使用 Diff_match_patch 完成文本的对比

爱被打了一巴掌 2023-09-30 17:41 46阅读 0赞

需求：一个字段在在修改前后，标记出他修改的位置，修改可以为增加、删除  
diff\_match\_patch为我们提供了一些方法，来帮助我们进行标记。  
源码：https://github.com/google/diff-match-patch/wiki/Language:-Java  
例如：  
**文本1：**

I am the very model of a modern Major-General,
    I've information vegetable, animal, and mineral,
    I know the kings of England, and I quote the fights historical,
    From Marathon to Waterloo, in order categorical.

**文本2：**

I am the very model of a cartoon individual,
    My animation's comical, unusual, and whimsical,
    I'm quite adept at funny gags, comedic theory I have read,
    From wicked puns and stupid jokes to anvils that drop on your head.

对比后：  
![在这里插入图片描述][8e8ae6c4cba845d6a585ad94cdcf9353.png]  
但是在他提供的方法并没有提供修改字段的具体位置，但他很友好的帮助我们返回了这样一个链表：

[Diff(EQUAL,"I am the very model of a "), Diff(DELETE,"ca"), Diff(INSERT,"mode"), Diff(EQUAL,"r"), Diff(DELETE,"too"), Diff(EQUAL,"n "), Diff(DELETE,"i"), Diff(INSERT,"Major-Ge"), Diff(EQUAL,"n"), Diff(DELETE,"dividu"), Diff(INSERT,"er"), Diff(EQUAL,"al,¶"), Diff(DELETE,"My"), Diff(INSERT,"I've"), Diff(EQUAL," "), Diff(DELETE,"a"), Diff(INSERT,"i"), Diff(EQUAL,"n"), Diff(DELETE,"i"), Diff(INSERT,"for"), Diff(EQUAL,"mation"), Diff(DELETE,"'s"), Diff(EQUAL," "), Diff(DELETE,"comic"), Diff(INSERT,"veget"), Diff(EQUAL,"a"), Diff(INSERT,"b"), Diff(EQUAL,"l"), Diff(INSERT,"e"), Diff(EQUAL,", "), Diff(DELETE,"u"), Diff(INSERT,"a"), Diff(EQUAL,"n"), Diff(DELETE,"usu"), Diff(INSERT,"im"), Diff(EQUAL,"al, and "), Diff(DELETE,"whi"), Diff(EQUAL,"m"), Diff(DELETE,"s"), Diff(EQUAL,"i"), Diff(DELETE,"c"), Diff(INSERT,"ner"), Diff(EQUAL,"al,¶")]

每个节点有两个值,Operation和Text，  
Operation表示字段的类型，Text为该字段的内容

public enum Operation {
        
        DELETE, INSERT, EQUAL
      }

但标识字段需要提供更改字段的具体位置。  
建立一个范围类：

@Data
    @AllArgsConstructor
    public class Range {
        
        private Integer start;
        private Integer end;
    
    }

建立解析工具类：

public class ParserTools {
        
        private String firstText;
        private String secondText;
        private String longText;
        private LinkedList<Diff_match_patch.Diff> diffLinkedList;
    
        private LinkedList<Diff_match_patch.Diff> insertLinkedList = new LinkedList<>();
        private LinkedList<Diff_match_patch.Diff> equalLinkedList = new LinkedList<>();
        private LinkedList<Diff_match_patch.Diff> deleteLinkedList = new LinkedList<>();
        private ArrayList<Range> insertRangeList = new ArrayList<>();
        private ArrayList<Range> equalRangeList = new ArrayList<>();
        private ArrayList<Range> deleteRangeList = new ArrayList<>();
        private ArrayList<String> insertList = new ArrayList<>();
        private ArrayList<String> equalList = new ArrayList<>();
        private ArrayList<String> deleteList = new ArrayList<>();
        private Diff_match_patch diff = new Diff_match_patch();
    
        /**
         * 获取增加或删除后总的长字符串
         * @return
         */
        public String getLongText() {
        
            return longText;
        }
    
        public ParserTools(String firstText, String secondText) {
        
            this.firstText = firstText;
            this.secondText = secondText;
            this.diffLinkedList = diff.diff_main(firstText, secondText, false);
            this.sort();
        }
    
        public LinkedList<Diff_match_patch.Diff> getinsertLinkedList() {
        
            return insertLinkedList;
        }
    
        public LinkedList<Diff_match_patch.Diff> getequalLinkedList() {
        
            return equalLinkedList;
        }
    
        public LinkedList<Diff_match_patch.Diff> getdeleteLinkedList() {
        
            return deleteLinkedList;
        }
    
        public String getFirstText() {
        
            return firstText;
        }
    
    
        public String getSecondText() {
        
            return secondText;
        }
    
    
        /**
         * 获取 secondText对比 firstText 增加的语句拼接
         * @return
         */
        public String getInsert() {
        
