java:网络图片与二进制互转工具类、读取配置文件工具类

一、图片

import lombok.extern.slf4j.Slf4j;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.*;
import java.net.ConnectException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

@Slf4j
public class ImageUtils {

    public static byte[] getImageBytes(String imgUrl) {
        URL url = null;
        InputStream is = null;
        ByteArrayOutputStream outStream = null;
        HttpURLConnection httpUrl = null;
        try {
            url = new URL(imgUrl);
            httpUrl = (HttpURLConnection) url.openConnection();
            httpUrl.connect();
            httpUrl.getInputStream();
            is = httpUrl.getInputStream();
            outStream = new ByteArrayOutputStream();
            //创建一个Buffer字符串
            byte[] buffer = new byte[1024];
            //每次读取的字符串长度，如果为-1，代表全部读取完毕
            int len = 0;
            //使用一个输入流从buffer里把数据读取出来
            while ((len = is.read(buffer)) != -1) {
                //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
                outStream.write(buffer, 0, len);
            }
            // 对字节数组Base64编码
            return outStream.toByteArray();
        } catch (ConnectException e) {
            log.error("获取图片时连接异常，url:{}",imgUrl,e);
        } catch (MalformedURLException e) {
            log.error("url出现异常，url:{}",imgUrl,e);
        } catch (IOException e) {
            log.error("读取图片时发生异常，url:{}",imgUrl,e);
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (outStream != null) {
                try {
                    outStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (httpUrl != null) {
                httpUrl.disconnect();
            }
        }
        return null;
    }
	//做校验使用
    public static void bytesToImage(byte[] bytes1) {
        try {
            ByteArrayInputStream bais = new ByteArrayInputStream(bytes1);
            BufferedImage bi1 = ImageIO.read(bais);
            File w2 = new File("C:\\Users\\Desktop\\test\\test.jpg");
            ImageIO.write(bi1, "jpg", w2);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

获取配置文件

我是只读取一个配置文件，需要读取不同的配置文件自己改改就好，难度不大。
statis代码块是默认只加载一次的，可以自行了解。

import lombok.extern.slf4j.Slf4j;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;


@Slf4j
public class PropertiesUtil {

    private static Properties props;

    static {
        loadProps("config");
    }

    private static void loadProps(String propName) {

        props = new Properties();
        InputStream in = null;
        try {
            /*
             * <!--第一种，通过类加载器进行获取properties文件流-->
             * in = PropertyUtil.class.getClassLoader().getResourceAsStream(
             * "jdbc.properties");
             * <!--第二种，通过类进行获取properties文件流-->
             */
            in = PropertiesUtil.class.getResourceAsStream("/"+propName+".properties");
            props.load(in);
        } catch (FileNotFoundException e) {
            log.error(propName+".properties文件未找到",e);
        } catch (IOException e) {
            log.error("出现IOException",e);
        } finally {
            try {
                if (null != in) {
                    in.close();
                }
            } catch (IOException e) {
                log.error(".properties文件流关闭出现异常",e);
            }
        }
    }

    public static String getProperties(String key) {
        if (null == props) {
            return null;
        }
        return props.getProperty(key);
    }
}

用法：

    private static  String brokerURL;
    static {
        ActiveMqUtil.brokerURL = PropertiesUtil.getProperties("linewell.activemq.brockerURL");
    }