java - 异常未处理
问题描述
当我打开视图窗口时,我输入了 FacultyCode 的值,如果我输入一个现有的值,那么一切都很好,如果我输入一个不存在的值,那么窗口就会冻结并且什么也没有发生
客户
@FXML
void initialize() {
showButton.setOnAction(actionEvent -> {
String input = null;
try {
socket = new Socket("127.0.0.1",3024);
outputStream = new DataOutputStream(socket.getOutputStream());
inputStream = new DataInputStream(socket.getInputStream());
} catch (IOException e) {
e.printStackTrace();
}
String facultyCode = facultyCodeArea.getText();
String output = "SELECT * FROM Faculty WHERE facultyCode = " + facultyCode + ";";
try {
outputStream.writeUTF(output);
outputStream.flush();
input = inputStream.readUTF(); //if the input is incorrect, input is not assigned to
//anything
} catch (IOException e) {
e.printStackTrace();
}
String[] dataServer = input.split(" ");
String name = dataServer[0];
nameArea.setText(name);
String code = dataServer[1];
facultyCodeArea.setText(code);
String number = dataServer[2];
numberSubjectsArea.setText(number);
String main = dataServer[3];
mainSubjectArea.setText(main);
String dean = dataServer[4];
deanArea.setText(dean);
String language = dataServer[5];
languageStudyArea.setText(language);
});
}
服务器
else if (isSelectQuery(input)) {
statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery(input);
while (resultSet.next()) {
String name = resultSet.getString("name");
int codeFaculty = resultSet.getInt("facultyCode");
int numberSubject = resultSet.getInt("numberSubjects");
String mainSubject = resultSet.getString("mainSubject");
String dean = resultSet.getString("dean");
String languageStudy = resultSet.getString("languageStudy");
String output = name + " " +
codeFaculty + " " +
numberSubject + " " +
mainSubject + " " +
dean + " " +
languageStudy;
outputStream.writeUTF(output);
outputStream.flush();
}
}
如果发生异常,我尝试关闭窗口,如果输入 = null,我也尝试关闭窗口,但没有帮助
解决方案
服务器
String output = "error";
else if (isSelectQuery(input)) {
statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery(input);
while (resultSet.next()) {
String name = resultSet.getString("name");
int codeFaculty = resultSet.getInt("facultyCode");
int numberSubject = resultSet.getInt("numberSubjects");
String mainSubject = resultSet.getString("mainSubject");
String dean = resultSet.getString("dean");
String languageStudy = resultSet.getString("languageStudy");
output = name + " " +
codeFaculty + " " +
numberSubject + " " +
mainSubject + " " +
dean + " " +
languageStudy;
}
outputStream.writeUTF(output);
outputStream.flush();
}
客户
@FXML
void initialize() {
showButton.setOnAction(actionEvent -> {
String input = null;
try {
socket = new Socket("127.0.0.1",3024);
outputStream = new DataOutputStream(socket.getOutputStream());
inputStream = new DataInputStream(socket.getInputStream());
} catch (IOException e) {
e.printStackTrace();
}
String facultyCode = facultyCodeArea.getText();
String output = "SELECT * FROM Faculty WHERE facultyCode = " + facultyCode + ";";
try {
outputStream.writeUTF(output);
outputStream.flush();
input = inputStream.readUTF();
} catch (IOException e) {
e.printStackTrace();
}
String[] dataServer = input.split(" ");
if(!dataServer[0].equals("error")) {
String name = dataServer[0];
nameArea.setText(name);
String code = dataServer[1];
facultyCodeArea.setText(code);
String number = dataServer[2];
numberSubjectsArea.setText(number);
String main = dataServer[3];
mainSubjectArea.setText(main);
String dean = dataServer[4];
deanArea.setText(dean);
String language = dataServer[5];
languageStudyArea.setText(language);
}
else {
errorArea.setText("Not exist");
}
});
}
所以我首先赋值 output = error ,如果请求没有返回任何东西,那么我将它发送给客户端,如果请求有东西来,我分配值并将它发送给客户端。接下来,我在客户端处理数据