Android如何实现URL转换成二维码

public static boolean createqrimage(string content, int widthpix, int heightpix, bitmap logobm, string filepath) {
    try {
      if (content == null || "".equals(content)) {
        return false;
      }

      //配置参数
      map<encodehinttype, object> hints = new hashmap<>();
      hints.put(encodehinttype.character_set, "utf-8");
      //容错级别
      hints.put(encodehinttype.error_correction, errorcorrectionlevel.h);
      //设置空白边距的宽度
      hints.put(encodehinttype.margin, 2); //default is 4

      // 图像数据转换，使用了矩阵转换
      bitmatrix bitmatrix = new qrcodewriter().encode(content, barcodeformat.qr_code, widthpix, heightpix, hints);
      int[] pixels = new int[widthpix * heightpix];
      // 下面这里按照二维码的算法，逐个生成二维码的图片，
      // 两个for循环是图片横列扫描的结果
      for (int y = 0; y < heightpix; y++) {
        for (int x = 0; x < widthpix; x++) {
          if (bitmatrix.get(x, y)) {
            pixels[y * widthpix + x] = 0xff000000;
          } else {
            pixels[y * widthpix + x] = 0xffffffff;
          }
        }
      }

      // 生成二维码图片的格式，使用argb_8888
      bitmap bitmap = bitmap.createbitmap(widthpix, heightpix, bitmap.config.argb_8888);
      bitmap.setpixels(pixels, 0, widthpix, 0, 0, widthpix, heightpix);

      if (logobm != null) {
        bitmap = addlogo(bitmap, logobm);
      }

      //必须使用compress方法将bitmap保存到文件中再进行读取。直接返回的bitmap是没有任何压缩的，内存消耗巨大！
      return bitmap != null && bitmap.compress(bitmap.compressformat.jpeg, 100, new fileoutputstream(filepath));
    } catch (writerexception | ioexception e) {
      e.printstacktrace();
    }

    return false;
  }

private static bitmap addlogo(bitmap src, bitmap logo) {
    if (src == null) {
      return null;
    }

    if (logo == null) {
      return src;
    }

    //获取图片的宽高
    int srcwidth = src.getwidth();
    int srcheight = src.getheight();
    int logowidth = logo.getwidth();
    int logoheight = logo.getheight();

    if (srcwidth == 0 || srcheight == 0) {
      return null;
    }

    if (logowidth == 0 || logoheight == 0) {
      return src;
    }

    //logo大小为二维码整体大小的1/5
    float scalefactor = srcwidth * 1.0f / 5 / logowidth;
    bitmap bitmap = bitmap.createbitmap(srcwidth, srcheight, bitmap.config.argb_8888);
    try {
      canvas canvas = new canvas(bitmap);
      canvas.drawbitmap(src, 0, 0, null);
      canvas.scale(scalefactor, scalefactor, srcwidth / 2, srcheight / 2);
      canvas.drawbitmap(logo, (srcwidth - logowidth) / 2, (srcheight - logoheight) / 2, null);

      canvas.save(canvas.all_save_flag);
      canvas.restore();
    } catch (exception e) {
      bitmap = null;
      e.getstacktrace();
    }

    return bitmap;
  }

private static string getfileroot(context context) {
    if (environment.getexternalstoragestate().equals(environment.media_mounted)) {
      file external = context.getexternalfilesdir(null);
      if (external != null) {
        return external.getabsolutepath();
      }
    }

    return context.getfilesdir().getabsolutepath();
  }

public class sputil {

  private static final string config = "config";

  /**
   * 获取sharedpreferences实例对象
   *
   * @param filename
   */
  private static sharedpreferences getsharedpreference(string filename) {
    return qrcodeapplication.getinstance().getsharedpreferences(filename, context.mode_private);
  }

  /**
   * 保存一个string类型的值！
   */
  public static void putstring(string key, string value) {
    sharedpreferences.editor editor = getsharedpreference(config).edit();
    editor.putstring(key, value).apply();
  }

  /**
   * 获取string的value
   */
  public static string getstring(string key, string defvalue) {
    sharedpreferences sharedpreference = getsharedpreference(config);
    return sharedpreference.getstring(key, defvalue);
  }

}

public static void showthreadimage(final activity mcontext, final string text, final imageview imageview, final int centerphoto) {
    string precontent = sputil.getstring("share_code_content", "");
    if (text.equals(precontent)) {
      string prefilepath = sputil.getstring("share_code_filepath", "");
      imageview.setimagebitmap(bitmapfactory.decodefile(prefilepath));

    } else {
      sputil.putstring("share_code_content", text);
      final string filepath = getfileroot(mcontext) + file.separator + "qr_" + system.currenttimemillis() + ".jpg";
      sputil.putstring("share_code_filepath", filepath);

      //二维码图片较大时，生成图片、保存文件的时间可能较长，因此放在新线程中
      new thread(new runnable() {
        @override
        public void run() {
          boolean success = qrcodeutil.createqrimage(text, 800, 800, bitmapfactory.decoderesource(mcontext.getresources(), centerphoto),
              filepath);

          if (success) {
            mcontext.runonuithread(new runnable() {
              @override
              public void run() {
                imageview.setimagebitmap(bitmapfactory.decodefile(filepath));
              }
            });
          }
        }
      }).start();
    }
  }

public class contentactivity extends appcompatactivity implements view.onclicklistener {

  private edittext eturl;

  private button btnconvert;

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_content);

    initview();
  }

  private void initview() {
    eturl = (edittext) findviewbyid(r.id.et_url);
    btnconvert = (button) findviewbyid(r.id.btn_convert);

    btnconvert.setonclicklistener(this);

  }

  @override
  public void onclick(view v) {
    switch (v.getid()) {
      case r.id.btn_convert:
        string str_url = "https://" + eturl.gettext().tostring();
        bundle bundle = new bundle();
        bundle.putstring("url", str_url);
        // 当输入框为空时，提示用户
        if (str_url.equals("https://")) {
          toast.maketext(getapplicationcontext(), "输入框不能为空", toast.length_short).show();
        } else {
          intent intent = new intent(contentactivity.this, mainactivity.class);
          intent.putextras(bundle);
          startactivity(intent);
        }
        break;
      default:
        break;
    }
  }
}

public class mainactivity extends appcompatactivity {

  private imageview iv;

//  private string url = "http://weibo.com/cnwutianhao";

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);

    string str_url = getintent().getextras().getstring("url");

    iv = (imageview) findviewbyid(r.id.iv_qrcode);

    qrcodeutil.showthreadimage(this, str_url, iv, r.mipmap.ic_launcher);
  }
}

<?xml version="1.0" encoding="utf-8"?>
<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"
  android:padding="10dp">

  <edittext
    android:id="@+id/et_url"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_margintop="100dp"
    android:hint="请输入网址"
    android:inputtype="texturi" />

  <button
    android:id="@+id/btn_convert"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignparentbottom="true"
    android:layout_centerhorizontal="true"
    android:layout_marginbottom="20dp"
    android:text="转换成二维码" />

</relativelayout>

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context="com.tnnowu.android.qrcode.mainactivity">

  <imageview
    android:id="@+id/iv_qrcode"
    android:layout_width="220dp"
    android:layout_height="220dp"
    android:layout_centerinparent="true"
    android:layout_margintop="40dp"
    android:background="#ffffff" />

</relativelayout>