hutool常用方法

1、树结构工具-TreeUtil

构建Tree示例

package com.sl.transport.common.util;import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.lang.tree.Tree;
import cn.hutool.core.lang.tree.TreeNode;
import cn.hutool.core.lang.tree.TreeNodeConfig;
import cn.hutool.core.lang.tree.TreeUtil;
import cn.hutool.json.JSONUtil;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.Test;import java.util.List;@Slf4j
class TreeUtilTest {@Testvoid treeTest() {// 构建node列表List<TreeNode<String>> nodeList = CollUtil.newArrayList();nodeList.add(new TreeNode<>("1", "0", "系统管理", 5));nodeList.add(new TreeNode<>("11", "1", "用户管理", 222222));nodeList.add(new TreeNode<>("111", "11", "用户添加", 0));nodeList.add(new TreeNode<>("2", "0", "店铺管理", 1));nodeList.add(new TreeNode<>("21", "2", "商品管理", 44));nodeList.add(new TreeNode<>("221", "2", "添加商品", 2));//配置TreeNodeConfig treeNodeConfig = new TreeNodeConfig();// 自定义属性名 都要默认值的treeNodeConfig.setWeightKey("weight");treeNodeConfig.setIdKey("id");// 最大递归深度treeNodeConfig.setDeep(3);//构造树结构List<Tree<String>> treeNodes = TreeUtil.build(nodeList, "0",(treeNode, tree) -> {tree.setId(treeNode.getId());tree.setParentId(treeNode.getParentId());tree.putAll(BeanUtil.beanToMap(treeNode));tree.remove("bid");});log.info("treeNodes {}", JSONUtil.toJsonStr(treeNodes));}
}

输出结果

[{"id": "2","parentId": "0","name": "店铺管理","weight": 1,"children": [{"id": "221","parentId": "2","name": "添加商品","weight": 2}, {"id": "21","parentId": "2","name": "商品管理","weight": 44}]
}, {"id": "1","parentId": "0","name": "系统管理","weight": 5,"children": [{"id": "11","parentId": "1","name": "用户管理","weight": 222222,"children": [{"id": "111","parentId": "11","name": "用户添加","weight": 0}]}]
}]

2、Bean工具-BeanUtil

对象转Bean

@Slf4j
public class BeanUtilTest {@Getter@Setterpublic static class SubPerson extends Person {public static final String SUBNAME = "TEST";private UUID id;private String subName;private Boolean slow;private LocalDateTime date;private LocalDate date2;}@Getter@Setterpublic static class Person {private String name;private int age;private String openid;}/*** 对象转Bean*/@Testpublic void toBeanTest() {SubPerson person = new SubPerson();person.setAge(14);person.setOpenid("11213232");person.setName("测试A11");person.setSubName("sub名字");Map<?, ?> map = BeanUtil.toBean(person, Map.class);Assert.assertEquals("测试A11", map.get("name"));Assert.assertEquals(14, map.get("age"));Assert.assertEquals("11213232", map.get("openid"));// static属性应被忽略log.info("map是否包含名为SUBNAME的key {}", map.containsKey("SUBNAME"));}
}

输出结果

map是否包含名为SUBNAME的key false

3、验证码工具-CaptchaUtil

生成验证码

package com.sl.transport.common.util;import cn.hutool.captcha.CaptchaUtil;
import cn.hutool.captcha.LineCaptcha;
import lombok.extern.slf4j.Slf4j;
import org.junit.Assert;
import org.junit.Test;/**
* 直线干扰验证码单元测试
*
* @author looly
*/
@Slf4j
public class CaptchaTest {/*** 生成验证码*/@Testpublic void lineCaptchaTest1() {// 定义图形验证码的长和宽LineCaptcha lineCaptcha = CaptchaUtil.createLineCaptcha(200, 100);Assert.assertNotNull(lineCaptcha.getCode());log.info("直线干扰验证码: {}", lineCaptcha.getCode());log.info("直线干扰验证码验证结果: {}",lineCaptcha.verify(lineCaptcha.getCode()));}
}

输出结果

直线干扰验证码: 5ku0o
直线干扰验证码验证结果: true

4、类型转换工具类-Convert

转换值为指定类型

/**
* 转换值为指定类型
*/
@Test
public void toObjectTest() {final Object result = Convert.convert(Object.class, "aaaa");log.info(result + "");
}

输出结果

aaaa

5、对象工具-ObjectUtil

对象相等

/**
* 比较两个对象是否相等
*/
@Test
public void equalsTest() {Object a = null;Object b = null;log.info("是否相等：{}" , ObjectUtil.equals(a, b));
}

输出结果

是否相等：true

6、数字工具-NumberUtil

加法运算

/**
* 提供精确的加法运算
*/
@Test
public void addTest() {final Float a = 3.15f;final Double b = 4.22;final double result = NumberUtil.add(a, b).doubleValue();log.info(result + "");
}

输出结果

7.37

7、日期时间工具-DateUtil

当前时间

/**
* 当前时间
*/
@Test
public void nowTest() {// 当前时间final Date date = DateUtil.date();Assert.assertNotNull(date);// 当前时间final Date date2 = DateUtil.date(Calendar.getInstance());Assert.assertNotNull(date2);// 当前时间final Date date3 = DateUtil.date(System.currentTimeMillis());Assert.assertNotNull(date3);// 当前日期字符串，格式：yyyy-MM-dd HH:mm:ssfinal String now = DateUtil.now();Assert.assertNotNull(now);// 当前日期字符串，格式：yyyy-MM-ddfinal String today = DateUtil.today();log.info(today);
}

输出结果

2023-03-10

8、集合工具-CollUtil

自定义函数判断集合是否包含某类值

/**
* 自定义函数判断集合是否包含某类值
*/
@Test
public void testPredicateContains() {final ArrayList<String> list = CollUtil.newArrayList("bbbbb", "aaaaa", "ccccc");log.info( "" + CollUtil.contains(list, s -> s.startsWith("a")));log.info( "" + CollUtil.contains(list, s -> s.startsWith("d")));
}

输出结果

true
false

9、集合串行流工具-CollStreamUtil

将Collection转化为map

/**
* 将Collection转化为map(value类型与collection的泛型不同)
*/
@Test
public void testToMap() {Map<Long, String> map = CollStreamUtil.toMap(null, Student::getStudentId, Student::getName);Assert.assertEquals(map, Collections.EMPTY_MAP);List<Student> list = new ArrayList<>();map = CollStreamUtil.toMap(list, Student::getStudentId, Student::getName);Assert.assertEquals(map, Collections.EMPTY_MAP);list.add(new Student(1, 1, 1, "张三"));list.add(new Student(1, 1, 2, "李四"));list.add(new Student(1, 1, 3, "王五"));map = CollStreamUtil.toMap(list, Student::getStudentId, Student::getName);Assert.assertEquals(map.get(1L), "张三");Assert.assertEquals(map.get(2L), "李四");Assert.assertEquals(map.get(3L), "王五");Assert.assertNull(map.get(4L));// 测试value为空时list.add(new Student(1, 1, 4, null));map = CollStreamUtil.toMap(list, Student::getStudentId, Student::getName);log.info(map.get(4L));
}

输出结果

null

10、JSON工具-JSONUtil

JSON字符串转JSONObject对象

/**
* JSON字符串转JSONObject对象
*/
@Test
public void toJsonStrTest2() {final Map<String, Object> model = new HashMap<>();model.put("mobile", "17610836523");model.put("type", 1);final Map<String, Object> data = new HashMap<>();data.put("model", model);data.put("model2", model);final JSONObject jsonObject = JSONUtil.parseObj(data);log.info("是否相等{}", ObjectUtil.equals( "17610836523", jsonObject.getJSONObject("model").getStr("mobile")));
}

输出结果

是否相等true

11、唯一ID工具-IdUtil

获取随机UUID

/**
*获取随机UUID
*/
@Test
public void randomUUIDTest() {String randomUUID = IdUtil.randomUUID();log.info(randomUUID);
}

输出结果

e514518b-21d7-4918-9b34-792b21b0b64f

12、枚举工具-EnumUtil

枚举类中所有枚举对象的name列表

public enum TestEnum{TEST1("type1"), TEST2("type2"), TEST3("type3");TestEnum(String type) {this.type = type;}private final String type;@SuppressWarnings("unused")private String name;public String getType() {return this.type;}public String getName() {return this.name;}
}/**
* 枚举类中所有枚举对象的name列表
*/
@Test
public void getNamesTest() {List<String> names = EnumUtil.getNames(TestEnum.class);boolean equalList = CollUtil.isEqualList(CollUtil.newArrayList("TEST1", "TEST2", "TEST3"), names);log.info(equalList + "");
}

输出结果

true

13、HTTP客户端（Hutool-http）

本质上，HttpUtil中的get和post工具方法都是HttpRequest对象的封装，因此如果想更加灵活操作Http请求，可以使用HttpRequest。
HttpResponse是HttpRequest执行execute()方法后返回的一个对象，我们可以通过此对象获取服务端返回的：
- Http状态码（getStatus方法）
- 返回内容编码（contentEncoding方法）
- 是否Gzip内容（isGzip方法）
- 返回内容（body、bodyBytes、bodyStream方法）
- 响应头信息（header方法）

// 发送HTTP POST请求，并记录响应结果
HttpResponse httpResponse =HttpRequest.post(Constast.JR_DEPT_URL) // 发送POST请求到指定URL.header("grantType", Constast.GRANT_TYPE_SIGN) // 设置请求头.contentType("application/json") // 设置内容类型为JSON.body(JSON.toJSONString(requestParam, filter)) // 将请求参数对象转换为JSON字符串并设置为请求体.timeout(5000) // 设置请求超时时间为5000毫秒.execute(); // 执行请求// 如果请求成功
if (httpResponse.getStatus() == HttpStatus.HTTP_OK) {// 同步成功，后续操作
}