Spring MVC Thymeleaf binding List with check boxes

问题

I am trying to create a form using thymeleaf that contains a series of checkboxes. The object source that I am passing through to the thymeleaf template contains a String and a List.

package com.controller;

import java.util.List;

public class Source {
private String sourceName;
private List<String> testList;

public String getSourceName()
{
    return sourceName;
}

public void setSourceName(String name)
{
    this.sourceName = name;
}

public List<String> getTestList()
{
    return testList;
}

public void setTestList(List<String> list)
{
    this.testList = list;
}

}

I pass an object of type source into the template using this MVC controller.

package com.controller;


import java.io.IOException;
import java.util.List;
import java.util.Locale;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.View;
import org.thymeleaf.spring4.view.ThymeleafViewResolver;

import com.web_application.AllEnvironmentsFromFile;
import com.web_application.AllTestsAndPaths;
import com.web_application.RunDao;
import com.web_application.TestAndPath;


@RestController
public class ManualTestController {
@Autowired
private ThymeleafViewResolver resolver;

@Autowired
RunDao rDao;

@Autowired
AllEnvironmentsFromFile environments;


@RequestMapping(value="/manualTest", method=RequestMethod.GET)
public View greetingForm(Model model) throws Exception {

    AllTestsAndPaths a = new AllTestsAndPaths();
    List<TestAndPath> testList = a.testsAndPaths();     
    String[] environmentList = new String[environments.getEnvironments().size()];
    for(int i = 0; i < environments.getEnvironments().size(); i++)
    {
        environmentList[i] = environments.getEnvironments().get(i).getName();
    }

    model.addAttribute("testList", testList);
    model.addAttribute("source", new Source());
    model.addAttribute("environmentList", environmentList);
    return resolver.resolveViewName("manualTest", Locale.US);    }

@RequestMapping(value="/manualTest", method=RequestMethod.POST)
public String greetingSubmit(@ModelAttribute Source source, Model model) {
    System.out.println(source.getSourceName());
    for(String hello : source.getTestList())
    {
        System.out.println(hello);
    }
    model.addAttribute("source", source);
    return "result";
}

}

The manualTest template looks like this

<!DOCTYPE html>
<html>
<head>
<title>Insert title here</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
 <form action="#" th:action="@{/manualTest}" th:object="${source}" method="post">
    <p>Source: <input type="text" th:field="*{sourceName}" /></p>

<table border="1">
<tr>
    <td>Test Name</td>
    <td th:each="environment : ${environmentList}"
    th:text="${environment}">Tests</td>
</tr>
<th:block th:each="test : ${testList}">
<tr>
    <td th:text="${test.name}">A Test'</td>
    <th:block th:each="enviro : ${environmentList}">
        <td><input type="checkbox" path="${testList}" value="hello" /></td>
    </th:block>

</tr>
</th:block>

</table>
<p><input type="submit" value="Submit" /> <input type="reset" value="Reset" /></p>
</form>
</body>
</html>

My problem is that the values of the checkbox are not being stored in the array. When i run this code and click submit i get a null pointer exception because the list in the source object is empty. The sourceName works perfectly but the checkboxes are not actually adding anything.

回答1:

THis code ended up working, You need to pass in an object containing an arrayList. Also it helped that I combined two variables into one string and i later separated them by -.

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<title>Insert title here</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
 <form action="#" th:action="@{/manualTest}" th:object="${source}" method="post">

<table border="1">
<tr>
    <td>Test Name</td>
    <td th:each="environment : ${environmentList}"
    th:text="${environment}">Tests</td>
</tr>
<th:block th:each="test : ${testList}">
<tr>
    <td th:text="${test.name}">A Test'</td>
    <th:block th:each="enviro : ${environmentList}">
        <td><input type="checkbox" th:field="*{testList}" th:value="|${test.name}-${enviro}|" /></td>
    </th:block>

</tr>
</th:block>

</table>
<p><input type="submit" value="Submit" /> <input type="reset" value="Reset" /></p>
</form>
</body>
</html>

来源：https://stackoverflow.com/questions/24957738/spring-mvc-thymeleaf-binding-list-with-check-boxes

标签

Spring

checkbox

bind

thymeleaf