今天接到一個任務：生成一個二維碼介面傳遞給php端，通過掃描二維碼連線到網站。

雖然很早接觸到二維碼，但是一直沒有研究過，本文只是記錄這次生成二維碼的過程，留待本人檢視，望大家交流學習！

看了幾個帖子，大部分都是用的google的二維碼jar

1.首先要下載ZXing的jar包，maven專案，也可以直接用maven repository 下載已經編譯好的jar包

<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>3.2.1</version>
</dependency>

2.第二步，我們需要一個工具類MatrixToImageWriter來處理我們的需求

直接上程式碼了

package com.echin.tool;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;
import javax.imageio.ImageIO;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;

public class MatrixToImageWriter {

 private static final int BLACK = 0xFF000000;
  private static final int WHITE = 0xFFFFFFFF;
 
  private MatrixToImageWriter() {}
 
  public static BufferedImage toBufferedImage(BitMatrix matrix) {
    int width = matrix.getWidth();
    int height = matrix.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, matrix.get(x, y) ? BLACK : WHITE);
      }
    }
    return image;
  }
 
  public static void writeToFile(BitMatrix matrix, String format, File file)
      throws IOException {
    BufferedImage image = toBufferedImage(matrix);
    if (!ImageIO.write(image, format, file)) {
      throw new IOException("Could not write an image of format " + format + " to " + file);
    }
  }
 
  public static void writeToStream(BitMatrix matrix, String format, OutputStream stream)
      throws IOException {
    BufferedImage image = toBufferedImage(matrix);
    if (!ImageIO.write(image, format, stream)) {
      throw new IOException("Could not write an image of format " + format);
    }
  }
  public static void main(String[] args) {
  try {
            
    String content = "嶽茂葉Happy Birthday！";
    String path = "E:\\upload";
    
    MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
    
    Map hints = new HashMap();
    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    BitMatrix bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, 400, 400,hints);
    File file1 = new File(path,"二維碼.jpg");
    MatrixToImageWriter.writeToFile(bitMatrix, "jpg", file1);
    
} catch (Exception e) {
    e.printStackTrace();
}
}
}

3.根據不同的需求，呼叫不同的方法

（1）writeToFile：生成本地的檔案二維碼

 （2）writeToStream：以檔案流的格式傳遞到頁面啊，客戶端等

4.下面一個是我自己傳遞到頁面的controller

@RequestMapping("/qrcode")
@ResponseBody
public void list(String content,HttpServletResponse response){

response.setContentType("image/jpeg");//設定相應型別,告訴瀏覽器輸出的內容為圖片
response.setHeader("Pragma", "No-cache");//設定響應頭資訊，告訴瀏覽器不要快取此內容
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expire", 0);
try {
//    String content = "Happy Birthday！";
    MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
    Map hints = new HashMap();
    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    BitMatrix bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, 200, 200,hints);
    MatrixToImageWriter.writeToStream(bitMatrix, "JPEG", response.getOutputStream());
} catch (Exception e) {
    e.printStackTrace();
}

}

5.大功告成，這時候可以訪問自己的ip，看下自己的二維碼了，掃描下驗證是不是自己要的內容