如何使用 servlet 创建像此代码（见下文）的 JSON 数组？现在我在 String 中手动编写代码并将其转换为 JSON 数组，但我总是得到一个错误：
错误：
Error parsing data org.json.JSONException: Expected literal value at character 982 of
{
"question": [
{
"text": "",
"answers": [ { "a1": "" }, { "a2": "" }, { "a3": "" } ],
"correctAnswers": [ { "ra1": "" }, { "ra2": "" }, { "ra3": "" } ],
"explanation": ""
},
.
.
.
]
}
这是 servlet 代码：有些部分是德文的，如果您在理解上有问题，请见谅
StringBuffer sb = new StringBuffer();
ArrayList<Integer> kapitel = new ArrayList<Integer>();
String text = "false";
// boolean check = false;
for (int i = 0; i < 14; i++) {
if ("1".equals(request.getParameter("k" + (i + 1))))
kapitel.add(i + 1);
}
String arrayFragen[][] = null;
String arrayAntworten[][] = null;
String[] antwortSeatze = null;
String[] richtigeAntwortSeatze = null;
Main main = new Main();
Datenbank db = new Datenbank();
main.frageAntworten(kapitel);
arrayAntworten = main.antworten;
arrayFragen = main.fragen;
int zeahler = 1;
String frageId;
sb.append("{");
sb.append("\n\"frage\": [");
for (int i = 0; i < arrayFragen.length - 1; i++) {
frageId = arrayFragen[i][0];
sb.append("\n{");
sb.append("\n\"text\": \"" + arrayFragen[i][1] + "\", ");
sb.append("\n\"antworten\": [");
antwortSeatze = new String[db.arraySizeAntwortenSeatze(frageId,
arrayAntworten)];
int x = 0;
for (int j = 0; j < arrayAntworten.length; j++) {
if (arrayAntworten[j][0].equals(frageId))
antwortSeatze[x++] = arrayAntworten[j][1];
}
zeahler = 1;
for (int j = 0; j < antwortSeatze.length - 1; j++) {
sb.append("\n{\"a" + zeahler++ + "\": \"" + antwortSeatze[j]
+ "\"}, ");
}
// letze Antwortmöglichkeit
sb.append("\n{\"a" + zeahler++ + "\": \""
+ antwortSeatze[antwortSeatze.length - 1] + "\"} ");
sb.append("\n],");
richtigeAntwortSeatze = new String[db.arraySizeAntwortenSeatze(
frageId, arrayAntworten)];
// Richige Antworten
sb.append("\n\"richtigeantworten\": [");
antwortSeatze = new String[db.arraySizeAntwortenSeatze(frageId,
arrayAntworten)];
int y = 0;
for (int j = 0; j < richtigeAntwortSeatze.length; j++) {
if (arrayAntworten[j][0].equals(frageId))
if (arrayAntworten[j][2].equals("false"))
antwortSeatze[y++] = "null";
if (!(arrayAntworten[j][2].equals("false")))
antwortSeatze[y++] = arrayAntworten[j][1];
}
zeahler = 1;
for (int j = 0; j < antwortSeatze.length - 1; j++) {
sb.append("\n{\"ra" + zeahler++ + "\": \"" + antwortSeatze[j]
+ "\"}, ");
// letze Richtige Antwortmöglichkeit
}
sb.append("\n{\"ra" + zeahler++ + "\": \""
+ antwortSeatze[antwortSeatze.length - 1] + "\"} ");
sb.append("\n],");
richtigeAntwortSeatze = new String[db.arraySizeAntwortenSeatze(
frageId, arrayAntworten)];
sb.append("\n\"erklaerung\": \"" + arrayFragen[i][2] + "\", ");
sb.append("\n},");
}
// Letzte Frage
frageId = arrayFragen[arrayFragen.length - 1][0];
sb.append("\n{");
sb.append("\n\"text\": \"" + arrayFragen[arrayFragen.length - 1][1]
+ "\", ");
sb.append("\n\"antworten\": [");
antwortSeatze = new String[db.arraySizeAntwortenSeatze(frageId,
arrayAntworten)];
int x = 0;
for (int j = 0; j < arrayAntworten.length; j++) {
if (arrayAntworten[j][0].equals(frageId))
antwortSeatze[x++] = arrayAntworten[j][1];
}
zeahler = 1;
for (int j = 0; j < antwortSeatze.length - 1; j++) {
sb.append("\n{\"a" + zeahler++ + "\": \"" + antwortSeatze[j] + "\"},");
}
// letze Antwort möglichkeit
sb.append("\n{\"a" + zeahler++ + "\": \""
+ antwortSeatze[antwortSeatze.length - 1] + "\"} ");
sb.append("\n],");
