在java中使用GSON從JSON中提取數據

Question

請幫助，這是我第一次使用JSON/GSON。 我從Google地理編碼API獲取了此JSON數據，但無法弄清楚如何從中提取「formatted_address」。

{ 
    "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" 
} 

這是我做過嘗試，但它拋出IndexOutOfBoundsException異常：

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

我只能妄自猜測，你的眼前是什麼錯誤沒有一個堆棧跟蹤，但你試圖訪問只包含一個項目數組的第二個項目：

• 的results陣列包含一個元素（一個對象，其字段是address_components陣列，formatted_address，geometry，place_id和types）

• 你想用jArray.get(1)（數組訪問它的第二個元素是用Java 0索引）

這是IndexOutOfBoundsException的典型原因。

您可能想要訪問jArray.get(0)的唯一項目，您可以將其作爲JsonObject進行操作，其字段可以訪問。

Answer 2

你寫jObject = jArray.get(1).getAsJsonObject();，但您的陣列只包含一個元素。請記住，Java中的數組是0索引。您應該使用jObject = jArray.get(0).getAsJsonObject();。

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; 
    } 
}