SpringMVC Hello World 实例

时间 2019-11-11

标签 springmvc hello world 实例栏目 Spring 繁體版

原文原文链接

环境的准备

安装JDK

下载地址：http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html 选择 JDK7u80html
安装JDKjava
配置 JAVE_HOME CLASSPATH PATH 环境变量web

安装tomcat

下载地址：http://tomcat.apache.org/download-80.cgi
解压到规划的目录

安装eclipse for j2ee

下载地址：http://www.eclipse.org/downloads/
选择Eclipse IDE for Java EE Developers
解压到规划目录

下载spring-framework

下载地址：http://repo.springsource.org/libs-release-local/org/springframework/spring/
选择版本4.1.8.RELEASE
解压到规划目录

下载依赖包

下载commons-logging，地址：http://commons.apache.org/proper/commons-logging/download_logging.cgispring
下载log4j，地址：http://logging.apache.org/log4j/1.2/download.htmlapache

配置开发环境

启动eclipse
配置tomcate。windows-->preferences-->server-->runtime environments。add tomcat，安装地址为tomcat8的解压目录，jre选择jre7

开发Hello World

新建web工程

新建 Dynamic Web Project

target runtime 选择 Apache Tomcat v8.0windows

Dynamic web module version 选择 3.1。注意 tomcat7,不支持高版本浏览器

Configuration 选择 Tomcat v8.0tomcat

添加 source folder

配置 web module

勾选 Generate web.xml deployment descriptororacle

添加工程内容

添加依赖包

将spring-framework的包拷贝到WebContent/WEB_INF/lib下。app

将commons-logging的包拷贝到WebContent/WEB_INF/lib下。

将log4j的包拷贝到WebContent/WEB_INF/lib下。

修改web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://xmlns.jcp.org/xml/ns/javaee"
	xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
	id="WebApp_ID" version="3.1">
	<display-name>SpringMVC</display-name>
	<welcome-file-list>
		<welcome-file>index.html</welcome-file>
		<welcome-file>index.htm</welcome-file>
		<welcome-file>index.jsp</welcome-file>
		<welcome-file>default.html</welcome-file>
		<welcome-file>default.htm</welcome-file>
		<welcome-file>default.jsp</welcome-file>
	</welcome-file-list>

	<servlet>
		<servlet-name>SpringMVC</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>SpringMVC</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>
</web-app>

添加servlet 在WebContent/WEB_INF下添加 SpringMVC-servlet.xml文件，内容以下：

<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"
	xsi:schemaLocation="
   http://www.springframework.org/schema/beans     
   http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
   http://www.springframework.org/schema/context 
   http://www.springframework.org/schema/context/spring-context-4.1.xsd">

	<context:component-scan base-package="com.tutorialspoint" />

	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/jsp/" />
		<property name="suffix" value=".jsp" />
	</bean>

</beans>

添加jsp文件在WebContent/WEB_INF/jsp下添加 hello.jsp，内容以下：

<%@ page contentType="text/html; charset=UTF-8" %>
<html>
<head>
	<title>Hello World</title>
</head>
<body>
   <h2>${message}</h2>
</body>
</html>

添加controller 在src下添加class文件：HelloController.java，内容以下：

package org.springtest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.ui.ModelMap;

@Controller
public class HelloController{
 
   @RequestMapping(value = "/hello", method = RequestMethod.GET)
   public String printHello(ModelMap model) {
      model.addAttribute("message", "Hello Spring MVC Framework World!");

      return "hello";
   }
}

运行工程

新建tomcat server 在servers视图中新建一个server

直接点击finish

配置tomcat server

选择server，而后右键，能够看到有 open start stop restart等操做

运行spring工程

右键web porject， Run As --> Run on Server.

在eclipse的浏览器，或者本机的浏览器地址栏输入：http://localhost:808/SpringMVC/hello 就能够看到输出的内容

调试

当修改了java的内容后，等上几秒钟就会从新编译，而且推送到tomcat目录下，刷新页面就能够看到变化。

常见问题

访问tomcat 404

是由于在servers视图中建立了server，可是没有配置使用tocat的安装目录致使。

解决方法：在servers视图删除server，并新建，新建后勾选 “server location” 下的 “use tomcat installation”，并保存

若是“server locations”下为灰色，则删除server后重建，或者多删除几回。

spring工程没法启动

表现为tomcat没法启动

启动spring工程报错，异常信息以下：

严重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SpringMVC]]
	at java.util.concurrent.FutureTask.report(Unknown Source)
	at java.util.concurrent.FutureTask.get(Unknown Source)
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:916)
	at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:871)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1408)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SpringMVC]]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
	... 6 more
Caused by: java.lang.NoClassDefFoundError: Lorg/apache/commons/logging/Log;
	at java.lang.Class.getDeclaredFields0(Native Method)
	at java.lang.Class.privateGetDeclaredFields(Unknown Source)
	at java.lang.Class.getDeclaredFields(Unknown Source)
	at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106)
	at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:256)
	at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:132)
	at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:65)
	at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:334)
	at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:774)
	at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:305)
	at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
	at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5066)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	... 6 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.Log
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1332)
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1166)
	... 20 more

观察日志能够看出，是因为缺乏了 common-logging 和 log4j的包

访问spring工程报404

访问地址： http://localhost:8080/SpringMVC/hello 报404 是因为在servers视图，没有勾选 “server options” 下的 “publish module contexts to separate XML files”，并保存。

解决办法：勾选“publish module contexts to separate XML files”