Google Maps API Web Services(一：The Google Geocoding API)

程序开发 2023-09-20 22:14:48

The Google Geocoding API provides a direct way to access a these services via an HTTP request.

So：通过输入所要查询的地名，来获取具体的相关信息。

一：直接使用new Thread(r).start()，然后在r的run()方法里面处理逻辑获取返回的json数据。（FC）

package cn.yh.googlemapwebservice;import java.io.BufferedReader;
 import java.io.InputStreamReader;import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.impl.client.DefaultHttpClient;import android.app.Activity;
 import android.os.Bundle;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
 import cn.yh.bean.Results;
 import cn.yh.googlemapwebservice.R;import com.google.gson.Gson;public class MainActivity extends Activity {private EditText editText;private Button button;private String path;private String jsonData = "";private TextView resultTV;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);editText = (EditText) findViewById(R.id.path);button = (Button) findViewById(R.id.button);resultTV = (TextView) findViewById(R.id.resultTV);button.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {button.setEnabled(false);path = "http://maps.googleapis.com/maps/api/geocode/json?address="+ editText.getText().toString().trim()+ "&sensor=false";System.out.println(path);Runnable r = new Runnable() {@Overridepublic void run() {try {HttpClient httpClient = new DefaultHttpClient();HttpResponse httpResponse = httpClient.execute(new HttpGet(path));HttpEntity entity = httpResponse.getEntity();BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(entity.getContent()));String line = "";while ((line = bufferedReader.readLine()) != null) {jsonData += line;}System.out.println(jsonData);} catch (Exception e) {System.out.println(e.toString());}}};new Thread(r).start();Gson gson = new Gson();if (jsonData != null && jsonData != "") {if (jsonData.endsWith("}")) {Results results = gson.fromJson(jsonData, Results.class);System.out.println(results.toString());resultTV.setText(results.toString());button.setEnabled(true);}}}});}}

二：使用AsyncTask进行处理。一个AsyncTask仅执行一次，不能重复执行，快餐类的线程，一次用完。FC频发。

package cn.yh.googlemapwebservice;import java.io.BufferedReader;
 import java.io.InputStreamReader;import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.impl.client.DefaultHttpClient;import android.app.Activity;
 import android.os.AsyncTask;
 import android.os.Bundle;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
 import cn.yh.bean.Results;
 import cn.yh.googlemapwebservice.R;import com.google.gson.Gson;public class MainActivity extends Activity {private EditText editText;private Button button;private String path;private String jsonData = "";private TextView resultTV;private GetDataAsync getDataAsync;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);editText = (EditText) findViewById(R.id.path);button = (Button) findViewById(R.id.button);resultTV = (TextView) findViewById(R.id.resultTV);getDataAsync = new GetDataAsync();button.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {button.setEnabled(false);path = "http://maps.googleapis.com/maps/api/geocode/json?address="+ editText.getText().toString().trim()+ "&sensor=false";System.out.println(path);getDataAsync.execute();}});}private class GetDataAsync extends AsyncTask {@Overrideprotected String doInBackground(Void... params) {try {HttpClient httpClient = new DefaultHttpClient();HttpResponse httpResponse = httpClient.execute(new HttpGet(path));HttpEntity entity = httpResponse.getEntity();BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(entity.getContent()));String line = "";while ((line = bufferedReader.readLine()) != null) {jsonData += line;}System.out.println(jsonData);} catch (Exception e) {System.out.println(e.toString());}return jsonData;}@Overrideprotected void onPostExecute(String result) {Gson gson = new Gson();if (jsonData != null && jsonData != "") {if (result.endsWith("}")) {Results results = gson.fromJson(result, Results.class);System.out.println(results.toString());resultTV.setText(results.toString());button.setEnabled(true);}}}}
 }

