注：用static去定义一个注入的方法或者配置文件值变量，编译时不会有任何异常，运行时会报空指针。
Spring官方不推荐此种方法。
原理：
https://www.cnblogs.com/chenfeng1122/p/6270217.html
解决办法
利用spring的set注入方法，通过非静态的setter方法注入静态变量 ，我们可以改成这样就静态变量可以获取到你配置的信息了。
把get,set方法的static 修饰符去掉，然后在set方法上面加@Autowired即可
/** 阿里云OSS配置查询 */
private static OSSConfMapper ossConfMapper;
/** 阿里云OSS图片上传 */
private static UploadImgOSS uploadImgOSS;
public OSSConfMapper getOssConfMapper() {
return ossConfMapper;
}
@Autowired
public void setOssConfMapper(OSSConfMapper ossConfMapper) {
UploadUtil.ossConfMapper = ossConfMapper;
}
public UploadImgOSS getUploadImgOSS() {
return uploadImgOSS;
}
@Autowired
public void setUploadImgOSS(UploadImgOSS uploadImgOSS) {
UploadUtil.uploadImgOSS = uploadImgOSS;
}
参考文档
https://blog.csdn.net/kongrun12/article/details/76246369
https://blog.csdn.net/zxl646801924/article/details/81738231
https://blog.csdn.net/u014079773/article/details/66973830
经过尝试，有两种实现方式
方式一：声明一个静态的变量或方法，再相应的注入一个对应的变量和方法，最后PostConstruct注解在init时实现。
代码如下
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.stereotype.Component;
import tylin.paas.transfers.util.DateUtil;
import javax.annotation.PostConstruct;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;
@Slf4j
@Component
public class ErrorHandler {
@Value("${customer.mail.bankMail.sender}")
private String configSender;
private static String sender;
@Value("${customer.mail.bankMail.receiver}")
private String configReceiver;
private static String receiver;
public static ErrorHandler errorHandler;
@Autowired
JavaMailSender autoJavaMailSender;
private static JavaMailSender javaMailSender;
@PostConstruct
public void init() {
sender = configSender;
receiver = configReceiver;
javaMailSender = autoJavaMailSender;
errorHandler = this;
}
public static void sendMail() {
SimpleMailMessage message = new SimpleMailMessage();
message.setFrom(sender);
message.setTo(receiver.split(";"));
message.setSubject("your subject");
message.setText("your content text");
try {
javaMailSender.send(message);
log.info("发送邮件成功！");
} catch (Exception e) {
log.error("发送邮件时发生异常！", e);
}
}
}
方式二：
在set时注入
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.stereotype.Component;
import org.springframework.test.context.junit4.SpringRunner;
import org.tylin.TylinERPApplication;
import java.text.SimpleDateFormat;
import java.util.Date;
@Slf4j
@Component
@SpringBootTest(classes = TylinERPApplication.class)
@RunWith(SpringRunner.class)
public class MailAutoSendTest {
private static String sender;
//可以不要
public String getSender() {
return sender;
}
@Value("${customer.mail.bankMail.sender}")
public void setSender(String sender) {
MailAutoSendTest.sender = sender;
}
private static String receiver;
//可以不要
public String getReceiver() {
return receiver;
}
@Value("${customer.mail.bankMail.receiver}")
public void setReceiver(String receiver) {
MailAutoSendTest.receiver = receiver;
}
private static JavaMailSender javaMailSender;
public JavaMailSender getJavaMailSender(){
return javaMailSender;
}
@Autowired
public void setJavaMailSender(JavaMailSender javaMailSender){
MailAutoSendTest.javaMailSender = javaMailSender;
}
@Test
public void sendMail() {
SimpleMailMessage message = new SimpleMailMessage();
message.setFrom(sender);
log.info(sender);
log.info(receiver);
message.setTo(receiver.split(";"));
message.setSubject("xxxx");
Date date = new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
message.setText("xxxx"+dateFormat.format(date));
try {
javaMailSender.send(message);
log.info("简单邮件已经发送。");
} catch (Exception e) {
log.error("发送简单邮件时发生异常！", e);
}
}
}
