java，不要忘记servlet在web.xml中需要注册。

项目结构：

code:

ServletDemo1.java

package com.servlet.demo;import java.io.IOException;import java.sql.ResultSet;import java.sql.SQLException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import net.sf.json.JSON;import net.sf.json.JSONArray;import net.sf.json.JSONObject;import util.DatabaseUtil;public class ServletDemo1 extends HttpServlet {private static final long serialVersionUID = 1L;public ServletDemo1() {super();}protected void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doPost(request, response);}protected void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {String sql = "select * from user";JSONArray jsonArray=new JSONArray(); //json数组try {ResultSet result = DatabaseUtil.query(sql);while (result.next()) {JSONObject jObject=new JSONObject(); //json临时对象jObject.put("id", result.getInt(1));jObject.put("username", result.getString(2));jObject.put("password", result.getString(3));jsonArray.add(jObject); //将封装好的json对象放入json数组}} catch (SQLException e) {e.printStackTrace();}String jsondata=jsonArray.toString(); //将json数组转换成字符串，供下面返回给android端使用//System.out.println(jsondata); //本地测试用response.getWriter().append(jsondata).flush();}}

DatabaseUtil.java

package util;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import com.mysql.jdbc.Statement;public class DatabaseUtil {private static Connection mConnection;private static Connection getConnection() {if (mConnection == null) {String url = "jdbc:mysql://localhost:3306/mybatis"; try {Class.forName("com.mysql.jdbc.Driver"); mConnection = (Connection) DriverManager.getConnection(url, "root", "123");} catch (Exception e) {e.printStackTrace();}}return mConnection;}//这里只用了查询操作public static ResultSet query(String querySql) throws SQLException {Statement stateMent = (Statement) getConnection().createStatement();return stateMent.executeQuery(querySql);}public static void closeConnection() {if (mConnection != null) {try {mConnection.close();mConnection = null;} catch (SQLException e) {e.printStackTrace();}}}}

web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="/2001/XMLSchema-instance" xmlns="/xml/ns/javaee" xsi:schemaLocation="/xml/ns/javaee /xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1"><display-name>ConnectTest</display-name><welcome-file-list><welcome-file>index.html</welcome-file><welcome-file>index.htm</welcome-file><welcome-file>index.jsp</welcome-file><welcome-file>default.html</welcome-file><welcome-file>default.htm</welcome-file><welcome-file>default.jsp</welcome-file></welcome-file-list><servlet><servlet-name>ServletDemo1</servlet-name><servlet-class>com.servlet.demo.ServletDemo1</servlet-class></servlet><servlet-mapping><servlet-name>ServletDemo1</servlet-name><url-pattern>/ServletDemo1</url-pattern></servlet-mapping></web-app>

本地测试结果

在浏览器地址栏里输入（端口啥的自己改了的话用自己的，不多说）

http://localhost:8080/ConnectTest/ServletDemo1

测试结果：

android端

也比较简单，有两个activity，在mainactivity中有个button按钮，点击后跳转到第二个activity,我这里是ListActivity ,在listactivity中显示获取到的json数据。

用到的jar包

类

布局

code

工具类 HttpUtil

package util;import okhttp3.OkHttpClient;import okhttp3.Request;public class HttpUtil {public static void sendOkHttpRequest(String address,okhttp3.Callback callback){OkHttpClient client=new OkHttpClient();Request request=new Request.Builder().url(address).build();client.newCall(request).enqueue(callback);}}

实体类 User

package c.connecttest.activity;public class User {private int id;private String username;private String password;public User(int id,String username, String password){this.id=id;this.username=username;this.password=password;}public int getId() {return id;}public String getUsername() {return username;}public String getPassword() {return password;}}

