Java 从网络中读取图片 转换成Base64字符串

package com.readerpicture; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.HttpURLConnection; import java.net.URL; import Decoder.BASE64Decoder; import Decoder.BASE64Encoder; public class Controller { private HttpURLConnection httpUrl = null; public static void main(String[] args) throws Exception { Controller c = new Controller(); String url = "http://localhost:8088/tomcat.png"; String path = "D:/0000.JPG"; InputStream in = c.saveToFile(url); //从URL读取图片 String str = c.GetImageStrByInPut(in); //读取输入流,转换为Base64字符 System.out.println(str); generateImage(str, path); //将Base64字符转换为图片 c.closeHttpConn(); } public void closeHttpConn(){ httpUrl.disconnect(); } /** * 从URL中读取图片,转换成流形式. * @param destUrl * @return */ public InputStream saveToFile(String destUrl){ URL url = null; InputStream in = null; try{ url = new URL(destUrl); httpUrl = (HttpURLConnection) url.openConnection(); httpUrl.connect(); httpUrl.getInputStream(); in = httpUrl.getInputStream(); return in; }catch (Exception e) { e.printStackTrace(); } return null; } /** * 读取输入流,转换为Base64字符串 * @param input * @return */ public String GetImageStrByInPut(InputStream input) { byte[] data = null; // 读取图片字节数组 try { data = new byte[input.available()]; input.read(data); input.close(); } catch (IOException e) { e.printStackTrace(); } // 对字节数组Base64编码 BASE64Encoder encoder = new BASE64Encoder(); return encoder.encode(data);// 返回Base64编码过的字节数组字符串 } /** * 图片转化成base64字符串 将图片文 件转化为字节数组字符串，并对其进行Base64编码处理 * * @return */ public static String GetImageStr(File file) { InputStream in = null; byte[] data = null; // 读取图片字节数组 try { in = new FileInputStream(file); data = new byte[in.available()]; in.read(data); in.close(); } catch (IOException e) { e.printStackTrace(); } // 对字节数组Base64编码 BASE64Encoder encoder = new BASE64Encoder(); return encoder.encode(data);// 返回Base64编码过的字节数组字符串 } /** * base64字符串转化成图片 对字节数组字符串进行Base64解码并生成图片 * * @param imgStr * 数据内容(字符串) * @param path * 输出路径 * @return */ public static boolean generateImage(String imgStr, String path) { if (imgStr == null) // 图像数据为空 return false; BASE64Decoder decoder = new BASE64Decoder(); try { byte[] b = decoder.decodeBuffer(imgStr);// Base64解码 for (int i = 0; i < b.length; ++i) { if (b[i] < 0) {// 调整异常数据 b[i] += 256; } } // 生成jpeg图片 OutputStream out = new FileOutputStream(path); out.write(b); out.flush(); out.close(); return true; } catch (Exception e) { return false; } } }