通过流式集合接口对list集合进行模糊查询和筛选

阳光穿透心脏的1/2处 2024-04-17 05:26 28阅读 0赞

**一.通过Matcher中的find()方法对list集合进行模糊查询操作**

1.创建实体对象:

public class User {
    
        private Integer id;
        private String name;
        private String password;
        
        public User() {
        }
        public User(Integer id, String name, String password) {
            this.id = id;
            this.name = name;
            this.password = password;
        }
        public Integer getId() {
            return id;
        }
        public void setId(Integer id) {
            this.id = id;
        }
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public String getPassword() {
            return password;
        }
        public void setPassword(String password) {
            this.password = password;
        }
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    ", password='" + password + '\'' +
                    '}';
        }
    
    }

2.创建数据以及对数据进行模糊查询操作

import java.util.ArrayList;
    import java.util.Collections;
    import java.util.List;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    /**
     *  对List集合中的数据 name, password 进行模糊查询
     */
    public class TestList {
        public static void main(String[] args) {
            List<User> users = Collections.synchronizedList(new ArrayList<User>());
            User u1 = new User(1, "李国辉", "1");
            User u2 = new User(2, "小辉", "22");
            User u3 = new User(3, "李国辉", "33");
            User u4 = new User(4, "哈喽", "42");
            User u5 = new User(5, "哈哈", "25");
            users.add(u1);
            users.add(u2);
            users.add(u3);
            users.add(u4);
            users.add(u5);
            System.out.println("源数据...");
            users.forEach(System.out::println);
    
            System.out.println();
            System.out.println("对list集合进行模糊查询操作...");
    
            /**
             *  传入模糊查询的参数
             */
            Pattern pattern = Pattern.compile("小辉");
            Pattern pattern1 = Pattern.compile("2");
    
            List list = new ArrayList();
            for(int i=0;i<users.size();i++){
                Matcher matcher = pattern.matcher(users.get(i).getName());
                Matcher matcher1 = pattern1.matcher(users.get(i).getPassword());
                //调用模糊查询方法
                if(matcher.find() || matcher1.find()){
                    list.add(users.get(i));
                }
            }
            list.forEach(System.out::println);
    
        }
    }

3.运行结果:  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpZ2hfc3Fo_size_16_color_FFFFFF_t_70]

二.通过Matcher中的matches()方法对list集合进行匹配筛选操作

1.使用上面之前的源数据进行测试

public class TestList {
        public static void main(String[] args) {
            List<User> users = Collections.synchronizedList(new ArrayList<User>());
            User u1 = new User(1, "李国辉", "1");
            User u2 = new User(2, "小辉", "22");
            User u3 = new User(3, "李国辉", "33");
            User u4 = new User(4, "哈喽", "42");
            User u5 = new User(5, "哈哈", "25");
            users.add(u1);
            users.add(u2);
            users.add(u3);
            users.add(u4);
            users.add(u5);
            System.out.println("源数据...");
            users.forEach(System.out::println);
            System.out.println();
    
            System.out.println("匹配筛选...");
            Pattern pattern1 = Pattern.compile("李国辉");
            Pattern pattern2 = Pattern.compile("5");
            List list = new ArrayList();
            for(int i=0;i<users.size();i++){
                Matcher matcher1 = pattern1.matcher(users.get(i).getName());
                Matcher matcher2 = pattern2.matcher(users.get(i).getId().toString());
                if(matcher1.matches() || matcher2.matches()){
                    list.add(users.get(i));
                }
            }
            list.forEach(System.out::println); 
        }
    }

2.测试结果:  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpZ2hfc3Fo_size_16_color_FFFFFF_t_70 1]

以上是对Matcher中的两个方法的运用,在项目开发中很重要…

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpZ2hfc3Fo_size_16_color_FFFFFF_t_70]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/cb10563656fd4e14b597af9493e8c684.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpZ2hfc3Fo_size_16_color_FFFFFF_t_70 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/6a2ca2f960ee447496e6168c759c75b4.png