责任链模式

src/main/java/top/fjy8018/designpattern/pattern/behavior/chainofresponsibility/Approver.java

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+package top.fjy8018.designpattern.pattern.behavior.chainofresponsibility;
+
+import javax.servlet.FilterChain;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+
+/**
+ * 模拟二级审批场景
+ * <p>
+ * 审批抽象
+ * <p>
+ * java 过滤器实现 {@link javax.servlet.Filter#doFilter(ServletRequest, ServletResponse, FilterChain)}
+ * 实现 {@link FilterChain#doFilter(ServletRequest, ServletResponse)} 接口的组成一条过滤器链
+ * 所有子类通过调用 chain.doFilter(request, response) 实现链式传递
+ * <p>
+ * SpringSecurity过滤器链实现也类似
+ *
+ * @author F嘉阳
+ * @date 2020/7/21 16:59
+ */
+public abstract class Approver {
+    /**
+     * 责任链核心：包含与自身相同的类型对象
+     */
+    protected Approver approver;
+
+    /**
+     * 设置下一个节点，组成链条
+     *
+     * @param approver
+     */
+    public void setNextApprover(Approver approver) {
+        this.approver = approver;
+    }
+
+    /**
+     * 交由子类实现
+     *
+     * @param course
+     */
+    public abstract void deploy(Course course);
+}

src/main/java/top/fjy8018/designpattern/pattern/behavior/chainofresponsibility/ArticleApprover.java

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+package top.fjy8018.designpattern.pattern.behavior.chainofresponsibility;
+
+import org.apache.commons.lang3.StringUtils;
+
+/**
+ * 手记审批
+ *
+ * @author F嘉阳
+ * @date 2020/7/21 16:59
+ */
+public class ArticleApprover extends Approver {
+    @Override
+    public void deploy(Course course) {
+        if (StringUtils.isNotEmpty(course.getArticle())) {
+            System.out.println(course.getName() + "含有手记,批准");
+            // 是否为末尾
+            if (approver != null) {
+                // 执行下一个处理链
+                approver.deploy(course);
+            }
+        } else {
+            System.out.println(course.getName() + "不含有手记,不批准,流程结束");
+            return;
+        }
+    }
+}

src/main/java/top/fjy8018/designpattern/pattern/behavior/chainofresponsibility/Course.java

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+package top.fjy8018.designpattern.pattern.behavior.chainofresponsibility;
+
+import lombok.Data;
+
+/**
+ * 课程
+ *
+ * @author F嘉阳
+ * @date 2020/7/21 16:59
+ */
+@Data
+public class Course {
+    private String name;
+
+    private String article;
+
+    private String video;
+}

src/main/java/top/fjy8018/designpattern/pattern/behavior/chainofresponsibility/VideoApprover.java

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+package top.fjy8018.designpattern.pattern.behavior.chainofresponsibility;
+
+import org.apache.commons.lang3.StringUtils;
+
+/**
+ * 视频审批
+ *
+ * @author F嘉阳
+ * @date 2020/7/21 16:59
+ */
+public class VideoApprover extends Approver {
+    @Override
+    public void deploy(Course course) {
+        if (StringUtils.isNotEmpty(course.getVideo())) {
+            System.out.println(course.getName() + "含有视频,批准");
+            if (approver != null) {
+                approver.deploy(course);
+            }
+        } else {
+            System.out.println(course.getName() + "不含有视频,不批准,流程结束");
+            return;
+        }
+    }
+}

src/test/java/top/fjy8018/designpattern/pattern/behavior/chainofresponsibility/ChainofResponsibilityTest.java

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+package top.fjy8018.designpattern.pattern.behavior.chainofresponsibility;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * @author F嘉阳
+ * @date 2020/7/21 15:06
+ */
+class ChainofResponsibilityTest {
+
+    @Test
+    void doTest() {
+        Approver articleApprover = new ArticleApprover();
+        Approver videoApprover = new VideoApprover();
+
+        Course course = new Course();
+        course.setName("Java设计模式");
+        course.setArticle("Java设计模式的手记");
+        course.setVideo("Java设计模式的视频");
+
+        articleApprover.setNextApprover(videoApprover);
+
+        articleApprover.deploy(course);
+    }
+}