json2picture
1:我们知道前端页面直接写base64码,就会显示图片
2:那么后端只要把json转换为base64码传给前段不就可以了
-----------------------------QRCodeUtil工具类-----------------------------------------------
package com.example.demo.utils;
import java.awt.BasicStroke;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Shape;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Hashtable;
import java.util.Random;
import javax.imageio.ImageIO;
//import com.google.gson.JsonObject;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.Result;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import sun.misc.BASE64Encoder;
public class QRCodeUtil {
private static final String CHARSET = "utf-8";
private static final String FORMAT = "JPG";
// 二维码尺寸
private static final int QRCODE_SIZE = 300;
// LOGO宽度
private static final int LOGO_WIDTH = 60;
// LOGO高度
private static final int LOGO_HEIGHT = 60;
private static BufferedImage createImage(String content, String logoPath, boolean needCompress) throws Exception {
Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
hints.put(EncodeHintType.MARGIN, 1);
BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE,
hints);
int width = bitMatrix.getWidth();
int height = bitMatrix.getHeight();
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
}
}
if (logoPath == null || "".equals(logoPath)) {
return image;
}
// 插入图片
QRCodeUtil.insertImage(image, logoPath, needCompress);
return image;
}
/**
* 插入LOGO
*
* @param source 二维码图片
* @param logoPath LOGO图片地址
* @param needCompress 是否压缩
* @throws Exception
*/
private static void insertImage(BufferedImage source, String logoPath, boolean needCompress) throws Exception {
File file = new File(logoPath);
if (!file.exists()) {
throw new Exception("logo file not found.");
}
Image src = ImageIO.read(new File(logoPath));
int width = src.getWidth(null);
int height = src.getHeight(null);
if (needCompress) { // 压缩LOGO
if (width > LOGO_WIDTH) {
width = LOGO_WIDTH;
}
if (height > LOGO_HEIGHT) {
height = LOGO_HEIGHT;
}
Image image = src.getScaledInstance(width, height, Image.SCALE_SMOOTH);
BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = tag.getGraphics();
g.drawImage(image, 0, 0, null); // 绘制缩小后的图
g.dispose();
src = image;
}
// 插入LOGO
Graphics2D graph = source.createGraphics();
int x = (QRCODE_SIZE - width) / 2;
int y = (QRCODE_SIZE - height) / 2;
graph.drawImage(src, x, y, width, height, null);
Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
graph.setStroke(new BasicStroke(3f));
graph.draw(shape);
graph.dispose();
}
/**
* 生成二维码(内嵌LOGO)
* 二维码文件名随机，文件名可能会有重复
*
* @param content 内容
* @param logoPath LOGO地址
* @param destPath 存放目录
* @param needCompress 是否压缩LOGO
* @throws Exception
*/
public static String encode(String content, String logoPath, String destPath, boolean needCompress) throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, logoPath, needCompress);
mkdirs(destPath);
String fileName = new Random().nextInt(99999999) + "." + FORMAT.toLowerCase();
ImageIO.write(image, FORMAT, new File(destPath + "/" + fileName));
return fileName;
}
/**
* 生成二维码(内嵌LOGO)
* 调用者指定二维码文件名
*
* @param content 内容
* @param logoPath LOGO地址
* @param destPath 存放目录
* @param fileName 二维码文件名
* @param needCompress 是否压缩LOGO
* @throws Exception
*/
public static String encode(String content, String logoPath, String destPath, String fileName, boolean needCompress) throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, logoPath, needCompress);
mkdirs(destPath);
fileName = fileName.substring(0, fileName.indexOf(".") > 0 ? fileName.indexOf(".") : fileName.length())
+ "." + FORMAT.toLowerCase();
ImageIO.write(image, FORMAT, new File(destPath + "/" + fileName));
return fileName;
}
/**
* 当文件夹不存在时，mkdirs会自动创建多层目录，区别于mkdir．
* (mkdir如果父目录不存在则会抛出异常)
*
* @param destPath 存放目录
*/
public static void mkdirs(String destPath) {
File file = new File(destPath);
if (!file.exists() && !file.isDirectory()) {
file.mkdirs();
}
}
/**
* 生成二维码(内嵌LOGO)
*
* @param content 内容
* @param logoPath LOGO地址
* @param destPath 存储地址
* @throws Exception
*/
public static String encode(String content, String logoPath, String destPath) throws Exception {
