java对接三方支付
- 相关知识
- 二维码
- RSA加密算法
- md5加密
- 开发思路
- 三方后台相关参数的含义
- 工具类
- 二维码生成工具类
- 支付相关代码
相关知识
对接支付必须要有企业认证
二维码
二维码由黑白相间的小方块组成,黑色方块代表0,白色方块代表1,实际为01二进制数,三角的三个方块用于判断二维码的从何处开始扫描,手机解析出来是字符串,当然也可以是链接。
RSA加密算法
rsa加密为非对称加密算法,即加密和解密的算法不同,可用于数字签名和认证
私钥:加密,请求支付接口时,需要携带参数,通过私钥和特定的加密算法生成sign,平台再对sign通过公钥进行解密,对比传参是否被修改,当参数被修改时,sign解密得到信息与参数信息不一致,验证失败,这样保证了参数传递过程中的安全性,例如支付时金额从1块改为100块,平台验证签名变回失败,保证安全行。
公钥:解密,平台返回结果时,我们可以根据公钥解密,验证参数。
md5加密
md5加密是不可逆的,生成加密信息后很难解密为原来的信息,一般用来对密码的加密,但是通过撞库破解,即事先生成大量的密码信息存在数据库中,对比 数据库获取原文。这里可以对密码进行加盐在进行加密,如存储为12346的秘密加后缀00后在进行md5加密。
开发思路
对于开发者来说只用写两个接口
1、支付接口:支付接口向平台提交交易订单,包括订单号,金额信息,交易内容,平台返回支付链接,我们可以根据链接生成二维码。
2、支付回调接口:接收平台返回的支付结果,一般有金额,订单号,签名等相关信息,支付成功后我们可以将订单信息入库。
三方后台相关参数的含义
appid:商户id,平台用来确认钱是转给谁。
privateKey:商家私钥,用来加密
publicKey:平台公钥,一般由商家的公钥兑换而来,用来解密
orderId:用来确认拉起支付的唯一性,一笔订单只能支付一次。
工具类
二维码生成工具类
这里是封装的google的zxing的工具类
测试
public class QRCodeTest {
public static void main(String[] args) throws Exception {
String imgPath = "D:/picture/2.jpeg";
// 生成的二维码的路径及名称
String destPath = "D:/picture/2qr.jpg";
//生成二维码
QRCodeUtil.encode("https://www.fangqing.site", imgPath, destPath, true);
// 解析二维码
String str = QRCodeUtil.decode(destPath);
// 打印出解析出的内容
System.out.println(str);
}
}
生成的对应二维码如下,如果要返回给前端,返回对应的字节码byte[]即可,
import com.google.zxing.*;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.OutputStream;
import java.util.Hashtable;
/**
* @Author forsake
* @Description
* @Date 10:42 2022/6/13
**/
public class QRCodeUtil {
private static final String CHARSET = "utf-8";
private static final String FORMAT_NAME = "JPG";
// 二维码尺寸
private static final int QRCODE_SIZE = 300;
// LOGO宽度
private static final int WIDTH = 90;
// LOGO高度
private static final int HEIGHT = 90;
/**
* @Author xuke
* @Description 二维码生成的方法
* @Date 0:45 2021/4/2
* @Param [content, imgPath, needCompress]
* @return java.awt.image.BufferedImage
**/
private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception {
Hashtable hints = new Hashtable();
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 (imgPath == null || "".equals(imgPath)) {
return image;
}
// 插入图片
QRCodeUtil.insertImage(image, imgPath, needCompress);
return image;
}
private static void insertImage(BufferedImage source, String imgPath, boolean needCompress) throws Exception {
File file = new File(imgPath);
if (!file.exists()) {
System.err.println("" + imgPath + " 该文件不存在!");
return;
}
Image src = ImageIO.read(new File(imgPath));
int width = src.getWidth(null);
int height = src.getHeight(null);
if (needCompress) { // 压缩LOGO
if (width > WIDTH) {
width = WIDTH;
}
if (height > HEIGHT) {
height = 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();
}
public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
mkdirs(destPath);
ImageIO.write(image, FORMAT_NAME, new File(destPath));
}
public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
return image;
}
public static void mkdirs(String destPath) {
File file = new File(destPath);
// 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)
if (!file.exists() && !file.isDirectory()) {
file.mkdirs();
}
}
public static void encode(String content, String imgPath, String destPath) throws Exception {
QRCodeUtil.encode(content, imgPath, destPath, false);
}
public static void encode(String content, String destPath) throws Exception {
QRCodeUtil.encode(content, null, destPath, false);
}
public static void encode(String content, String imgPath, OutputStream output, boolean needCompress)
throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
ImageIO.write(image, FORMAT_NAME, output);
}
public static void encode(String content, OutputStream output) throws Exception {
QRCodeUtil.encode(content, null, output, false);
}
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 hints = new Hashtable();
hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
result = new MultiFormatReader().decode(bitmap, hints);
String resultStr = result.getText();
return resultStr;
}
public static String decode(String path) throws Exception {
return QRCodeUtil.decode(new File(path));
}
}
import com.google.zxing.LuminanceSource;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
public class BufferedImageLuminanceSource extends LuminanceSource {
private final BufferedImage image;
private final int left;
private final int top;
public BufferedImageLuminanceSource(BufferedImage image) {
this(image, 0, 0, image.getWidth(), image.getHeight());
}
public BufferedImageLuminanceSource(BufferedImage image, int left, int top, int width, int height) {
super(width, height);
int sourceWidth = image.getWidth();
int sourceHeight = image.getHeight();
if (left + width > sourceWidth || top + height > sourceHeight) {
throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
}
for (int y = top; y < top + height; y++) {
for (int x = left; x < left + width; x++) {
if ((image.getRGB(x, y) & 0xFF000000) == 0) {
image.setRGB(x, y, 0xFFFFFFFF); // = white
}
}
}
this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);
this.image.getGraphics().drawImage(image, 0, 0, null);
this.left = left;
this.top = top;
}
@Override
public byte[] getRow(int y, byte[] row) {
if (y < 0 || y >= getHeight()) {
throw new IllegalArgumentException("Requested row is outside the image: " + y);
}
int width = getWidth();
if (row == null || row.length < width) {
row = new byte[width];
}
image.getRaster().getDataElements(left, top + y, width, 1, row);
return row;
}
@Override
public byte[] getMatrix() {
int width = getWidth();
int height = getHeight();
int area = width * height;
byte[] matrix = new byte[area];
image.getRaster().getDataElements(left, top, width, height, matrix);
return matrix;
}
@Override
public boolean isCropSupported() {
return true;
}
@Override
public LuminanceSource crop(int left, int top, int width, int height) {
return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);
}
@Override
public boolean isRotateSupported() {
return true;
}
@Override
public LuminanceSource rotateCounterClockwise() {
int sourceWidth = image.getWidth();
int sourceHeight = image.getHeight();
AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);
BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
Graphics2D g = rotatedImage.createGraphics();
g.drawImage(image, transform, null);
g.dispose();
int width = getWidth();
return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);
}
}