图片转二进制（互转）

2024-01-21 14:40| 来源: 网络整理| 查看: 265

Note: 图片转二进制数据只需转化为bate数组二进制数据即可，例如要求httpclient发送图片二进制数据即是把生成的bate数组数据发送过去。如果对方明确提出是字符串格式编码，再进一步转化就好了

使用Base64转换图片

利用Base64实现二进制和图片之间的转换，具体代码如下：

import java.awt.image.BufferedImage; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.IOException; import javax.imageio.ImageIO; import org.apache.tomcat.util.codec.binary.Base64; public class ImageBinary { public static void main(String[] args) { String fileName = "D://code//test.jpg"; System.out.println(getImageBinary(fileName)); saveImage(getImageBinary(fileName)); } /* * 图片转换为二进制 * * @param fileName * 本地图片路径 * @return * 图片二进制流 * */ public static String getImageBinary(String fileName) { File f = new File(fileName); BufferedImage bi; try { bi = ImageIO.read(f); ByteArrayOutputStream baos = new ByteArrayOutputStream(); ImageIO.write(bi, "jpg", baos); byte[] bytes = baos.toByteArray(); return Base64.encodeBase64String(bytes); //return encoder.encodeBuffer(bytes).trim(); } catch (IOException e) { e.printStackTrace(); } return null; } /** * 将二进制转换为图片 * * @param base64String * 图片二进制流 * */ public static void saveImage(String base64String) { try { byte[] bytes1 = Base64.decodeBase64(base64String); ByteArrayInputStream bais = new ByteArrayInputStream(bytes1); BufferedImage bi1 = ImageIO.read(bais); File w2 = new File("D://code//22.jpg");// 可以是jpg,png,gif格式 ImageIO.write(bi1, "jpg", w2);// 不管输出什么格式图片，此处不需改动 } catch (IOException e) { e.printStackTrace(); } } } 网络地址url与本地图片获取图片字节流

若通过url访问图片并转换为二进制流，就不能按照上述方法。通过url获取图片涉及url、网络状态等各种情况。在代码中涉及两种不同的方法：一个是通过url的形式，另一个是直接访问本地资源（即图片路径）。详见以下代码：

import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; public class ImageUtil { /** * 根据地址获得数据的字节流 * * @param strUrl * 网络连接地址 * @return */ public static byte[] getImageFromNetByUrl(String strUrl) { try { URL url = new URL(strUrl); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod("GET"); conn.setConnectTimeout(5 * 1000); InputStream inStream = conn.getInputStream();// 通过输入流获取图片数据 byte[] btImg = readInputStream(inStream);// 得到图片的二进制数据 return btImg; } catch (Exception e) { e.printStackTrace(); } return null; } /** * 根据地址获得数据的字节流 * * @param strUrl * 本地连接地址 * @return */ public byte[] getImageFromLocalByUrl(String strUrl) { try { File imageFile = new File(strUrl); InputStream inStream = new FileInputStream(imageFile); byte[] btImg = readInputStream(inStream);// 得到图片的二进制数据 return btImg; } catch (Exception e) { e.printStackTrace(); } return null; } /** * 从输入流中获取数据 * * @param inStream * 输入流 * @return * @throws IOException * @throws Exception */ private static byte[] readInputStream(InputStream inStream) throws IOException { ByteArrayOutputStream outStream = new ByteArrayOutputStream(); byte[] buffer = new byte[10240]; int len = 0; while ((len = inStream.read(buffer)) != -1) { outStream.write(buffer, 0, len); } inStream.close(); return outStream.toByteArray(); } public static void main(String[] args) { String url = "//images0.cnblogs.com/blog/536814/201412/051633343733092.png"; byte[] b = getImageFromNetByUrl(url); System.out.println(b); } } url获取图片字节流