return QRCodeUtil.encode(content, logoPath, destPath, false);
}
/**
* 生成二维码
*
* @param content 内容
* @param destPath 存储地址
* @param needCompress 是否压缩LOGO
* @throws Exception
*/
public static String encode(String content, String destPath, boolean needCompress) throws Exception {
return QRCodeUtil.encode(content, null, destPath, needCompress);
}
/**
* 生成二维码
*
* @param content 内容
* @param destPath 存储地址
* @throws Exception
*/
public static String encode(String content, String destPath) throws Exception {
return QRCodeUtil.encode(content, null, destPath, false);
}
/**
* 生成二维码(内嵌LOGO)
*
* @param content 内容
* @param logoPath LOGO地址
* @param output 输出流
* @param needCompress 是否压缩LOGO
* @throws Exception
*/
public static void encode(String content, String logoPath, OutputStream output, boolean needCompress)
throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, logoPath, needCompress);
ImageIO.write(image, FORMAT, output);
}
/**
* 生成二维码
*
* @param content 内容
* @param output 输出流
* @throws Exception
*/
public static void encode(String content, OutputStream output) throws Exception {
QRCodeUtil.encode(content, null, output, false);
}
/**
* 解析二维码
*
* @param file 二维码图片
* @return
* @throws Exception
*/
public static String decode(File file) throws Exception {
BufferedImage image;
image = ImageIO.read(file);
if (image == null) {
return null;
}
BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
Result result;
Hashtable<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
result = new MultiFormatReader().decode(bitmap, hints);
String resultStr = result.getText();
return resultStr;
}
/**
* 解析二维码
*
* @param path 二维码图片地址
* @return
* @throws Exception
*/
public static String decode(String path) throws Exception {
return QRCodeUtil.decode(new File(path));
}
/**
* 二维码转换为base64字符串
*
* @param path 二维码图片地址
* @return
* @throws Exception
*/
public static String image2base64(String path) {
String imgStr = "";
try {
File file = new File(path);
FileInputStream fis = new FileInputStream(file);
byte[] buffer = new byte[(int) file.length()];
int offset = 0;
int numRead = 0;
while (offset < buffer.length && (numRead = fis.read(buffer, offset, buffer.length - offset)) >= 0) {
offset += numRead;
}
if (offset != buffer.length) {
throw new IOException("Could not completely read file "
+ file.getName());
}
fis.close();
BASE64Encoder encoder = new BASE64Encoder();
imgStr = encoder.encode(buffer);
} catch (Exception e) {
e.printStackTrace();
}
return "data:image/jpeg;base64," + imgStr;
}
/**
* json转换为base64字符串
*
* @param json json字符串
* @return
* @throws Exception
*/
public static String json2base64(String json){
String path = "D:\\";
String base64Str = null;
try{
String str = QRCodeUtil.encode(json,path);
base64Str = QRCodeUtil.image2base64(path + str);
}catch (Exception e){
e.getMessage();
}
return StringUtil.leftRightCenterTrim(base64Str);
}
public static void main(String[] args) throws Exception {
String text = "{ \"GeekPlusA\": \"GeekPlusA\", \"GeekPlusA\": \"GeekPlusA\" }";
String json = QRCodeUtil.json2base64(text);
System.out.println(json);
System.out.println(StringUtil.leftRightCenterTrim(json));
}
-----------------------------StringUtil工具类-----------------------------------------------
package com.example.demo.utils;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class StringUtil {
/**
* 去掉字符串前后中间空白、换行、制表
*
* @param str 字符串
* @return 新字符串
*/
public static String leftRightCenterTrim(String str){
String dest = "";
if (null != str) {
Pattern p = Pattern.compile("\\s*|\t|\r|\n");
Matcher m = p.matcher(str);
dest = m.replaceAll("");
}
return dest;
}
}
-------------------------------------实例-----------------------------------------------
生成不带logo 的二维码
程序代码如下：
public static void main(String[] args) throws Exception {
String text = "http://www.dans88.com.cn";
QRCodeUtil.encode(text,"","d:/MyWorkDoc",true);
}
生成带logo 的二维码
logo 可以用自己的头像，或者自己喜欢的一个图片都可以 , 采用如下代码，程序代码如下：
public static void main(String[] args) throws Exception {
String text = "http://www.dans88.com.cn";
QRCodeUtil.encode(text, "d:/MyWorkDoc/my180.jpg", "d:/MyWorkDoc", true);
}
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