adding cors filters to jbpm examples (apache#12)

Author: Tihomir Surdilovic

jbpm-quarkus-example/src/main/java/com/myspace/CorsFilter.java

@@ -0,0 +1,77 @@
+package com.myspace;
+
+import java.io.IOException;
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.annotation.WebFilter;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+@WebFilter(filterName = "CorsFilter", urlPatterns = "/*", asyncSupported = true)
+public class CorsFilter implements Filter {
+
+    private static final String ACCESS_CONTROL_ALLOW_ORIGIN = "Access-Control-Allow-Origin";
+
+    private static final String ACCESS_CONTROL_ALLOW_CREDENTIALS = "Access-Control-Allow-Credentials";
+
+    private static final String ACCESS_CONTROL_ALLOW_METHODS = "Access-Control-Allow-Methods";
+
+    private static final String ACCESS_CONTROL_ALLOW_HEADERS = "Access-Control-Allow-Headers";
+
+    private static final String ORIGIN = "Origin";
+
+    private static final String ACCESS_CONTROL_REQUEST_METHOD = "Access-Control-Request-Method";
+
+    private static final String ACCESS_CONTROL_EXPOSE_HEADERS = "Access-Control-Expose-Headers";
+
+    private static final String ACCESS_CONTROL_REQUEST_HEADERS = "Access-Control-Request-Headers";
+
+    @Override
+    public void init(FilterConfig filterConfig) {
+    }
+
+    @Override
+    public void doFilter(ServletRequest servletRequest,
+                         ServletResponse servletResponse,
+                         FilterChain chain) throws IOException, ServletException {
+        HttpServletRequest request = (HttpServletRequest) servletRequest;
+        HttpServletResponse response = (HttpServletResponse) servletResponse;
+        String origin = request.getHeader(ORIGIN);
+        if (origin == null) {
+            chain.doFilter(servletRequest,
+                           servletResponse);
+        } else {
+            String requestMethods = request.getHeader(ACCESS_CONTROL_REQUEST_METHOD);
+            if (requestMethods != null) {
+                response.setHeader(ACCESS_CONTROL_ALLOW_METHODS,
+                                   requestMethods);
+            }
+            String allowHeaders = request.getHeader(ACCESS_CONTROL_REQUEST_HEADERS);
+            if (allowHeaders != null) {
+                response.setHeader(ACCESS_CONTROL_ALLOW_HEADERS,
+                                   allowHeaders);
+            }
+            response.setHeader(ACCESS_CONTROL_ALLOW_ORIGIN,
+                               origin);
+            response.setHeader(ACCESS_CONTROL_ALLOW_CREDENTIALS,
+                               "true");
+            response.setHeader(ACCESS_CONTROL_EXPOSE_HEADERS,
+                               "Content-Disposition");
+            if (!"OPTIONS".equalsIgnoreCase(request.getMethod())) {
+                chain.doFilter(servletRequest,
+                               servletResponse);
+            } else {
+                response.flushBuffer();
+            }
+        }
+    }
+
+    @Override
+    public void destroy() {
+
+    }
+}

jbpm-springboot-example/src/main/java/com/example/demo/CorsConfig.java

@@ -0,0 +1,30 @@
+package com.example.demo;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.cors.CorsConfiguration;
+import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
+import org.springframework.web.filter.CorsFilter;
+
+@Configuration
+public class CorsConfig {
+
+    @Bean
+    public CorsFilter corsFilter() {
+        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
+
+        CorsConfiguration config = new CorsConfiguration();
+        config.setAllowCredentials(true);
+        config.addAllowedOrigin("*");
+        config.addAllowedHeader("*");
+        config.addAllowedMethod("OPTIONS");
+        config.addAllowedMethod("GET");
+        config.addAllowedMethod("POST");
+        config.addAllowedMethod("PUT");
+        config.addAllowedMethod("DELETE");
+        source.registerCorsConfiguration("/**",
+                                         config);
+
+        return new CorsFilter(source);
+    }
+}