JSON之三:获取JSON文本并解释(以google的天气API为例)


google提供了天气的api,以广州天气为例,地址为:

http://api.openweathermap.org/data/2.5/weather?q=guangzhou

返回的结果为:

{
    "coord": {
        "lon": 113.25,
        "lat": 23.12
    },
    "sys": {
        "message": 0.2088,
        "country": "CN",
        "sunrise": 1400017567,
        "sunset": 1400065233
    },
    "weather": [
        {
            "id": 501,
            "main": "Rain",
            "description": "moderate rain",
            "icon": "10d"
        }
    ],
    "base": "cmc stations",
    "main": {
        "temp": 299.818,
        "temp_min": 299.818,
        "temp_max": 299.818,
        "pressure": 1004.54,
        "sea_level": 1014.72,
        "grnd_level": 1004.54,
        "humidity": 97
    },
    "wind": {
        "speed": 4.42,
        "deg": 201.501
    },
    "rain": {
        "3h": 6
    },
    "clouds": {
        "all": 44
    },
    "dt": 1400055192,
    "id": 1809858,
    "name": "Guangzhou",
    "cod": 200
}

因此,在本范例中,写一个天气查询的DEMO,用于输入地点,并查询天气情况。

项目更新请见:https://code.csdn.net/jediael_lu/googleweatherparse/tree/master


效果如下:



详细步骤如下:

1、主界面布局文件

<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: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=".MainActivity" >

   <TextView
      android:id="@+id/textView1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentLeft="true"
      android:layout_alignParentTop="true"
      android:layout_marginTop="15dp"
      android:text="@string/location"
      android:textAppearance="?android:attr/textAppearanceMedium" />

   <EditText
      android:id="@+id/editText1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBottom="@+id/textView1"
      android:layout_alignParentRight="true"
      android:ems="10" />

   <TextView
      android:id="@+id/textView2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignLeft="@+id/textView1"
      android:layout_below="@+id/textView1"
      android:layout_marginTop="68dp"
      android:text="@string/country"
      android:textAppearance="?android:attr/textAppearanceSmall" />

   <TextView
      android:id="@+id/textView3"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@+id/textView2"
      android:layout_marginTop="19dp"
      android:text="@string/temperature"
      android:textAppearance="?android:attr/textAppearanceSmall" />

   <TextView
      android:id="@+id/textView4"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignLeft="@+id/textView3"
      android:layout_below="@+id/textView3"
      android:layout_marginTop="32dp"
      android:text="@string/humidity"
      android:textAppearance="?android:attr/textAppearanceSmall" />

   <TextView
      android:id="@+id/textView5"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignLeft="@+id/textView4"
      android:layout_below="@+id/textView4"
      android:layout_marginTop="21dp"
      android:text="@string/pressure"
      android:textAppearance="?android:attr/textAppearanceSmall" />

   <EditText
      android:id="@+id/editText2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_above="@+id/textView3"
      android:layout_toRightOf="@+id/textView3"
      android:ems="10" >

      <requestFocus />
   </EditText>

   <EditText
      android:id="@+id/editText3"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBaseline="@+id/textView3"
      android:layout_alignBottom="@+id/textView3"
      android:layout_alignLeft="@+id/editText2"
      android:ems="10" />

   <EditText
      android:id="@+id/editText4"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_above="@+id/textView5"
      android:layout_alignLeft="@+id/editText1"
      android:ems="10" />

   <EditText
      android:id="@+id/editText5"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBaseline="@+id/textView5"
      android:layout_alignBottom="@+id/textView5"
      android:layout_alignRight="@+id/editText4"
      android:ems="10" />

   <Button
      android:id="@+id/button1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignLeft="@+id/editText2"
      android:layout_below="@+id/editText1"
      android:onClick="open"
      android:text="@string/weather" />

</RelativeLayout>

2、定义String.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <string name="app_name">JSONParser</string>
   <string name="action_settings">Settings</string>
   <string name="hello_world">Hello world!</string>
   <string name="location">Location</string>
   <string name="country">Country:</string>
   <string name="temperature">Temperature:</string>
   <string name="humidity">Humidity:</string>
   <string name="pressure">Pressure:</string>
   <string name="weather">Weather</string>
</resources>

