Json----Json解析-优快云博客

本文详细介绍了如何在Android应用中集成并解析JSON数据，包括获取JSON内容、解析JSON对象为实体类的过程，以及如何从JSON数组中提取数据。

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package com.android.myjson;

import java.util.List;
import java.util.Map;

import com.android.myjson.domain.Person;
import com.android.myjson.http.HttpUtils;
import com.android.myjson.json.JsonTools;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Main extends Activity implements OnClickListener {
	/** Called when the activity is first created. */
	private Button person, persons, liststring, listmap;
	private static final String TAG = "Main";

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		person = (Button) this.findViewById(R.id.person);
		persons = (Button) this.findViewById(R.id.persons);
		liststring = (Button) this.findViewById(R.id.liststring);
		listmap = (Button) this.findViewById(R.id.listmap);
		person.setOnClickListener(this);
		persons.setOnClickListener(this);
		liststring.setOnClickListener(this);
		listmap.setOnClickListener(this);

	}

	public void onClick(View v) {
		// TODO Auto-generated method stub
		switch (v.getId()) {
		case R.id.person:
			String path = "http://192.168.0.102:8080/jsonProject/servlet/JsonAction?action_flag=person";
			String jsonString = HttpUtils.getJsonContent(path);
			Person person = JsonTools.getPerson("person", jsonString);
			Log.i(TAG, person.toString());
			break;
		case R.id.persons:
			String path2 = "http://192.168.0.102:8080/jsonProject/servlet/JsonAction?action_flag=persons";
			String jsonString2 = HttpUtils.getJsonContent(path2);
			List<Person> list2 = JsonTools.getPersons("persons", jsonString2);
			Log.i(TAG, list2.toString());
			break;
		case R.id.liststring:
			String path3 = "http://192.168.0.102:8080/jsonProject/servlet/JsonAction?action_flag=liststring";
			String jsonString3 = HttpUtils.getJsonContent(path3);
			List<String> list3 = JsonTools.getList("liststring", jsonString3);
			Log.i(TAG, list3.toString());
			break;
		case R.id.listmap:
			String path4 = "http://192.168.0.102:8080/jsonProject/servlet/JsonAction?action_flag=listmap";
			String jsonString4 = HttpUtils.getJsonContent(path4);
			List<Map<String, Object>> list4 = JsonTools.listKeyMaps("listmap",
					jsonString4);
			Log.i(TAG, list4.toString());
			break;
		}
	}
}

package com.android.myjson.http;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpUtils {

	public HttpUtils() {
		// TODO Auto-generated constructor stub
	}

	public static String getJsonContent(String url_path) {
		try {
			URL url = new URL(url_path);
			HttpURLConnection connection = (HttpURLConnection) url
					.openConnection();
			connection.setConnectTimeout(3000);
			connection.setRequestMethod("GET");
			connection.setDoInput(true);
			int code = connection.getResponseCode();
			if (code == 200) {
				return changeInputStream(connection.getInputStream());
			}
		} catch (Exception e) {
			// TODO: handle exception
		}
		return "";
	}

	private static String changeInputStream(InputStream inputStream) {
		// TODO Auto-generated method stub
		String jsonString = "";
		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
		int len = 0;
		byte[] data = new byte[1024];
		try {
			while ((len = inputStream.read(data)) != -1) {
				outputStream.write(data, 0, len);
			}
			jsonString = new String(outputStream.toByteArray());
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return jsonString;
	}
}

关键类：

JSONObject jsonObject = new JSONObject(jsonString);// 返回json的数组

JSONArray jsonArray = jsonObject.getJSONArray(key);

package com.android.myjson.json;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

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

import com.android.myjson.domain.Person;

/**
 * 完成对json数据的解析
 * 
 * @author jack
 * 
 */
public class JsonTools {

	public JsonTools() {
		// TODO Auto-generated constructor stub
	}

	public static Person getPerson(String key, String jsonString) {
		Person person = new Person();
		try {
			JSONObject jsonObject = new JSONObject(jsonString);
			JSONObject personObject = jsonObject.getJSONObject("person");
			person.setId(personObject.getInt("id"));
			person.setName(personObject.getString("name"));
			person.setAddress(personObject.getString("address"));
		} catch (Exception e) {
			// TODO: handle exception
		}
		return person;
	}

	public static List<Person> getPersons(String key, String jsonString) {
		List<Person> list = new ArrayList<Person>();
		try {
			JSONObject jsonObject = new JSONObject(jsonString);
			// 返回json的数组
			JSONArray jsonArray = jsonObject.getJSONArray(key);
			for (int i = 0; i < jsonArray.length(); i++) {
				JSONObject jsonObject2 = jsonArray.getJSONObject(i);
				Person person = new Person();
				person.setId(jsonObject2.getInt("id"));
				person.setName(jsonObject2.getString("name"));
				person.setAddress(jsonObject2.getString("address"));
				list.add(person);
			}
		} catch (Exception e) {
			// TODO: handle exception
		}
		return list;
	}

	public static List<String> getList(String key, String jsonString) {
		List<String> list = new ArrayList<String>();
		try {
			JSONObject jsonObject = new JSONObject(jsonString);
			JSONArray jsonArray = jsonObject.getJSONArray(key);
			for (int i = 0; i < jsonArray.length(); i++) {
				String msg = jsonArray.getString(i);
				list.add(msg);
			}
		} catch (Exception e) {
			// TODO: handle exception
		}
		return list;
	}

	public static List<Map<String, Object>> listKeyMaps(String key,
			String jsonString) {
		List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
		try {
			JSONObject jsonObject = new JSONObject(jsonString);
			JSONArray jsonArray = jsonObject.getJSONArray(key);
			for (int i = 0; i < jsonArray.length(); i++) {
				JSONObject jsonObject2 = jsonArray.getJSONObject(i);
				Map<String, Object> map = new HashMap<String, Object>();
				Iterator<String> iterator = jsonObject2.keys();
				while (iterator.hasNext()) {
					String json_key = iterator.next();
					Object json_value = jsonObject2.get(json_key);
					if (json_value == null) {
						json_value = "";
					}
					map.put(json_key, json_value);
				}
				list.add(map);
			}
		} catch (Exception e) {
			// TODO: handle exception
		}
		return list;
	}
}

package com.android.myjson.domain;

public class Person {

	private int id;
	private String name;

	public Person(int id, String name, String address) {
		super();
		this.id = id;
		this.name = name;
		this.address = address;
	}

	private String address;

	public int getId() {
		return id;
	}

	@Override
	public String toString() {
		return "Person [address=" + address + ", id=" + id + ", name=" + name
				+ "]";
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

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

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	public Person() {
		// TODO Auto-generated constructor stub
	}

}