Json获取、解析案例演示

标签：

JSON有两种表示结构，对象和数组.

对象结构以”{”大括号开始，以”}”大括号结束。中间部分由0或多个以”，”分隔的”key(关键字)/value(值)”对构成，关键字和值之间以”：”分隔，语法结构如代码。

其中关键字是字符串，而值可以是字符串，数值，true,false,null,对象或数组

数组结构以”[”开始，”]”结束。中间由0或多个以”，”分隔的值列表组成，语法结构如代码。 

****************************************************案例*******************************************

这里先贴出bean类

Result

package com.lw.bean;

import java.util.ArrayList;
import java.util.List;

public class Result {
	//结果值，如果为2说明返回正确
	private int result;
	private List<Person> personData =  new ArrayList<Person>();
	public int getResult() {
		return result;
	}
	public void setResult(int result) {
		this.result = result;
	}
	public List<Person> getPersonData() {
		return personData;
	}
	public void setPersonData(List<Person> personData) {
		this.personData = personData;
	}
	
	
}

package com.lw.bean;

import java.util.List;

public class Person {
	private String url;
	private String name;
	private int age;
	private List<SchoolInfo> schoolInfo;


	public List<SchoolInfo> getSchoolInfo() {
		return schoolInfo;
	}

	public void setSchoolInfo(List<SchoolInfo> schoolInfo) {
		this.schoolInfo = schoolInfo;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public String getUrl() {
		return url;
	}

	public void setUrl(String url) {
		this.url = url;
	}
}

package com.lw.bean;

public class SchoolInfo {
	private String name;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}

json.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@+id/listView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="150dp"
        android:layout_height="100dp"
        android:layout_alignParentLeft="true" />

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="100dp"
        android:layout_toRightOf="@id/imageView"
        android:padding="10dp" >

        <TextView
            android:id="@+id/name"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="name" />

        <TextView
            android:id="@+id/age"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/name"
            android:text="age" />

        <TextView
            android:id="@+id/school1"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/age"
            android:text="school1"
            android:textSize="20dp" />

        <TextView
            android:id="@+id/school2"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/school1"
            android:text="school2"
            android:textSize="20dp" />
    </RelativeLayout>

</RelativeLayout>

JsonActivyty

package com.lw.http01;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.widget.ListView;

public class JsonActivyty extends Activity {

	private ListView listView;
	private JsonAdapter jsonAdapter;
	private Handler handler = new Handler();

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		/** json布局文件中，只有一个listview控件 */
		setContentView(R.layout.json);
		listView = (ListView) findViewById(R.id.listView);
		/**
		 * 一开始是没有数据的，后来从服务器获取在子线程中跟新数据和ui界面的
		 * 
		 */
		jsonAdapter = new JsonAdapter(this);
		
		/**
		 * 服务度http://192.168.79.101:8080/testAndroidServer/jsonServlet就能获取到json数据
		 * 这里没有贴出服务端代码,知道上面一句话就够了
		 */
		new JsonThread(
				"http://192.168.79.101:8080/testAndroidServer/jsonServlet",
				this, listView, jsonAdapter, handler).start();
	}
}

JsonThread

package com.lw.http01;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.content.Context;
import android.os.Handler;
import android.widget.ListView;
import android.widget.Toast;

import com.lw.bean.Person;
import com.lw.bean.SchoolInfo;

public class JsonThread extends Thread {

	/**
	 * url是服务器地址
	 * context是环境，需要toast提示
	 * listview是需要setadapter的设置适配器
	 * jsonAdapter是需要设置数据的
	 * handler是需要子线程更新ui的
	 */
	private String url;
	private Context context;
	private ListView listView;
	private JsonAdapter jsonAdapter;
	private Handler handler;

	public JsonThread(String url, Context context, ListView listView,
			JsonAdapter jsonAdapter, Handler handler) {
		this.url = url;
		this.context = context;
		this.listView = listView;
		this.jsonAdapter = jsonAdapter;
		this.handler = handler;
	}

	@Override
	public void run() {
		try {
			// 创建URL对象，并且设置相应的参数
			URL httpurl = new URL(url);
			//打开连接
			HttpURLConnection conn = (HttpURLConnection) httpurl
					.openConnection();
			conn.setReadTimeout(5000);
			conn.setRequestMethod("GET");

			// 从服务器读取数据，需要读入流
			BufferedReader reader = new BufferedReader(new InputStreamReader(
					conn.getInputStream()));

			// 读取完毕，就存放到StringBuffer容器中
			StringBuffer sb = new StringBuffer();
			String str = "";
			while ((str = reader.readLine()) != null) {
				// 当读取完毕，就添加到容器中
				sb.append(str);
			}
			// 将读取到的Json字符串，进行解析为Person对象集合
			final List<Person> parseJson = parseJson(sb.toString());
			// handler在子线程中更新数据
			handler.post(new Runnable() {

				@Override
				public void run() {
					// 设置数据到adapter视图中，使其获取到数据
					jsonAdapter.setData(parseJson);
					// 设置适配器
					listView.setAdapter(jsonAdapter);
				}
			});

