SpringMVC Hello World 實例

時間 2019-11-11

標籤 springmvc hello world 實例欄目 Spring 简体版

原文原文鏈接

環境的準備

安裝JDK

下載地址：http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html 選擇 JDK7u80html
安裝JDKjava
配置 JAVE_HOME CLASSPATH PATH 環境變量web

安裝tomcat

下載地址：http://tomcat.apache.org/download-80.cgi
解壓到規劃的目錄

安裝eclipse for j2ee

下載地址：http://www.eclipse.org/downloads/
選擇Eclipse IDE for Java EE Developers
解壓到規劃目錄

下載spring-framework

下載地址：http://repo.springsource.org/libs-release-local/org/springframework/spring/
選擇版本4.1.8.RELEASE
解壓到規劃目錄

下載依賴包

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

配置開發環境

啓動eclipse
配置tomcate。windows-->preferences-->server-->runtime environments。add tomcat，安裝地址爲tomcat8的解壓目錄，jre選擇jre7

開發Hello World

新建web工程

新建 Dynamic Web Project

target runtime 選擇 Apache Tomcat v8.0windows

Dynamic web module version 選擇 3.1。注意 tomcat7,不支持高版本瀏覽器

Configuration 選擇 Tomcat v8.0tomcat

添加 source folder

配置 web module

勾選 Generate web.xml deployment descriptororacle

添加工程內容

添加依賴包

將spring-framework的包拷貝到WebContent/WEB_INF/lib下。app

將commons-logging的包拷貝到WebContent/WEB_INF/lib下。

將log4j的包拷貝到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，內容以下：

<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，內容以下：

<%@ 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，內容以下：

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";
   }
}

運行工程

新建tomcat server 在servers視圖中新建一個server

直接點擊finish

配置tomcat server

選擇server，而後右鍵，能夠看到有 open start stop restart等操做

運行spring工程

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

在eclipse的瀏覽器，或者本機的瀏覽器地址欄輸入：http://localhost:808/SpringMVC/hello 就能夠看到輸出的內容

調試

當修改了java的內容後，等上幾秒鐘就會從新編譯，而且推送到tomcat目錄下，刷新頁面就能夠看到變化。

常見問題

訪問tomcat 404

是由於在servers視圖中建立了server，可是沒有配置使用tocat的安裝目錄致使。

解決方法：在servers視圖刪除server，並新建，新建後勾選「server location」下的「use tomcat installation」，並保存

若是「server locations」下爲灰色，則刪除server後重建，或者多刪除幾回。

spring工程沒法啓動

表現爲tomcat沒法啓動

啓動spring工程報錯，異常信息以下：

嚴重: 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

觀察日誌能夠看出，是因爲缺乏了 common-logging 和 log4j的包