本节介绍的方法可以说是前两种方法的结合体，但是在两者的基础上有所优化，如对url的状态做判断，此方法仅供参考，可根据具体需求做相应调整。

import java.awt.image.BufferedImage; import java.io.BufferedInputStream; import java.io.ByteArrayOutputStream; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLConnection; import javax.imageio.ImageIO; import com.sun.org.apache.xerces.internal.impl.dv.util.Base64; public class ImageUtils { /* * 获取原图片二进制流 * * @param imageUrl * 原图片地址 * */ public static String getImageBinary(String imageUrl) { String data = null; try { int HttpResult = 0; // 服务器返回的状态 URL url = new URL(imageUrl); // 创建URL URLConnection urlconn = url.openConnection(); // 试图连接并取得返回状态码 urlconn.connect(); HttpURLConnection httpconn = (HttpURLConnection) urlconn; HttpResult = httpconn.getResponseCode(); if (HttpResult != HttpURLConnection.HTTP_OK) // 不等于HTTP_OK则连接不成功 System.out.print("failed"); else { BufferedInputStream bis = new BufferedInputStream(urlconn.getInputStream()); BufferedImage bm = ImageIO.read(bis); ByteArrayOutputStream bos = new ByteArrayOutputStream(); String type = imageUrl.substring(imageUrl.length() - 3); ImageIO.write(bm, type, bos); bos.flush(); data = Base64.encode(bos.toByteArray()); bos.close(); } } catch (Exception e) { e.printStackTrace(); } return data; } public static void main(String[] args) { String url = "//images0.cnblogs.com/blog/536814/201412/051633343733092.png"; String result = getImageBinary(url); System.out.println(result); } } url获取图片字节流

本方法实现了主要实现了以下几个功能：

1、通过url将图片转换为字节流（十六进制的形式），并实现字节流与图片之间的相互转换；

2、将本地图片转换为字节流（十六进制的形式），并实现字节流与图片之间的相互转换；

import java.awt.image.BufferedImage; import java.io.BufferedInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.RandomAccessFile; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLConnection; import javax.imageio.ImageIO; public class Utils { /** * 图片转换成二进制字符串 * * @param imageUrl * 图片url * @return String 二进制流 */ public static String getImgeHexStringByUrl(String imageUrl) { String res = null; try { int HttpResult = 0; // 服务器返回的状态 URL url = new URL(imageUrl); // 创建URL URLConnection urlconn = url.openConnection(); // 试图连接并取得返回状态码 urlconn.connect(); HttpURLConnection httpconn = (HttpURLConnection) urlconn; HttpResult = httpconn.getResponseCode(); if (HttpResult != HttpURLConnection.HTTP_OK) // 不等于HTTP_OK则连接不成功 System.out.print("failed"); else { BufferedInputStream bis = new BufferedInputStream(urlconn.getInputStream()); BufferedImage bm = ImageIO.read(bis); ByteArrayOutputStream bos = new ByteArrayOutputStream(); String type = imageUrl.substring(imageUrl.length() - 3); ImageIO.write(bm, type, bos); bos.flush(); byte[] data = bos.toByteArray(); res = byte2hex(data); bos.close(); } } catch (Exception e) { e.printStackTrace(); } return res; } /** * 本地图片转换成二进制字符串 * * @param imageUrl * 图片url * @return String 二进制流 */ public static String getImgeHexStringByLocalUrl(String imageUrl) { String res = null; try { File imageFile = new File(imageUrl); InputStream inStream = new FileInputStream(imageFile); BufferedInputStream bis = new BufferedInputStream(inStream); BufferedImage bm = ImageIO.read(bis); ByteArrayOutputStream bos = new ByteArrayOutputStream(); String type = imageUrl.substring(imageUrl.length() - 3); ImageIO.write(bm, type, bos); bos.flush(); byte[] data = bos.toByteArray(); res = byte2hex(data); bos.close(); } catch (Exception e) { e.printStackTrace(); } return res; } /** * @title 根据二进制字符串生成图片 * @param data * 生成图片的二进制字符串 * @param fileName * 图片名称(完整路径) * @param type * 图片类型 * @return */ public static void saveImage(String data, String fileName, String type) { BufferedImage image = new BufferedImage(300, 300, BufferedImage.TYPE_BYTE_BINARY); ByteArrayOutputStream byteOutputStream = new ByteArrayOutputStream(); try { ImageIO.write(image, type, byteOutputStream); // byte[] date = byteOutputStream.toByteArray(); byte[] bytes = hex2byte(data); RandomAccessFile file = new RandomAccessFile(fileName, "rw"); file.write(bytes); file.close(); } catch (IOException e) { e.printStackTrace(); } } /** * 反格式化byte * * @param s * @return */ public static byte[] hex2byte(String s) { byte[] src = s.toLowerCase().getBytes(); byte[] ret = new byte[src.length / 2]; for (int i = 0; i < src.length; i += 2) { byte hi = src[i]; byte low = src[i + 1]; hi = (byte) ((hi >= 'a' && hi = 'a' && low > 4) & 0X0F]; out[i * 2 + 1] = Digit[c & 0X0F]; } return new String(out); } public static void main(String[] args) { String fileName = "D://code//cc.png"; String url = "//images0.cnblogs.com/blog/536814/201412/051633343733092.png"; String outImage = "D://code//11.png"; /* * url形式 * */ String result = getImgeHexStringByUrl(url); System.out.println(result); saveImage(result,fileName,"png"); /* * 本地图片形式 * */ String result1 = getImgeHexStringByLocalUrl(fileName); System.out.println(result1); saveImage(result1,outImage,"png"); } } 通过url下载图片

