所以，我刚刚进入摇摆工作者，我不知道如何阻止它我尝试boolean方式。它不能正常工作，你可以编辑我的代码，使其成为可行的方式！非常感谢！
没有错误显示它只是没有停止！
class MessageBox {
public static void infoBox(String infoMessage, String location)
{
JOptionPane.showMessageDialog(null, infoMessage, "Message: " + location, JOptionPane.INFORMATION_MESSAGE);
}
}
public class GUI extends JFrame
{
private JButton button1;
private JPanel Gpanel;
private JTextField textField1;
private JTextField howmany;
private JLabel countlabel;
private JLabel statuslabel;
private JCheckBox anyEmail;
private JButton stopButton;
private boolean stopped;
public GUI() {
super("Program V0.1");
this.setIconImage(new ImageIcon(getClass().getResource("icon.png")).getImage());
setContentPane(Gpanel);
pack();
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setVisible(true);
button1.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
start();
}
});
stopButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
stopped = true;
}
});
}
private void start() {
SwingWorker<Void, Void> worker = new SwingWorker<Void, Void>() {
@Override
protected Void doInBackground() throws Exception {
if (!stopped){
for (int i = 0; i < Integer.parseInt(howmany.getText()); i++) {
if (anyEmail.isSelected()) {
URL url = null;
try {
String Hostemail = "http://example.com/";
url = new URL(Hostemail);
} catch (MalformedURLException e) {
e.printStackTrace();
}
Map<String, Object> variables = new LinkedHashMap<>();
variables.put("email", textField1.getText());
variables.put("fullname", "");
variables.put("pw", "");
variables.put("pw-conf", "");
variables.put("digest", "1");
variables.put("email-button", "Subscribe");
StringBuilder postData = new StringBuilder();
for (Map.Entry<String, Object> param : variables.entrySet()) {
if (postData.length() != 0) {
postData.append('&');
}
try {
postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
postData.append('=');
try {
postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
byte[] postDataBytes = new byte[0];
try {
postDataBytes = postData.toString().getBytes("UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
String line;
HttpURLConnection conn = null;
try {
assert url != null;
conn = (HttpURLConnection) url.openConnection();
} catch (IOException e) {
e.printStackTrace();
}
try {
assert conn != null;
conn.setRequestMethod("POST");
} catch (ProtocolException e) {
e.printStackTrace();
}
conn.setRequestProperty("Cache-Control", "no-cache,private,Private");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
conn.setDoOutput(true);
try {
conn.getOutputStream().write(postDataBytes);
} catch (IOException e) {
e.printStackTrace();
}
BufferedReader in = null;
try {
in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
} catch (IOException e) {
e.printStackTrace();
}
try {
assert in != null;
while ((line = in.readLine()) != null) {
String success = "Your subscription request has been received";
if (line.contains(success)) {
countlabel.setText(String.valueOf(i));
}
}
} catch (IOException e) {
e.printStackTrace();
}
} else {
URL url = null;
try {
String Host = "http://example2.com";
url = new URL(Host);
} catch (MalformedURLException e) {
e.printStackTrace();
}
Map<String, Object> variables = new LinkedHashMap<>();
variables.put("strEmail", textField1.getText());
StringBuilder postData = new StringBuilder();
for (Map.Entry<String, Object> param : variables.entrySet()) {
if (postData.length() != 0) {
postData.append('&');
}
try {
postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
postData.append('=');
try {
postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
byte[] postDataBytes = new byte[0];
try {
postDataBytes = postData.toString().getBytes("UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
String line;
HttpURLConnection conn = null;
try {
assert url != null;
conn = (HttpURLConnection) url.openConnection();
} catch (IOException e) {
e.printStackTrace();
}
try {
assert conn != null;
conn.setRequestMethod("POST");
} catch (ProtocolException e) {
e.printStackTrace();
}
conn.setRequestProperty("Cache-Control", "no-cache,private,Private");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
conn.setDoOutput(true);
try {
conn.getOutputStream().write(postDataBytes);
} catch (IOException e) {
e.printStackTrace();
}
BufferedReader in = null;
try {
in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
} catch (IOException e) {
e.printStackTrace();
}
try {
statuslabel.setText("Sending Emails...");
assert in != null;
while ((line = in.readLine()) != null) {
String success = "success";
String error = "not";
if (line.contains(success)) {
countlabel.setText(String.valueOf(i));
} else if (line.contains(error)) {
MessageBox.infoBox("[Email Not Found]: " + textField1.getText(), "Error");
break;
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
statuslabel.setText("Done");
return null;
}
};
worker.execute();
if (stopped){
worker.cancel(true);
}
}
}
答案 0 :(得分：1)
您可以利用SwingWorker Future遗产并使用isCancelled和cancel功能......
protected Void doInBackground() throws Exception {
int i = 0;
while (!isCancelled() && i < howMany) {
...
为了能够取消工人，你需要参考它......
private SwingWorker worker;
//...
stopButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (worker != null) {
worker.cancel(true);
}
}
});
注意，SwingWorker不应该访问或引用任何UI组件（事实上，你应该尽可能避免引用它之外的任何值），因为它在后台运行，你运行（不仅）违反Swing的单线程规则的风险，而且在处理时还会改变您所依赖的信息。
您应该在开始之前收集SwingWorker所需的所有信息并将该信息传递给它（通过构造函数或setter方法）。这意味着工作人员孤立地运行，没有其他数据更改的风险，这可能会导致其他随机问题。
答案 1 :(得分：1)
我认为问题是，在您通过调用worker.execute()方法启动swingworker之后，立即检查是否stopped == true。由于execute()方法是非阻塞的，因此只需在调用execute()之后评估if语句。此时，已停止的值只能是true，因此您的工作人员不会被取消。一种解决方案是，让您的工作人员成为实例成员，并且更像这样：
private SwingWorker worker;
// ...
stopButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (worker != null && !worker.isCanceled()) {
worker.cancel(true);
}
}
});
此外，如果您有从不同线程访问和更改的成员，则应同步该访问权限。
答案 2 :(得分：0)
一旦每个循环交互，您需要检查stopped是否为真，而不是在循环之前检查一次。您可以将您的工作人员改写为：
@Override
protected Void doInBackground() throws Exception {
for (int i = 0; i < Integer.parseInt(howmany.getText()); i++) {
if(stopped){return null;}
//your existing loop contents
}
}
这会在尝试执行下一次迭代时停止循环。但是，除非您中断线程或以其他方式强制停止，否则当前迭代将完成。
此外，您需要确保在被声明的地方将被标记为易失性。