三：Handler。handler.post(r)这样并不会新起线程，只是执行的runnable里的run()方法，却没有执行start()方法，所以runnable走的还是MAIN线程。通过HandlerThread获取到looper却是可以新起线程，构建两个Handler，无参handler用来发送消息和处理消息，用开启新线程的handler来处理逻辑。（暂无FC）

package cn.yh.googlemapwebservice;import java.io.BufferedReader;
 import java.io.InputStreamReader;import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.impl.client.DefaultHttpClient;import android.app.Activity;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Message;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
 import cn.yh.bean.Results;
 import cn.yh.googlemapwebservice.R;import com.google.gson.Gson;public class MainActivity extends Activity {private EditText editText;private Button button;private String path;private String jsonData = "";private TextView resultTV;private Handler handler;private Handler mainhandler = new Handler() {@Overridepublic void handleMessage(Message msg) {jsonData = msg.getData().getString("jsonData");Gson gson = new Gson();if (jsonData != null && jsonData != "") {if (jsonData.endsWith("}")) {Results results = gson.fromJson(jsonData, Results.class);System.out.println(results.toString());resultTV.setText(results.toString());button.setEnabled(true);}}}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);editText = (EditText) findViewById(R.id.path);button = (Button) findViewById(R.id.button);resultTV = (TextView) findViewById(R.id.resultTV);button.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {button.setEnabled(false);path = "http://maps.googleapis.com/maps/api/geocode/json?address="+ editText.getText().toString().trim()+ "&sensor=false";System.out.println(path);HandlerThread ht = new HandlerThread("handler thread");ht.start();handler = new Handler(ht.getLooper());handler.post(thread);}});}Runnable thread = new Runnable() {@Overridepublic void run() {try {jsonData = "";HttpClient httpClient = new DefaultHttpClient();HttpResponse httpResponse = httpClient.execute(new HttpGet(path));HttpEntity entity = httpResponse.getEntity();BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(entity.getContent()));String line = "";while ((line = bufferedReader.readLine()) != null) {jsonData += line;}System.out.println(jsonData);} catch (Exception e) {System.out.println(e.toString());}Message msg = mainhandler.obtainMessage();msg.getData().putString("jsonData", jsonData);mainhandler.sendMessage(msg);}};
 }

实际上不需要开启新线程的Handler，只需要直接new Runnable()接口即可。

布局文件：

加入：权限，也是因为Internet访问不能再MAIN线程，所以需要开启新线程。

官方参考：https://developers.google.com/maps/documentation/geocoding/

其中Gson处理json数据：

返回json数据格式：

{"results" : [{"address_components" : [{"long_name" : "纳斯","short_name" : "纳斯","types" : [ "locality", "political" ]},{"long_name" : "基尔代尔郡","short_name" : "基尔代尔郡","types" : [ "administrative_area_level_2", "political" ]},{"long_name" : "基尔德尔","short_name" : "基尔德尔","types" : [ "administrative_area_level_1", "political" ]},{"long_name" : "爱尔兰","short_name" : "IE","types" : [ "country", "political" ]}],"formatted_address" : "爱尔兰共和国基尔德尔纳斯","geometry" : {"bounds" : {"northeast" : {"lat" : 53.2416,"lng" : -6.62979},"southwest" : {"lat" : 53.19867,"lng" : -6.68849}},"location" : {"lat" : 53.2205654,"lng" : -6.6593079},"location_type" : "APPROXIMATE","viewport" : {"northeast" : {"lat" : 53.2416,"lng" : -6.62979},"southwest" : {"lat" : 53.19867,"lng" : -6.68849}}},"types" : [ "locality", "political" ]}],"status" : "OK"
 }

对应xml数据分析：

http://maps.googleapis.com/maps/api/geocode/xml?address=nao&sensor=false

Gson解析json对应简单javaBean：

package cn.yh.bean;import java.util.List;public class Results {private String status;private List results;public String getStatus() {return status;}public void setStatus(String status) {this.status = status;}public List getResults() {return results;}public void setResults(List results) {this.results = results;}@Overridepublic String toString() {String Sresults = "";for(Result r : results){Sresults += r.toString();}return "Results [status=" + status + ", results=" + Sresults + "]";}}

package cn.yh.bean;import java.util.Arrays;public class Result {private String[] types;private String formatted_address;public String[] getTypes() {return types;}public void setTypes(String[] types) {this.types = types;}public String getFormatted_address() {return formatted_address;}public void setFormatted_address(String formatted_address) {this.formatted_address = formatted_address;}@Overridepublic String toString() {return "Result [types=" + Arrays.toString(types)+ ", formatted_address=" + formatted_address + "]";}
 }

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Google Maps API Web Services(一：The Google Geocoding API)

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