Struts文件上传API突然行为，并且通过struts API

Question

我有Web项目我正在使用Struts2框架。在这个人上传pdf文件，因为我使用了struts文件上传API。

但奇怪的是，每次第二次文件上传都在服务器上损坏，当我尝试打开文件时，它给了我错误：

打开此文档时出错。该文件已损坏且无法修复。 enter image description here

struts.xml中

<action name="uploadFiles" class="org.webpannel.action.FileHandlingAction"
        method="saveFiles">
        <interceptor-ref name="customeUploadStack" />
        <result name="success">/admin/WindowCloser.jsp</result>
        <result name="input">/service/AttachmentPopup.jsp</result>
    </action>

FileHandlingAction：

public class FileHandlingAction extends BaseAction implements Preparable{
/**
 * 
 */
private static final long serialVersionUID = -470622101009022548L;
private File[] file;
private String[] contentType;
private String[] filename;
private List<String> attachmentsList= new ArrayList<String>();
private String directoryPath;
// the name is written like this, so that no one can easily manipulate.
private String istbamefi;
private static Logger logger = Logger.getLogger(FileHandlingAction.class);

public void prepare() throws Exception {

    directoryPath = getText("attachments.dirctory")+File.separator+getS3IdFromSession();
    System.out.println("directoryPath::"+directoryPath);
}
@Override
public String execute() throws Exception {
    try{

        File[] filesStored = Utility.listFilesInDirectory(directoryPath);
        if(filesStored==null){
            return SUCCESS;
        }
        for(File fil : filesStored){
            attachmentsList.add(fil.getName());
        }
    }catch(Exception e1){
        logger.error(e1.getMessage(),e1);
    }
    return SUCCESS;
}
public String saveFiles() {
    logger.info("Going to save the Uploaded files");
    if(logger.isDebugEnabled()){
        logger.debug("Directory path :"+directoryPath);
        if(file==null){
            addActionMessage("Please Select a file to upload");
            return INPUT;
        }
        for (File f : file) {
            logger.debug("File :"+f);
        }
    }
    for (int i = 0; i < file.length; i++) {
        try {
            uploadDocument(file[i], filename[i]);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    logger.info("Exiting successfully after saving the files:");
    setMessage("succesfully saved the files");
    return SUCCESS;
}
public String removeFile(){
    logger.debug("Going to delete file:"+istbamefi);

    File file = new File(directoryPath+File.separator+istbamefi);
    if(file.exists()){
        logger.debug("File found");
        file.delete();
        logger.debug("File Deleted");
    }else{
        logger.debug("File Doest not exists");
        setMessage("File Does not exists");
        return SUCCESS;
    }
    setMessage("File Successfully Removed");
    return SUCCESS;
}
private void uploadDocument(File file, String fileName) throws IOException {

    FileInputStream in = null;
    FileOutputStream out = null;
    File dir = new File(directoryPath);
    if (!dir.exists()) {
        dir.mkdir();
    }
     logger.info("Uploaded File Name :" +fileName);
     logger.info("Uploaded File Length :" +file.length());
    String targetPath = dir.getPath() + File.separator + fileName;
    System.out.println("targetPath::"+targetPath);
    File picDestination = new File(targetPath);
     logger.info("Destination Path :"+picDestination);
    try {
        in = new FileInputStream(file);
        out = new FileOutputStream(picDestination);
        int c;

        while ((c = in.read()) != -1) {
            out.write(c);


        }

    } finally {
        if (in != null) {
            in.close();
        }
        if (out != null) {
            out.close();
        }
    }
}
public List<String> getAttachmentsList() {
    return attachmentsList;
}
public void setAttachmentsList(List<String> attachmentsList) {
    this.attachmentsList = attachmentsList;
}
public File[] getFile() {
    return file;
}
public void setFile(File[] file) {
    this.file = file;
}
public String[] getContentType() {
    return contentType;
}
public void setContentType(String[] contentType) {
    this.contentType = contentType;
}
public String[] getFilename() {
    return filename;
}
public void setUpload(File[] file) {
    this.file = file;
}

public void setUploadContentType(String[] contentType) {
    this.contentType = contentType;
}

public void setUploadFileName(String[] filename) {
    this.filename = filename;
}
public void setFilename(String[] filename) {
    this.filename = filename;
}
public String getDirectoryPath() {
    return directoryPath;
}
public void setDirectoryPath(String directoryPath) {
    this.directoryPath = directoryPath;
}
public String getIstbamefi() {
    return istbamefi;
}
public void setIstbamefi(String istbamefi) {
    this.istbamefi = istbamefi;
}

}