【Spring】web开发 javaConfig方式 图解

spring3.2之后开始支持java配置方式开发web项目，不使用web.xml，但需要在servlet3.0环境，一般tomcat7会支持，6不行

下图中：MyAppInitializer和SpringServletContainerInitializer是查找关系，没有继承

创建maven的web项目 

容器首先会加载这个类

package org.spitter.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class MyAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer{
	
//	抽象类的实现类会自动地配置DispatcherServlet 和 spring 应用的上下文
	@Override
	protected Class<?>[] getRootConfigClasses() {
		
		return new Class<?>[]{RootConfig.class};
	}
	@Override
	protected Class<?>[] getServletConfigClasses() {
		return new Class<?>[]{WebConfig.class};
	}
	@Override
	protected String[] getServletMappings() {
		return new String[]{"/"};
	}

}

然后是RootConfig.class

package org.spitter.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScan.Filter;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;

@Configuration
@ComponentScan(basePackages={"org.spitter"},
	excludeFilters={@Filter(type=FilterType.ANNOTATION,value=EnableWebMvc.class)})
public class RootConfig {

}

然后是WebConfig.class

package org.spitter.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"org.spitter.web"})
public class WebConfig extends WebMvcConfigurerAdapter {

//	配置视图解析器
	@Bean
	public ViewResolver viewResolver() {
		InternalResourceViewResolver resolver = new InternalResourceViewResolver();
		resolver.setPrefix("/page/");
		resolver.setSuffix(".jsp");
		resolver.setExposeContextBeansAsAttributes(true);
		return resolver;
	}
//	配置静态资源的处理
	@Override
	public void configureDefaultServletHandling( DefaultServletHandlerConfigurer configurer) {
		configurer.enable();
	}
}

最后写一个Controller

package org.spitter.web;

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

@Controller
public class HomeController {

	@RequestMapping(value="/myhome",method=RequestMethod.GET)
	public String home(){
		return "home";
	}
}

这样，初始web项目完成，可以启动tomcat加载了