细节之处见真章 - 请求对象 trim 最佳实践

public PageResult<Student> queryStudents(StudentQuery query){
   //1 执行 trim
    String name = query.getName();
    if (name != null && !name.isEmpty()) {
      query.setName(name.trim());
    }

    String nickname = query.getNickname();
    if (nickname != null && !nickname.isEmpty()) {
      query.setNickname(nickname.trim());
    }

   //2 执行查询
    studentService.pageQuery(query);
}

package org.example.demo;

// 定义一个学生查询类
public class StudentQuery {
    // 定义学生的学号、姓名、昵称属性
    private String id; // 学号
    private String name; // 姓名
    private String nickname; // 昵称

    public StudentQuery() {
    }

    // 定义构造方法，用于创建学生查询对象
    public StudentQuery(String id, String name, String nickname) {
        this.id = id;
        this.name = name;
        this.nickname = nickname;

        // 自动 trim
        trim();
    }

    // 定义获取和设置属性的方法
    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getNickname() {
        return nickname;
    }

    public void setNickname(String nickname) {
        this.nickname = nickname;
    }

   // 定义一个 trim 方法，用于去除属性的空格
    public void trim() {
        // 调用 trim 方法赋值给 name 属性
        name = StringUtils.trimToNull(name);

        // 调用 trim 方法赋值给 nickname 属性
        nickname = StringUtils.trimToNull(nickname);
    }
}

    /**
     * <p>Removes control characters (char &lt;= 32) from both
     * ends of this String returning {@code null} if the String is
     * empty ("") after the trim or if it is {@code null}.
     *
     * <p>The String is trimmed using {@link String#trim()}.
     * Trim removes start and end characters &lt;= 32.
     * To strip whitespace use {@link #stripToNull(String)}.</p>
     *
     * <pre>
     * StringUtils.trimToNull(null)          = null
     * StringUtils.trimToNull("")            = null
     * StringUtils.trimToNull("     ")       = null
     * StringUtils.trimToNull("abc")         = "abc"
     * StringUtils.trimToNull("    abc    ") = "abc"
     * </pre>
     *
     * @param str  the String to be trimmed, may be null
     * @return the trimmed String,
     *  {@code null} if only chars &lt;= 32, empty or null String input
     * @since 2.0
     */
    public static String trimToNull(final String str) {
        final String ts = trim(str);
        return isEmpty(ts) ? null : ts;
    }

import org.junit.Test;

import static org.junit.Assert.assertEquals;


public class StudentQueryTest {

    // 直接使用全参构造方法
    @Test
    public void testStudentQueryAllArgs() {
        // 构造一个 StudentQuery 对象
        StudentQuery sq = new StudentQuery("001", " Alice ", "  Bob ");

        // 断言属性的值是否符合预期
        assertEquals("001", sq.getId());
        assertEquals("Alice", sq.getName());
        assertEquals("Bob", sq.getNickname());
    }

    // 使用午无参构造方法
    @Test
    public void testStudentQueryNoArgs() {
        // 构造一个 StudentQuery 对象
        StudentQuery sq = new StudentQuery();
        // 调用 set 方法给出一些随机值
        sq.setId("002");
        sq.setName(" Charlie");
        sq.setNickname(" David ");
        // 调用 trim 方法去除空格
        sq.trim();

        // 断言属性的值是否符合预期
        assertEquals("002", sq.getId());
        assertEquals("Charlie", sq.getName());
        assertEquals("David", sq.getNickname());
    }
}

public PageResult<Student> queryStudents(StudentQuery query){
   //1 执行 trim
    query.trim();

   //2 执行查询
    studentService.pageQuery(query);
}