Java 使用MockMultipartTTPServletRequest进行单元测试（在ItemInputStream.makeAvailable中抛出NullPointerException）

我已经编写了一个transformer类，它接受一个HttpServletRequest并将其转换为另一个类型，该类型保存一个指向servlet请求的InputStream的指针。（想法是从请求处理中抽象出传入的传输协议，因此我也可以从FTP中编写类似的转换器。）

现在我正试图为此编写一个单元测试，但我遇到了一些问题。我已经设法找到了正确的样板文件来创建一个有效的多部分HTTP请求（使用Spring类MockMultipartTTpServletRequest和MockMultipartFile），但是现在我在我的

UploadRequest

类的

initialize（）

方法中得到了一个NullPointerException。我猜问题在于mockmultipartttpServletRequest中的流没有被正确初始化，但是我不知道应该做什么不同

任何建议都将被感激地接受

这是堆栈跟踪：

java.lang.NullPointerException
    at org.apache.commons.fileupload.MultipartStream$ItemInputStream.makeAvailable(MultipartStream.java:976)
    at org.apache.commons.fileupload.MultipartStream$ItemInputStream.read(MultipartStream.java:886)
    at java.io.InputStream.read(InputStream.java:82)
    at org.apache.commons.fileupload.util.Streams.copy(Streams.java:96)
    at org.apache.commons.fileupload.util.Streams.copy(Streams.java:66)
    at org.apache.commons.fileupload.MultipartStream.readBodyData(MultipartStream.java:592)
    at org.apache.commons.fileupload.MultipartStream.discardBodyData(MultipartStream.java:618)
    at org.apache.commons.fileupload.MultipartStream.skipPreamble(MultipartStream.java:637)
    at org.apache.commons.fileupload.FileUploadBase$FileItemIteratorImpl.findNextItem(FileUploadBase.java:984)
    at org.apache.commons.fileupload.FileUploadBase$FileItemIteratorImpl.<init>(FileUploadBase.java:965)
    at org.apache.commons.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:331)
    at org.apache.commons.fileupload.servlet.ServletFileUpload.getItemIterator(ServletFileUpload.java:148)
    at com.ooyala.UploadRequest.initialize(UploadRequest.java:51)
    at com.ooyala.UploadRequestTest.testCreateFromServletRequest(UploadRequestTest.java:57)

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我也有同样的问题，我在谷歌上搜索过，但没有答案。我从库中插入源代码，你需要发送内容，无论什么。库可能需要在skip方法中检查它是否为null

MockMultipartHttpServletRequest request
request.setContent("whatever".getBytes());

为其他人张贴在这里

添加边界条件

生成如下内容

MockMultipartHttpServletRequest request = 
    this.generateMockMultiPartHttpServletRequest(true);
MockMultipartFile mockMultipartFile = null;
try {
    request.setContentType("multipart/form-data; boundary=-----1234");
    request.setCharacterEncoding("text/plain");
    String endline = "\r\n";
    String bondary = "-----1234";
    String textFile = this.encodeTextFile("-----1234", "\r\n", "file","test.csv",
        "text/UTF-8", FileUtils.readFileToString((new File(csvFilePath)), "UTF-8"));
    StringBuilder content = new StringBuilder(textFile.toString());
    content.append(endline);
    content.append(endline);
    content.append(endline);
    content.append("--");
    content.append(bondary);
    content.append("--");
    content.append(endline);
    request.setContent(content.toString().getBytes());
    request.setMethod("POST");
    mockMultipartFile = new MockMultipartFile("file",
    FileUtils.readFileToByteArray(new File(csvFilePath)));
} catch (Exception e1) {
    e1.printStackTrace();
}
 request.addFile(mockMultipartFile);

函数对文本进行编码

    private String encodeTextFile(String bondary, String endline, String name, 
        String filename, String contentType, String content) {

        final StringBuilder sb = new StringBuilder(64);
        sb.append(endline);
        sb.append("--");
        sb.append(bondary);
        sb.append(endline);
        sb.append("Content-Disposition: form-data; name=\"");
        sb.append(name);
        sb.append("\"; filename=\"");
        sb.append(filename);
        sb.append("\"");
        sb.append(endline);
        sb.append("Content-Type: ");
        sb.append(contentType);
        sb.append(endline);
        sb.append(endline);
        sb.append(content);
        return sb.toString();
    }

---

我也遇到了同样的问题，在搜索了很多之后，我得到了这篇文章，在其中我用解决我问题的代码进行了回答

Shriprasad的解决方案适用于文本文件。但是我有一些二进制文件的问题

MockMultipartHttpServletRequest request = 
    this.generateMockMultiPartHttpServletRequest(true);
MockMultipartFile mockMultipartFile = null;
try {
    request.setContentType("multipart/form-data; boundary=-----1234");
    request.setCharacterEncoding("text/plain");
    String endline = "\r\n";
    String bondary = "-----1234";
    String textFile = this.encodeTextFile("-----1234", "\r\n", "file","test.csv",
        "text/UTF-8", FileUtils.readFileToString((new File(csvFilePath)), "UTF-8"));
    StringBuilder content = new StringBuilder(textFile.toString());
    content.append(endline);
    content.append(endline);
    content.append(endline);
    content.append("--");
    content.append(bondary);
    content.append("--");
    content.append(endline);
    request.setContent(content.toString().getBytes());
    request.setMethod("POST");
    mockMultipartFile = new MockMultipartFile("file",
    FileUtils.readFileToByteArray(new File(csvFilePath)));
} catch (Exception e1) {
    e1.printStackTrace();
}
 request.addFile(mockMultipartFile);

    private String encodeTextFile(String bondary, String endline, String name, 
        String filename, String contentType, String content) {

        final StringBuilder sb = new StringBuilder(64);
        sb.append(endline);
        sb.append("--");
        sb.append(bondary);
        sb.append(endline);
        sb.append("Content-Disposition: form-data; name=\"");
        sb.append(name);
        sb.append("\"; filename=\"");
        sb.append(filename);
        sb.append("\"");
        sb.append(endline);
        sb.append("Content-Type: ");
        sb.append(contentType);
        sb.append(endline);
        sb.append(endline);
        sb.append(content);
        return sb.toString();
    }