Filter拦截器实现请求跨域转发
因为公司项目需求，项目中前端请求需要通过一个类似中转的服务转发(请求在该服务中会重新包装一些通用参数)
在使用Filter实现转发后特做一次记录
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
package com.unicloud.cce.Filter; import com.alibaba.fastjson.JSON;import com.unicloud.cce.common.RestfulEntity;import com.unicloud.cce.service.CloudosService;import org.apache.commons.io.IOUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.http.*;import org.springframework.stereotype.Component;import org.springframework.util.AntPathMatcher;import org.springframework.util.StringUtils;import org.springframework.web.client.RestTemplate; import javax.servlet.*;import javax.servlet.annotation.WebFilter;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.PrintWriter;import java.util.*; /** * @author skyxt * Created 2019-06-11 18:46 * Email skyxt.yang@gmail.com */@WebFilter(filterName = "authFilter", urlPatterns = { "/*" })@Componentpublic class RequestFilter implements Filter { //该处配置需要转发的路径 public static final Set<String> FILTER_URL = Collections.unmodifiableSet(new HashSet<>(Arrays.asList( "/config/*" ))); @Autowired private RestTemplate restTemplate; @Autowired private CloudosService cloudosService; private final static Logger logger = LoggerFactory.getLogger(RequestFilter.class); @Override public void init(FilterConfig filterConfig) throws ServletException { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { if (!(request instanceof HttpServletRequest) || !(response instanceof HttpServletResponse)) { return; } HttpServletRequest req = (HttpServletRequest) request; HttpServletResponse rsp = (HttpServletResponse) response; AntPathMatcher matcher = new AntPathMatcher(); Optional<String> cloudIp = Optional.empty();// for (String url : FILTER_URL) {// if (matcher.match(url, req.getRequestURI().substring(req.getContextPath().length()))) {// cloudIp = cloudosService.cloudosList("", "").stream().filter(cloudos ->// cloudos.getId().equals(((HttpServletRequest) request).getHeader("cloudId"))// ).map(Cloudos::getCloudIp).findFirst();// }// } cloudIp = Optional.of("localhost"); if (cloudIp.isPresent()) { switch (req.getMethod()) { case "GET": { request(req, rsp, HttpMethod.GET, cloudIp.get()); break; } case "POST": { request(req, rsp, HttpMethod.POST, cloudIp.get()); break; } case "PUT": { request(req, rsp, HttpMethod.PUT, cloudIp.get()); break; } case "PATCH": { request(req, rsp, HttpMethod.PATCH, cloudIp.get()); break; } case "DELETE": { request(req, rsp, HttpMethod.DELETE, cloudIp.get()); break; } default:{ logger.error("unknow request method:" + req.getMethod()); rsp.setCharacterEncoding("UTF-8"); try (PrintWriter out = rsp.getWriter()) { out.write("请求方法未知"); } catch (Exception e1) { logger.error(e1.getMessage() + e1); } } } } else { chain.doFilter(request, response); } } @Override public void destroy() { } private void request(HttpServletRequest req, HttpServletResponse rsp, HttpMethod method, String cloudIp) throws IOException { rsp.setCharacterEncoding("UTF-8"); String requestBody = IOUtils.toString(req.getInputStream(), "UTF-8"); Object body = null; if (StringUtils.hasText(requestBody)) { body = JSON.parse(requestBody); } HttpHeaders headers = new HttpHeaders(); Enumeration<String> headerNames = req.getHeaderNames(); while (headerNames.hasMoreElements()) { String name = headerNames.nextElement(); headers.add(name, req.getHeader(name)); } String url; if (StringUtils.hasText(req.getQueryString())) { url = String.format( "http://%s:15120%s?%s", cloudIp, req.getRequestURI().substring(req.getContextPath().length()), req.getQueryString() ); } else { url = String.format( "http://%s:15120%s", cloudIp, req.getRequestURI().substring(req.getContextPath().length()) ); } HttpEntity<Object> httpEntity = new HttpEntity<>(body, headers); ResponseEntity<RestfulEntity> exchange = null; try { exchange = restTemplate.exchange( url, method, httpEntity, RestfulEntity.class ); } catch (Exception e) { logger.error(e.getMessage(), e); try (PrintWriter out = rsp.getWriter()) { out.write("请求异常"); } catch (Exception e1) { logger.error(e1.getMessage() + e1); } } if (exchange != null) { exchange.getStatusCode(); rsp.setStatus(exchange.getStatusCodeValue()); exchange.getHeaders().entrySet().stream().forEach(entry -> { String value = entry.getValue().toString(); rsp.addHeader(entry.getKey(), value.substring(1, value.length()-1)); }); try (PrintWriter out = rsp.getWriter()) { out.write(JSON.toJSONString(exchange.getBody())); } catch (Exception e) { logger.error(e.getMessage(), e); } } else { logger.info("error: URL:" + "http://" + cloudIp + ":15120" + req.getRequestURI().substring(req.getContextPath().length())); try (PrintWriter out = rsp.getWriter()) { out.write("请求异常"); } catch (Exception e1) { logger.error(e1.getMessage() + e1); } } }} |
使用filter解决跨域
在web.xml配置拦截器
|
1
2
3
4
5
6
7
8
|
<filter> <filter-name>servletFilterTest</filter-name> <filter-class>cn.test.intercepter.ServletFilterTest</filter-class></filter><filter-mapping> <filter-name>servletFilterTest</filter-name> <url-pattern>/*</url-pattern></filter-mapping> |
过滤器代码
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
|
import org.springframework.web.bind.annotation.RequestMethod;import javax.servlet.*;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;public class ServletFilterTest implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException { } @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException { HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest; httpServletRequest.getSession(); HttpServletResponse httpResponse = (HttpServletResponse) servletResponse; httpResponse.setHeader("Access-Control-Allow-Origin", "*"); httpResponse.setHeader("Access-Control-Allow-Methods", "*"); httpResponse.setHeader("Access-Control-Max-Age", "3600"); httpResponse.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Connection, User-Agent, Cookie"); httpResponse.setHeader("Access-Control-Allow-Credentials", "true"); httpResponse.setHeader("Content-type", "application/json"); httpResponse.setHeader("Cache-Control", "no-cache, must-revalidate"); if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())) { return ; } filterChain.doFilter(httpServletRequest, httpResponse); } @Override public void destroy() { }} |
以上为个人经验，希望能给大家一个参考，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/weixin_37774620/article/details/91544007
