ParseJson.java，如果没有数组名称，则解析结果？
[英]ParseJson.java, Parsing result if NO array name?
问题描述
这是我的代码：
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
/**
* Created by Belal on 9/22/2015.
*/
public class ParseJSON {
public static String[] make;
public static String[] model;
public static String[] sixMonthRate;
public static final String JSON_ARRAY = "result";
public static final String KEY_MAKE = "make";
public static final String KEY_MODEL = "model";
public static final String KEY_SIXMONTHRATE = "sixMonthRate";
private JSONArray vehicle = null;
private String json;
public ParseJSON(String json){
this.json = json;
}
protected void parseJSON(){
JSONObject jsonObject=null;
try {
jsonObject = new JSONObject(json);
vehicle = jsonObject.getJSONArray(JSON_ARRAY);
make = new String[vehicle.length()];
model = new String[vehicle.length()];
sixMonthRate = new String[vehicle.length()];
for(int i=0;i<vehicle.length();i++){
JSONObject jo = vehicle.getJSONObject(i);
make[i] = jo.getString(KEY_MAKE);
model[i] = jo.getString(KEY_MODEL);
sixMonthRate[i] = jo.getString(KEY_SIXMONTHRATE);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
如果我将使用DVLA JSON DATABASE并且没有ARRAY名称，那么我应该如何更改代码才能使其正常工作？
目前，如果我按下按钮获取数据，我的结果是应用已关闭。
我正在使用这个教程 - 这里
错误得到
03-26 02:49:43.467 23673-23673/com.sandro.openalprsample W/System.err: org.json.JSONException: No value for result
03-26 02:49:43.467 23673-23673/com.sandro.openalprsample W/System.err: at org.json.JSONObject.get(JSONObject.java:389)
03-26 02:49:43.467 23673-23673/com.sandro.openalprsample W/System.err: at org.json.JSONObject.getJSONArray(JSONObject.java:584)
03-26 02:49:43.467 23673-23673/com.sandro.openalprsample W/System.err: at com.sandro.openalprsample.ParseJSON.parseJSON(ParseJSON.java:42)
03-26 02:49:43.467 23673-23673/com.sandro.openalprsample W/System.err: at com.sandro.openalprsample.DVLAresult.showJSON(DVLAresult.java:60)
03-26 02:49:43.467 23673-23673/com.sandro.openalprsample W/System.err: at com.sandro.openalprsample.DVLAresult.access$000(DVLAresult.java:18)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at com.sandro.openalprsample.DVLAresult$1.onResponse(DVLAresult.java:44)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at com.sandro.openalprsample.DVLAresult$1.onResponse(DVLAresult.java:41)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:60)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at android.os.Handler.handleCallback(Handler.java:739)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at android.os.Handler.dispatchMessage(Handler.java:95)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at android.os.Looper.loop(Looper.java:145)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5832)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at java.lang.reflect.Method.invoke(Native Method)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at java.lang.reflect.Method.invoke(Method.java:372)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample D/AndroidRuntime: Shutting down VM
03-26 02:49:43.472 23673-23673/com.sandro.openalprsample E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.sandro.openalprsample, PID: 23673
java.lang.NullPointerException: storage == null
at java.util.Arrays$ArrayList.<init>(Arrays.java:38)
at java.util.Arrays.asList(Arrays.java:155)
at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:128)
at com.sandro.openalprsample.CustomList.<init>(CustomList.java:21)
at com.sandro.openalprsample.DVLAresult.showJSON(DVLAresult.java:61)
at com.sandro.openalprsample.DVLAresult.access$000(DVLAresult.java:18)
at com.sandro.openalprsample.DVLAresult$1.onResponse(DVLAresult.java:44)
at com.sandro.openalprsample.DVLAresult$1.onResponse(DVLAresult.java:41)
at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:60)
at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30)
at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5832)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
2 个解决方案
解决方案1
0 2016-03-26 03:21:06
DVLA JSON DATABASE应该是JSON_ARRAY的内容吗？
如果是这样，那么您应该调用getJsonObject而不是getJsonArray ，然后像这样遍历它们：
for(String key : vehicle.keySet() {
// Do something with the key and object.
