我正在向JSP发送Map<String entityDescription, Entity entity>来填充定义为的<form:select>：
<form:form id="form" modelAttribute="pojo" action="create" method="post">
<div>
<label for="ftpConnection">FTP Connection: </label>
<form:select path="ftpConnection">
<form:options items="${ftpList}" itemLabel="description" />
</form:select>
</div>
</form:form>
DTO具有FTPConnection ftpConnection字段，该字段应接收在
<form:select>元素的path属性上定义的ftpConnection。POST方法大致定义为：
@RequestMapping(value = "/parameter/create", method = RequestMethod.POST)
public String createPost(@ModelAttribute("pojo") ParameterPojo pojo, ModelMap model, Errors errors) throws IOException, Exception {
// validate entities
// save what has to be saved
return "where it has to go";
}
此实例的FtpConnection bean是一个非常简单的POJO，定义为：
@Entity
@Table(name = "ftp")
public class FtpConnection extends BasePojo {
@Column(name = "description")
private String description;
@Column(name = "url")
private String url;
@Column(name = "port")
private String port;
@Column(name = "username")
private String username;
@Column(name = "password")
private String password;
// getters and setters
}
DTO称为ParameterPojo是另一个非常简单的POJO：
public static class ParameterPojo {
private String id;
private String description;
private String agentId;
private FtpConnection ftpConnection;
// getters and setters
}
我得到的唯一输出是在浏览器上，如下面的图像。
没有控制台输出。
我该如何解决？
最佳答案
好吧，我为您写了一本小诗，对我有用。
DTO是一样的
我不知道您是否为FtpConnection bean开发了自定义转换器，我想是的，但是如果您未实现此原因，则是因为在提交表单时出现spring导致400错误的原因，所以您不知道该转换器是bean在某种程度上，我向开发者提交了信息，我开发了这样的转换器：
public class FtpToStringConverter implements Converter<FtpConnection, String> {
@Override
public String convert(FtpConnection ftpConnection) {
ObjectMapper objectMapper = new ObjectMapper();
try {
return objectMapper.writeValueAsString(ftpConnection);
} catch (IOException e) {
return "{}";
}
}
}
public class StringToFtpConverter implements Converter<String, FtpConnection> {
@Override
public FtpConnection convert(String s) {
ObjectMapper objectMapper = new ObjectMapper();
try {
return objectMapper.readValue(new StringReader(s),FtpConnection.class);
} catch (IOException e) {
return null;
}
}
}
然后我以这种方式注册自定义转换器
@Component
public class MyDefaultConversionService extends DefaultConversionService {
@Override
public void addConverter(Converter<?, ?> converter) {
super.addConverter(converter);
super.addConverter(new StringToFtpConverter());
super.addConverter(new FtpToStringConverter());
}
}
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="com.springapp.mvc"/>
<mvc:annotation-driven conversion-service="myDefaultConversionService"/>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/pages/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
然后我实现了像这样的Simpel控制器
@Controller
public class HelloController {
@RequestMapping(value = {"/index"}, method = RequestMethod.GET)
public String printWelcome(ModelMap model) {
model.addAttribute("message", "Hello world!");
List<FtpConnection> ftpConnections = new ArrayList<FtpConnection>();
FtpConnection ftpConnection = new FtpConnection();
ftpConnection.setUrl("url1");
ftpConnection.setPort("22");
ftpConnection.setUsername("user1");
ftpConnection.setPassword("pass1");
ftpConnection.setDescription("desc1");
ftpConnections.add(ftpConnection);
ftpConnection = new FtpConnection();
ftpConnection.setUrl("url1");
ftpConnection.setPort("21");
ftpConnection.setUsername("user2");
ftpConnection.setPassword("pass2");
ftpConnection.setDescription("desc2");
ftpConnections.add(ftpConnection);
model.addAttribute("ftpList", ftpConnections);
model.addAttribute("pojo",new ParamiterPojo());
return "hello";
}
@RequestMapping(value = "/paramiter/create" , method = RequestMethod.POST)
public String post(@ModelAttribute("pojo") ParamiterPojo paramiterPojo, ModelMap modelMap, Errors errors){
System.out.println(paramiterPojo);
return "hello";
}
}
这是我的hello.jsp
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<html>
<body>
<h1>${message}</h1>
<form:form modelAttribute="pojo" method="post" action="paramiter/create">
<div>
<form:select path="ftpConnection">
<form:options items="${ftpList}" itemLabel="description" />
</form:select>
</div>
<button> Submit</button>
</form:form>
</body>
</html>
当然，这是一个非常简单的示例，您认为这是poc。
恢复我在您的代码中发现的问题是：
没有转换器
jsp中的错误操作
我希望对我的解决方案的详细描述足够细致。