richtigeAntwortSeatze = new String[db.arraySizeAntwortenSeatze(frageId,
arrayAntworten)];
sb.append("\n\"richtigeantworten\": [");
antwortSeatze = new String[db.arraySizeAntwortenSeatze(frageId,
arrayAntworten)];
int y = 0;
for (int j = 0; j < richtigeAntwortSeatze.length; j++) {
if (arrayAntworten[j][0].equals(frageId))
if (arrayAntworten[j][2].equals("false"))
antwortSeatze[y++] = "null";
if (!(arrayAntworten[j][2].equals("false")))
antwortSeatze[y++] = arrayAntworten[j][1];
}
zeahler = 1;
for (int j = 0; j < antwortSeatze.length - 1; j++) {
sb.append("\n{\"ra" + zeahler++ + "\": \"" + antwortSeatze[j]
+ "\" },");
}
// letze Richtige Antwortmöglichkeit
sb.append("\n{\"ra" + zeahler++ + "\": \""
+ antwortSeatze[antwortSeatze.length - 1] + "\"} ");
sb.append("\n],");
richtigeAntwortSeatze = new String[db.arraySizeAntwortenSeatze(frageId,
arrayAntworten)];
sb.append("\n\"erklaerung\": \"" + arrayFragen[arrayFragen.length - 1][2]
+ "\", ");
sb.append("\n}");
sb.append("\n]");
sb.append("\n}");
text = sb.toString();
response.getWriter().print(text);
System.out.println(text);
安卓部分：
private class JSONParser extends AsyncTask<URL, String, String> {
@Override
protected String doInBackground(URL... url) {
InputStream is = null;
String json = "";
// VERBINDUNGSAUFBAU
try {
URLConnection connection = url[0].openConnection();
HttpURLConnection http = (HttpURLConnection)connection;
int response = http.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
is = http.getInputStream();}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// CONVERTIERUNG VON INPUTSTREAM ZU STRING
try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line);
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
return json;
// InputStream is = m.getData(url[0]);
// String json = m.InputstreamToString(is);
// return json;
}
protected void onPostExecute(String json) {
TextView fragenNr = (TextView)
findViewById(R.id.FragenText);
fragenNr.setText(json);
JSONObject jObj = null;
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
try {
frage = jObj.getJSONArray(TAG_FRAGE);
for (int i = 0; i < frage.length(); i++) {
JSONObject f = frage.getJSONObject(i);
// Storing each json item in variable
String text = f.getString(TAG_TEXT);
String erklaerung = f.getString(TAG_ERKLAERUNG);
HashMap<String, Object> map = new HashMap<String, Object>();
map.put(TAG_TEXT, text);
map.put(TAG_ERKLAERUNG, erklaerung);
ArrayList<String> antwortenArray = new ArrayList<String>();
JSONArray antworten = f.getJSONArray(TAG_ANTWORTEN);
for (int j = 0; j < antworten.length(); j++) {
JSONObject a = antworten.getJSONObject(j);
String tag = TAG_ANTWORTEN_a + (j + 1);
antwortenArray.add(a.getString(tag));
map.put(tag, antwortenArray.get(j));
}
map.put("anzahlAntworten", antworten.length());
ArrayList<String> richtigeantwortenArray = new ArrayList<String>();
JSONArray richtigeantworten = f
.getJSONArray(TAG_RICHTIGEANTWORTEN);
for (int k = 0; k < richtigeantworten.length(); k++) {
JSONObject ra = richtigeantworten.getJSONObject(k);
String tag = TAG_RICHTIGEANTWORTEN_ra + (k + 1);
richtigeantwortenArray.add(ra.getString(tag));
map.put(tag, richtigeantwortenArray.get(k));
}
map.put("anzahlRichtigerAntworten",richtigeantworten.length());
fragenUndAntworten.add(map);
fragenListe.add(text);
}
} catch (JSONException e) {
e.printStackTrace();
}
View weiterButton = findViewById(R.id.weiterButton);
weiterButton.setOnClickListener(Fragen.this);
weiterButton.performClick();
}
}