移動開發現在是一個非常火爆的行業，那麼作為掃一掃就可以添加神器——微信的二維碼來說，那自然也是相當的牛逼的了。
不多說了，先看看要生成一個二維碼，需要幾步？
1.準備工作，一個生成二維碼中間的圖示，可選擇；一個是第三方的工具，java這邊的話生成二維碼有很多開發的jar包如 zxing,qrcode（ 前者是谷歌開發的後者則是小日本開發的 ） ，這裡的話我使用zxing的開發包來弄。
2.到網站上去下載下傳zxing包。 http://code.google.com/p/zxing/ 可以選擇版本下載下傳.
3.直接上幹貨，不需要過多的配置操作。
代碼片一：
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;
}
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;
}
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;
}
public boolean isCropSupported() {
return true;
}
public LuminanceSource crop(int left, int top, int width, int height) {
return new BufferedImageLuminanceSource(image, this.left + left,
this.top + top, width, height);
}
public boolean isRotateSupported() {
return true;
}
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);
}
}
生成二維碼代碼片二：
public class CodeUtil {
private static final String CHARSET = "utf-8";
private static final String FORMAT_NAME = "JPG";
// 二維碼尺寸
private static final int QRCODE_SIZE = 300;
// LOGO寬度
private static final int WIDTH = 60;
// LOGO高度
private static final int HEIGHT = 60;
private static BufferedImage createImage(String content, String imgPath,
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 (imgPath == null || "".equals(imgPath)) {
return image;
}
// 插入圖檔
CodeUtil.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+" 該檔案不存在！");
return;
}
Image src = ImageIO.read(new File(imgPath));
int width = src.getWidth(null);
int height = src.getHeight(null);
if (needCompress) { // 壓縮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); // 繪制縮小後的圖
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 = CodeUtil.createImage(content, imgPath,
needCompress);
mkdirs(destPath);
String file = new Random().nextInt(99999999)+".jpg";
ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
}
public static void mkdirs(String destPath) {
File file =new File(destPath);
//當檔案夾不存在時，mkdirs會自動建立多層目錄，差別于mkdir．(mkdir如果父目錄不存在則會抛出異常)
if (!file.exists() && !file.isDirectory()) {
file.mkdirs();
}
}
public static void encode(String content, String imgPath, String destPath)
throws Exception {
CodeUtil.encode(content, imgPath, destPath, false);
}
public static void encode(String content, String destPath,
boolean needCompress) throws Exception {
CodeUtil.encode(content, null, destPath, needCompress);
}
public static void encode(String content, String destPath) throws Exception {
CodeUtil.encode(content, null, destPath, false);
}
public static void encode(String content, String imgPath,
OutputStream output, boolean needCompress) throws Exception {
BufferedImage image = CodeUtil.createImage(content, imgPath,
needCompress);
ImageIO.write(image, FORMAT_NAME, output);
}
public static void encode(String content, OutputStream output)
throws Exception {
CodeUtil.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<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;
}
public static String decode(String path) throws Exception {
return CodeUtil.decode(new File(path));
}
public static void main(String[] args) throws Exception {
String text = "http://www.baidu.com";
CodeUtil.encode(text, "f:/baidu.jpg", "f:/code", true);
}
}
4.
問題總結：
1. ZXing掃描二維碼出現中文亂碼的問題：
ZXing 掃條形碼沒有問題，但是掃描二維碼的時候卻有一部分是亂碼，或者不是中文的問題。
隻要以ISO- 8859 - 1 的格式來編碼,取出結果再進行相應的轉換，問題就解決了，并不需要修改源碼，可以參考上面的代碼。
2. 報錯:java.lang.UnsupportedClassVersionError: com/google/zxing/client/j2se/MatrixToImageWriter
遇到這個問題的話，98%的機率是JDK的版本與ZXing版不搭了，上面已經說過了，2.2版本在JDK1.6應該是沒問題的，2.3的話應該是對JDK1.7有依賴了。
使用者在使用這個的時候要注意，防止出現了問題。
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