Spring MVC中使用Controller如何进行重定向

package edu.mvcdemo.controller; 
import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import edu.mvcdemo.utils.StringUtils;
 
/**
 * @编写人： yh.zeng
 * @编写时间：2017-7-13 上午9:10:29
 * @文件描述: Spring MVC重定向demo
 */
@Controller
@Scope("singleton") //只实例化一个bean对象（即每次请求都使用同一个bean对象），默认是singleton
@RequestMapping("/redirect")
public class RedirectURLController {	
	private Logger logger = Logger.getLogger(RedirectURLController.class);	
	
	/**
	 * 方式一：方法返回的URI（相对路径）中加上"redirect:"前缀，声明要重定向到该地址
	 *        "redirect:"后面跟着的是"/"和不跟着"/"是不一样的：
	 *        1) "redirect:"后面跟着"/"： 说明该URI是相对于项目的Context ROOT的相对路径
	 *        2) "redirect:"后面没有跟着"/"： 说明该URI是相对于当前路径
	 * @return
	 */
	@RequestMapping(value="/demo1", method=RequestMethod.GET)
	private String testRedirect1(){
		//注意："redirect:/hello/world" 和 "redirect:hello/world"这两种写法是不一样的！！
		//     本案例中：
		//     "redirect:/hello/world" 重定向到的URL路径为：协议://服务器IP或服务器主机名:端口号/项目的Context ROOT/hello/world
		//     "redirect:hello/world"  重定向到的URL路径为：协议://服务器IP或服务器主机名:端口号/项目的Context ROOT/redirect/hello/world
		return "redirect:/hello/world";
	}
	
	/**
	 * 方式二：使用HttpServletResponse对象进行重定向，HttpServletResponse对象通过方法入参传入
	 * @param request
	 * @param response
	 * @return
	 * @throws IOException 
	 */
	@RequestMapping(value="/demo2", method=RequestMethod.GET)
	private void testRedirect2(HttpServletRequest request ,HttpServletResponse response){
        String pathPrefix = StringUtils.getWebContextPath(request);
        String redirectURL = pathPrefix + "/hello/world";
		logger.info(redirectURL);
		try {
			response.sendRedirect(redirectURL);
		} catch (IOException e) {
			logger.error(StringUtils.getExceptionMessage(e));
		}
	} 
}

package edu.mvcdemo.utils; 
import java.io.PrintWriter;
import java.io.StringWriter;
import javax.servlet.http.HttpServletRequest; 
/**
 * @编写人： yh.zeng
 * @编写时间：2017-7-9 下午2:56:21
 * @文件描述: todo
 */
public class StringUtils {	
    /**
     * 获取异常信息
     *
     * @param e
     * @return
     */
    public static String getExceptionMessage(Exception e) { 
        StringWriter stringWriter = new StringWriter();
        PrintWriter printWriter = new PrintWriter(stringWriter);
        e.printStackTrace(printWriter); 
        return stringWriter.toString();
    }    
 
    /**
     * 返回web项目的context path，格式 为：协议://服务器IP或服务器主机名:端口号/项目的Context ROOT
     * @param request
     * @return
     */
    public static String getWebContextPath(HttpServletRequest request){
		StringBuilder webContextPathBuilder = new StringBuilder();
		webContextPathBuilder.append(request.getScheme())
		                     .append("://")
		                     .append(request.getServerName())
		                     .append(":")
		                     .append(request.getServerPort())
		                     .append(request.getContextPath());
		return webContextPathBuilder.toString();
    } 
}

  @GetMapping(value = "/index")
    @ApiOperation("首页")
    public void index(HttpServletRequest request, HttpServletResponse response)  throws Exception  {
   request.getRequestDispatcher("/index.html").forward(request, response);
   }

 @GetMapping(value = "/index")
    @ApiOperation("首页")
    public void index(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.sendRedirect("/index.html");
    }

return new ModelAndView(“redirect:/toList”);