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》
《Maven依赖加载错误的情况分析》
《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
*/
@Controller
public 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。