SpringBoot接口服务处理Whitelabel Error Page

转载请注明来源：http://blog.csdn.net/loongshawn/article/details/50915979

• 《SpringBoot接口服务处理Whitelabel Error Page》
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• 《Java Web工程转换为基于Maven的Web工程》
• 《Maven Web工程运行异常:Maven.multiModuleProjectDirectory system propery is not set的问题》
• 《Maven运行异常:Exception in thread “main” java.lang.UnsupportedClassVersionError》

1.0 异常说明

SpringBoot搭建的接口服务，如果请求非注册类的无效接口地址，则返回该页面。主要问题就是没有对异常请求做处理。

举例，定义有效接口地址如：http://ip/user,http://ip/age。则其它地址均为无效地址，若请求则返回上述Whitelabel Error Page页面。

2.0 异常处理

主要是添加一个AppErrorController的Controller类，这里我定义了异常返回页面。

package com.autonavi.controller;import java.util.Map;import javax.servlet.http.HttpServletRequest;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.autoconfigure.web.ErrorAttributes;import org.springframework.boot.autoconfigure.web.ErrorController;import org.springframework.http.HttpStatus;import org.springframework.http.ResponseEntity;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import org.springframework.web.context.request.RequestAttributes;import org.springframework.web.context.request.ServletRequestAttributes;import org.springframework.web.servlet.ModelAndView;/** * <p>Author: loongshawn * <p>Date: 16-03-17 * <p>Version: 1.0 */@Controllerpublic class AppErrorController implements ErrorController{    private static final Logger logger = LoggerFactory.getLogger(AppErrorController.class);    private static AppErrorController appErrorController;     /**     * Error Attributes in the Application     */    @Autowired    private ErrorAttributes errorAttributes;    private final static String ERROR_PATH = "/error";    /**     * Controller for the Error Controller     * @param errorAttributes     * @return      */     public AppErrorController(ErrorAttributes errorAttributes) {        this.errorAttributes = errorAttributes;    }    public AppErrorController() {        if(appErrorController == null){            appErrorController = new AppErrorController(errorAttributes);        }    }    /**     * Supports the HTML Error View     * @param request     * @return     */    @RequestMapping(value = ERROR_PATH, produces = "text/html")    public ModelAndView errorHtml(HttpServletRequest request) {        return new ModelAndView("greeting", getErrorAttributes(request, false));    }    /**     * Supports other formats like JSON, XML     * @param request     * @return     */    @RequestMapping(value = ERROR_PATH)    @ResponseBody    public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {        Map<String, Object> body = getErrorAttributes(request, getTraceParameter(request));        HttpStatus status = getStatus(request);        return new ResponseEntity<Map<String, Object>>(body, status);    }    /**     * Returns the path of the error page.     *     * @return the error path     */    @Override    public String getErrorPath() {        return ERROR_PATH;    }    private boolean getTraceParameter(HttpServletRequest request) {        String parameter = request.getParameter("trace");        if (parameter == null) {            return false;        }        return !"false".equals(parameter.toLowerCase());    }    private Map<String, Object> getErrorAttributes(HttpServletRequest request,                                                   boolean includeStackTrace) {             RequestAttributes requestAttributes = new ServletRequestAttributes(request);               Map<String, Object> map = this.errorAttributes.getErrorAttributes(requestAttributes,includeStackTrace);          String URL = request.getRequestURL().toString();        map.put("URL", URL);                logger.debug("AppErrorController.method [error info]: status-" + map.get("status") +", request url-" + URL);                    return map;    }    private HttpStatus getStatus(HttpServletRequest request) {        Integer statusCode = (Integer) request                .getAttribute("javax.servlet.error.status_code");        if (statusCode != null) {            try {                return HttpStatus.valueOf(statusCode);            }            catch (Exception ex) {            }        }        return HttpStatus.INTERNAL_SERVER_ERROR;    }   }

这个类实现了ErrorController接口，用来处理请求的各种异常。其中定义了一个greeting的html模版，用来显示返回结果。初始化此类模版需要在pom中加入以下依赖：

<dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-thymeleaf</artifactId></dependency>

这个依赖主要是给SpringBoot中加载html等类型的模版服务。其支持的模版类型如下：

 Template modes:[THYMELEAF]     * XHTML[THYMELEAF]     * XML[THYMELEAF]     * HTML5[THYMELEAF]     * LEGACYHTML5[THYMELEAF]     * VALIDXHTML[THYMELEAF]     * VALIDXML

SpringBoot项目配置模版路径的方法如下：

1、在main的resources路径下新建templates文件夹

2、在templates文件夹中新建模版文件greeting.html

<!DOCTYPE HTML><html xmlns:th="http://www.thymeleaf.org"><head>    <title>Error Pages</title>    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /></head><body>    <p th:text="'Url:' + ${URL}" />    <p th:text="'Error:' + ${error}" />    <p th:text="'Status:' + ${status}" />    <p th:text="'Timestamp:' + ${timestamp}" /></body></html>

3.0 处理结果

无效请求地址均会返回此页面，只是其中的返回值不同。