JAVA后台常用方法_一蓑烟雨任平生

Springboot

获取某字段的总和

Double total = list.stream().collect(Collectors.summingDouble(AgriculturalCropYieldVO::getProportion));

时间转换类,越用越爽

package com.hnyfkj.productmarket.web.config;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalTimeSerializer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.convert.converter.Converter;

import java.io.IOException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.util.Date;

@Configuration
public class DateConfig {

	/**
	 * 默认日期时间格式
	 */
	public static final String DEFAULT_DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
	/**
	 * 默认日期格式
	 */
	public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd";
	/**
	 * 默认时间格式
	 */
	public static final String DEFAULT_TIME_FORMAT = "HH:mm:ss";

	/**
	 * LocalDate转换器，用于转换RequestParam和PathVariable参数
	 */
	@Bean
	public Converter<String, LocalDate> localDateConverter() {
		return new Converter<String, LocalDate>() {
			@Override
			public LocalDate convert(String source) {

				if (source.isEmpty()) {
					return null;
				}

				return LocalDate.parse(source, DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));
			}
		};
	}

	/**
	 * LocalDateTime转换器，用于转换RequestParam和PathVariable参数
	 */
	@Bean
	public Converter<String, LocalDateTime> localDateTimeConverter() {
		return new Converter<String, LocalDateTime>() {
			@Override
			public LocalDateTime convert(String source) {
				if (source.isEmpty()) {
					return null;
				}
				return LocalDateTime.parse(source, DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));
			}
		};
	}

	/**
	 * LocalTime转换器，用于转换RequestParam和PathVariable参数
	 */
	@Bean
	public Converter<String, LocalTime> localTimeConverter() {
		return new Converter<String, LocalTime>() {
			@Override
			public LocalTime convert(String source) {
				if (source.isEmpty()) {
					return null;
				}
				return LocalTime.parse(source, DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));
			}
		};
	}

	/**
	 * Date转换器，用于转换RequestParam和PathVariable参数
	 */
	@Bean
	public Converter<String, Date> dateConverter() {
		return new Converter<String, Date>() {
			@Override
			public Date convert(String source) {
				if (source.isEmpty()) {
					return null;
				}
				SimpleDateFormat format = new SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);
				try {
					return format.parse(source);
				} catch (ParseException e) {
					throw new RuntimeException(e);
				}
			}
		};
	}

	/**
	 * Json序列化和反序列化转换器，用于转换Post请求体中的json以及将我们的对象序列化为返回响应的json
	 */
	@Bean
	public ObjectMapper objectMapper() {
		ObjectMapper objectMapper = new ObjectMapper();
		objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
		objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);
		// ObjectMapper忽略多余字段
		objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
		objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
		// LocalDateTime系列序列化和反序列化模块，继承自jsr310，我们在这里修改了日期格式
		JavaTimeModule javaTimeModule = new JavaTimeModule();
		javaTimeModule.addSerializer(LocalDateTime.class,
				new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));
		javaTimeModule.addSerializer(LocalDate.class,
				new LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));
		javaTimeModule.addSerializer(LocalTime.class,
				new LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));
		javaTimeModule.addDeserializer(LocalDateTime.class,
				new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));
		javaTimeModule.addDeserializer(LocalDate.class,
				new LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));
		javaTimeModule.addDeserializer(LocalTime.class,
				new LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));

		// Date序列化和反序列化
		javaTimeModule.addSerializer(Date.class, new JsonSerializer<Date>() {
			@Override
			public void serialize(Date date, JsonGenerator jsonGenerator, SerializerProvider serializerProvider)
					throws IOException {
				SimpleDateFormat formatter = new SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);
				String formattedDate = formatter.format(date);
				jsonGenerator.writeString(formattedDate);
			}
		});
		javaTimeModule.addDeserializer(Date.class, new JsonDeserializer<Date>() {
			@Override
			public Date deserialize(JsonParser jsonParser, DeserializationContext deserializationContext)
					throws IOException, JsonProcessingException {
				SimpleDateFormat format = new SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);
				String date = jsonParser.getText();
				try {
					return format.parse(date);
				} catch (ParseException e) {
					throw new RuntimeException(e);
				}
			}
		});
		// 注册新的模块到objectMapper
		objectMapper.registerModule(javaTimeModule);
		return objectMapper;
	}
}

后台跨域配置

package com.hnyfkj.productmarket.web.config;

import org.springframework.context.annotation.Bean;
import org.springframework.web.servlet.config.annotation.CorsRegistry;

import com.google.common.net.HttpHeaders;

/**
 * 跨域配置
 */
//@Configuration
public class CorsConfig extends WebMvcConfigurer {

    @Bean
    public WebMvcConfigurer corsConfigurer()
    {
        return new WebMvcConfigurer() {
            @Override
            public void addCorsMappings(CorsRegistry registry) {
                registry.addMapping("/**").
                        allowedOrigins("*"). //允许跨域的域名，可以用*表示允许任何域名使用
                        allowedMethods("*"). //允许任何方法（post、get等）
                        allowedHeaders("*"). //允许任何请求头
                        allowCredentials(true). //带上cookie信息
                        exposedHeaders(HttpHeaders.SET_COOKIE).maxAge(3600L); //maxAge(3600)表明在3600秒内，不需要再发送预检验请求，可以缓存该结果
            }
        };
    }
}

引入用过中心过滤器(单点登录必用)

package com.hnyfkj.productmarket.web.config;

import com.hnyfkj.garden.user.core.conf.Conf;
import com.hnyfkj.garden.user.core.filter.HnyfkjSsoTokenFilter;
import com.hnyfkj.garden.user.core.filter.HnyfkjSsoWebFilter;
import com.hnyfkj.garden.user.core.user.JedisUtil;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * sso 配置
 * @date 2020-02-20
 * @author zzw
 * @version v0.0.1
 */
@Configuration
public class HnyfkjSsoConfig implements DisposableBean {

