我的问题是我编写了一个登录网站并下载所需数据的程序。一切都很好，程序在突然停止工作时工作。在代码中，没有任何变化，即使程序开始每次都抛出异常。什么可能导致这种情况？我该如何解决？
例外是：
Exception in thread "main" java.lang.NullPointerException
at gui.JsoupClass.checkLogin(JsoupClass.java:55)
at gui.JsoupClass.<init>(JsoupClass.java:31)
at gui.JsoupClass.main(JsoupClass.java:22)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
这是我的代码，也许我看不到你们中的一些人会看到的东西：
package gui;
import dao.*;
import org.jsoup.Connection;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.select.Elements;
import javax.swing.*;
import java.io.IOException;
import java.net.SocketTimeoutException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class JsoupClass
{
static String value[] = new String[3];
static String name[] = new String[3];
public static void main(String args[]) {
new JsoupClass("email@gmail.com", "yourpassword", null);
}
public JsoupClass(String emailText, String passText, MainFrame mainFrame) {
Connection.Response res;
res = getLoginData();
res = doLogin(res, emailText, passText);
if (checkLogin(res).hasText()) {
setUpTrafficPayment(res);
setUpEwalletData(res);
setUpPanelsData(res);
setUpPaymentData(res);
try {
if (mainFrame != null)
mainFrame.dispose();
new StatisticFrame();
} catch (ParseException e1) {
e1.printStackTrace();
}
} else {
JOptionPane.showMessageDialog(RunFrame.getInstance(),
"Wrong Login Data!",
"Warning",
JOptionPane.WARNING_MESSAGE);
}
}
public Elements checkLogin(Connection.Response res) {
Document doc = null;
Elements elements;
try {
doc = res.parse();
} catch (IOException e) {
e.printStackTrace();
}
elements = doc.select("div#topuserinfo > a > span");
if (elements.hasText()) {
UserData userData = UserData.getInstance();
userData.setNameValue(elements.text());
}
return elements;
}
public Document getPage(Connection.Response res, String pageAddres) {
Document doc = null;
try {
doc = Jsoup
.connect(pageAddres)
.cookie("PHPSESSID", res.cookie("PHPSESSID"))
.get();
} catch (SocketTimeoutException e) {
JOptionPane.showMessageDialog(RunFrame.getInstance(),
"Read timed out! Could not open connection to Banners Broker!",
"Error",
JOptionPane.ERROR_MESSAGE);
} catch (IOException e) {
e.printStackTrace();
}
return doc;
}
public Connection.Response doLogin(Connection.Response res, String email, String pass) {
Connection.Response res2 = null;
try {
res2 = Jsoup
.connect("https://bannersbroker.com//user/login?event=doLogin")
.cookies(res.cookies())
.data("email", email)
.data("pass", pass)
.data(name[0], value[0])
.data(name[1], value[1])
.data(name[2], value[2])
.method(Connection.Method.POST)
.execute();
} catch (IOException ioe) {
} catch (IllegalArgumentException ioe) {
JOptionPane.showMessageDialog(RunFrame.getInstance(),
"Could not open connection to Banners Broker!",
"Error",
JOptionPane.ERROR_MESSAGE);
} catch (NullPointerException ioe) {
JOptionPane.showMessageDialog(RunFrame.getInstance(),
"Could not open connection to Banners Broker!",
"Error",
JOptionPane.ERROR_MESSAGE);
}
return res2;
}
public Connection.Response getLoginData() {
Connection.Response res = null;
try {
String html;
int length, counter;
res = Jsoup
.connect("https://bannersbroker.com//user/login?event=doLogin")
.execute();
html = res.parse().toString();
length = html.length();
counter = 0;
for (int i = 0; i < length; i++) {
if (html.startsWith("document.write", i)) {
name[counter] = html.substring(i + 41, i + 144);
value[counter] = "Login";
counter++;
}
if (html.startsWith("hidden", i)) {
name[counter] = html.substring(i + 13, i + 81);
value[counter] = html.substring(i + 90, i + 123);
counter++;
}
}
} catch (IOException ioe) {
} catch (NullPointerException ioe) {
JOptionPane.showMessageDialog(RunFrame.getInstance(),
"Could not open connection to Banners Broker!",
"Error",
JOptionPane.ERROR_MESSAGE);
}
return res;
}
public void setUpEwalletData(Connection.Response res) {
Document doc;
Elements elements;
doc = getPage(res, "http://bannersbroker.com/adpubcombo_ewallet/ewallet");
elements = doc.select("p[class=ewallet_numbers");
EwalletData ewalletData = EwalletData.getInstance();
ewalletData.setWalletValue(Double.parseDouble(elements.first().text().replaceAll("[\\D&&[^.]&&[^-]]+", "")));
}
public void setUpPanelsData(Connection.Response res) {
MacroData macroData = MacroData.getInstance();
TrafficData trafficData = TrafficData.getInstance();
PanelsData panelsData = PanelsData.getInstance();
String strona;
Document doc;
Elements elements;
int[] traffic = new int[8];
int[] macro = new int[7];
for (int i = 1; i < 8; i++) {
