在Java中使用GSON从JSON提取数据

Question

Help please, this is my first time using JSON/GSON. I've got this JSON data from google geocoding API and can't figure out how to extract "formatted_address" from it.

{
   "results" : [
      {
         "address_components" : [
            {
               "long_name" : "Google Building 41",
               "short_name" : "Google Bldg 41",
               "types" : [ "premise" ]
            },
            {
               "long_name" : "1600",
               "short_name" : "1600",
               "types" : [ "street_number" ]
            },
            {
               "long_name" : "Amphitheatre Parkway",
               "short_name" : "Amphitheatre Pkwy",
               "types" : [ "route" ]
            },
            {
               "long_name" : "Mountain View",
               "short_name" : "Mountain View",
               "types" : [ "locality", "political" ]
            },
            {
               "long_name" : "Santa Clara County",
               "short_name" : "Santa Clara County",
               "types" : [ "administrative_area_level_2", "political" ]
            },
            {
               "long_name" : "California",
               "short_name" : "CA",
               "types" : [ "administrative_area_level_1", "political" ]
            },
            {
               "long_name" : "United States",
               "short_name" : "US",
               "types" : [ "country", "political" ]
            },
            {
               "long_name" : "94043",
               "short_name" : "94043",
               "types" : [ "postal_code" ]
            }
         ],
         "formatted_address" : "Google Bldg 41, 1600 Amphitheatre Pkwy, Mountain View, CA 94043, USA",
         "geometry" : {
            "bounds" : {
               "northeast" : {
                  "lat" : 37.4228642,
                  "lng" : -122.0851557
               },
               "southwest" : {
                  "lat" : 37.4221145,
                  "lng" : -122.0859841
               }
            },
            "location" : {
               "lat" : 37.4224082,
               "lng" : -122.0856086
            },
            "location_type" : "ROOFTOP",
            "viewport" : {
               "northeast" : {
                  "lat" : 37.4238383302915,
                  "lng" : -122.0842209197085
               },
               "southwest" : {
                  "lat" : 37.4211403697085,
                  "lng" : -122.0869188802915
               }
            }
         },
         "place_id" : "ChIJxQvW8wK6j4AR3ukttGy3w2s",
         "types" : [ "premise" ]
      }
   ],
   "status" : "OK"
}

This is what I've tried but it throws IndexOutOfBoundsException:

public String getLocationData(String location) {

        try {

            URL url = new URL(location);
            HttpURLConnection request = (HttpURLConnection) url.openConnection();
            request.connect();

            JsonParser parser = new JsonParser();
            JsonElement content = parser.parse(new InputStreamReader((InputStream) request.getContent()));
            JsonObject jObject = content.getAsJsonObject();
            JsonArray jArray = jObject.getAsJsonArray("results");
            jObject = jArray.get(1).getAsJsonObject();

            String result = jObject.getAsString();

            return result;

        } catch (MalformedURLException ex) {
            ex.printStackTrace();

        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return "fail";
    }

Answer 1

You wrote jObject = jArray.get(1).getAsJsonObject(); , but your array only contains one element. Remember that arrays are 0-indexed in Java. You should use jObject = jArray.get(0).getAsJsonObject(); instead.

Answer 2

I can only hazard a guess as to what your immediate error is without a stacktrace, but you're trying to access the second item of an array that only contains one item :

• the results array contains a single element (an object whose fields are the address_components array, formatted_address , geometry , place_id and types )

• you're trying to access its second element with jArray.get(1) (arrays in Java are 0-indexed)

This is a typical cause of IndexOutOfBoundsException .

You probably want to access the only item with jArray.get(0) which you will be able to manipulate as a JsonObject whose fields you will be able to access.

Answer 3

//URL url = new URL("http://localhost:7001/JMR_SERVICE/services/CalSerice?wsdl");

URL endPointUrl= new URL("http://192.168.0.161:7200/JMR_SERVICE/services/CalSerice?wsdl");

org.apache.axis.client.Service service=new  org.apache.axis.client.Service();


CalSericeSoapBindingStub stub=new CalSericeSoapBindingStub( endPointUrl,service);

String msg=stub.hello("hello how are you..............?");
String resp=stub.getID("ADMINUSER4");

Answer 4

public class Dao {        
    String result="";
    public String  getDetails(int empid)
    {
        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        Connection con = null;
        try {
            con = DriverManager.getConnection( "jdbc:oracle:thin:@localhost:1521:xe","system","om");
        } catch (SQLException e) {
            e.printStackTrace();
        }
        System.out.println("connected data base");

        try
        {
            //stmt.execute("create table com (sno int,name varchar(90),age int)");
            System.out.println("connection is established");
        }
        catch(Exception ex)
        {
            ex.printStackTrace();
        }
        try
        {
            PreparedStatement psmt=con.prepareStatement("select name from emp122 where id=id");
            //psmt.setInt(2,id);

            String query="select name from  emp120 where id='emid'";
            ResultSet rs=psmt.executeQuery();
            //String result="";
            while(rs.next())
            {
                result=rs.getString(1);
            }
            System.out.println(result);

        }
        catch(Exception ex)
        {
            ex.printStackTrace();
            return "Not Record found";
        }


        return result;

   }

    public ArrayList<String[]> getconnection(String id)throws ClassNotFoundException, SQLException
    {
        System.out.println("collection jdbc");
        ArrayList ls=new ArrayList();

        Class.forName("oracle.jdbc.driver.OracleDriver");
        Connection con=DriverManager.getConnection( "jdbc:oracle:thin:@192.168.1.92:1521:FCARB01","EODMS","eodms");
        System.out.println("connected data base");
        Statement stmt=con.createStatement();
        String sql="select QRY_TEXT from EOD_QRY_EXEC_LOG where OPERATOR_ID ='"+id+"'";
        System.out.println("fetching value....");
        ResultSet rs=stmt.executeQuery(sql);

        System.out.println("resulsetmetadata");
        ResultSetMetaData rsmd=rs.getMetaData();
        int a=rsmd.getColumnCount();
        while(rs.next())
        {
            for(int i=1;i<=a;i++)
            {
                ls.add(rs.getString(i));
            }
        }

        return ls;
    }
}