适配器 UserAdapter

package c.connecttest.activity;import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.TextView;import c.connecttest.R;import java.util.List;public class UserAdapter extends ArrayAdapter<User> {private int resourceId;public UserAdapter(Context context, int resourceId, List<User> objects) {super(context, resourceId,objects);this.resourceId=resourceId;}@Overridepublic View getView(int position, View convertView,ViewGroup parent) {User user=getItem(position);View view;ViewHolder viewHolder;if(convertView==null){view= LayoutInflater.from(getContext()).inflate(resourceId,parent,false);viewHolder=new ViewHolder();viewHolder.userid=(TextView)view.findViewById(R.id.tv_id);viewHolder.username=(TextView)view.findViewById(R.id.tv_username);viewHolder.userpassword=(TextView)view.findViewById(R.id.tv_password);view.setTag(viewHolder); //将viewHolder存储在view中}else{view=convertView;viewHolder=(ViewHolder)view.getTag();}viewHolder.userid.setText(String.valueOf(user.getId()));viewHolder.username.setText(user.getUsername());viewHolder.userpassword.setText(user.getPassword());return view;}static class ViewHolder{TextView userid;TextView username;TextView userpassword;}}

显示的页面 ListActivity

package c.connecttest.activity;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.widget.ListView;import c.connecttest.R;import org.json.JSONArray;import org.json.JSONException;import org.json.JSONObject;import java.io.IOException;import java.util.ArrayList;import java.util.List;import okhttp3.Call;import okhttp3.Callback;import okhttp3.Response;import util.HttpUtil;public class ListActivity extends AppCompatActivity {private List<User> userList=new ArrayList<>();private ListView listView;private String json_url="http://192.168.2.133:8080/ConnectTest/ServletDemo1";//本地Tomcat刚才测试的地址@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_list);queryFromServer(json_url); //处理取得数据listView=findViewById(R.id.lv);UserAdapter adapter = new UserAdapter(ListActivity.this, R.layout.user, userList);listView.setAdapter(adapter);}private void queryFromServer(String json_url) {HttpUtil.sendOkHttpRequest(json_url, new Callback() {@Overridepublic void onFailure(Call call, IOException e) {Log.i("error","出现错误！");}@Overridepublic void onResponse(Call call, Response response) throws IOException {String responseText=response.body().string();try {JSONArray jsonArray=new JSONArray(responseText);for(int i=0;i<jsonArray.length();i++){JSONObject jsonObject=jsonArray.getJSONObject(i);String id=jsonObject.getString("id");String username=jsonObject.getString("username");String password=jsonObject.getString("password");User user=new User(Integer.parseInt(id),username,password);userList.add(user);Log.i("user","添加了一个User");}} catch (JSONException e) {e.printStackTrace();}}});}}

主页面 MainActivity

package c.connecttest.activity;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.Button;import c.connecttest.R;public class MainActivity extends Activity {private Button button;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);button=findViewById(R.id.btnSign);//点击跳转到显示页面button.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {startActivity(new Intent(MainActivity.this, ListActivity.class));}});}}

配置 AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="/apk/res/android"package="c.connecttest"><uses-permission android:name="android.permission.INTERNET" /><applicationandroid:allowBackup="true"android:icon="@mipmap/ic_launcher"android:label="@string/app_name"android:roundIcon="@mipmap/ic_launcher_round"android:supportsRtl="true"android:theme="@style/AppTheme"><activity android:name=".activity.MainActivity"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity><activity android:name=".activity.ListActivity"/></application></manifest>

布局

activity_main.xml:

<LinearLayout xmlns:android="/apk/res/android"xmlns:tools="/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical" ><Buttonandroid:layout_marginTop="200dp"android:id="@+id/btnSign"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_gravity="center_horizontal"android:text="获取" /></LinearLayout

activity_list.xml:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><ListViewandroid:id="@+id/lv"android:layout_width="match_parent"android:layout_height="wrap_content"/></LinearLayout>

listview每一项适配文件： user.xml

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:padding="15dp"><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="vertical"><TextViewandroid:id="@+id/tv_id"android:text="1111"android:layout_width="wrap_content"android:layout_height="wrap_content"android:textSize="18sp" /><TextViewandroid:text="2222"android:id="@+id/tv_username"android:layout_width="wrap_content"android:layout_height="wrap_content"android:textSize="14sp" /><TextViewandroid:text="3333"android:id="@+id/tv_password"android:layout_width="wrap_content"android:layout_height="wrap_content"android:textColor="#d97e87"android:textSize="16sp" /></LinearLayout></RelativeLayout>