教你一步一步用 java 设计生成二维码
在物联网的时代，二维码是个很重要的东西了，现在无论什么东西都要搞个二维码标志，唯恐落伍，就差人没有用二维码识别了。也许有一天生分证或者户口本都会用二维码识别了。今天心血来潮，看见别人都为自己的博客添加了二维码，我也想搞一个测试一下.
主要用来实现两点：
1. 生成任意文字的二维码.
2. 在二维码的中间加入图像.
一、准备工作。
准备qr二维码3.0 版本的core包和一张jpg图片。
下载qr二维码包。
首先得下载 zxing.jar 包, 我这里用的是3.0 版本的core包
下载地址: 现在已经迁移到了github: https://github.com/zxing/zxing/wiki/getting-started-developing,
当然你也可以从maven仓库下载jar 包: http://central.maven.org/maven2/com/google/zxing/core/
二、程序设计
1、启动eclipse，新建一个java项目，命好项目名（本例取名为qrcodesoft）。点下一步：
2、导入zxing.jar 包, 我这里用的是3.0 版本的core包：点“添加外部jar(x)…”。
3、新建两个类，分别是：
bufferedimageluminancesource.java
qrcodeutil.java
关键代码在于：bufferedimageluminancesource.java 和qrcodeutil.java , 其中测试的main 方法位于 qrcodeutil.java 中。
bufferedimageluminancesource.java程序代码：
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package com.yihaomen.barcode;
import java.awt.graphics2d;
import java.awt.geom.affinetransform;
import java.awt.image.bufferedimage;
import com.google.zxing.luminancesource;
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);
}
}
qrcodeutil.java的程序代码：
package com.yihaomen.barcode;
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.file;
import java.io.outputstream;
import java.util.hashtable;
import java.util.random;
import javax.imageio.imageio;
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.common.bitmatrix;
import com.google.zxing.common.hybridbinarizer;
import com.google.zxing.qrcode.decoder.errorcorrectionlevel;
/**
* 二维码工具类
*
*/
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 = 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;
}
// 插入图片
qrcodeutil.insertimage(image, imgpath, needcompress);
return image;
}
/**
* 插入logo
*
* @param source
* 二维码图片
* @param imgpath
* logo图片地址
* @param needcompress
* 是否压缩
* @throws exception
*/
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();
}
/**
* 生成二维码(内嵌logo)
*
* @param content
* 内容
* @param imgpath
* logo地址
* @param destpath
* 存放目录
* @param needcompress
* 是否压缩logo
* @throws exception
*/
public static void encode(string content, string imgpath, string destpath,
boolean needcompress) throws exception {
bufferedimage image = qrcodeutil.createimage(content, imgpath,
needcompress);
mkdirs(destpath);
string file = new random().nextint(99999999)+".jpg";
imageio.write(image, format_name, new file(destpath+"/"+file));
}
/**
* 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)
* @author lanyuan
* email: mmm333zzz520@163.com
* @date 2013-12-11 上午10:16:36
* @param destpath 存放目录
*/
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();
}
}
/**
* 生成二维码(内嵌logo)
*
* @param content
* 内容
* @param imgpath
* logo地址
* @param destpath
* 存储地址
* @throws exception
*/
public static void encode(string content, string imgpath, string destpath)
throws exception {
qrcodeutil.encode(content, imgpath, 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 void encode(string content, string destpath,
boolean needcompress) throws exception {
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 void encode(string content, string destpath) throws exception {
qrcodeutil.encode(content, null, destpath, false);
}
/**
* 生成二维码(内嵌logo)
*
* @param content
* 内容
* @param imgpath
* logo地址
* @param output
* 输出流
* @param needcompress
* 是否压缩logo
* @throws exception
*/
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);
}
/**
* 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));
}
public static void main(string[] args) throws exception {
string text = "http://www.yihaomen.com";
qrcodeutil.encode(text, "c:/me.jpg", "c:/barcode", true);
}
}
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);
}
运行这个测试方法，生成的二维码不带 logo , 样式如下:
有兴趣可以用手机扫描一下
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);
}
唯一的区别是，在前面的基础上指定了logo 的地址，这里测试都用了c盘的图片文件
用手机扫描，能出现要出现的文字，点击就进入自己的网站。
以上就是用java 设计生成二维码,有兴趣的朋友可以参考下，谢谢大家对本站的支持！
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