java 图片转换成base64字符串

import java.io.ByteArrayOutputStream;

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 com.github.pagehelper.util.StringUtil;

//import com.steward.utils.StringUtil;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public class Base64Utils {

/**
* 本地图片转换成base64字符串
*
* @param imgFile
* 图片本地路径
* @return
*
* @author ZHANGJL
* @dateTime 2018-02-23 14:40:46
*/
public static String ImageToBase64ByLocal(String imgFile) {// 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

InputStream in = null;
byte[] data = null;

// 读取图片字节数组
try {
in = new FileInputStream(imgFile);

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
}

/**
* 图片转换
*
* @param imgURL
* @return
*/
public static String ImageToBase64ByOnline(String imgURL) {
ByteArrayOutputStream data = new ByteArrayOutputStream();
try {
// 创建URL
URL url = new URL(imgURL);
byte[] by = new byte[1024];
// 创建链接
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5000);
conn.setRequestProperty("User-Agent",
"Mozilla/5.0 (Linux;U;Android 2.3;en-us;Nexus One Build/FRF91)AppleWebKit/999+(KHTML, like Gecko)Version/4.0 Mobile Safari/999.9");
InputStream is = conn.getInputStream();
// 将内容读取内存中
int len = -1;
while ((len = is.read(by)) != -1) {
data.write(by, 0, len);
}
// 关闭流
is.close();
} catch (IOException e) {
e.printStackTrace();
return null;
}
// 对字节数组Base64编码
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(data.toByteArray());
}

/**
* 在线图片转换成base64字符串
*
* @param imgURL
* 图片线上路径
* @return
*
* @author ZHANGJL
* @dateTime 2018-02-23 14:43:18
*/
public static String ImageToBase64ByOnlineMobile(String imgURL) {
ByteArrayOutputStream data = new ByteArrayOutputStream();
try {
// 创建URL
URL url = new URL(imgURL);
byte[] by = new byte[1024];
// 创建链接
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5000);
conn.setRequestProperty("User-Agent",
"Mozilla/5.0 (Linux;U;Android 2.3;en-us;Nexus One Build/FRF91)AppleWebKit/999+(KHTML, like Gecko)Version/4.0 Mobile Safari/999.9");
InputStream is = conn.getInputStream();
// 将内容读取内存中
int len = -1;
while ((len = is.read(by)) != -1) {
data.write(by, 0, len);
}
// 关闭流
is.close();
} catch (IOException e) {
e.printStackTrace();
return null;
}
// 对字节数组Base64编码
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(data.toByteArray());
}

/**
* base64字符串转换成图片
*
* @param imgStr
* base64字符串
* @param imgFilePath
* 图片存放路径
* @return
*
* @author ZHANGJL
* @dateTime 2018-02-23 14:42:17
*/
public static boolean Base64ToImage(String imgStr, String imgFilePath) { // 对字节数组字符串进行Base64解码并生成图片
if (StringUtil.isEmpty(imgStr)) // 图像数据为空
return false;
BASE64Decoder decoder = new BASE64Decoder();
try {
// Base64解码
byte[] b = decoder.decodeBuffer(imgStr);
for (int i = 0; i < b.length; ++i) {
if (b[i] < 0) {// 调整异常数据
b[i] += 256;
}
}

OutputStream out = new FileOutputStream(imgFilePath);
out.write(b);
out.flush();
out.close();
return true;
} catch (Exception e) {
return false;
}
}

}