在给定url的情况下，可将url所访问的图片下载至本地。具体代码如下：

import java.io.BufferedInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.net.HttpURLConnection; import java.net.URL; public class downimageUtil { private static final String filePath = "C://Users//lizhihui//Desktop//"; /* * 根据url下载图片 * * @param destUrl * url连接 * @return * 图片保存路径 * */ public String saveToFile(String destUrl) { String fileName = ""; FileOutputStream fos = null; BufferedInputStream bis = null; HttpURLConnection httpUrl = null; URL url = null; int BUFFER_SIZE = 1024; byte[] buf = new byte[BUFFER_SIZE]; int size = 0; try { url = new URL(destUrl); httpUrl = (HttpURLConnection) url.openConnection(); httpUrl.connect(); bis = new BufferedInputStream(httpUrl.getInputStream()); for (String string : destUrl.split("/")) { if (string.contains("png") || string.contains("png") || string.contains("gif")) { fileName = string; } } fos = new FileOutputStream(filePath + fileName); while ((size = bis.read(buf)) != -1) { fos.write(buf, 0, size); } fos.flush(); } catch (IOException e) { } catch (ClassCastException e) { } finally { try { fos.close(); bis.close(); httpUrl.disconnect(); } catch (IOException e) { } catch (NullPointerException e) { } } return filePath + fileName; } public static void main(String[] args) { downimageUtil dw = new downimageUtil(); String url = "//images0.cnblogs.com/blog/536814/201412/051633343733092.png"; System.out.println(dw.saveToFile(url)); } } 根据图片网络地址获取二进制与二进制转图片亲测实例： /** * 根据图片地址获得数据的字节流 * * @param strUrl * @return */ public static byte[] getImageFromNetByUrl(String strUrl) { try { URL url = new URL(strUrl); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod("GET"); conn.setConnectTimeout(5 * 1000); InputStream inStream = conn.getInputStream();// 通过输入流获取图片数据 ByteArrayOutputStream outStream = new ByteArrayOutputStream(); byte[] buffer = new byte[1024]; int len = 0; while ((len = inStream.read(buffer)) != -1) { outStream.write(buffer, 0, len); } byte[] btImg = outStream.toByteArray();// 得到图片的二进制数据 inStream.close(); outStream.close(); conn.disconnect(); return btImg; } catch (Exception e) { e.printStackTrace(); } return null; } //byte数组到图片 public static void byte2image(byte[] data,String path){ if(data.length

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