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/***
	 * 解析服务端返回的Json字符串数据，因为adapter的视图中item是一个个Person对象，所以返回Person集合即可
	 * 这里用android的原生解析
	 */
	private List<Person> parseJson(String json) {
		//json解析完毕，返回person的集合对象
		List<Person> persons = new ArrayList<Person>();
		try {
			/**
			 * {"1":[{person对象},{person对象},{person对象}]}
			 * 所以整体是个json对象，而不是json数组
			 * 所以创建JSONObject对象
			 */
			
			JSONObject jsonObj = new JSONObject(json);
			//获取result值
			int result = jsonObj.getInt("result");

			//如果为2说明返回正确
			if (result == 2) {
				//获取person的json数组
				JSONArray personData = jsonObj.getJSONArray("personData");

				/**
				 * 循环解析每一个person对象
				 */
				for (int i = 0; i < personData.length(); i++) {
					//创建person对象
					Person personObj = new Person();
					List<SchoolInfo> scInfos = new ArrayList<SchoolInfo>();

					//从json对象数组中获取每一个json类型的person对象
					JSONObject person = personData.getJSONObject(i);
					//为person对象设置json类型的person对象的值
					personObj.setName(person.getString("name"));
					personObj.setAge(person.getInt("age"));
					personObj.setUrl(person.getString("url"));


					/**获取json类型的person中的school信息*/
					JSONArray scs = person.getJSONArray("schoolInfo");
					for (int j = 0; j < scs.length(); j++) {
						SchoolInfo schoolObj = new SchoolInfo();
						JSONObject school = scs.getJSONObject(j);
						schoolObj.setName(school.getString("name"));
						scInfos.add(schoolObj);
					}

					personObj.setSchoolInfo(scInfos);
					persons.add(personObj);

				}
			} else {
				Toast.makeText(context, "error", 1);
			}
		} catch (JSONException e) {
			e.printStackTrace();
		}
		return persons;
	}

}

JsonAdapter

package com.lw.http01;

import java.util.List;

import android.content.Context;
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.TextView;

import com.lw.bean.Person;
import com.lw.bean.SchoolInfo;

public class JsonAdapter extends BaseAdapter {

	private List<Person> list;
	private Context context;
	private LayoutInflater inflater;
	private Handler handler = new Handler();
	
	public JsonAdapter(Context context) {
		this.context = context;
		inflater = LayoutInflater.from(context);
	}

	public JsonAdapter(List<Person> list, Context context) {
		this.list = list;
		this.context = context;
		inflater = LayoutInflater.from(context);
	}
	/**
	 * 设置数据的，数据是从服务器解析过来的
	 * @param list
	 */
	public void setData(List<Person> list){
		this.list = list;
	}

	@Override
	public int getCount() {
		return list.size();
	}

	@Override
	public Object getItem(int position) {
		return list.get(position);
	}

	@Override
	public long getItemId(int position) {
		return position;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		ViewHolder holder = null;
		if (convertView == null) {
			convertView = inflater.inflate(R.layout.item, null);
			holder = new ViewHolder(convertView);
			convertView.setTag(holder);
		} else {
			holder = (ViewHolder) convertView.getTag();
		}
		/***
		 * item的数据是从setData中得来的，是jsonThread中handler操作的
		 */
		Person person = list.get(position);
		holder.name.setText(person.getName());
		holder.age.setText(person.getAge()+"");

		List<SchoolInfo> scs = person.getSchoolInfo();
		holder.school1.setText(scs.get(0).getName());
		holder.school2.setText(scs.get(1).getName());
		//这里的图片信息，也是需要开启子线程，进行获取，需要传递这3个参数
		new HttpImage(holder.imageView, person.getUrl(), handler).start();
		return convertView;
	}

	/**
	 * viewHodler不解释
	 *
	 */
	class ViewHolder {
		private TextView name;
		private TextView age;
		private TextView school1;
		private TextView school2;
		private ImageView imageView;

		public ViewHolder(View view) {
			name = (TextView) view.findViewById(R.id.name);
			age = (TextView) view.findViewById(R.id.age);
			school1 = (TextView) view.findViewById(R.id.school1);
			school2 = (TextView) view.findViewById(R.id.school2);
			imageView = (ImageView) view.findViewById(R.id.imageView);
		}
	}
}

HttpImage

package com.lw.http01;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.widget.ImageView;

public class HttpImage extends Thread {
	/**
	 * imageview是需要在分线程中handler更新ui的
	 * url是图片的url
	 * handler是子线程跟新ui操作的
	 */
	private ImageView imageView;
	private String url;
	private Handler handler;

	public HttpImage(ImageView imageView, String url, Handler handler) {
		this.imageView = imageView;
		this.url = url;
		this.handler = handler;
	}

	@Override
	public void run() {
		try {
			/**
			 * 跟jsonThread操作一样，系列的参数
			 */
			URL httpurl = new URL(url);
			HttpURLConnection conn = (HttpURLConnection) httpurl.openConnection();
			conn.setReadTimeout(5000);
			conn.setRequestMethod("GET");
			//这样的方式也可以获取一个图片  decodeStream
			final Bitmap bitmap = BitmapFactory.decodeStream(conn.getInputStream());
			
			handler.post(new Runnable() {
				
				@Override
				public void run() {
					//子线程中直接更新界面
					imageView.setImageBitmap(bitmap);
				}
			});
			
			
		} catch (MalformedURLException e) {
			e.printStackTrace();
		} catch (ProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	

}

Json获取、解析案例演示

标签：

原文地址：http://blog.csdn.net/u013210620/article/details/47193867