    @Value("${hnyfkj.sso.server}")
    private String hnyfkjSsoServer;//http://127.0.0.1:8080/

    @Value("${hnyfkj.sso.logout.path}")
    private String hnyfkjSsoLogoutPath;///logout

    @Value("${hnyfkj.sso.excluded.paths}")
    private String hnyfkjSsoExcludedPaths;

    @Value("${hnyfkj.sso.redis.address}")
    private String hnyfkjSsoRedisAddress;//redis://127.0.0.1:6379

    @Bean
    public FilterRegistrationBean<HnyfkjSsoWebFilter> hnyfkjSsoFilterRegistration() {

        // hnyfkj-sso, redis init
        JedisUtil.init(hnyfkjSsoRedisAddress);

        // hnyfkj-sso, filter init
        FilterRegistrationBean<HnyfkjSsoWebFilter> registration = new FilterRegistrationBean<>();

        registration.setName("hnyfkjSsoWebFilter");
        registration.setOrder(1);
        registration.addUrlPatterns("/*");
        registration.setFilter(new HnyfkjSsoWebFilter());
        registration.addInitParameter(Conf.SSO_SERVER, hnyfkjSsoServer);
        registration.addInitParameter(Conf.SSO_LOGOUT_PATH, hnyfkjSsoLogoutPath);
        registration.addInitParameter(Conf.SSO_EXCLUDED_PATHS, hnyfkjSsoExcludedPaths);

        return registration;
    }

    @Bean
    public FilterRegistrationBean<HnyfkjSsoTokenFilter> hnyfkjSsoTokenFilterRegistration() {

        // hnyfkj-sso, redis init
        JedisUtil.init(hnyfkjSsoRedisAddress);

        // hnyfkj-sso, filter init
        FilterRegistrationBean<HnyfkjSsoTokenFilter> registration = new FilterRegistrationBean<>();

        registration.setName("HnyfkjSsoTokenFilter");
        registration.setOrder(1);

        registration.addUrlPatterns("/*");
        registration.setFilter(new HnyfkjSsoTokenFilter());
        registration.addInitParameter(Conf.SSO_SERVER, hnyfkjSsoServer);
        registration.addInitParameter(Conf.SSO_LOGOUT_PATH, hnyfkjSsoLogoutPath);
        registration.addInitParameter(Conf.SSO_EXCLUDED_PATHS, hnyfkjSsoExcludedPaths);
        return registration;
    }

    @Override
    public void destroy() throws Exception {

        // hnyfkj-sso, redis close
        JedisUtil.close();
    }
}

分页配置加扫描包,不用启动类配置scan了

二选一

package com.hnyfkj.productmarket.web.config;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * mybatis plus 配置
 * 
 * @author 2020-02-13 zhangzw
 * @version v0.0.1
 */
@Configuration
@MapperScan("com.hnyfkj.productmarket.web.mapper")
public class MybatisPlusConfig {
    /**
     * 配置分页拦截器
     * 
     * @return
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        paginationInterceptor.setOverflow(true);
        paginationInterceptor.setLimit(500);
        return paginationInterceptor;
    }
}

@Configuration
public class MybatisPlusConfig {

	@Bean
	public MapperScannerConfigurer mapperScannerConfigurer() {
		final MapperScannerConfigurer scannerConfigurer = new MapperScannerConfigurer();
		scannerConfigurer.setBasePackage("com.hnyfkj.**.dao");
		return scannerConfigurer;
	}

}

封装异常类捕获,哪里需要异常返回直接

throw new BusinessException (“提示信息”)就可以了

public class BusinessException extends RuntimeException {

	private static final long serialVersionUID = 1L;

	private String msg;
	private int code = 500;

	public BusinessException(final String msg) {
		super(msg);
		this.msg = msg;
	}

	public BusinessException(final String msg, final Throwable e) {
		super(msg, e);
		this.msg = msg;
	}

	public BusinessException(final String msg, final int code) {
		super(msg);
		this.msg = msg;
		this.code = code;
	}

	public BusinessException(final String msg, final int code, final Throwable e) {
		super(msg, e);
		this.msg = msg;
		this.code = code;
	}

	public String getMsg() {
		return msg;
	}

	public void setMsg(final String msg) {
		this.msg = msg;
	}

	public int getCode() {
		return code;
	}

	public void setCode(final int code) {
		this.code = code;
	}

}

多少天以后的日期

 GetDay(day) {
        var time = new Date(this.Vatime);
        time.setDate(time.getDate() + day); //获取Day天后的日期
        var y = time.getFullYear();
        var m = time.getMonth() + 1; //获取当前月份的日期
        var d = time.getDate();
        return y + "-" + m + "-" + d
      }

生成0-9的随机数

Math.floor(Math.random()*10);

电话号码只显示前后

replaceAll("(\\d{4})\\d{10}(\\d{4})","$1****$2")

冒泡排序

for (int i = 0; i < sort.length - 1; i++) {
for (int j = 0; j < sort.length - i - 1; j++) {
if (sort[j] < sort[j + 1]) {
temp = sort[j];
sort[j] = sort[j + 1];
sort[j + 1] = temp;
}
}
}

启动关闭RabbitMQ

net stop RabbitMQ && net start RabbitMQ

查看进程,线程

netstat -a -n

Eclipse超好用的码云插件,一键拉取项目

http://kesin.oschina.io/update-site/4.5/