增加准则：在重定向前对输入数据进行验证

sonar-keyware-plugins-java/src/main/java/com/keyware/sonar/java/rules/checkers/RedirectUrlChecker.java

@@ -2,8 +2,8 @@ package com.keyware.sonar.java.rules.checkers;
 
 import org.sonar.check.Rule;
 import org.sonar.java.ast.visitors.SubscriptionVisitor;
-import org.sonar.plugins.java.api.JavaFileScannerContext;
 import org.sonar.plugins.java.api.tree.*;
+import org.springframework.lang.NonNull;
 
 import java.util.Arrays;
 import java.util.List;
@@ -23,12 +23,12 @@ public class RedirectUrlChecker extends SubscriptionVisitor {
     }
 
     @Override
-    public void visitNode(Tree tree) {
+    public void visitNode(@NonNull Tree tree) {
         MethodTree methodTree = (MethodTree) tree;
         BlockTree block = methodTree.block();
         // 方法的参数列表
         List<? extends VariableTree> parameters = methodTree.parameters();
-        if (block != null && !parameters.isEmpty() && isHttpRequestHandlerMethod(methodTree)) {
+        if (block != null && !parameters.isEmpty() && isHttpRequestHandlerMethod(methodTree) && methodTree.returnType() != null) {
             // 判断方法的返回节点的类型为RedirectView 或 String 类型
             if ("RedirectView".equals(methodTree.returnType().toString())) {
                 // 传递上下文，和方法的参数列表