我的JSON文件只返回存储在其中的前四个值，然后将其返回为null。
这是我的JSON文件编写代码
JSONArray data = new JSONArray();
JSONObject object = new JSONObject();
try
{
object.put("Event Name: ", Event);
object.put("College Name: ", College);
object.put("Category: ", Category);
object.put("Sub-Category: ", Sub);
object.put("Date From: ", Dfrom);
object.put("Date to :", Dto);
object.put("City: ", City);
object.put("State: ", State);
object.put("Venue: ", Venue);
object.put("Website: ", URL);
object.put("Registration Form Link: ", Form);
object.put("Contact Number: ", Number);
object.put("E-mail Id: ", Email);
data.put(object);
String text = data.toString();
FileOutputStream fos = openFileOutput("event.json", MODE_PRIVATE);
OutputStreamWriter writer = new OutputStreamWriter(fos);
writer.write(text);
writer.flush();
writer.close();
Toast.makeText(getApplicationContext(), "Event Successfully Submitted", Toast.LENGTH_SHORT)
.show();
}
其中Dfrom和Dto是DatePicker选择的日期。
这是我的JSON文件读取编码
public void readForm()
{
String path = getFilesDir().getAbsolutePath() +"\n"+ "/event.json";
File f = new File(path);
f.setReadable(true, false);
try
{
FileInputStream fis = openFileInput("event.json");
BufferedInputStream bis = new BufferedInputStream(fis);
StringBuffer b = new StringBuffer();
while (bis.available()!=0)
{
char c = (char) bis.read();
b.append(c);
}
bis.close();
fis.close();
JSONArray data = new JSONArray(b.toString());
event1 = data.getJSONObject(0).getString("Event Name: ");
college1 = data.getJSONObject(0).getString("College Name: ");
category1 = data.getJSONObject(0).getString("Category: ");
sub1 = data.getJSONObject(0).getString("Sub-Category: ");
dfrom1 = data.getJSONObject(0).getString("Date From:");
dto1 = data.getJSONObject(0).getString("Date To: ");
city1 = data.getJSONObject(0).getString("City: ");
state1 = data.getJSONObject(0).getString("State: ");
venue1 = data.getJSONObject(0).getString("Venue: ");
url1 = data.getJSONObject(0).getString("Website: ");
form1 = data.getJSONObject(0).getString("Registration Form Link: ");
number1 = data.getJSONObject(0).getString("Contact Number: ");
email1 = data.getJSONObject(0).getString("E-mail Id: ");
}
之后，我将这些值传递给TextViews，只有前四个返回值，其余为null。
DatePicker编码
DatePickerDialog.OnDateSetListener from_dateListener = new DatePickerDialog.OnDateSetListener() {
// when dialog box is closed, below method will be called.
public void onDateSet(DatePicker view, int selectedYear,
int selectedMonth, int selectedDay) {
year = selectedYear;
month = selectedMonth;
day = selectedDay;
// set selected date into textview
abcd = (new StringBuilder().append(day)
.append("-").append(month + 1).append("-").append(year)
.append(" ")).toString();
from.setText(abcd);
Dfrom = abcd;
// set selected date into datepicker also
}
};
即使我尝试显示从Dfrom到电子邮件的值，所有都返回null 请帮忙
答案 0 :(得分：0)
我认为问题是关键值未命中匹配
例如
您正在设置
object.put("Date From: ", Dfrom);
object.put("Date to :", Dto);
试图获得
dfrom1 = data.getJSONObject(0).getString("Date From:");
dto1 = data.getJSONObject(0).getString("Date To: ");
在＆＃34;日期之间做差异：＆＃34;和＆＃34;日期自：＆＃34;是＆＃34;之后的空间：＆＃34; 所以请交叉检查所有。
答案 1 :(得分：0)
您的密钥可能存在问题，因为密钥在json中不匹配：
尝试以下代码：
public static final String KEY_EVENT = "event";
public static final String KEY_COLLEGE = "college";
public static final String KEY_CATEGORY = "category";
public static final String KEY_SUB_CATEGORY = "sub-category";
public static final String KEY_DATE_TO = "dateto";
public static final String KEY_DATE_FROM = "datefrom";
public static final String KEY_CITY = "city";
public static final String KEY_STATE = "state";
public static final String KEY_VENUE = "venue";
public static final String KEY_WEBSITE = "website";
public static final String KEY_LINK_REGISTRATION = "registration";
public static final String KEY_CONTACT = "contact";
public static final String KEY_EMAIL = "email";
public void writeFile() {
JSONArray data = new JSONArray();
JSONObject object = new JSONObject();
try {
object.put(KEY_EVENT, "name");
object.put(KEY_COLLEGE, "college");
object.put(KEY_CATEGORY, "category");
object.put(KEY_SUB_CATEGORY, "sub");
object.put(KEY_DATE_FROM, "dfrom");
object.put(KEY_DATE_TO, "dto");
object.put(KEY_CITY, "city");
object.put(KEY_STATE, "state");
object.put(KEY_VENUE, "venue");
object.put(KEY_WEBSITE, "url");
object.put(KEY_LINK_REGISTRATION, "form");
object.put(KEY_CONTACT, "number");
object.put(KEY_EMAIL, "email");
data.put(object);
String text = data.toString();
FileOutputStream fos = openFileOutput("event.json", MODE_PRIVATE);
OutputStreamWriter writer = new OutputStreamWriter(fos);
writer.write(text);
writer.flush();
writer.close();
Toast.makeText(getApplicationContext(), "Event Successfully Submitted", Toast.LENGTH_SHORT)
.show();
} catch (Exception e) {
e.printStackTrace();
}
}
public void readFile() {
String path = getFilesDir().getAbsolutePath() + "\n" + "/event.json";
File f = new File(path);
f.setReadable(true, false);
try {
FileInputStream fis = openFileInput("event.json");
BufferedInputStream bis = new BufferedInputStream(fis);
StringBuffer b = new StringBuffer();
while (bis.available() != 0) {
char c = (char) bis.read();
b.append(c);
}
bis.close();
fis.close();
JSONArray data = new JSONArray(b.toString());
String event1 = data.getJSONObject(0).getString(KEY_EVENT);
String college1 = data.getJSONObject(0).getString(KEY_COLLEGE);
String category1 = data.getJSONObject(0).getString(KEY_CATEGORY);
String sub1 = data.getJSONObject(0).getString(KEY_SUB_CATEGORY);
String dfrom1 = data.getJSONObject(0).getString(KEY_DATE_FROM);
String dto1 = data.getJSONObject(0).getString(KEY_DATE_TO);
String city1 = data.getJSONObject(0).getString(KEY_CITY);
String state1 = data.getJSONObject(0).getString(KEY_STATE);
String venue1 = data.getJSONObject(0).getString(KEY_VENUE);
String url1 = data.getJSONObject(0).getString(KEY_WEBSITE);
String form1 = data.getJSONObject(0).getString(KEY_LINK_REGISTRATION);
String number1 = data.getJSONObject(0).getString(KEY_CONTACT);
String email1 = data.getJSONObject(0).getString(KEY_EMAIL);
} catch (Exception e) {
e.printStackTrace();
}
}
感谢和GT; !!