500错误-嵌套异常是org.springframework.mail.MailPreparationException: Could not prepare mail;嵌套异常是java.lang.NullPointerException
我正在尝试使用smtp服务器生成电子邮件。我能够在不添加内联图像的情况下生成电子邮件，而当我添加"addinline"函数时，我在输出屏幕中得到空指针错误，无法生成电子邮件，图像无法从系统中获取。当我试图发送附件时，我得到同样的错误。提前感谢。
in dao实现
@Autowired
private JavaMailSender mailSender;
mailSender.send(new MimeMessagePreparator() {
public void prepare(MimeMessage mimeMessage) throws MessagingException, IOException {
MimeMessageHelper message = new MimeMessageHelper(mimeMessage, true, "UTF-8");
message.setFrom(from);
message.setTo(recipientAddress);
message.setSubject("Subject");
message.setText("<html><body><img src="cid:identifier1234"/></body></html>", true);
FileSystemResource res = new FileSystemResource(new File("D:imagesphoto.svg.png"));
message.addInline("identifier1234", res);
}
});
xml中的Bean类
<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
<property name="host" value="smtp.com" />
<property name="port" value="25" />
<property name="username" value="Sender.email@abc.com" />
<property name="password" value="password@123" />
<property name="javaMailProperties">
<props>
<prop key="mail.transport.protocol">smtp</prop>
<prop key="mail.smtp.auth">true</prop>
<prop key="mail.smtp.starttls.enable">true</prop>
</props>
</property>
</bean>
输出窗口错误
SEVERE: Servlet.service() for servlet [welcome] in context with path [/registrationForm] threw exception [Request processing failed; nested exception is org.springframework.mail.MailPreparationException: Could not prepare mail; nested exception is java.lang.NullPointerException] with root cause
java.lang.NullPointerException
at javax.mail.internet.MimeUtility.getEncoding(MimeUtility.java:226)
at javax.mail.internet.MimeUtility.getEncoding(MimeUtility.java:299)
at javax.mail.internet.MimeBodyPart.updateHeaders(MimeBodyPart.java:1375)
at javax.mail.internet.MimeBodyPart.updateHeaders(MimeBodyPart.java:1021)
at javax.mail.internet.MimeMultipart.updateHeaders(MimeMultipart.java:419)
at javax.mail.internet.MimeBodyPart.updateHeaders(MimeBodyPart.java:1354)
at javax.mail.internet.MimeBodyPart.updateHeaders(MimeBodyPart.java:1021)
at javax.mail.internet.MimeMultipart.updateHeaders(MimeMultipart.java:419)
at javax.mail.internet.MimeBodyPart.updateHeaders(MimeBodyPart.java:1354)
at javax.mail.internet.MimeMessage.updateHeaders(MimeMessage.java:2107)
at javax.mail.internet.MimeMessage.saveChanges(MimeMessage.java:2075)
at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:411)
at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:340)
at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:355)
at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:344)
at com.registrationForm.dao.DocumentDaoImpl.generateEmail(DocumentDaoImpl.java:182)
at com.registrationForm.service.DocumentServiceImpl.generateEmail(DocumentServiceImpl.java:45)
at com.registrationForm.controller.DocumentController.saveForm(DocumentController.java:84)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:96)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:617)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
在DAO实现中哪一行是182 ?我猜是FileSystemResource声明。试着像这样分割这一行:
File file = new File(/* your file path*/);
if(!file.exists())System.out.println("File doesn't exist");
else {
//do stuff
}
如果你在控制台看到消息，你的文件路径是错误的