创建DiskFileItem时出现java.lang.NullPointerException
内容导读
互联网集市收集整理的这篇技术教程文章主要介绍了创建DiskFileItem时出现java.lang.NullPointerException,小编现在分享给大家,供广大互联网技能从业者学习和参考。文章包含3976字,纯文字阅读大概需要6分钟。
内容图文
![创建DiskFileItem时出现java.lang.NullPointerException](/upload/InfoBanner/zyjiaocheng/813/74c31775ea2a45d4a391b4268d40bd7d.jpg)
我正在尝试使用Spring 3编写一个单元测试来处理文件上传控制器.现在,如果我通过控制器将图像发送到我的服务方法,一切正常.但是在进行直接单元测试时,我得到一个空指针异常.
看来DiskFilteItem中的属性“dfos”在我手动实例化时为null,但是在从控制器检索MultipartFile时会填充它.
File file = new File("//Users//test//Downloads//testimage.jpg");
log.info("found file: " +file.exists());
log.info("file size: " +file.length());
String fieldName = "field";
String contentType = "image/jpeg";
boolean isFormField = false;
String fileName = "testimage.jpg";
int sizeThreshold = 10240;
DiskFileItemFactory factory = new DiskFileItemFactory();
DiskFileItemFactory factory = new DiskFileItemFactory();
// throws null pointer
FileItem fi = factory.createItem(fieldName,contentType,isFormField,fileName);
// so does this one
DiskFileItem item = new DiskFileItem(fieldName, contentType, isFormField, fileName, sizeThreshold, file);
MultipartFile f = new CommonsMultipartFile(item);
我觉得我在设置中遗漏了一些愚蠢的东西.我的pom文件包含以下依赖项.
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.2.2</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.0</version>
</dependency>
此代码抛出以下堆栈跟踪
java.lang.NullPointerException at org.apache.commons.fileupload.disk.DiskFileItem.getSize(DiskFileItem.java:316) at org.springframework.web.multipart.commons.CommonsMultipartFile.(CommonsMultipartFile.java:60) at ImgurClientTest.testUploadImage(ImgurClientTest.java:58) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20) at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74) at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:82) at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:240) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184) at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) at org.junit.runners.ParentRunner.run(ParentRunner.java:236) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:180) at org.junit.runner.JUnitCore.run(JUnitCore.java:157) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:65)
解决方法:
我遇到了同样的问题.问题是DiskFileItem.getSize()在时间上与DiskFileItem.getOutputStream()耦合,因为内部字段在getOutputStream中初始化并在getSize中使用.
解决方案是做
final File TEST_FILE = new File("src/test/resources/test.jpg");
final DiskFileItem diskFileItem = new DiskFileItem("file", "image/jpeg", true, TEST_FILE.getName(), 100000000, TEST_FILE.getParentFile());
diskFileItem.getOutputStream();
在将diskFileItem传递给CommonsMultipartFile的构造函数之前.
内容总结
以上是互联网集市为您收集整理的创建DiskFileItem时出现java.lang.NullPointerException全部内容,希望文章能够帮你解决创建DiskFileItem时出现java.lang.NullPointerException所遇到的程序开发问题。 如果觉得互联网集市技术教程内容还不错,欢迎将互联网集市网站推荐给程序员好友。
内容备注
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 gblab@vip.qq.com 举报,一经查实,本站将立刻删除。
内容手机端
扫描二维码推送至手机访问。