Question

我正在做一个简单的用户问题。

我的ApplicationUser具有以下属性：

private Long id;
private String password;
private String username;
private Collection<Authority> myAuthorities;
private boolean isAccountNonExpired;
private boolean isAccountNonLocked;
private boolean isCredentialsNonExpired;
private boolean isEnabled;

权威类有：

private Long id;
private String authority;
private String name;

在我的jsp中，我的视图有以下形式：

<form:form modelAttribute="applicationUser"
    action="add" method="post">
    <fieldset>

    <form:hidden path="id" />

    <legend><fmt:message key="user.form.legend" /></legend>
    <p><form:label for="username" path="username" cssErrorClass="error"><fmt:message key="user.form.username" /></form:label><br />
    <form:input path="username" /> <form:errors path="username" /></p>

    <p><form:label for="password" path="password"
        cssErrorClass="error"><fmt:message key="user.form.password" /></form:label><br />
    <form:password path="password" /> <form:errors path="password" /></p>

    <p><form:label for="password" path="password"
        cssErrorClass="error"><fmt:message key="user.form.password2" /></form:label><br />
    <form:password path="password" /> <form:errors path="password" /></p>

    <p><form:label for="myAuthorities" path="myAuthorities"
        cssErrorClass="error"><fmt:message key="user.form.autorities" /></form:label><br />
    <form:checkboxes items="${allAuthorities}" path="myAuthorities" itemLabel="name"/><form:errors path="myAuthorities" /></p>

    <p><input type="submit"/></p>
    </fieldset>
</form:form>

jsp从此获得allAuthorities：

@ModelAttribute("allAuthorities")
public List<Authority> populateAuthorities() {
  return authorityService.findAll();
}

当我填写表格时，我得到：

无法转换属性值输入java.lang.String到必需的类型 java.util.Collection属性 myAuthorities;嵌套异常是 java.lang.IllegalStateException：无法转换类型的值 [java.lang.String]到必需的类型 [com.tda.model.applicationuser.Authority] 对于财产myAuthorities [0]：没有匹配编辑或转换战略发现

解决这个问题的正确方法是什么？

Answer 1

当您的Authority是复杂的bean时，HTML表单仅使用字符串值。您需要配置PropertyEditor以执行Authority和String之间的转换：

@InitBinder 
public void initBinder(WebDataBinder b) {
    b.registerCustomEditor(Authority.class, new AuthorityEditor());
}

private class AuthorityEditor extends PropertyEditorSupport {
    @Override
    public void setAsText(String text) throws IllegalArgumentException {
        setValue(authorityService.findById(Long.valueOf(text)));
    }

    @Override
    public String getAsText() {
        return ((Authority) getValue()).getId();
    }
}

Spring-mvc 3.0 crud with checkboxes问题

1 个答案: