【整理分享】8种开发工具，提升工作效率，再也不做加班人！

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<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.83</version>
</dependency>

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// 字符串转对象
Studen student = JSON.parseObject("{"name":"小明","age":18}", Student.class);
// 对象转字符串
String str = JSON.toJSONString(student);

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// 字符串转JSONObject对象
JSONObject jsonObject = JSONObject.parseObject("{"name":"小明","age":18}");
// JSONObject对象转字符串
String str = jsonObject.toJSONString();

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// 定义解析字符串
String studentListStr = "[{"name":"小明","age":18},{"name":"小牛","age":24}]";
// 解析为 List<Student>
List<Student> studentList = JSON.parseArray(studentListStr, Student.class);
// 定义解析字符串
String studentMapStr = "{"name":"小明","age":18}";
// 解析为 Map<String,String>
Map<String, String> stringStringMap = 
JSONObject.parseObject(studentMapStr, new TypeReference<Map<String, String>>(){});

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/**
* 无参的 GET 请求
*/
public static void noArgsGetHttp() throws IOException {
    // 定义 httpclient
    CloseableHttpClient httpClient = HttpClientBuilder.create().build();
    // 创建 httpGet
    HttpGet httpGet = new HttpGet("http://www.baidu.com");
    // 定义返回结果
    CloseableHttpResponse execute = null;
    // 发送执行
    execute = httpClient.execute(httpGet);
    // 获取返回值
    HttpEntity entity = execute.getEntity();
    System.out.println("响应状态为:" + execute.getStatusLine());
    if (Objects.nonNull(entity)) {
        System.out.println("响应内容长度为:" + entity.getContentLength());
        System.out.println("响应内容为:" + EntityUtils.toString(entity));
    }
    // 释放资源
    if (httpClient != null) {
        httpClient.close();
    }
    if (execute != null) {
        execute.close();
    }
}

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/**
* 有参的 GET 请求
*/
public static void haveArgsGetHttp() throws IOException, URISyntaxException {
    // 定义 httpclient
    CloseableHttpClient httpClient = HttpClientBuilder.create().build();
    // 创建参数列表
    List<NameValuePair> valueParamsList = new ArrayList<>();
    valueParamsList.add(new BasicNameValuePair("studentId","1"));
    // 创建对应请求 Uri
    URI uri = new URIBuilder()
        .setScheme("http")
        .setHost("localhost")
        .setPath("/getStudentInfo")
        .setParameters(valueParamsList)
        .build();
    // 根据 Uri 创建 httpGet
    HttpGet httpGet = new HttpGet(uri);
    // 定义返回结果
    CloseableHttpResponse execute = null;
    // 发送执行
    execute = httpClient.execute(httpGet);
    // 获取返回值
    HttpEntity entity = execute.getEntity();
    System.out.println("响应状态为:" + execute.getStatusLine());
    if (Objects.nonNull(entity)) {
        System.out.println("响应内容长度为:" + entity.getContentLength());
        System.out.println("响应内容为:" + EntityUtils.toString(entity));
    }
    // 释放资源
    if (httpClient != null) {
        httpClient.close();
    }
    if (execute != null) {
        execute.close();
    }
}

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/**
* post 有参数
*/
public static void haveArgsPosthttp() throws IOException {
    // 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
    CloseableHttpClient httpClient = HttpClientBuilder.create().build();
    // 创建Post请求
    HttpPost httpPost = new HttpPost("http://localhost:12345/posttest");
    JSONUtil.Student student = new JSONUtil.Student();
    student.setName("潘晓婷");
    student.setAge(18);

    String jsonString = JSON.toJSONString(student);
    StringEntity entity = new StringEntity(jsonString, "UTF-8");
    // post请求是将参数放在请求体里面传过去的;这里将entity放入post请求体中
    httpPost.setEntity(entity);
    httpPost.setHeader("Content-Type", "application/json;charset=utf8");
    // 响应模型
    CloseableHttpResponse response = httpClient.execute(httpPost);
    // 从响应模型中获取响应实体
    HttpEntity responseEntity = response.getEntity();
    System.out.println("响应状态为:" + response.getStatusLine());
    if (responseEntity != null) {
        System.out.println("响应内容长度为:" + responseEntity.getContentLength());
        System.out.println("响应内容为:" + EntityUtils.toString(responseEntity));
    }
    // 释放资源
    if (httpClient != null) {
        httpClient.close();
    }
    if (response != null) {
        response.close();
    }
}

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<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

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String str = " ";
// 是否不为空
boolean res1 = StringUtils.isNotBlank(str);
// 是否为空
boolean res2 = StringUtils.isBlank(str);

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String str = " ";
// 是否不为空
boolean res1 = StringUtils.isNotEmpty(str);
// 是否为空
boolean res2 = StringUtils.isEmpty(str);

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String str2 = "1,2,3";
String[] split = StringUtils.split(str2);
System.out.println(Arrays.toString(split));

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String str3 = "1";
boolean numeric = StringUtils.isNumeric(str3);
System.out.println(numeric);

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List<Integer> list = new ArrayList<>();
list.add(2);
list.add(1);
list.add(3);
//升序
Collections.sort(list);
System.out.println(list);
//降序
Collections.reverse(list);
System.out.println(list);

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// 最大值最小值
List<Integer> intList = new ArrayList<>();
intList.add(1);
intList.add(2);
intList.add(3);

Integer max = Collections.max(intList);
Integer min = Collections.min(intList);

System.out.println("集合元素最大值:" + max);
System.out.println("集合元素最小值:" + min);

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List<Integer> synchronizedList = Collections.synchronizedList(intList);

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List<String> stringList = new ArrayList<>();
boolean notEmpty = CollectionUtils.isNotEmpty(stringList);
System.out.println("集合不是空的吗？"+ notEmpty);

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List<Integer> list1 = new ArrayList<>();
list1.add(1);
list1.add(2);
list1.add(3);
List<Integer> list2 = new ArrayList<>();
list2.add(3);
list2.add(4);
// 获取并集
Collection<Integer> union = CollectionUtils.union(list1, list2);
System.out.println(union);

// 获取交集
Collection<Integer> intersection = CollectionUtils.intersection(list1, list2);
System.out.println(intersection);

//获取交集的补集
Collection<Integer> disjunctionList = CollectionUtils.disjunction(list1, list2);
System.out.println(disjunctionList);

// 获取差集
Collection<Integer> subtract = CollectionUtils.subtract(list1, list2);
System.out.println(subtract);

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// 判断两集合是否相等
List<Integer> list3 = new ArrayList<>();
list1.add(3);
list1.add(4);
List<Integer> list4 = new ArrayList<>();
list2.add(3);
list2.add(4);
boolean equalCollection = CollectionUtils.isEqualCollection(list3, list4);
System.out.println("两集合相等吗？:" + equalCollection);

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// 快速初始化集合
ArrayList<Integer> integers1 = Lists.newArrayList(1, 2, 3);
System.out.println(integers1);

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// 数组分页
ArrayList<Integer> list7 = Lists.newArrayList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
List<List<Integer>> partition = Lists.partition(list7, 5);
System.out.println(partition);

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// 将 test 写入 test.txt 文件
FileUtils.writeByteArrayToFile(new File("C:Userstest.txt"), "test".getBytes());

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// 读取 test.txt 文件
byte[] bytes = FileUtils.readFileToByteArray(new File("D:Userstest.txt"));
System.out.println("读取到的文本为：" + new String(bytes));

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// MD5 加密
String MD5 = DigestUtils.md2Hex("123");
System.out.println("加密后的结果：" + MD5);

//  sha（安全哈希算法） 加密
String sha256Hex = DigestUtils.sha256Hex("123");
System.out.println("sha256加密后：" + sha256Hex);

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Student student = new Student();
student.setName("小明");
student.setAge(18);
Student newStudent = new Student();
BeanUtils.copyProperties(student,newStudent);
System.out.println(newStudent);

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<dependency>
	<groupId>org.mapstruct</groupId>
	<!-- jdk8以下就使用mapstruct -->
	<artifactId>mapstruct-jdk8</artifactId>
	<version>1.2.0.Final</version>
</dependency>
<dependency>
	<groupId>org.mapstruct</groupId>
	<artifactId>mapstruct-processor</artifactId>
	<version>1.2.0.Final</version>
</dependency>

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@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student{
	private String name;
	private Integer age ;
}

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Teacher{
	private String name;
	private Integer age ;
}

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@Mapper
public interface UserCovertToTeacher {
    UserCovertToTeacher INSTANCE = Mappers.getMapper(UserCovertToTeacher.class);
    Teacher toCovert(Student student);
}

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Student student = new Student();
student.setName("小明");
student.setAge(18);
Teacher teacher = UserCovertToTeacher.INSTANCE.toCovert(student);
System.out.println(teacher);

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@Data
@AllArgsConstructor
@NoArgsConstructor
static class WeiXin{
	private String username;
	private Integer age ;
}

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@Mapper 
public interface UserCovertToWeinxin {
    UserCovertToWeinxin INSTANCE = Mappers.getMapper(UserCovertToWeinxin.class);
	// 配置字段映射规则
    @Mapping(source = "name",target = "username")
    BeanUtilTest.WeiXin toCovert(BeanUtilTest.Student student);
}

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Student student = new Student();
student.setName("小明");
student.setAge(18);
WeiXin weiXin = UserCovertToWeinxin.INSTANCE.toCovert(student);
System.out.println(weiXin);

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Cache<String, String> cache = CacheBuilder.newBuilder()
                .expireAfterWrite(10, TimeUnit.SECONDS)
                .build();
// 放入缓存
cache.put("小明","活着");
Thread.sleep(10000);
// 从缓存拿取值
System.out.println(cache.getIfPresent("小明"));

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Cache<String, String> cache = CacheBuilder.newBuilder()、
		    // 最大容量，超过按照 LRU 淘汰
                .maximumSize(100)
		    // 初始容量
                .initialCapacity(10)
		    // 并发等级 10
                .concurrencyLevel(10)
                .expireAfterWrite(10, TimeUnit.SECONDS)
                .build();

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RateLimiter rateLimiter = RateLimiter.create(1,1,TimeUnit.SECONDS);

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new Thread(()->{
	System.out.println("线程 1 获取到执行权限了吗？" + rateLimiter.tryAcquire());
}).start();

new Thread(()->{
	System.out.println("线程 2 获取到执行权限了吗？" + rateLimiter.tryAcquire());
}).start();