Android 实现json网络数据通过BaseAdapter加载到ListView中
效果图，有点没有设计美感，哈哈，凑合着看吧
关于json，我对json有一定的了解，所以这个项目我用自己构建的服务器输出json数据，文件名json.php
php代码如下
"{'data':1,'students':[{'name':'张三','age':22,'url':'http://192.168.1.103/pictures/pic1.jpg'},{'name':'李四','age':23,'url':'http://192.168.1.103/pictures/pic2.jpg'},{'name':'王五','age':26,'url':'http://192.168.1.103/pictures/pic3.jpg'},{'name':'刘流','age':32,'url':'http://192.168.1.103/pictures/pic4.jpg'},{'name':'陈曦','age':22,'url':'http://192.168.1.103/pictures/pic5.jpg'}]}";
echo $json;
?>
Android文件目录图：
Android配置页AndroidMenifests.xml代码如下
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.imooc.capton.json">
<uses-permission android:name="android.permission.INTERNET">uses-permission>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
intent-filter>
activity>
application>
manifest>activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.imooc.capton.json.MainActivity">
<ListView
android:id="@+id/listview"
android:layout_width="match_parent"
android:layout_height="match_parent">
ListView>
RelativeLayout>
student.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="180dp"
android:layout_height="120dp"
android:src="@mipmap/ic_launcher"
android:layout_gravity="center"
android:id="@+id/imageView" />
<LinearLayout
android:orientation="vertical"
android:layout_gravity="center"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:text="TextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20dp"
android:id="@+id/name" />
<TextView
android:text="TextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/age" />
LinearLayout>
LinearLayout>MainActivity.java
package com.imooc.capton.json;
import android.content.Context;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;
public class MainActivity extends AppCompatActivity {
Context context=this;
ListView listView;
Handler handler;
JsonAdapter jsonAdapter;
String url="http://192.168.1.103/json.php";//这个url随你设置的php页面而变动。
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView= (ListView) findViewById(R.id.listview);
handler=new Handler();//获得一个handler对象，为后面的各个线程提供处理UI的依据
new JsonThread(context, listView, url,handler).start();
}
}
JsonThread.java
package com.imooc.capton.json;
import android.content.Context;
import android.os.Handler;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
/**
* Created by CAPTON on 2016/11/25.
*/
//访问目标网址，得到json数据，保存List数据，等待传入JsonAdapter
public class JsonThread extends Thread {
Context context;
ListView listView;
String url;
Handler handler;//关键参数 整个小项目中的核心之一，会在JsonThread和JsonAdapter，ImageThread中传递，用于更新UI界面
List students;
JsonAdapter jsonAdapter;
public JsonThread(Context context, ListView listView, String url,Handler handler ) {
this.context=context;
this.listView=listView;
this.url=url;
this.handler=handler;
}
//从String中解析所需数据，如name，age，url，将他们装入Student中，再将Student逐条加入List中
private List getStudents(String data){
List students=new ArrayList();
try {
JSONObject object=new JSONObject(data);
if(object.getInt("data")==1){
JSONArray jsonArray=object.getJSONArray("students");
for(int i=0;inew Student();
student.name=studentObject.getString("name");
System.out.println(student.name);
student.age=studentObject.getInt("age");
System.out.println(student.age);
student.url=studentObject.getString("url");
System.out.println(student.url);
students.add(student);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return students;
}
@Override
public void run() {
//从网络中获取数据，转换为String类型
StringBuffer result=new StringBuffer();
try {
URL Url=new URL(url);
HttpURLConnection connection= (HttpURLConnection) Url.openConnection();
connection.setRequestMethod("GET");
connection.setReadTimeout(5000);
InputStream inputStream=connection.getInputStream();
BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line=bufferedReader.readLine())!=null){
result.append(line);
}
System.out.println(result);
students=getStudents(result.toString());//调用解析方法
inputStream.close();
bufferedReader.close();
handler.post(new Runnable() {
@Override
public void run() {
jsonAdapter=new JsonAdapter(context,handler,students); //传递关键参数MainActivity上下文对象context，MainActivity主线程的handler对象,处理好的List对象
listView.setAdapter(jsonAdapter);
}
});
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
super.run();
}
} JsonAdapter.java
package com.imooc.capton.json;
import android.content.Context;
import android.graphics.Bitmap;
import android.os.Handler;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import java.util.List;
/**
* Created by CAPTON on 2016/11/25.
*/
// 适配器，等待被JsonThread调用
public class JsonAdapter extends BaseAdapter {
List students;
Context context;
LayoutInflater inflater;
Handler handler;
public JsonAdapter(Context context,Handler handler,List students) {
this.handler=handler;
this.context=context;
this.students=students;
inflater=LayoutInflater.from(context);//从MainActivity中上下文对象中获取LayoutInflater；所以说这个context,和handler对象很重要，贯穿整项目
}
@Override
public int getCount() {
return students.size();
}
@Override
public Object getItem(int position) {
return students.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
//重写getView方法，即设置ListView每一项的视图
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder=null;
if(convertView==null){
convertView=inflater.inflate(R.layout.student,null);
holder=new ViewHolder(convertView);
convertView.setTag(holder);//设置tag
}else {
holder= (ViewHolder) convertView.getTag(); //获取tag
}
System.out.println(String.valueOf(students.get(position).age));//测试数据是否正常
holder.age.setText(String.valueOf(students.get(position).age));
holder.name.setText(students.get(position).name);
System.out.println(students.get(position).name);
new ImageThread(students.get(position).url, handler,holder.image).start();//开启新线程下载图片并在新线程中更新UI，所以要传递handler对象
return convertView;
}
//用于暂时保存视图对象
class ViewHolder{
public TextView name;
public TextView age;
public ImageView image;
public ViewHolder(View view){
name= (TextView) view.findViewById(R.id.name);
age= (TextView) view.findViewById(R.id.age);
image= (ImageView) view.findViewById(R.id.imageView);
}
}
} ImageThread.java
package com.imooc.capton.json;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.widget.ImageView;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.List;
/**
* Created by CAPTON on 2016/11/25.
*/
//根据url读取图片数据，把图片Bitmap保存下来等待 JsonAdapter调用
public class ImageThread extends Thread {
String url;
ImageView imageView;
Handler handler;
public ImageThread(String url, Handler handler,ImageView imageView) {
this.url = url;
this.imageView=imageView;
this.handler=handler;
}
@Override
public void run() {
try {
final Bitmap bitmap= BitmapFactory.decodeStream(new URL(url).openStream());//简单粗暴，可能有问题，自己做的时候注意
handler.post(new Runnable() {
@Override
public void run() {
imageView.setImageBitmap(bitmap);
}
});
} catch (IOException e) {
e.printStackTrace();
}
super.run();
}
}Student.java
package com.imooc.capton.json;
/**
* Created by CAPTON on 2016/11/25.
*/
// bean数据
public class Student {
public String name;
public String url;
public int age;
}到此整个项目代码如上，根据慕课网nate老师的视频教程纯手打实现，感觉比他的代码要简洁一些，毕竟没有源码，鄙人在此献上代码，欢迎各位指导评论