如何在Java中构建更优雅的API对象_方法链与流式接口设计

new StringBuilder()
    .append("Hello")
    .append(" ")
    .append("World")
    .toString();

public class User {
    private final String name;
    private final int age;
    private final String email;

    private User(Builder builder) {
        this.name = builder.name;
        this.age = builder.age;
        this.email = builder.email;
    }

    public static class Builder {
        private String name;
        private int age;
        private String email;

        public Builder name(String name) {
            this.name = name;
            return this;
        }

        public Builder age(int age) {
            this.age = age;
            return this;
        }

        public Builder email(String email) {
            this.email = email;
            return this;
        }

        public User build() {
            return new User(this);
        }
    }
}

User user = new User.Builder()
    .name("Alice")
    .age(25)
    .email("alice@example.com")
    .build();

public class Query {
    private String filter;
    private String orderBy;
    private int limit;

    public Query where(String condition) {
        this.filter = condition;
        return this;
    }

    public Query sortBy(String field) {
        this.orderBy = field;
        return this;
    }

    public Query maxResults(int n) {
        this.limit = n;
        return this;
    }

    public List<Object> execute() {
        // 执行查询逻辑
        return Collections.emptyList();
    }
}

List<Object> results = new Query()
    .where("status = 'active'")
    .sortBy("createdAt")
    .maxResults(10)
    .execute();