strona = "http://bannersbroker.com/adpubcombo_manageinventory/viewactivepanels?colour=" + i + "&sort=Qualified";
doc = getPage(res, strona);
elements = doc.select("span[id=limit2]");
macro[i - 1] = Integer.parseInt((elements.first().text().replaceAll("\\D+", "")));
elements = doc.select("div.number[id=js-tp-bank]");
traffic[i - 1] = Integer.parseInt((elements.first().text().replaceAll("\\D+", "")));
elements = doc.select("p[id^=QualDate]");
if (elements.hasText()) {
String[] luzem = elements.text().split("[\\D&&[^-]]+");
Date[] aray = new Date[luzem.length / 4];
try {
int j = 0;
while (elements.eq(j).hasText()) {
if (elements.eq(j).text() != "")
aray[j] = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").parse(elements.eq(j).text());
j++;
}
j = 0;
} catch (ParseException e) {
e.printStackTrace();
}
switch (i) {
case 1:
panelsData.setYellowDays(aray);
break;
case 2:
panelsData.setPurpleDays(aray);
break;
case 3:
panelsData.setBlueDays(aray);
break;
case 4:
panelsData.setGreenDays(aray);
break;
case 5:
panelsData.setRedDays(aray);
break;
case 6:
panelsData.setBlackDays(aray);
break;
case 7:
panelsData.setPrestigeDays(aray);
break;
default:
break;
}
}
elements = getPanelData(doc);
if (elements.hasText()) {
int size = getPanelData(doc).size();
for (int j = 1; j <= size / 2; j++) elements.remove(j);
String[] luzem = elements.text().split("[\\D&&[^.]]+");
Double[] aray = new Double[luzem.length];
for (int j = 0; j < luzem.length; j++)
aray[j] = Double.parseDouble(luzem[j]);
switch (i) {
case 1:
panelsData.setYellow(aray);
break;
case 2:
panelsData.setPurple(aray);
break;
case 3:
panelsData.setBlue(aray);
break;
case 4:
panelsData.setGreen(aray);
break;
case 5:
panelsData.setRed(aray);
break;
case 6:
panelsData.setBlack(aray);
break;
case 7:
panelsData.setPrestige(aray);
break;
default:
break;
}
}
}
doc = getPage(res, "http://bannersbroker.com/adpubcombo_trafficbank/managetraffic");
elements = doc.select("h4[id=trafficLeft_4]");
if (elements.first() != null)
traffic[7] = Integer.parseInt((elements.first().text().replaceAll("[\\D+]", "")));
trafficData.setTraffic(traffic);
macroData.setMacro(macro);
}
public static Elements getPanelData(Document doc) {
Elements elements = doc.select("span.cost");
return elements;
}
public void setUpPaymentData(Connection.Response res) {
Document doc;
Elements elements;
doc = getPage(res, "http://bannersbroker.com/adpubcombo_manageinventory/viewpackagespurchased");
elements = doc.select("tr > td[align=center][valign=middle] > div");
try {
PaymentData.getInstance().setAbonamentDate(new SimpleDateFormat("yyyy-MM-dd").parse(elements.last().text()));
} catch (ParseException e) {
e.printStackTrace();
}
}
public void setUpTrafficPayment(Connection.Response res) {
Document doc;
Elements elements;
doc = getPage(res, "https://bannersbroker.com/adpubcombo_account/account");
elements = doc.select("div[class=infogroup] > div[class=tablecont] > table > tbody > tr > td[align=center]:not(td[class])");
for (int i = 0; i < 5; i++) elements.remove(0);
int length = elements.size();
for (int i = 0; i < length / 3; i++) {
elements.remove(i);
elements.remove(i);
}
PaymentData.getInstance().setTpAmount(elements.size());
Date[] array = new Date[elements.size()];
for (int i = 0; i < elements.size(); i++)
try {
array[i] = new SimpleDateFormat("yyyy-MM-dd").parse(elements.eq(i).text());
} catch (ParseException e) {
e.printStackTrace();
}
PaymentData.getInstance().setTpDate(array);
}
}
构造函数获取电子邮件、密码和框架，在这种情况下，框架并不重要，所以我从主方法 null 发送，当我想从框架发送电子邮件和密码时它获取框架，但每次调试时都不方便这样做跳过登录窗口。
public JsoupClass(String emailText, String passText, MainFrame mainFrame) {
Connection.Response res;
res = getLoginData();
res = doLogin(res, emailText, passText);
if (checkLogin(res).hasText()) {
setUpTrafficPayment(res);
setUpEwalletData(res);
setUpPanelsData(res);
setUpPaymentData(res);
try {
if (mainFrame != null)
mainFrame.dispose();
new StatisticFrame();
} catch (ParseException e1) {
e1.printStackTrace();
}
} else {
JOptionPane.showMessageDialog(RunFrame.getInstance(),
"Wrong Login Data!",
"Warning",
JOptionPane.WARNING_MESSAGE);
}
}
getLoginData()方法解析 cookie 和登录所需的一些隐藏字段
doLogin(res, emailText, passText)使用从 获取的数据getLoginData()、我们的电子邮件和密码来登录。下一步是if (checkLogin(res).hasText())，checkLogin(res)返回元素，所以如果elements.hasText我们知道我们登录成功，否则不返回。然后当我们登录时，我解析所需的数据以挖掘类巫术方法：
setUpTrafficPayment(res);
setUpEwalletData(res);
setUpPanelsData(res);
setUpPaymentData(res);
正如我在开始时所说的那样，一切正常，突然间它开始每次都抛出异常。
Banners Broker 是一个私人市场，目前只能通过推荐进行注册。如果任何人想创建一个帐户并尝试登录这里有一个链接来注册。 https://bannersbroker.com/vardius