POST方法中的Spring MVC模型为空

Question

I´m developing a WebApp with Spring MVC. The Problem is that my model which I pass through with @ModelAttribute, in my POST Method of my Controller seems to be empty, despite I have filled out the form on the web page.

This is the GET Method of my Controller:

@RequestMapping(value = "/CircleUp", method = RequestMethod.GET)
public ModelAndView circleUpGet(Model _model) {
    ModelAndView modelAndView = new ModelAndView("CircleUp");

    CircleUpModel circleUpModel = new CircleUpModel();
    _model.addAttribute("circleUpModel", circleUpModel);

    return modelAndView;
}

This is the POST Method of my Controller:

@RequestMapping(value = "/CircleUp", method = RequestMethod.POST)
public ModelAndView circleUpPost(HttpServletRequest _request, Model _model, @ModelAttribute("circleUpModel") CircleUpModel _circleUpModel) {

    return this.doCircleUp(_request, _model, _circleUpModel);
}

Here the "_circleUpModel" does not have any values.

This is my form in the related .jsp File with the needed script:

<form:form method="post" modelAttribute="circleUpModel" id="circle_form" action="" enctype="multipart/form-data" >


    <form:input path="file" id="upload" type="file" />

    <form:checkbox path="mergeSameTickmarks" checked="true" />

    <form:checkbox path="deleteHighlights" checked="true" />

    <form:checkbox path="generateFigureLog" checked="true" />

    ...

    <input type="button" onclick="javascript:submitForm()"
        value="Start Circle Up">

function submitForm() {
    if (checkIfPdf() && checkSettings()) {
        $("#circle_form").submit()
        setTimeout(progress, 100);
    }
}

Of course the default values of the CircleUpModel are presented but if I enter some other values in the form of the web page this entrys are not considered in the POST Method, despite I added the modelAttribute="circleUpForm" in my form.

CircleUpModel:

import org.pdfclown.files.File;


public class CircleUpModel {

    // File
    private File    file;

    // FileName
    private String  fileName;

    private boolean mergeSameTickmarks;
    private boolean deleteHighlights;
    private boolean generateFigureLog;

    // Settings
    private double  circleBorderWidth;

    private double  customizeCircleUp;
    private double  customizeCircleDown;

    private double  gapLeft;
    private double  gapRight;
    private double  maxGap;

    private boolean tickmarkAlwaysUpperCase;

    public File getFile() {
        return file;
    }

    public void setFile(File file) {
        this.file = file;
    }

    public String getFileName() {
        return fileName;
    }

    public void setFileName(String fileName) {
        this.fileName = fileName;
    }

    public boolean isMergeSameTickmarks() {
        return mergeSameTickmarks;
    }

    public void setMergeSameTickmarks(boolean mergeSameTickmarks) {
        this.mergeSameTickmarks = mergeSameTickmarks;
    }

    public boolean isDeleteHighlights() {
        return deleteHighlights;
    }

    public void setDeleteHighlights(boolean deleteHighlights) {
        this.deleteHighlights = deleteHighlights;
    }

    public boolean isGenerateFigureLog() {
        return generateFigureLog;
    }

    public void setGenerateFigureLog(boolean generateFigureLog) {
        this.generateFigureLog = generateFigureLog;
    }

    public double getCircleBorderWidth() {
        return circleBorderWidth;
    }

    public void setCircleBorderWidth(double circleBorderWidth) {
        this.circleBorderWidth = circleBorderWidth;
    }

    public double getCustomizeCircleUp() {
        return customizeCircleUp;
    }

    public void setCustomizeCircleUp(double customizeCircleUp) {
        this.customizeCircleUp = customizeCircleUp;
    }

    public double getCustomizeCircleDown() {
        return customizeCircleDown;
    }

    public void setCustomizeCircleDown(double customizeCircleDown) {
        this.customizeCircleDown = customizeCircleDown;
    }

    public boolean isTickmarkAlwaysUpperCase() {
        return tickmarkAlwaysUpperCase;
    }

    public void setTickmarkAlwaysUpperCase(boolean tickmarkAlwaysUpperCase) {
        this.tickmarkAlwaysUpperCase = tickmarkAlwaysUpperCase;
    }

    public double getGapLeft() {
        return gapLeft;
    }

    public void setGapLeft(double gapLeft) {
        this.gapLeft = gapLeft;
    }

    public double getGapRight() {
        return gapRight;
    }

    public void setGapRight(double gapRight) {
        this.gapRight = gapRight;
    }

    public double getMaxGap() {
        return maxGap;
    }

    public void setMaxGap(double maxGap) {
        this.maxGap = maxGap;
    }

}

Answer 1

If you remove file upload stuff, you will be able to see the data in your model. But if you want to do file upload, you have to tweak your code as follows.

1. First, remove member 'file' and its setter and getter methods from model.

2. Second, replace the below tag in your JSP

    <form:input path="file" id="upload" type="file" /> 

with simple HTML tag.

    <input name="file" type="file"/>

3. Modify the signature of your POST method in controller to as follows.

    public ModelAndView circleUpPost(HttpServletRequest _request, @ModelAttribute("circleUpModel") CircleUpModel _circleUpModel, @RequestParam("file") MultipartFile _file) { //do your processing } 

Here the last parameter '_file' is of MultipartFile type and contains the file you upload from JSP.

4. Last and most important step is to register a multipart resolver in Spring configuration file.

    <beans:bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <beans:property name="maxUploadSize" value="100000" /> </beans:bean> 

Hope this helps.

Answer 2

This problem could be resolved by changing the type of the file in the model.

Previously it was a pdfclown file and now I have changed it into a MultipartFile. In my POST Method I have converted the file from MultipartFile into pdfclown File to be able to work with it like before.