Object obj = vehicle.get(key);
}
如果没有，我想我还不太了解你的问题
编辑
我不确定从哪里获取json值，但我将假定它是DVLA_JSON_DATABASE的内容
如果没有，只需复制粘贴以下内容：
JSONObject jsonObject = new JSONObject("{\"make\":\"VOLKSWAGEN\",\"model\":\"Tiguan\",\"sixMonthRate\":\"Unknown\",\"twelveMonthRate\":\"Unknown\",\"dateOfFirstRegistration\":\"23 July 2009\",\"yearOfManufacture\":\"2009\",\"cylinderCapacity\":\"1968cc\",\"co2Emissions\":\"167 g/km\",\"fuelType\":\"DIESEL\",\"taxStatus\":\"Taxed and due\",\"colour\":\"SILVER\",\"typeApproval\":\"M1\",\"wheelPlan\":\"2 AXLE RIGID BODY\",\"revenueWeight\":\"Not available\",\"taxDetails\":\"Tax due: 01 April 2016\",\"motDetails\":\"Expires: 21 April 2016\",\"taxed\":true,\"mot\":true}");
代替json
现在有些代码：
try {
jsonObject = new JSONObject(json);
String make = jsonObject.getString("make");
String model = jsonObject.getString("model");
String sixMonthRate = jo.getString("sixMonthRate");
// Do something with these variables
} catch (JSONException e) {
e.printStackTrace();
}
您可能已经注意到，但JSON包含一个key:value 。 您只需调用getString(key)来获取String值。 同样，您将调用“ getInt（key）”以获取一个Integer值
这里的所有都是它的！
解决方案2
0 已采纳 2016-03-27 12:03:44
不幸的是我不遵循你的代码。 根据您提供的内容，我没有看到任何JSON数组。 作为对此响应的扩展，我进行了很少的修改并访问JSON对象中的数据。 这里是补充。
从这里更新MainActivity.java
HandleJSON obj = new HandleJSON("");
obj.readAndParseJSON(responseOutput.toString());
output.append(System.getProperty("line.separator") + "\nJSON Object... " + System.getProperty("line.separator") + "Make : " + obj.getMake() + "\nModel : " + obj.getModel());
output.append("\nSix Month Rate : " + obj.getSixMonthRate() + "\nTwelve Month Rate : " + obj.getTwelveMonthRate() + "\nDate of First Registration : " + obj.getDateofFirstRegistrationegistration());
output.append("\nYear of Manufacture : " + obj.getYearOfManufacture() + "\nCylinder Capacity : " + obj.getCylinderCapacity() + "\nCO2 Emmissions : " + obj.getCo2Emissions());
HandleJSON.java
import org.json.JSONObject;
import android.annotation.SuppressLint;
public class HandleJSON {
private String make = "make";
private String model = "model";
private String sixMonthRate = "sixMonthRate";
private String twelveMonthRate = "twelveMonthRate";
private String dateofFirstRegistration = "dateofFirstRegistration";
private String yearOfManufacture = "yearOfManufacture";
private String cylinderCapacity = "cylinderCapacity";
private String co2Emissions= "co2Emissions";
public HandleJSON(String url) {this.urlString = url;}
public void setURL(String url){ this.urlString = url;}
public String getMake() {return make;}
public String getModel() {return model;}
public String getSixMonthRate() {return sixMonthRate;}
public String getTwelveMonthRate() {return twelveMonthRate;}
public String getDateofFirstRegistrationegistration() {return dateofFirstRegistration;}
public String getYearOfManufacture() {return yearOfManufacture;}
public String getCylinderCapacity() {return cylinderCapacity;}
public String getCo2Emissions() {return co2Emissions;}
@SuppressLint("NewApi")
public void readAndParseJSON(String in) {
try {
JSONObject reader = new JSONObject(in);
make = reader.getString("make");
model = reader.getString("model");
sixMonthRate = reader.getString("sixMonthRate");
twelveMonthRate = reader.getString("twelveMonthRate");
dateofFirstRegistration= reader.getString("dateOfFirstRegistration");
yearOfManufacture= reader.getString("yearOfManufacture");
cylinderCapacity= reader.getString("cylinderCapacity");
co2Emissions= reader.getString("co2Emissions");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
这是输出
参考文献：
HTML将Java结果解析为MATLAB
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