    
            StringBuilder insertBuilder = new StringBuilder();
            for (Diff_match_patch.Diff diff1 : insertLinkedList) {
        
                insertBuilder.append(diff1.text);
            }
            return insertBuilder.toString();
        }
    
        /**
         * 获取 secondText对比 firstText 删除的语句拼接
         * @return
         */
        public String getDelete() {
        
            StringBuilder deleteBuilder = new StringBuilder();
            for (Diff_match_patch.Diff diff1 : this.deleteLinkedList) {
        
                deleteBuilder.append(diff1.text);
            }
            return deleteBuilder.toString();
        }
    
        /**
         * 获取 secondText对比 firstText 未改变的语句拼接
         * @return
         */
        public String getEqual() {
        
            StringBuilder equalBuilder = new StringBuilder();
            for (Diff_match_patch.Diff diff1 : this.equalLinkedList) {
        
                equalBuilder.append(diff1.text);
            }
            return equalBuilder.toString();
        }
    
        /**
         * 获取 secondText对比 firstText 增加的语句集合
         * @return
         */
        public ArrayList<String> getInsertList() {
        
            for (Diff_match_patch.Diff diff1 : this.insertLinkedList) {
        
                insertList.add(diff1.text);
            }
            return insertList;
        }
    
        /**
         * 获取 secondText对比 firstText 未改变的语句集合
         * @return
         */
        public ArrayList<String> getEQUALList() {
        
            for (Diff_match_patch.Diff diff1 : this.equalLinkedList) {
        
                equalList.add(diff1.text);
            }
            return equalList;
        }
    
        /**
         * 获取 secondText对比 firstText 删除的语句集合
         * @return
         */
        public ArrayList<String> getDeleteList() {
        
            for (Diff_match_patch.Diff diff1 : this.deleteLinkedList) {
        
                deleteList.add(diff1.text);
            }
            return deleteList;
        }
    
        /**
         * 获取 secondText对比 firstText 增加的语句范围集合
         * @return
         */
        public ArrayList<Range> getInsertRangeList() {
        
            return insertRangeList;
        }
    
        /**
         * 获取 secondText对比 firstText 未改变的语句范围集合
         * @return
         */
        public ArrayList<Range> getEqualRangeList() {
        
            return equalRangeList;
        }
    
        /**
         * 获取 secondText对比 firstText 删除的语句范围集合
         * @return
         */
        public ArrayList<Range> getDeleteRangeList() {
        
            return deleteRangeList;
        }
    
        /**
         * 为各个属性添加值，（重要）
         */
        public void sort() {
        
            int count = 0;
            int flag = 0;
            StringBuilder text = new StringBuilder();
            for (Diff_match_patch.Diff diff1 : this.diffLinkedList) {
        
    
                Diff_match_patch.Operation operation = diff1.operation;
                if (Diff_match_patch.Operation.INSERT == operation) {
        
                    this.insertLinkedList.add(diff1);
                    flag = count + diff1.text.getBytes().length;
                    this.insertRangeList.add(new Range(count, flag));
                    text.append(diff1.text);
                } else if (Diff_match_patch.Operation.DELETE == operation) {
        
                    this.deleteLinkedList.add(diff1);
                    flag = count + diff1.text.getBytes().length;
                    this.deleteRangeList.add(new Range(count, flag));
    
                    text.append(diff1.text);
                } else if (Diff_match_patch.Operation.EQUAL == operation) {
        
                    this.equalLinkedList.add(diff1);
                    flag = count + diff1.text.getBytes().length;
                    this.equalRangeList.add(new Range(count, flag));
    
                    text.append(diff1.text);
                }
                count = flag;
            }
            this.longText = text.toString();
        }
    }

该工具类，能够帮助我们获取对应删除、添加的位置，删除的完整字符串

[8e8ae6c4cba845d6a585ad94cdcf9353.png]: https://img-blog.csdnimg.cn/8e8ae6c4cba845d6a585ad94cdcf9353.png