我正在尝试创建一个简单的应用程序，其中涉及一个 jsp 页面(只是一个用于输入查询的文本区域和一个提交按钮)、一个 Query 类(如下所示的非常简单的类)和一个与两者交互的 QueryController。我试图将 QueryController 打印到控制台来测试它，但没有输出打印到 Standard.out 。单击提交按钮会将我带到 http://localhost:8080/<PROJECT_NAME>/?queryField=<QUERY_TEXT>这会导致 404 错误，因为它不是有效的网页。三个[简单]类如下所示。感谢帮助。
查询类:
public class Query {
private String query;
public String getQuery() {
return query;
}
public void setQuery(String query) {
this.query = query;
}
}
查询.jsp:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<body>
<form action="query" method="post" commandName="queryForm">
<textarea name="queryField" cols="55" rows="1"></textarea><br>
<input type="submit" value="submit">
</form>
</body>
</html>
和我的简单 QueryController.java:
@Controller
@RequestMapping(value = "/query")
public class QueryController {
@RequestMapping(method = RequestMethod.POST)
public String processRegistration(@ModelAttribute("queryForm") Query query,
Map<String, Object> model) {
// for testing purpose:
System.out.println("query (from controller): " + query.getQuery());
return "someNextPageHere";
}
}
最佳答案
我们需要对 Spring 模块进行更多配置才能使其正常工作。您可以选择选项 1 - 使用 web.xml 或选项 2 - 不使用 web.xml:
选项 1 (web.xml)
1.将您的web.xml修改为:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<display-name>SimpleProject</display-name>
<servlet>
<servlet-name>SimpleProjectServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>
/WEB-INF/config/SimpleProjectServlet-servlet.xml
</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>SimpleProjectServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>query.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
</web-app>
2. 使用路径创建文件 - WEB-INF/config/SimpleProjectServlet-servlet.xml
3.将以下内容添加到步骤 2 中创建的文件中。您需要编辑 Spring 版本引用:
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd">
<context:component-scan base-package="com.mycompany.myproject" />
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/views/jsp/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>
<mvc:resources mapping="/resources/**" location="/resources/" />
<mvc:annotation-driven />
</beans>
4. 按照上述配置中的 context:component-scan 设置正确的包名称
选项 2(非 web.xml)
1.删除您的web.xml
2.为基于注释的Spring MVC添加Java Config
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;
@EnableWebMvc
@Configuration
@ComponentScan({ "com.mycompany.myproject" })
public class SpringWebConfig extends WebMvcConfigurerAdapter {
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/resources/**").addResourceLocations(
"/resources/");
}
@Bean
public InternalResourceViewResolver viewResolver() {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setViewClass(JstlView.class);
viewResolver.setPrefix("/WEB-INF/views/jsp/");
viewResolver.setSuffix(".jsp");
return viewResolver;
}
}
3.使用@ComponentScan处的正确包修改SpringWebConfig
4.为WebApplication添加Java Config。使用所需的配置创建一个扩展 WebApplicationInitializer 的类:
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
public class MyWebAppInitializer implements WebApplicationInitializer {
public void onStartup(ServletContext container) throws ServletException {
AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
ctx.register(SpringWebConfig.class);
ctx.setServletContext(container);
ServletRegistration.Dynamic servlet = container.addServlet(
"dispatcher", new DispatcherServlet(ctx));
servlet.setLoadOnStartup(1);
servlet.addMapping("/");
}
}
更新
这里我们有几个配置部分导致了这个错误:
DispatcherServlet配置为接受带有views/*的 url- 部署描述符没有
src\main\java到WEB-INF\classes - 用户在默认为
JDK-8的Tomcat 8上运行Spring 3，而ASM Loader无法运行加载文件。必须迁移到 Spring 版本4.0.1-RELEASE
关于Java Spring从html表单获取数据，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/32751840/