java基础 |

lombok.javac.apt.LombokProcessor could not be initialized解决办法

1月 31, 2023 | Nix.Huang

最近将IDEA 升级到IntelliJ IDEA 2022.3.1后原来可以运行的工程启动报: java: l […more]

Liquibase changelog 传参

1月 29, 2023 | Nix.Huang

changelog文件

--changeset javacoder:5 dbms:mysql
--preconditions onFail:MARK_RAN onError:HALT
--precondition-sql-check expectedResult:1 select count(1) from information_schema.COLUMNS where table_name='user' and column_name='email' and table_schema='${schema}'
--comment: 删除user.email 字段

ALTER TABLE user
    DROP COLUMN `email`;

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--changeset javacoder:5 dbms:mysql

--preconditions onFail:MARK_RAN onError:HALT

--precondition-sql-check expectedResult:1 select count(1) from information_schema.COLUMNS where table_name='user' and column_name='email' and table_schema='${schema}'

--comment: 删除user.email 字段

ALTER TABLE user

DROP COLUMN `email`;

使用 ${schem […more]

LockSupport简介

1月 11, 2023 | Nix.Huang

LockSupport简介 java并发包中很多类都基于LockSupport实现锁，而Thread.susp […more]

大文件上传

1月 10, 2023 | Nix.Huang

nginx 配置 client_max_body_size spring配置项 spring.servlet. […more]

HttpClient 使用chunked上传文件

1月 10, 2023 | Nix.Huang

java代码

CloseableHttpClient httpClient = HttpClients.createDefault();
HttpPost post = new HttpPost(url);
MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.setBoundary("123456789");
builder.setCharset(java.nio.charset.Charset.forName("UTF-8"));
builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);

// 文件流
builder.addBinaryBody("file", getInputStream(), ContentType.DEFAULT_BINARY, "xyz.txt");
builder.addPart("type", new StringBody("0", ContentType.TEXT_PLAIN));

//Finally
post.setEntity(builder.build());
CloseableHttpResponse response = httpClient.execute(post);
response.getEntity().writeTo(System.out);

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CloseableHttpClient httpClient = HttpClients.createDefault();

HttpPost post = new HttpPost(url);

MultipartEntityBuilder builder = MultipartEntityBuilder.create();

builder.setBoundary("123456789");

builder.setCharset(java.nio.charset.Charset.forName("UTF-8"));

builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);

// 文件流

builder.addBinaryBody("file", getInputStream(), ContentType.DEFAULT_BINARY, "xyz.txt");

builder.addPart("type", new StringBody("0", ContentType.TEXT_PLAIN));

//Finally

post.setEntity(builder.build());

CloseableHttpResponse response = httpClient.execute(post);

response.getEntity().writeTo(System.out);

生成的报文 POST /ebo […more]

CSS 相对单位em和rem

1月 6, 2023 | Nix.Huang

em相对于父级元素的排版大小，(typography,指定了font-size就以父元素的font-size为 […more]

使用axios发送Ajax理由

1月 2, 2023 | Nix.Huang

使用axios发送Ajax理由使用XMLHttpRequest 发送Ajax请求已经很简单，为啥很多工程使用 […more]

spring websocket连接被中断

12月 29, 2022 | Nix.Huang

code=1009, reason=The decoded text message was too big […more]

Lambda 获取setter对应的BiConsumer 函数对象

12月 28, 2022 | Nix.Huang

  public static <T, U> BiConsumer<T, U> getSetter(Class<T> clazz, String fieldName,
                                                    Class<U> fieldType) throws Throwable {

        MethodHandles.Lookup caller = MethodHandles.lookup();
        MethodType setter = MethodType.methodType(void.class, fieldType);
        MethodHandle target = caller.findVirtual(clazz, computeSetterName(fieldName), setter);

        CallSite site = LambdaMetafactory.metafactory(
                caller,
                "accept", //interfaceMethodName
                MethodType.methodType(BiConsumer.class), //factoryType
                //interfaceMethodType，泛型一律使用Object.class
                MethodType.methodType(void.class, Object.class, Object.class),
                target, //implementation
                target.type() //dynamicMethodType, 泛型对应的具体类型
        );

        MethodHandle factory = site.getTarget();
        return (BiConsumer<T, U>) factory.invokeExact();
    }
	
    public static String computeSetterName(String fieldName) {
        return "set" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);
    }

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public static <T, U> BiConsumer<T, U> getSetter(Class<T> clazz, String fieldName,

Class<U> fieldType) throws Throwable {

MethodHandles.Lookup caller = MethodHandles.lookup();

MethodType setter = MethodType.methodType(void.class, fieldType);

MethodHandle target = caller.findVirtual(clazz, computeSetterName(fieldName), setter);

CallSite site = LambdaMetafactory.metafactory(

caller,

"accept", //interfaceMethodName

MethodType.methodType(BiConsumer.class), //factoryType

//interfaceMethodType，泛型一律使用Object.class

MethodType.methodType(void.class, Object.class, Object.class),

target, //implementation

target.type() //dynamicMethodType, 泛型对应的具体类型

);

MethodHandle factory = site.getTarget();

return (BiConsumer<T, U>) factory.invokeExact();

}

public static String computeSetterName(String fieldName) {

return "set" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);

}

当获取的函数对象是泛型时，那么interfa […more]

CompletableFuture 介绍