java - 如何解决这个 java.lang.NullPointerException: date must not be null in my spring boot project [关闭]

package net.javaguides.ems.entity; //import java.sql.Date; import java.util.Date; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; import javax.validation.constraints.Email; import javax.validation.constraints.NotBlank; import javax.validation.constraints.NotNull; import javax.validation.constraints.Size; import org.springframework.format.annotation.DateTimeFormat; @Entity @Table(name = "employee") public class Employee { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; //Here, The values of this id field will be automatically generated by database on browser. private String firstName; private String lastName; private String email; private String gender; private String marriage; //@Column(name = "birthday") @DateTimeFormat(pattern = "dd-mm-yyyy") //@NotNull(message = "Please give a date of birth.") private Date birthday; private String workat; private String department; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public String getGender() { return gender; } public void setGender(String gender) { this.gender = gender; } public String getMarriage() { return marriage; } public void setMarriage(String marriage) { this.marriage = marriage; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public String getWorkat() { return workat; } public void setWorkat(String workat) { this.workat = workat; } public String getDepartment() { return department; } public void setDepartment(String department) { this.department = department; } }

package net.javaguides.ems.controller; import java.util.List; import javax.validation.Valid; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.validation.BindingResult; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.ModelAttribute; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import net.javaguides.ems.entity.Employee; @Controller // Controller Layer holds all Spring MVC Controllers public class EmployeeController { @Autowired EmployeeDao employeeDao; @RequestMapping("/employees") public String listEmployees(Model m){ List<Employee> list=employeeDao.getAllEmployees(); m.addAttribute("list",list); return "employees"; } @RequestMapping("/employees/new") public String createEmployeeForm(Model m){ m.addAttribute("employee", new Employee()); return "create_employee"; } @RequestMapping(value="/employees",method = RequestMethod.POST) public String saveEmployee(@ModelAttribute("employee") @Valid Employee employee, BindingResult bindingResult, Model model){ employeeDao.saveEmployee(employee); return "redirect:/employees";//will redirect to viewemp request mapping } @RequestMapping(value="/employees/edit/{id}") public String editEmployeeForm(@PathVariable Long id, Model m){ Employee employee = employeeDao.getEmployeeById(id); m.addAttribute("command",employee); return "edit_employee"; } @RequestMapping(value="/employees/{id}",method = RequestMethod.POST) public String updateEmployee(@ModelAttribute("employee") Employee employee){ employeeDao.updateEmployee(employee); return "redirect:/employees"; } @RequestMapping(value="/employees/{id}",method = RequestMethod.GET) public String deleteEmployee(@PathVariable Long id){ employeeDao.deleteEmployeeById(id); return "redirect:/employees"; } }

package net.javaguides.ems.controller; import java.util.Date; import java.util.List; import java.sql.ResultSet; import java.sql.SQLException; import java.text.ParseException; import java.text.SimpleDateFormat; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.BeanPropertyRowMapper; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.RowMapper; import org.springframework.stereotype.Service; import net.javaguides.ems.entity.Employee; @Service() public class EmployeeDao { @Autowired JdbcTemplate jdbcTemplate; /* * public void setJdbcTemplate(JdbcTemplate jdbcTemplate) { this.jdbcTemplate = * jdbcTemplate; } */ public List<Employee> getAllEmployees() { //List<Map<String,String>> data = new ArrayList<Map<String, String>>(); return jdbcTemplate.query("select * from employee", new RowMapper<Employee>() { public Employee mapRow(ResultSet rs, int row) throws SQLException { Employee emp = new Employee(); emp.setId(rs.getLong(1)); emp.setFirstName(rs.getString(2)); emp.setLastName(rs.getString(3)); emp.setEmail(rs.getString(4)); emp.setGender(rs.getString(5)); emp.setMarriage(rs.getString(6)); emp.setBirthday(rs.getDate(7)); emp.setWorkat(rs.getString(8)); emp.setDepartment(rs.getString(9)); return emp; } }); } public long saveEmployee(Employee p) { SimpleDateFormat format1 = new SimpleDateFormat("dd-MM-yyyy"); System.out.println("DOB ::"+p.getBirthday()+"::"+format1.format(p.getBirthday ())); String sql="insert into employee(firstName,lastName,email,gender,marriage,birthday,workat,department) values " + "('"+p.getFirstName()+"',"+p.getLastName()+","+p.getEmail()+","+p.getGender() +","+p.getMarriage()+","+p.getBirthday()+","+p.getWorkat()+",'"+p. getDepartment()+"')"; System.out.println("SQL ::"+sql); return jdbcTemplate.update(sql); // return jdbcTemplate.update(sql); } //@Deprecated public Employee getEmployeeById(Long id) { String sql="select * from employee where id=?"; //return jdbcTemplate.queryForObject("select * from employee where id=?",new BeanPropertyRowMapper<Employee>(Employee.class), new Object[]{id}); return jdbcTemplate.queryForObject(sql,new BeanPropertyRowMapper<Employee>(Employee.class),new Object[]{id}); } public long updateEmployee(Employee p) { String sql="update employee set firstName='"+p.getFirstName()+"', lastName="+p.getLastName()+",email="+p.getEmail()+",gender="+p.getGender()+",marriage="+p.getMarriage()+",birthday="+p.getBirthday()+",workat="+p.getWorkat()+",department='"+p.getDepartment()+"' where id="+p.getId()+""; return jdbcTemplate.update(sql); } public long deleteEmployeeById(Long id) { String sql="delete from employee where id="+id+""; return jdbcTemplate.update(sql); } } 4.Error Whitelabel Error Page This application has no explicit mapping for /error, so you are seeing this as a fallback. Sun Jul 11 21:26:43 IST 2021 There was an unexpected error (type=Internal Server Error, status=500). date must not be null java.lang.NullPointerException: date must not be null at java.base/java.util.Objects.requireNonNull(Objects.java:233) at java.base/java.util.Calendar.setTime(Calendar.java:1802) at java.base/java.text.SimpleDateFormat.format(SimpleDateFormat.java:975) at java.base/java.text.SimpleDateFormat.format(SimpleDateFormat.java:968) at java.base/java.text.DateFormat.format(DateFormat.java:375) at net.javaguides.ems.controller.EmployeeDao.saveEmployee(EmployeeDao.java:66) at net.javaguides.ems.controller.EmployeeController.saveEmployee(EmployeeController.java:77) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:567) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:197) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:141) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:894) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1063) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) at javax.servlet.http.HttpServlet.service(HttpServlet.java:681) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:228) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163) at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163) at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1723) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.base/java.lang.Thread.run(Thread.java:831)