3、在AndroidManifest.xml中添加internet访问权限。


4、创建一个bean,用于保存天气信息。

package com.example.jsonparser.model;

public class WeatherBean {
	
	private String country;
	private int Temperature;
	private int humidity;
	private int pressure;
	public String getCountry() {
		return country;
	}
	public void setCountry(String country) {
		this.country = country;
	}
	public int getTemperature() {
		return Temperature;
	}
	public void setTemperature(int temperature) {
		Temperature = temperature;
	}
	public int getHumidity() {
		return humidity;
	}
	public void setHumidity(int humidity) {
		this.humidity = humidity;
	}
	public int getPressure() {
		return pressure;
	}
	public void setPressure(int pressure) {
		this.pressure = pressure;
	}
	

}

5、创建用于访问网络的类,并返回JSON文本。

package com.example.jsonparser;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class JSONFetcher {
	
	private String jsonText = "";
	
	//本方法通过指定url访问网络数据,并返回JSON格式的string。
	public  String getJSONText(final URL url){
		
		
		Thread thread = new Thread(new Runnable(){

			@Override
			public void run() {
				InputStream is =null;
				BufferedReader in = null;
				
				try {
					HttpURLConnection conn = (HttpURLConnection) url.openConnection();
					conn.setReadTimeout(10000 /* milliseconds */);
					conn.setConnectTimeout(15000 /* milliseconds */);
					conn.setRequestMethod("GET");
					conn.setDoInput(true);
					conn.connect();
					
					is = conn.getInputStream();
					in = new BufferedReader(new InputStreamReader(is));
					String line = "";
					while((line = in.readLine()) != null){
						jsonText += line;
					}
					
				} catch (IOException e) {
					e.printStackTrace();
				}finally{
					try {
						in.close();
						is.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
					
				}
				
			}
			
		});
		
		thread.start();	
		
		//等待上述线程完成执行后再返回jsonText。
		try {
			Thread.sleep(1000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		
		return jsonText;
	}

}

6、创建用于处理JSON文本的类,返回一个WeatherBean对象。

package com.example.jsonparser;

import java.net.URL;

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

import com.example.jsonparser.model.WeatherBean;

public class JSONUtil {
	
	public static WeatherBean getWeatherBean(URL url){
		
		String jsonText = new JSONFetcher().getJSONText(url);
		System.out.println(jsonText);
		WeatherBean weather = new WeatherBean();
		
		try {
			JSONObject weatherJSONObject = new JSONObject(jsonText);
			
			JSONObject sysJSONObject = weatherJSONObject.getJSONObject("sys");
			String country = sysJSONObject.getString("country");
			JSONObject mainJSONObject = weatherJSONObject.getJSONObject("main");
			int temperature = mainJSONObject.getInt("temp");
			int pressure = mainJSONObject.getInt("pressure");
			int humidity = mainJSONObject.getInt("humidity");
			
			weather.setCountry(country);
			weather.setTemperature(temperature);
			weather.setHumidity(humidity);
			weather.setPressure(pressure);
		} catch (JSONException e) {
			System.out.println("test");
			e.printStackTrace();
		}
		
		return weather;
	}
}

7、主布局文件,将WeatherBean中的内容在手机中展现。

package com.example.jsonparser;

import java.net.URL;

import com.example.jsonparser.model.WeatherBean;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.EditText;

public class MainActivity extends Activity {

	private String url1 = "http://api.openweathermap.org/data/2.5/weather?q=";
	private EditText location, country, temperature, humidity, pressure;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		location = (EditText) findViewById(R.id.editText1);
		country = (EditText) findViewById(R.id.editText2);
		temperature = (EditText) findViewById(R.id.editText3);
		humidity = (EditText) findViewById(R.id.editText4);
		pressure = (EditText) findViewById(R.id.editText5);
	}

	public void open(View view) {

		try {
			URL url = new URL(url1 + location.getText().toString());
			System.out.println(url);
			WeatherBean weatherBean = JSONUtil.getWeatherBean(url);
			country.setText(weatherBean.getCountry());
			humidity.setText(weatherBean.getHumidity() + "");
			pressure.setText(weatherBean.getPressure() + "");
			temperature.setText(weatherBean.getTemperature() + "");
			System.out.println("test2");

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

















原文地址:https://www.cnblogs.com/eaglegeek/p/4557941.html